SurveyScoringGuidelines W-HTX 2000

Worldwide Heat Treat System Survey And Scoring Guidelines

This manual provides guidelines for evaluating the

Heat-treatment systems of a heat-treat manufacturing facility.

Distributed by Global Materials & Fastener Standards. For content and technical questions please contact: R.F. Buelow ([email protected]) or Y. Kim ([email protected])

Issue Date 2000 October 16 Printed copies of this documents are uncontrolled

Copyright 2000 Ford Global Technologies Incorporated


TABLE OF CONTENTS SECTION DESCRIPTION I. Introduction II. Application III. Requirements IV. Heat Treat Statistical Process Control Applications V. Heat Treat Process Strategy VI. Heat Treat System Survey Scoring Guidelines VII. Glossary

Heat Treat System Survey (Form) Manufacturing Standard W-HTX is available within Ford Motor Company at www.ctis.ford.com/gms/secure1/data/9200398.pdf. Customers outside of Ford need to contact their Ford Standards Provider.

http://www.ctis.ford.com/gms/secure1/data/9200398.pdf


SECTION I - INTRODUCTION This documentation has been prepared to achieve Ford's mission of never ending improvement at all Ford plants having Heat Treat operations and all heat treators, Tier 1 and Tier 2, It has been organized in a manner that it will be used as a tool to: • Define the requirements for the heat treat process and the heat treatment processor. • Assess heat treatment process controls, process capability and dedication to never-ending improvement

using Statistical Process Control. • Provide the opportunity to streamline auditing procedures for heat treat processes and heat treatment

processor. The following section will be used in defining the usage and application of the Heat Treat System Survey.

SECTION II - APPLICATION Application includes: • Heat Treat facilities found within a Ford Motor Company manufacturing facility. • Where the first tier heat treater to Ford Motor is performing a heat treat function, the Heat Treat System

Survey must be conducted in conjunction with QS-9000 System Survey. • Where a commercial heat treat source is a direct supplier of heat treat services to any Ford manufacturing

or assembly plant, this survey will be used. • If a heat treat source is a sub-supplier (e.g. second tier, third tier) to a Ford Manufacturing or Assembly

Operation, then the first tier supplier is responsible for conducting the Heat Treat Survey and submitting the survey to the responsible STA Engineer for review, as appropriate.

SECTION III - REQUIREMENTS Conformance to QS-9000, Heat Treat System Survey Scoring Guidelines and W-HTX requires at least a "7" rating on each individual element and at least a "160" (SPC section requires 40 points minimum) overall System Survey Rating. Suppliers shall provide improvement action plans for all areas with a rating below "7" within 60 days.


SECTION IV

HEAT TREATMENT STATISTICAL PROCESS CONTROL APPLICATIONS

STATISTICAL PROCESS CONTROL FOR DIMENSIONLESS AND PROCESS CHARACTERISTICS

OBJECTIVES When applying the principles of QS-9000 and the Fundamentals of Statistical Process Control it is important to ask the question "How I can improve the process?" and NOT "How can I apply an XR chart to this process?" Continuous improvement requires a different approach to the traditional perception of Quality that required conformance to specification within two predetermined limits. For a given property of any given product there will be an optimum value, within given cost constraints, at which maximum customer satisfaction will be achieved. Continually reducing ‘piece to piece’ variation and targeting production towards the desired nominal value can accomplish this. The most efficient ways of measuring and reducing variation are statistical analysis and control charting techniques. Control charts have two distinct roles: first, an operational tool enabling process operators to react to adverse signals and maintain statistical control (Defect Prevention), and second, as a judgmental tool in analysis of process performance and to promote action for improvement. The second is very beneficial in heat treat, chemical and process industries. The following pages discuss some of these techniques. Remember that the sole objective is process improvement and not merely the use of statistical techniques THE HEAT TREAT PROCESS Generally, the heat treat process may be described as a series of basic steps common to all other manufacturing processes. These are: A. Selection of heat treat process parameters for a given material. B. Loading of a product for heat-treating. C. Austenizing, Quenching, and Tempering of a product. D. Product testing. The traditional product quality control methods rely on evaluation of the finished product together with intermediate process checking. This type of testing methodology is based on defect detection when in actual fact defect prevention is far more desirable.


SELECTION OF HEAT TREAT PROCESS PARAMETERS FOR A GIVEN STEEL INCOMING The physical and chemical characteristics of steel may significantly affect performance parameters of a given product, e.g., percent carbon, hardenability of steel and core hardness, etc. Such variability should, wherever possible, be reduced to a minimum. Data to assess variability may be obtained in the following ways: A. From material heat treaters in the form of product certification or, B. From "In House" testing carried out on supplied material. In either case it is recommended that parameters selected for study be charted using applicable SPC charts (See pages 17-21). The choice of parameters for study may require preliminary analysis to evaluate their significance in subsequent processing operations. Some typical examples of parameters that may be studied are: • Chemical analysis and alloy content (normally for a specific element) • Prior microstructure (percent decarburization) • Hardenability • Quenchability of the quench media Having collected and charted sufficient data to permit control limits to be established, any subsequent "out of control" condition will become immediately apparent. In certain instances, no action is possible to improve the variability of a supplied material, but charting methods can still provide useful information by highlighting the need for early correction to subsequent processing.


LOADING, AUSTENITIZING, QUENCHING AND TEMPERING PROCESS In the majority of cases, this is a continuous process and the process affects the physical properties of the product being heat-treated. In this category typical parameters for study could include: • Weight (scale) • Belt speed • Total time in furnace (Austenitizing and tempering) • Zone temperature (Austenitizing and tempering) • Zone carbon potential • Endothermic generator carbon potential • Atmosphere furnace pressure (Per zone) • Air and natural gas flow rate • Ammonia flow rate • Electric usage • Quench media agitation • Quench media temperature • Quenching time • Quench media-level • Quench media concentration • Quench media filter pressure No attempt should be made to chart all of these and other related parameters because a number of these parameters may be interdependent and results will be difficult to interpret. Tracking these parameters may be by MA & MR and I & MR or other appropriate SPC methods. PRODUCT TESTING Assuming that the control charting of selected process characteristics has shown process stability and a reduction in variability, then a proper characteristic to gain process knowledge has been selected. The testing of the finished product is an "Indicator" by which the effect of process improvements can be monitored. In selecting properties to be tested, attention should be given to the prime requirement of the customer. Correlation studies should be conducted where tests may be repeated by the customer. The choice of properties for test will therefore rest with the 1st tier and/or Heat Treater and the end customer.


CONTROL CHARTS MOVING AVERAGE AND MOVING RANGE CONTROL CHARTS Conventional control charting techniques require that groups of measurements are taken together, typically from consecutive components or measurements. Under certain circumstances this method of collecting data may be either impractical or undesirable. Examples of such cases are: • Time consuming inspections or destructive tests where inspection costs prevent large groups of data from

being collected. • Chemical, or other continuous flow processes, where any readings taken at the same time would probably

be identical and would give a subgroup range equal to zero, i.e., due to auto correlation. • Processes where a single daily reading or total may be generated. Moving average and moving range charts can prove extremely useful on processes where infrequent or limited process data is available. The selection of which technique to use depends entirely on the type of process being monitored - an individuals chart will react positively towards sudden short term process fluctuations whereas a moving average chart is more sensitive to smaller long term changes in process performance. Checking frequencies and nominal subgroup sizes must be suited to process requirements and meet the requirements of W-HTX. Sample charts follow:

Process Control Chart ----- Moving Average & Moving Range Part Name No. 4 Steel

Characteristic Percentage Silicon Content

Specification 2.1 – 2.4%

Sampling – Frequency Twice per day

Op.

2.5

2.4

2.3

2.2

2.1

2.0

0.4

0.3

0.2

0.1

Shift

Time

Check No. 1

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

X1 2.25 2.20 2.25 2.30 2.25 2.35 2.20 2.10 2.15 2.15 2.20 2.10 2.35 2.25 2.25 2.10 2.25 2.20 2.40 2.35 2.30 2.30 2.20 2.25 2.25 2.15 X2

X3

X4

X5

Ó X

--------------

X

---------------

R 0.05 0.1 0.05 0.1 0.15 0.25 0.1 0.05 0.05 0.1 0.25 0.25 0.1 0.15 0.15 0.15 0.2 0.2 0.1 0.05 0.1 0.05 0.5 0.1

APC

Machine Number

Distribution of X

Remarks

Moving Average & Moving Range Subgroup size = 3

--------------

X = 2.23

---------------

R = 0.117

0.121

____ ___

UCLX = X + A2 R = 2.35 ____ ____

LCLX = X + D3 R = _________

____ ____

LCLX = X + A2 R = 2.11 ____ ___

UCLX = X + D3 R = 0.30

Contents

Sample Size -n A2 D2 D3

2 1.880 0 3.288

3 1.023 0 2.674

4 0.729 0 2.282

5 0.677 0 2.114

Process Control Chart ----- Individuals & Moving Range Part Name No. 4 Steel

Characteristic Percentage Silicon Content

Specification 2.1 – 2.4%

Sampling – Frequency Twice per day

Op.

2.5

2.4

2.3

2.2

2.1

2.0

0.4

0.3

0.2

0.1

Shift

Time

Check No. 1

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

X1 2.25 2.20 2.25 2.30 2.25 2.35 2.20 2.10 2.15 2.15 2.20 2.10 2.35 2.25 2.25 2.10 2.25 2.20 2.40 2.35 2.30 2.30 2.20 2.25 2.25 2.15 X2

X3

X4

X5

Ó X

--------------

X

---------------

R 0.05 0.1 0.05 0.1 0.15 0.25 0.1 0.05 0.05 0.1 0.25 0.25 0.1 0.15 0.15 0.15 0.2 0.2 0.1 0.05 0.1 0.05 0.5 0.1

APC

Machine Number

Distribution of X

Remarks

Individuals & Moving Range Subgroup size = 3 (d2 = 1.69)

--------------

X = 2.23

---------------

R = 0.117

Ô = 0.07 0.121 UCLX = 2.44 LCLX = 2.02 ____ ___

UCLX = X + A2 R = ___________ ____ ____

LCLX = X + D3 R = ___________

____ ____

LCLX = X + A2 R = ___________ ____ ___

UCLX = X + D3 R = 0.30

Contents

Sample Size -n A2 D2 D3

2 1.880 0 3.288

3 1.023 0 2.674

4 0.729 0 2.282

5 0.677 0 2.114


Section V - Heat Treat Process Strategy

CAUSAL FACTORS FOR HEAT TREAT RELATED CONCERNS CAUSAL FACTOR FOR SURFACE HARDNESS WHEN NEUTRAL HARDENING (i.e., QUENCH & TEMPER) Low • Variation in steel chemistry (e.g., % carbon at the low end of the specification). • Surface Decarburization in the furnace. (i.e., low carbon potential). • Delay quench (i.e., excessive hold time between austenizing furnace and quench). • Insufficient quench time. • Quench media temperature (high). • Quench media agitation (insufficient). • Tempering furnace temperature (high). High • Variation in steel chemistry (e.g., % carbon at the high end of the specification). • Improper austenizing furnace atmosphere (i.e., high carbon potential). • Quench media temperature (low). • Tempering furnace temperature (low). • Insufficient tempering (i.e., time/temperature relationship). WHEN NORMALIZING PROCESS High • Variation in steel chemistry (e.g., % carbon at the high end of the specification). • Improper austenizing furnace atmosphere (i.e., high carbon potential). • Wrong process (i.e., parts quenched). WHEN CARBURIZING AND CARBONITRIDING Low • Variation in steel chemistry (e.g., % carbon at the low end of the specification and/or insufficient

alloying elements). • Surface decarburization in the austenizing furnace (i.e., low carbon potential). • Retained austenite because of high carbon potential. • Delay quench (i.e., excessive hold time between austenizing furnace and quench). • Insufficient quench time causing part to temper, due to residual heat in the part. • Quench media temperature (high). • Quench media agitation (insufficient). • Tempering furnace temperature (high). High • Variation in steel chemistry (e.g., % carbon at the high end of the specification and/or insufficient

alloying elements). • Improper austenizing furnace atmosphere (i.e., high carbon potential). • Quench media temperature (low). • Tempering furnace temperature (low). • Insufficient tempering (i.e., time/temperature relationship).


CAUSAL FACTORS FOR CASE DEPTH WHEN CARBURIZING AND CARBONITRIDING TOTAL CASE DEPTH Low •• Variation in steel chemistry (i.e., % carbon high for the process). • Dirty parts • Austenizing furnace zone temperature (low). • Austenizing furnace cycle time (fast or short). • Improper austenizing furnace atmosphere (i.e., low carbon potential). High •• Austenizing furnace zone temperature (high). • Improper austenizing furnace atmosphere (i.e., high carbon potential). • Austenizing furnace cycle time (slow or long). EFFECTIVE CASE DEPTH Low •• Variation in steel chemistry (i.e., % carbon low). • Austenizing furnace zone temperature (low). • Austenizing furnace cycle time (fast or short). • Improper austenizing furnace atmosphere (i.e., low carbon potential). WHEN INDUCTION AND/OR FLAME HARDENING Low case depth • High current frequency. • Cycle time (short). High case depth • Low current frequency. • Cycle time. CAUSAL FACTORS FOR BRITTLENESS WHEN TEMPERING • Insufficient time. • Insufficient temperature. WHEN AUSTEMPERING • Insufficient time in salt (to insure transformation). • Insufficient salt temperature (to insure transformation). WHEN CARBURIZING/CARBONITRIDING • Excessive carbon (e.g., intergranular carbide formation). • Inadequate transformation during quenching.

Generic Cause and Effect Diagram For Annealing and Normalizing Heat Treat Processes

Furnace Quench* Temperature Time Zones Total time Cooling Rate Maintenance** Belt Speed Still Air Atmosphere Mass Distribution Forced Air Furn. Press. Flow Rate Product Cooling Rate# Circu. Fan Exothermic Gas Ammonia Nitrogen Prior Microstructure Incoming Specification Over Charge Hardenability Contamination Part Design Experienced Continuous Chemistry Grain Size Batch Clean/Dry Under Process Steel Training Special Fixturing Procedure Overload Heats Special Overload Fixturing

Materials Operator Loading Note:

* For normalizing only # Furnace Cooling for the Annealing Process only ** Maintenance = Reliability of the Process Monitoring Equipment

Annealing And/or Normalizing

Generic Cause and Effect Diagram For: Induction Hardening Process

Tooling Inductor Quench Temperature Temperature Induction Coil Coil Set Up Process Controller Ircon Design Instruction Time

Maintenance** Maintenance** Wear Total Time

Material Frequency Soak Time Leakage

Part Conf. Energy Monitor Low Agitation Runout Calibration High Delayed Quench Pumps/Propellers

Power Usage Flow Rate Prior Microstructure Incoming Specification Over Charge Hardenability Contamination Part Design Experienced Continuous Chemistry Grain Size Batch Clean/Dry Under Process Steel Training Special Fixturing Procedure Overload Heats Special Overload Fixturing


** Maintenance = Reliability of the Process Monitoring Equipment

Case Hardening

Generic Cause and Effect Diagram For: Neutral Hardening, Gas Carburizing and Carbo Nitriding Heat Treat Processing

Furnace Quench Temper Temperature Temperature Temperature

Time Zones Time Time Material Handling

Total time Maintenance** Maintenance** Maintenance** Belt Speed Soak Time Total Time Belt Speed Atmosphere Belt Speed Agitation Prior Microstructure Delayed Quench Carbon Poten Flow Rate Media Pumps/Propellers Circu. Fan Furn.Press Circu. Fan Endo Power Usage Natural Gas Properties Flow Rate Air Ammonia Prior Microstructure Incoming Specification Over Charge Hardenability Contamination Part Design Experienced Continuous Chemistry Grain Size Batch Clean/Dry Under Process Steel Training Special Fixturing Procedure Overload Heats Special Overload Fixturing


* For Carbo-Nitriding Process only ** Maintenance = Reliability of the Process Monitoring Equipment

Neutral and Case

Hardening


Elements of Heat Treat Process Control Strategy: Conventional wisdom has been to develop the Control Plan to detect the defects after the part(s) have completed a process in a given manufacturing sequence. In today's environment where defect prevention is an essential part of continuous improvement control plans have become an important tool for processing the part(s). To develop an effective Process Control Strategy it is imperative that we consider Heat Treat NOT as an ENIGMA but an ENGINEERED MANUFACTURING PROCESS. This will require heat treaters to analyze and understand each step of the process. Following is the sequence that should be followed in developing the control plan: Define the process flow for a selected Heat Treatment. e.g., Incoming materials • Loading of parts on the conveyor or basket. • Austenitizing process. • Quenching sequence. • Tempering process • Unloading/Packaging/Shipping • Etc. Develop a Cause and Effect diagram, for each process sequence identified, and analyze for Potential failures. Refer to pages 23 - 25 for typical cause and effect diagrams and pages 26 - 27 for causal factors for typical heat treat process failures. Utilize information in developing Potential Failure Mode and Effect Analysis document. Refer to next pages for a typical Process Failure Mode and Effect analysis. It is essential that Heat Treater have a FMEA for the part being analyzed so that the effects of Heat Treatment on design requirements can be understood. Note: Consult your STA engineer for latest revision to Ford's FMEA Manual and training requirements. Develop Control Plans for all of the causes identified, in the Cause & Effect and PFMEA documents for the failure modes identified in the reaction plan. Refer to page 18 for a typical Dimensional Control Plan.

POTENTIAL FAILURE MODE AND EFFECTS ANALYSIS (PROCESS FMEA)

Process Name/No: Pusher Furn Carburizing & Salt Quench Supplier & Plants Affected Prepared by: Part No: Gears Model Year/Vehicle(s) FMEA Date (orig.) Other Areas Involved Design/Mfg. Responsibility Key Production Date

Action Results

Process Description Process Purpose

Potential

Failure Mode

Potential

Effect(s) of Failure

S e v

D e l t a

Potential

Cause(s) of Failure

c u r

Current Controls

D e t e c

R P N

Recommended

Action(s)

Area/Individual Responsible &

Completion Date Actions Taken S e v

O c c

D e t

R P N

Case Hardening of all Gears

Abnormal Distortion Gear Characteristics (lead,TIR) out of spec. causing noise

5 Improper Fixturing 2 Process Sheet Leading Details

1 10 None

5 Carbonitriding Temperature set to high or low

3 Temp controls with verification by Operating personnel, Process Sheets

2 30 annual review Process eng. & LUBD

annual review 5 2 2 20

5 Excess Carburizing temperature from thermocouple or protection tube fail

3 Oxygen probes & visual by operating personnel

2 30 Replace T/C protection tube program

Elect. LUBD. Honeywell

visual checks and records, calibration

5 2 2 20

Total Case Depth Non conforming to print specification (Overcase)

Part Brittle, Distorted 8 Carbonitriding Temperature set to high or low


2 48 annual review process eng. & LUBD







8 2 2 32

Total Case Depth Non conforming to print specification (Undercase)

No wear or bending resistance, may fail minimum hardness

8 Carbonitriding Temperature set to high or low









8 2 2 32

8 Carbon potential of atmosphere to low (High Dew Pt.)

3 Oxygen probes & Dew Pt. Gage

1 24 None

Surface Hardness Non Conforming to print specification (Soft)

No wear or bending resistance, may fail minimum hardness

5 Carbon potential of atmosphere to low (High Dew Pt.)

3 Oxygen probes & Dew Pt. Gage

1 15 None

5 Carbonitriding

Temperature set to high or low




POTENTIAL FAILURE MODE AND EFFECTS ANALYSIS (PROCESS FMEA)

Process Name/No: Modular Endothermic Generator (Surface) Suppliers Prepared by: Part No: Heat Treat Model Year/Vehicle(s) FMEA Date (orig.) 6/9/97 (Rev.) 6/9/97 Other Areas Involved Design/Mfg. Responsibility Key Production Date

Action Results

Process Description Process Purpose

Potential

Failure Mode

Potential

Effest(s) of Failure

S e v

D e l t a

Potential

Cause(s) of Failure

c u r

Current Controls

D e t e c

R P N

Recommended

Action(s)

Area/Individual Responsible &

Completion Date Actions Taken S e v

O c c

D e t

R P N

Operation (heat Treat). Supply Endothermic Gas to Furnace

Cooling Fans Fail Hot Rx Gas 6 Gas Cooler motor fails 1 Operation audio and visual alarm

1 6 None

6

Airpathway is plugged 1 Visual 2 12

Mixer pump failure Lose supply of endothermic gas to the header

4 Broken motor/pump belt

2 Visual 1 8

4

Mixer motor failure 1 Audio/visual alarm 1 4

4

Mixer pump failure 2 Visual 1 8

Hole in Retort Endo gas leaking. flames out of retort

6 Lack of burnout, old tubes

1 Visual 1 6

6 Excess Carburizing temperture from thermocouple or protection tube fail

2 Visual 1 12

Air blower failure no individual burnout

1 Blower motor failure 1 Visual 1 1

Datalyst is not reacting

High dew point, no Rx gas being made

6 Soot buildup, causing poor flow across catalyst

1 High dew point 1 6

6 Catalyst was oxidized preventing surface contact

1 High dew point 1 6

Carbon controller failure

Dualpro is unresponsive, High or low dew pt.

1 Dualpro failure or asco valve on flow meter has failed

1 Manual check of dew point 1 1

E-stop failure E-stop failure electricity and gas continue to run through generator

8 Electrical Failure 1 Shut off gas valves and pull main disconnect

1 8

DIMENSIONAL CONTROL II (WORKSHEET)

November 5, 1997

REVISIONS CHG NO.

DESCRIPTION

CMG By

Approved By

Effective Date

RESPONSIBILITY CODES

RELATED INSTRUCTIONS

PROGRAM . PLANT . PART NAME . PART NO. . B/P DATE . 01/11/91 DEPT NO. . OP. - STA. NO . 40 S.T. NO. SHEET . 1 OF 1 INITIAL DATE . 11/03/93 EFFECTIVE THRU . 12/31/98

1 2 3 4 5 6 7 8 9

10/31/97 CHANGE FREQUENCY ON HARDNESS, CD. PARAMETER SCREEN 10/31/97 CHANGE FREQUENCY TO 1 SHIFT ON QUENCH CONCENTRATION 11/27/97 CHANGES PER AUDIT COMMENTS 10/31/98 CHANGES PER W-HTX 09/20/99 UPDATE GAGE R&R

CB CB EZ CB CB

EZ EZ EZ EZ EZ

10/31/94 10/31/94 11/27/94 11/06/95 11/20/96

O = OPERATOR T = MFG TECM L = LAYOUT Q = QUALITY TECH M = MAINTENANCE C = CHEM/MET LAB G = GAGE REPAIR U = LIGHT UP

S = SETUP O = OPERATOR M = MAINTENANCE L = LUBRICATION G = GAGING/CALIBRATION D= OPERATION DETAIL

PRODUCT CONTROL ITEM PROCESS CHECK ITEM Capability

Sampling

ID

Description

Spec

Type

Imp. Lvl

Cont. Fact.

Tool T - 0

M/S S

P/Cp

F/Cpk Date

Control Method (Record) Siz

e Frequency

R E S

Gage

Description

V / A

R&R

%

Check Item

Aff ID’s

Spec

Control Method (Record)

Check Freq.

Check Method

RI EM LS

R E S

92A

92B

92C

92D

92E

92F

92G

92H

PATTERN LOCATION

MICROSTRUCTURE

SURFACE HARDNESS SPLINE

HARDNESS TESTER VERIFICATION

HR 15N

EFFECTIVE CASE DEPTH – SPLINE TO 83.0 HR 15N

CRITICAL PARAMETER

TREND REVIEW ENERGY/QUENCH

FLOW QUENCH

TEMPERATURE ROTATION SPEED

EPF CASE TO 80.5 HR15N

W-HTX

W-HTX

85.5 HR15N

W-HTX

0.5MM MIN BELOW ROOT

W-HTX

0.5MM MIN BELOW ROOT

IP

IP

ES

IP

IP

IP

ES

2

2

2

S.T

T,S

T,S

1

1

1

1

1

1

NA NA

NA NA

NA NA

NA NA

NA NA

NA NA

NA NA

NA NA

NA NA

1.373 3.240

NA NA

2.930 2.676

NA NA

NA NA

01/25/93 07/23/92

01/25/92 07/23/92

CHECK SHEET

CHECK SHEET

RUN CHART

TREND CHART

RUN CHART

TREND SCREEN/ CHECK SHEET

1

1

3

1

1

AFTER COIL CHANGE OR

POWER CHANGE

ONCE/WEEK &

AFTER COIL CHANGE OR

POWER CHANGE

AT START UP, SET UP, AND

EVERY 4 HOURS

ONCE/SHIFT

AT START UP, SET UP , AND

EVERY 4 HOURS

EVERY 4 HOURS

AND CHANGE

REF IP 92E

T

C

T

T

T

T

METALLURGICAL

INSPECTION STATION

DELIVER TO MET LAB FOR

METALLURGICAL EVALUATION

METALLURGICAL

INSPECTION STATION

HARDNESS TESTER

METALLURGICAL INSPECTION

STATION

TCP SCREEN

V

V

V

V

V A

8.6

QUENCH

PRESSURE

ENERGY MONITOR QUENCH FLOW QUENCH TEMP

ROTATION SPEED

QUENCH CONCEN. (RECORD ADJ.

ON CHART LOG)

QUENCH SLUDGE

92A-C,B

92A-C,B

92A-C,E

92A-C,E

NA

TCP

5-1.5%

NA

AUTO

REJECT

AUTOMATIC REJECT OF

PARTS

RUN CHART

AUTO REJ.

100%

100%

ONCE/SHIFT

& AFTER CHANGE

100%

PRESSURE

SWITCH

AUTOMATIC TRENDING/TC

P

REFRACTO-METER

DIFFERENTIAL

T

T

T

T


SECTION VI

HEAT TREAT SYSTEM SURVEY SCORING GUIDELINES These guidelines are an expansion of the Heat Treat System Survey questions with examples of typical Heat Treat situations and the points to be assigned for these situations. In practice, all point assignments should be based on written commentary which answers each question in terms of the heat treater's size, processes and products. Any point values from zero to ten may be used as the rating for any of the questions. The lack of an example in the Guideline for a particular rating does not preclude the use of that rating so long as the rating assigned is supported by the comments. On those questions for which a range of ratings is specified (e.g., 9 to 10), the STA Engineer or Heat Treat Engineer's judgment should be used to select the proper rating with appropriate documentation in the report. Fractional ratings (e.g., 6.5) shall not be used. References to appropriate sections of Ford Manufacturing Standard, W-HTX , "Control of Heat Treating Processes and Auxiliary Equipment" and QS-9000 are included in parentheses. The use of all other heat treat related Ford Motor Company manufacturing standards, when required, shall be used in conjunction with the W-HTX manufacturing standard.


Guide for Making Point Assessment for Element No. 1

0 The heat treater has no quality planning effort. 1 to 2 The heat treater claims to perform quality planning, but has little or no supporting documentation. 3 to 4 There is no written procedure for quality planning, but there is some documentation or other

evidence (list it) that effective quality planning has occurred. Also, the heat treater's quality planning effort is largely limited to the quality activity.

5 to 6 An adequate written procedure on quality planning is available, but there is inadequate evidence

that the procedure is followed. 7 to 8 Quality planning activity is well defined with specific tasks identified for most of the appropriate

functional activities in the heat treater's organization. The aspects of quality planning are well documented. Evidence shows that the procedures are rigorously followed.

9 to 10 There is evidence that the quality planning process is extremely well thought out and effectively

uses quality planning teams.


A. PLANNING FOR QUALITY

l. Is the responsibility for quality planning of heat treat processes clearly defined? (QS-9000, Element 4.2) (W-HTX, 1.1)

Within the scope of planning for quality: ♦♦ The Quality Planning Process is to consist of a detailed written procedure defining: • Organization team and individual members mission. • Process review/Development and Feasibility analysis. ♦♦ Feasibility means- Joint determination, with appropriate customer's activity representatives, 1st tier supplier and the Heat Treater to obtain detailed information about the product to be heat treated. Issues to be discussed should include (but are not limited to): � Product Specification: • Is product chemistry the optimum for the selected heat treatment? • What is the intended use of the heat treated product? • Have special characteristics been identified? � Product Design: • Are design requirements feasible with the selected heat treat process (stress crack potential, effect of part

geometry on dimensional and heat treat requirements, etc.)? • Effect of inherent manufacturing defects of the product on the heat treatment results? � Qualification Testing: • What type and frequency of inspection/testing does the product require? • How will the testing equipment correlation study between the heat treater, customer and end user on the

selected tests be established? � Reprocess Authorization: • Product which does not meet B/P specification after initial heat treatment and could be corrected with

reheat treatment, may require prior engineering approval. � Development of manufacturing systems and controls, i.e., • Process Flow diagrams, Process FMEA & Cause and Effect Diagram • Control Plan • Process monitoring instructions • Production Process Verification Run and Process Capability • Measurement System Evaluation (Product/Process) • Material Handling and Packaging � Production Process and/or Manufacturing process sign-off ♦♦ Assess the adequacy of the heat treater's quality planning effort. Review any available documentation ( procedures, meeting minutes, timing charts, open issues, closures,

APQP requirements, etc.) that would indicate how well the heat treater's quality planning effort operates. ♦♦ Identify the key contact personnel/department for quality planning and quality concern resolution.

Include names, department names, and phone numbers.



0 The heat treater has no documented evidence of quality planning. 1 to 2 The heat treater's quality planning efforts are rudimentary and have major deficiencies. 3 to 4 The quality planning effort is very limited e.g., has some written heat treat instructions. 5 to 6 The heat treater has some quality planning documentation which includes Process Flow Diagrams,

PFMEA's and Control Plans. However, the controls are limited to Detection Versus Prevention and has inadequate customer involvement.

7 to 8 The heat treater has satisfactorily completed FMEAs and Control Plans for all processes, or similar

documents providing the same information unique to a heat treat process. 9 to 10 The heat treater is customer focused and has documented evidence of a close and very effective

working relationship with the customers. Planning for quality process puts additional emphasis on preventive systems for the manufacturing processes.

2. Are Control Plans and Process Failure Mode and Effects Analyses (PFMEA) used as a basis for

establishing quality programs for heat treat processes? (QS-9000, Element 4.2 and 4.9) (W-HTX, 1.5) ♦♦ Evaluate heat treater's use of a documented method to develop manufacturing quality plans for heat

treat processes by reviewing items such as: • Cause and effect diagrams. • Process flow diagrams, • Design/Process FMEA's, • Control Plans It is essential that the documentation is developed using information such as: material specifications, material hardenability range, furnace loading, temperature control (austenitizing/tempering furnaces and quench systems), atmosphere control for generators and furnaces, flow rates, discharge mechanisms to the quench system, quenchant properties and conditions, etc. ♦♦ Does the heat treater use the above mentioned analysis process to determine significant

characteristics and process parameters? Review the heat treater's methodology to resolve potential problem areas in the process.

♦♦ Is the customer/end user of the heat treated product brought into the quality planning process? Has

the customer approved the Control Plan(s) (e.g., First tier supplier for second tier supplier)?



0 The heat treater has no system for communicating changes to the customers. 1 to 2 The heat treater relies on verbal communication to activities concerned and has a rudimentary

change communication procedure. 3 to 4 The heat treater has, historically, communicated changes effectively to customers. However, the

procedure needs minor improvement in the areas defined. 5 to 6 Procedures have been implemented, less than a year, and actions appear successful. 7 to 8 Manage the change policy is clearly defined and a documented procedure has been implemented.

Evidence shows that the procedure is being followed. 9 to 10 The change procedure has been effectively utilized and updated FMEAs and Control Plans are

reviewed with the customers, prior to changes. 3. Does the heat treater have available and use a procedure for reviewing part design and heat treat

process changes prior to implementation? (QS-9000, Elements 4.4 and 4.16) The goal is an effective, documented process for obtaining customer approval of heat treat process changes. While many drawings and engineering specifications (ES) require such communication, the heat treater must have an appropriate system to bring this about. The heat treater must effectively notify all affected activities both internally (Manufacturing, Engineering, Production, Quality, Maintenance) and externally (Product Engineering, STA, Purchasing, Receiving Locations). ♦♦ Are FMEAs and Control Plans reviewed and updated as part of the procedure? ♦♦ Is customer approval obtained prior to implementing changes? • When product drawing has a note stating that "change in design, composition, heat treat location, or

process from parts previously approved for part production" the heat treater will be required to obtain prior engineering approval (Supplier Request for Engineering Approval Form 1638). (http:\\www-wise.ford.com/html/forms.html)

• Internal Ford plant use of WERS Alert System ♦♦ Is there a procedure for updating operator instructions and visual aids for process and product

changes?



0 The heat treater has no SPC in use. 1 to 2 The heat treater has no SPC in use, but has begun training appropriate personnel (operator

through Plant Manager) and has commenced data collection. 3 to 4 The heat treater has one or more statistical process control applications implemented in the past

six months. Documented reaction to out-of-control conditions has many deficiencies. 5 to 6 The heat treater has been utilizing SPC for a number of control and special characteristics and/or

process parameters for at least one year. Reaction to out-of-control conditions is generally well documented and with only minor shortcomings (5), and well documented for all shortcomings. (6)

7 to 8 The heat treater has been effectively using appropriate SPC methods on all control and special

characteristics and/or process parameters. Reaction to out-of-control conditions is well documented for virtually all out-of-control conditions (7), and well documented for all out-of-control conditions. (8)

9 As per all of the requirements for a Score of 8, plus numerous control charts show evidence of

process improvement through reduction of common cause variation. 10 All heat treat processes show evidence of process improvement through reduction of common

cause variation.


B. STATISTICAL METHODS

4. Is Statistical Process Control (SPC) utilized for product characteristics and process parameters?

(QS-9000, Element 4.9, 4.18, 4.20)(W-HTX, 1.6, 2.6.2, 2.6.3, 3.5, 3.6.2, 3.6.3) (HTSS, Section 6) Indicate which process parameters (e.g., furnace time, temperature, atmosphere, flow meter, carbon potential, recovery time, quench temperature, concentration and/or quenchability, etc.) are currently controlled using SPC. ♦♦ How are the Special characteristics chosen (e.g., hardness after quench and after tempering, case

depth and dimension, as required, etc.)? ♦♦ Does the heat treater use the cross-functional team approach? Is there a documented process for

determining Special characteristics and process parameters? Are the characteristics chosen actually the control, significant and important ones?

♦♦ Describe the SPC methods used? Are they appropriate to the factors being controlled? • List SPC methods in use (e.g., trend charts, I-MR, median charts, moving average and moving range

charts, histograms, attributes charts, P-charts.) Are variables-type charts used wherever appropriate? Are previous charts available for trend analysis?

• For case depth and hardness, refer to Question 5, paragraph 2 and Section VI and W-HTX, 2.6.2, 2.6.3,

3.6.2 and 3.6.3. ♦♦ Evaluate the heat treater's reaction to out-of-control conditions. Is the reaction as specified in the

Control Plan? What is the role of the operator? • Who is responsible for reacting? Are root causes determined? Are concerns permanently resolved or do

they "recur"? Review appropriate records. • Is there an internal review of the charts to verify accuracy and proper analysis? ♦♦ Evaluate heat treater's application of SPC, based on the evidence of the control charts, process logs

and other appropriate documentation.



0 The heat treater has no documented evidence of having conducted preliminary statistical studies. 1 to 2 Preliminary statistical studies have been conducted occasionally, but they did not include

appropriate analysis and additionally, the studies were not properly documented and are not a regular part of the new product launch process.

3 to 4 There is evidence that preliminary statistical studies have been frequently conducted, but the

method was inadequate. For example, a plot on normal probability paper was made, but no control chart was used, and the time sequence of the data was not considered.

5 to 6 Acceptable preliminary statistical studies have been conducted on one or two isolated

characteristics. Or: Preliminary statistical studies have been conducted on all or most of the control and/or special

characteristics, but there are deficiencies in the conduct of the studies or in the response to unacceptable results.

7 to 8 Process improvement actions are initiated when unacceptable results are obtained. Records show

that preliminary statistical studies are conducted for all control, special characteristics and process parameters.

9 to 10 No process is used for production until a process meets Ppk requirements of 1.67 and evidence

exists that many needed improvements have occurred during the launch phase.


5 Are process verification/capability studies conducted on new product (i.e., a new initial sample)

characteristics and heat treat process parameters? (QS-9000, 4.9.2) (HTSS, attachment A) (W-HTX, 1.6) Preliminary statistical studies are early, short term evaluation of a process to gain information on both the variability of the process and its potential for producing products meeting specifications. The data must be analyzed using control charts or similar time sequence methods so that changes occurring during the production run will be evident. While the short duration of typical process capability studies makes this a very limited test for stability, any instability that does occur (e.g., quench hardness, cracks, distortion or shifts in values of characteristics or parameters) must be noted, understood, and reconciled to the satisfaction of all parties. • For certain heat treat characteristics such as hardness, microstructure, case depth, etc., the following SPC

method will be considered acceptable: For continuous process: use individual moving range chart Select sub-group sample size of 4 or 5 taken over time of the entire production run. For the individual

chart, print specification can be used for upper and lower control limits. However for the range (r) chart the upper control limits must be developed using D4*R(average). The study will be considered stable and capable if all individual readings fall within B/P specification limits, for each sub-group, and no points fall outside the Upper Control Limit of the range. For capability indices data can be presented as 100 %, when all points in the range chart fall within the Upper Control Limit. Reported percentage should be reduced for number of points out of control.

Note: For other appropriate methods for charting please refer to Section IV. For batch process: use histogram analysis Randomly select minimum samples of 30 pieces (for each batch load), from different layers or location

whichever best represents potential process concerns, from an entire Product Verification Run and measure the characteristics. A histogram must be developed and analyzed if the universe of the individual values is normally distributed. The study will be judged acceptable if all samples meet print specification.

When the Ppk requirement of QS-9000 is not met process improvement actions and repetition of the preliminary studies are required. If Ppk requirements cannot be met then containment actions must be provided in the Control Plan. Note: The index Ppk is used to distinguish preliminary statistical results from longer term process

capability index, Cpk.



0 Control charts are not in use for special characteristics and process parameters so no conclusions

about capability can be drawn. 1 to 2 Control charts are available for some special characteristics and process parameters, but do not

show statistical control.(1) No conclusions about capability can be drawn, and there is no evidence of improvement actions to help stabilize the process.(2)

3 to 4 Most special characteristics and process parameters are control charted and all or most of the

charts show statistical control.(3) However, one or more of these operations is not capable and no definite plan exists (i.e., specific actions/target dates) to attain capability.(4)

5 to 6 Control charts are in use for all special characteristics and process parameters, and statistical

control has been shown.(5) There are convincing action plans available for any non-capable process(es).(6)

7 Control charts show most or all special product characteristics and process parameters to be in

control. 8 The heat treater has achieved at least 99.994% capability on a majority of the Special

Characteristics. 9 As per all of the requirements for a Score of 8, and knowledgeable use of statistical methods has

provided documented customer benefits. 10 As per all of the requirements for a Score of 9, and knowledgeable use of statistical problem

solving methods has resulted in documented product and/or process improvements.


6. Are statistical control charts being used effectively to monitor the process? Do control charts indicate

that statistical control has been achieved and that process capability has been demonstrated? (QS-9000, Table A, Table B, Element 4.20) (W-HTX, 1.6, 2.6.2, 2.6.3, 3.6.2, 3.6.3)(HTSS, attachment A)

♦♦ How are statistical tools chosen for each special characteristic? Is there evidence that the heat treater

understands and uses a variety of statistical tools? ♦♦ What is the heat treaters actual definition of instability? Are trends, runs, and other non random

patterns perceived as instability? Note: Plotted information on the furnace chart recorder is not considered a statistical process control chart unless

statistically calculated control limits are shown on the recorder charts and are being used to control the process parameters.

It is mandatory that statistical control (stability) be demonstrated before any statement of capability (Cp/Cpk) can be calculated. ♦♦ Is the potential for "over control" recognized? Do all personnel understand the significance of various

signals from control charts? Capability applies only to characteristics that can be evaluated using variable data. For characteristics that can only be evaluated with the attributes data, efforts shall be directed towards achieving stability and then reducing the absolute level of concerns. The method of calculating the standard deviation for capability evaluations shall be reviewed and verified to be statistically appropriate. ♦♦ Are unstable and non-capable processes given high priority for process improvement? Are there

documented action plans and indications of improvement on such processes? Processes that have historically (30 days or more) been stable and capable and which have recently gone out-of-control will be considered as stable and capable, provided that appropriate, documented containment actions have been taken and a rigorous effort to eliminate the special cause is in progress.



0 There is no evidence (as opposed to discussion) that the heat treater is committed to continuous

improvement in quality and productivity. 1 to 2 The heat treater has a document such as a policy or a procedure stating that continuous

improvement is a major business objective. However, there is no evidence that the policy is being implemented.

3 to 6 Implementation of a continuous improvement policy ranges from “very spotty" (3) to "fairly

consistent" (6). However, the actual improvement to date is minimal. 7 Implementation of improvement actions have occurred for some of the various heat treat

processes e.g., planned upgrading of the equipment, improvement in material handling system and upgrading of the instrumentation to enhance the preventive maintenance system, etc.

8 Implementation of improvement actions have occurred for all heat treat processes requiring

improvement actions. 9 to 10 The heat treater has implemented a comprehensive Quality/Business Operating System (QOS).(9)

Verification of the QOS indicators shows that the heat treater has achieved continuous improvement.(10)

7. Does the heat treater have a definite program to bring about continual improvement in quality and

productivity? (QS-9000, Section II)(W-HTX, 1.1) Improvement plans must be detailed and specific, e.g., improve the first-run capability of specific operations by evaluating different process parameters (temperatures, pressure, atmosphere, cycle time, furnace loading, etc.). ♦♦ Describe the program. Indicate how responsibility is assigned and how progress is evaluated. • Include the statistical methods and other tools used to promote continuous improvement. List any methods

for which documented evidence is available. • Evaluate the scheduled preventive maintenance program for the heat treat process and measurement

system. • Review the heat treater's Quality/Business Operating System (QOS). Evaluate the significance of the

selected indicators to the philosophy of continuos improvement. Note: Quality/Business operating indicators should be jointly selected between the Heat Treater, first tier heat-treater and the Ford Powertrain Plant.



0 The heat treater has no documented records of Tier 1 and Tier 2 heat treater control methods. 1 to 2 The heat treater has written letters to one or more key material sub-heat treaters specifically

requesting an appropriate document verifying heat treater products. 3 to 4 The heat treater performs receiving inspection. However, the procedure allows acceptance of

products which do not meet the specification. 5 to 6 The heat treater receives verifiable certification of incoming products and confirms or recertifies the

products at a specified frequency. 7 to 8 Statistical evidence of stability and capability is available from all key material producers.

Documented and effective containment actions are used when required. Verifiable documentation is also available from all service heat treater's.

9 to 10 The heat treater has an effective Quality Assurance program for its material and service suppliers. 8. Does the heat treater have an effective system for ensuring the quality of incoming products (such as

gases, quench oils, salts, etc.) and services (instrumentation, furnace calibration, metallurgical and physical analysis etc.) How is SPC encouraged at Tier 1 and Tier 2 suppliers? (QS-9000, Element 4.10 and 4.11)

The acceptable methods for controlling incoming quality are heat treater implementation of SPC and receiving inspection. The supplier must ensure that its Tier 1 and Tier 2 heat treaters have quality systems incorporating acceptable quality principles. ♦♦ Assess the adequacy of the heat treater’s control on the quality of the service it receives. • Describe the heat treaters audit program, in detail, to ensure the quality of the services it receives. • Does the heat treater have a formal STA program to audit its material and service suppliers.



0 The heat treater has no process control program of any type. 1 to 2 The heat treater has a process control program, but does not comply with W-HTX. 3 to 4 The heat treater has a detailed product control program, but it is defect detection, rather than

defect prevention, oriented. Examples of defect detection programs are any lot acceptance sampling programs.

5 to 6 The heat treater's product control program focuses on defect prevention, but does not meet the

requirements of W-HTX and Ford Manufacturing heat treat standards as applicable. 7 The heat treater meets the requirements of W-HTX and Ford Manufacturing heat treat standards

as applicable. 8 The heat treater has full laboratory capability to perform product monitoring and process parameter

control auditing functions. 9 to 10 The heat treater uses graphic and pictorial methods to define the process function, significant

events and audit results to facilitate comprehension.


C. GENERAL

9. Are process/product monitoring and control functions and responsibilities clearly defined? (QS-9000,

Element 4.10, 4.12 and 4.17; Table A and Table B)

Indicate which plant activities conduct process/product monitoring and control (e.g., quality control inspectors, production operators, laboratory technician). Assess the adequacy of the heat treater's control program.

This question seeks information on every aspect of the heat treater's control, checking or inspection program. Typical examples of audits are: • Process Parameter Measurements audit • First Piece Inspection (after quench and/or temper) • Operator Checking (frequently used with SPC) • Roving Inspection (also called In-Process or Floor Inspection) • Internal Systems Audits (of the engineering and processing procedures) • Quality Systems Audits (of performance to procedures) • Final Inspection (visual, dimensional or functional - sample or 100%) • Laboratory Tests • ES Tests, i.e., Product Qualification. ♦♦ Assess heat treater's chemical and metallurgical laboratory capability to perform the minimum product

process control functions. Note: It may be necessary for a heat treater to have the capability to perform metallographic analysis,

micro and macro hardness testing, carbon analysis, etc. ♦♦ Assess the adequacy of the heat treater's auditing program. The type of heat treat processes performed in the heat treater's plant will have some effect on the types of controls chosen by the heat treater. A basic principle is that a control should be located as close as possible (both in space and time) to the process being controlled. Identification of inspected products by time, shift, date and/or operator is considered a good practice and should be followed.



0 No procedures of any sort are available. 1 to 2 Only verbal procedures are used. 3 to 4 Some written procedures exist, however they are incomplete or inappropriate. Not all quality

related functions are covered. 5 to 6 Good written procedures exist and cover all but one or two quality related functions. 7 to 8 Good written procedures are available for all quality functions and there is a formal review system

in place to verify that procedures are followed. 9 to 10 Extremely thorough procedures are available for all quality related functions. 10. Are written procedures defining quality-related functions available (i.e., a quality manual)?

(QS-9000, Element 4.2; Section III, Ford Specific)(W-HTX, 1.3, 1.4, 1.5, 1.6, 1.7, 2.1.4, 2.1.6) Procedures should be available for the following quality related functions when these functions exist in the heat treater's plant • General Operations • Feasibility Review and Quality Planning (new product/process launch procedure) • Process Potential and Capability Studies • Receiving Inspection • Ongoing SPC • First-piece Inspection as dictated by Heat Treat Process (e.g., following quench and temper operations) • In-process Auditing(Process and Product Parameters) • Final Inspection • Status Identification (tagging) • Heat Treat Process Specification Documentation • Ongoing Process parameter Monitoring (e.g., cycle times, gas flow rates, temperatures, loading rates, pressures, etc.) • Thermocouple/Protection Tube Checking and Replacement • Emergency Start-up and Shutdown

• Lot Traceability (customers material heat code, etc.) • ES Testing Documentation and Response to Failures • Process Monitors/Test Equipment Calibration and Maintenance • Inspection/Test Equipment (Measurement systems) Variation Studies • Purchased Product and Service Analysis (Audit) • Returned Product Analysis (TOPS) Drawing and Change Control (including deviations) • Records Retention (breakdown, process revision, etc.) • Reprocess Authorization • Internal Auditing of Procedure • Furnace Atmosphere Purging (W-HTX, 2.1.6) • Quench Solution Maintenance • Bond Crib/Quarantine Area • Furnace/Generator Burnout • Laboratory Test Instruction Sheets • Other Routine Functions Affecting Product Quality

♦♦ Are these procedures appropriate to and adequate for the heat treater's operations? ♦♦ Are the procedures implemented as written? Is there a review process to verify implementation? The number of procedures and the amount of detail required will vary according to the size of the heat treater's operations and the complexity of the process involved. Provide descriptive commentary and rationale for the determination of adequacy or inadequacy. ♦♦ Is there an adequate procedure for reacting to ES, product qualification, and test failures?



0 No written process monitoring and control instructions are available. 1 to 2 Written instructions exist, but are inadequate/incomplete regarding many of the requirements. 3 to 4 Written instructions exist, but have two or three significant shortcomings to W-HTX. 5 to 6 Written instructions are generally complete, but have one major deficiency to W-HTX. 7 to 8 Written instructions are complete and do not contain any deficiencies to W-HTX. 9 to 10 Written instructions are complete and surpass the W-HTX requirements. 11. Are written process monitoring and control instructions available for incoming, in process, laboratory,

dimensional inspection and outgoing auditing? (QS-9000, Element 4.9, 4.10, 4.18, 4.20)(W-HTX, 2.4, 2.5, 2.6, 2.6.2, 3.4, 3.5, 3.6, 4.0, and 5.0)

Process monitoring and control instructions (including instructions for specialized process controllers and test equipment) must be available in written form. If not, a zero must be assigned for this question. These instructions may be combined with process sheets or data log sheets so long as all required information is included. ♦♦ Are all special parameters included, particularly those affecting function and durability? Review part drawings, Product/Process Control Plans, and any other available documents indicating special characteristics. If these are inadequate or unavailable, contact Product Engineering and the consumer plant Manufacturing Engineering/Quality activity for this information. ♦♦ Are special characteristics and related operations identified? ♦♦ Are there instructions available for ES and ES-M requirements? ♦♦ Are sample sizes and frequencies adequate? (W-HTX, 4.0, 5.0) The sampling plan must be developed to address the important source of variation to allow assessment of stability and capability. For SPC with variables data, an initial sample size of five units per hour is suggested unless some other sample size/frequency is specified in a customer approved product/process control plan. After statistical control and capability are demonstrated, gradual reductions of either sample size or frequency are often appropriate. For attribute checks, either product qualification or 100% inspection is required with appropriate control charting. • Metallurgical Properties for Ford Parts, must be checked at least once for every material lot change. • For case depth, microstructure and hardness refer to Question 5 paragraph 2 and section VI of this Heat

Treat System Survey guide. ♦♦ Is appropriate statistical analysis specified? An appropriate control chart should be used for each significant checking or inspection operation as specified by the Product/Process Control Plan. For variables data (to be obtained wherever feasible); X-MR, X-s, or median charts may be used. For either product qualification or 100% inspection, the appropriate attributes chart (p, np, c or u) should be used. Refer to section 4 for additional details.



0 Necessary process monitoring and test equipment is not available. 1 to 2 Only general purpose processing (temperature indicators versus indicator recorders) and

inspection/test equipment (test files, microscope, etc.) is available when specialized equipment is required.

3 to 4 Same as "1" with evidence of definite plans for improvement of process equipment and/or

inspection test equipment 5 to 6 Complete processing and inspection/test equipment is available for all special characteristics.

Automatic processing equipment with automatic chart recorders and controllers is available. 7 to 8 All inspection and test equipment is calibrated and measurement system variation, GR&R, analysis

is performed on a scheduled basis. 9 Some processing and inspection/test equipment for process parameters and special

characteristics provide input directly to analytical equipment for statistical analysis. 10 All processing and inspection/test equipment for process parameters and special characteristics

provide input directly to analytical equipment for statistical analysis. 12. Are appropriate process monitors, thermocouple and inspection/test equipment available to facilitate

process control? Does the heat treater have an effective equipment calibration and measurement program. (QS-9000, Element 4.11)(W-HTX, 2.1.1, 2.6, 3.1.1, 3.6)

♦♦ Are process inspection and test equipment available to provide process operators with variables data

whenever such data can feasibly be obtained? • Are all special process parameters/product features being accurately measured? • Are inspection/test equipment and personnel appropriately located throughout the heat treat operations? • Does the heat treater have event recorders or equivalent to provide a record of furnace operations? • Are inspection/test equipment and process monitoring equipment variation studies used to evaluate these

devices for stability and capability? Each process operator should have, or have immediate access to, inspection and test equipment providing relevant data on the product characteristics/process parameters under the operator's control. Any chemical/metallurgical laboratory equipment needed to conduct ES and ES-M tests should be available. ♦♦ Are over temperature and under temperature (when applicable) controls in place and being utilized on

all zones of furnaces, quench systems and tempering operations? (W-HTX, 2.1.1) ♦♦ Is non-contact infrared thermometry being used (in addition to conventional thermocouple) to monitor

high heat zones of furnaces or individual induction/flame hardening part temperatures. (W-HTX, 2.1.1) ♦♦ Are heat monitor/control instruments properly placed to avoid extremes in ambient temperature,

humidity, vibration, dust and corrosive elements? Are instruments and thermocouple circuits shielded from electromagnetic fields associated with high amperage furnace heating elements?



0 There is no preventive maintenance program for process equipment, process monitors and

thermocouples. 1 There are some elements of a preventive maintenance program for process equipment, process

monitors and thermocouples. However, the program is neither well thought out nor well implemented.

2 There are elements of a preventive maintenance program for process equipment, process monitors

and thermocouples, however, they are neither complete or well implemented. 3 There is a fairly well planned preventive maintenance program for some process equipment,

process monitors and thermocouples. 4 There is a fairly well planned preventive maintenance program for most process equipment,

process monitors and thermocouples. 5 There is a fairly well planned preventive maintenance program for all process equipment, process

monitors and thermocouples, but was not found not to be well implemented. 6 The evidence shows that the heat treater has effectively implemented a preventive maintenance

program for some process equipment, process monitors and thermocouples, but certain aspects of the program require written development.

7 The evidence shows that the heat treater has effectively implemented a preventive maintenance

program for all process equipment, process monitors and thermocouples, but certain aspects of the program require written development.

8 The evidence shows that the heat treater has effectively implemented a preventive maintenance

program for all process equipment, process monitors and thermocouples, but minor written development is required.

9 There is a well planned and effectively implemented preventive maintenance program with no

further written development required. All preventive maintenance tasks are complete to the schedule.

10 There is a well planned and effectively implemented, i.e., computerized and close looped,

preventive maintenance program for all process equipment, process monitors and thermocouples.


13. Does the heat treater have an effective preventive maintenance program for heat treat process

equipment, thermocouple and process monitoring equipment? (QS-9000, Element 4.9)(W-HTX, 1.7, 2.0, 2.1, 2.1.4, 3.0, 3.1, 6.2, 6.3)

♦♦ Indicate the system (e.g., card file, computer) that the heat treater uses to keep track of preventive

maintenance on process equipment, process monitors and thermocouples. • Does the heat treater have a "reactive" or "proactive" preventive maintenance program? • Describe the preventive maintenance program and review records for compliance. Note: It is recommended that the preventive maintenance system be computerized and close looped with

production and quality related concerns, e.g., analysis of unscheduled downtime versus scheduled downtime, first time capability of acceptable product produced etc.

• Does the heat treater have spare part control program? Review the program and evaluate its overall effectiveness. ♦♦ Does heat treater perform furnace temperature uniformity surveys (thermal profiles)?

Review application to batch and/or continuous process. Check for adequacy of records. ♦♦ Are new process monitors, thermocouples and inspection/test equipment inspected to design

specifications, calibrated, and approved before being used? (W-HTX, 6.3)

Review documentation of process monitors, thermocouple and inspection/test equipment calibration results. ♦♦ Do records indicate that process monitors, thermocouples and inspection test equipment are

periodically inspected and calibrated? (W-HTX, 2.0, 2.1.4, and 3.0)

Review appropriate records to determine if process monitors, thermocouple and inspection/test equipment inspection and recalibration is planned and carried out on a regular basis. Is there a preventive maintenance check list? Are preventive maintenance tasks performed to schedule?



0 There is no method of indicating processing/inspection status and no quarantine areas are

available. 1 to 2 The method indicating product status is haphazard. Quarantine areas, if available, are not well

defined. 3 to 4 A potentially effective method of status indication is available, but is not consistently used. A

parallel condition applies to quarantine areas in this and following points. 5 to 6 The available status indication method is consistently implemented, but needs further development. 7 to 8 The heat treater has a well planned and well executed method of product status identification with

one exception that presents a risk. 9 to 10 The heat treaters method of product status identification is unusually well thought out and,

according to the records and spot checks, is always followed. 14. What controls does the heat treater use to indicate the processing and inspection status of products

throughout the heat treating system. (QS-9000, Elements 4.8, 4.12 and 4.16) (Section III-Control Items) (HTX, 2.4, 3.4)

♦♦ Evaluate the method(s) used to show processing status: • Before heat treating vs. after heat treating • Inspection status of parts, i.e., OK/rejected/hold. • Positive identification procedure for accepted as well as rejected products. Note: Fastener or control item processing may require special attention based on the processing

requirement imposed by the "end user/customer." ♦♦ Are effective controls in place to provide accurate part processing information throughout processing,

storage, packaging and shipping?

Describe in detail the type of shop traveler in use. ♦♦ Are controls adequate to prevent movement of nonconforming rejected in-process products into the

production system?

Describe what measures (e.g., rejected material quarantine areas-see W-HTX, 2.4, 3.4 for requirements) are employed to prevent usage and/or shipment of defective and non conforming materials and products.

♦♦ Material from different steel mill heats or metals which require different austenitizing, quenching, or

tempering times and/or temperatures SHALL NOT BE MIXED OR PROCESSED TOGETHER.



0 There is no evidence to support any PPAP documents submitted to Ford during the past two years. 1 to 2 There is evidence supporting one or more PPAP samples which is incomplete in one of the major

areas, e.g., material test, ES test and/or engineering approval of samples, preliminary statistical studies (for process or product) and/or Product/Process Control Plan.

3 to 5 Complete supporting evidence is available for PPAP documents reviewed, but one or more

discrepancies to engineering requirements was identified without authorizing documentation. 6 to 7 Complete supporting evidence is available for all PPAP documents reviewed (6) with minor

discrepancies to engineering requirements, (7) with NO discrepancies to engineering requirements identified.

8 Documented evidence indicates that the heat treater has a comprehensive PPAP program that is

utilized for all programs and customers. 9 to 10 There is documented evidence that the heat treater has an exceptional program for launching new

parts and has conducted capability studies to gain process knowledge to provide 1st tier or end user benefits.

15. Does the heat treater have complete records supporting Production Part Approval (PPAP) certification?

(QS-9000 4.12, 4.16, PPAP), Section II) ♦♦ For PPAP samples submitted during the past two years, detailed, well organized supporting data is

available? ♦♦ Is actual heat treat process related data available? ♦♦ Are preliminary statistical studies or process capability data available for all significant process

parameters and/or product parameters? Are containment actions in place where required? ♦♦ Are Process FMEA and Dimensional/Process Control Plan available for each part or family of parts? ♦♦ When required, has product engineering approval of Product/Process Control Plans, samples and test

equipment been documented? ♦♦ Are RSIR's performed according to plant procedures? The essential point here is that complete supporting evidence must be available for the part of the process performed by the heat treater which impacts the PPAP. The STA or Heat Treat engineer must review several of the initial samples certified over the past two years. Note: Where the heat treater is a second tier heat treater to Ford's first tier heat treater it will be essential

that the second tier heat treater perform PPAP, with submission of all necessary dimensional and physical data including FMEA and Product/ Process Control Plan, and required capability studies, to first tier heat supplier.



0 There is no evidence of a process to communicate quality concerns. Returned products are not

analyzed to determine the cause of failure. No disciplined problem solving methods are utilized. 1 to 4 Communication of quality concerns, returned product analysis, and problem solving is handled

entirely on a verbal basis (1) a potentially-adequate means of communicating quality concerns both verbal and written exists (2), but root cause of concern(s) not isolated (3) and major concerns exist concerning product analysis methods (4).

5 to 6 A satisfactory quality concern communication system exists. A disciplined problem solving method

is generally used. Return product analysis is performed, but could be greatly improved through communications within the work force and by employing a qualified individual in metallurgical systems.

7 to 8 There are effective systems to communicate quality concerns to the work force and to

management. Returned product is analyzed. A discipline problem solving method is used with routine end user or 1st tier visitation program.

9 to 10 The heat treater is very aggressive in utilizing Quality/Business Operating System (QOS) indicators

to solve identified quality systems concerns. Furthermore, the heat treater also has used methods such as Design of Experiment (DOE), to solve chronic quality and productivity concerns.

16. Does the heat treater react appropriately to customer concerns (internal or external indicators)? (QS-

9000, Elements 4.14 and 4.16) ♦♦ Are in-house and customer quality concerns effectively communicated to all members of the

organization? How are quality concerns communicated to production and support personnel? What methods are used to alert the entire production and support staff to quality concerns? (Typical methods are nonconforming parts displays and Pareto charts.) How is management alerted to quality concerns? ♦♦ Are nonconforming parts returned by customers analyzed? Is the root cause of failure (i.e., process

and/ or system) determined, verified and corrective action taken? Is the heat treat plant well facilitized to analyze nonconforming parts (e.g., stereo microscope, spectrometer,

Magnaflux, eddy current, micro and macro hardness tester, etc.)? Does the heat treater have a certified individual(s), on staff, to perform metallurgical and non destructive analysis? Does the heat treater have a method to perform metallurgical and non destructive analysis if there is not a certified

individual(s) on staff? ♦♦ Is a disciplined method of problem solving, e.g., the Eight Discipline format, utilized? Are these indicators part of the heat treater's "Quality/Business Operating System" to evaluate continuous

improvement? (e.g., Is the PPM (Parts Per Million) concept used to drive Continuous Improvement?)



0 No records are available and there is no (other than verbal) indication that inspections/tests are

being adequately performed. 1 to 4 Observation indicates that process monitoring and inspections/tests are being performed, but the

records of the efforts are nonexistent (3), or seriously inadequate.(4) 5 Observation and a review of the records indicate that process monitoring and inspections/tests are

being performed, with some question of accuracy of the findings. 6 Observation and a review of the records indicate that process monitoring and inspections/tests are

being performed, but there are some deficiencies (e.g., lack of adequate detail) in the records that require correction.

7 to 8 Observation indicates that process monitoring and inspections/tests are being properly

performed.(7) This is confirmed by the existence of complete and detailed records.(8) 9 The heat treater has performed at least one process parameter and product characteristic

interaction study to improve product characteristic capability, (e.g., Design of Experiments). 10 The heat treater has performed several (2 or more) process parameter and product characteristic

interaction studies to improve product characteristic capability (e.g., Design of Experiments).


E. IN-PROCESS AND OUTGOING

17. Are process monitoring and inspections/tests performed according to the instruction sheets? Are there

adequate records of inspections and tests? (QS-9000, Element 4.10)(W-HTX) This question requires both observation of process monitoring and inspection/testing being performed at the

moment and a review of the records of these efforts. Special attention should be directed at process monitors, laboratory control tests and in-process tests as specified in W-HTX, 4.0 and 5.0. Instructions must be available to perform ES-M and ES testing as appropriate.

♦♦ Are appropriate records being maintained for the following temperature control related inspections and

tests: • Indicated temperatures (W-HTX, 2.1.1 and 3.1.1) � Temperature controlling and indicating instruments. � Recording chart controlling instruments. Are log books/chart retained as records? Non-recording

instruments. � Are temperature/chart recorders programmable? � Initialing and dating of charts is required for both non-computerized and non-alarmed furnaces. • Standardized temperature controllers requiring a daily manual check and balance against a standard. (W-HTX, 2.1.2) • Thermocouple and protection tubes. (W-HTX, 2.1.3, 6.0) ♦♦ Are appropriate records being maintained for the following atmosphere control related inspections and

tests: • Carbon potential checks of all carbon-bearing atmospheres by means of oxygen partial pressure, electrical

resistance, complete gas analysis or CO2 content? (W-HTX, 2.1.4) Note: Dew point may be used as the sole control only for atmosphere generators. • Correlation between the control variable (CO2 content, O2 partial pressure, etc.) and the actual carbon

potential of reactive carbon-bearing atmospheres (endothermic, carbon-enriched nitrogen, etc.) by means of shim stock, carbon gradient, etc.?

• Calibration of atmosphere controlling/monitoring equipment to assure accuracy of the readings in

accordance with the manufacturers instructions? (W-HTX, 2.1.4) ♦♦ Are instruments which monitor and record furnace push/cycles in use and appropriate records

maintained? (W-HTX, 2.3) ♦♦ Are all temperature instruments (indicator, recording, controlling) labeled with identification of the

calibrating company and most recent calibration date? ♦♦ Are records maintained of furnace temperature uniformity surveys (thermal profiles), where applicable,

by use of a traveling thermocouple? (W-HTX, 2.1.1) ♦♦ For Induction Hardening review the heat treater's:

• Temperature control systems,(e.g., infra red units). • Inductors case depth/runout capability. • Energy Monitor Operation.



0 The heat treater has no documented reject, reprocessing or scrap procedures or no audit is made

on reprocessed/sorted products. 1 to 2 Only verbal procedures are used to manage rejects, scrap and reprocessing. Specific concerns

exist due to this (1), but no part has reached the customer (2). 3 to 4 Rudimentary written reject, reprocessing or scrap procedures exist, but have significant

deficiencies. However, reprocessed material is audited. 5 to 6 Documented reject, rework and scrap standards and procedures are available. A satisfactory post

reprocessing audit is utilized for overall conformance to customer requirements. There is no specific program in place to reduce reprocessing requirement.

7 to 8 Appropriate reprocessing procedures are available and an adequate post reprocessing audit is

performed. An effective reprocessing and scrap reduction program is in place. 9 to 10 Same as all the requirements for a score of (8), plus the reduction programs have provided

documented improvement (9) and this has a potential to virtually eliminate reprocessing and scrap.(10)

18. Are documented heat treat reject, reprocessing or scrap procedures available? Are reprocessed or

sorted products subjected to an audit for conformance to all customer requirements? Assess the adequacy of the heat treater's reprocessing and sorting operation. (QS-9000, Element 4.13)

Three basic areas should be reviewed:

♦♦ Are all reprocessing and scrap situations covered by documented procedures and standards? These standards must clearly define what conditions require reprocess and what conditions require scrapping the

part. Note: Product which does not meet print specification after initial heat treatment and which could be

corrected with reprocessing, may require prior engineering approval. An effective lot control system must be in place to ensure their movement and processing.

♦♦ Are reprocessed parts audited for conformance to all customer requirements? Since reprocessing can cause new nonconformance (e.g., physical and mechanical properties of the parts), a

complete check of all special characteristics is required. Also, visual and functional checks (ES tests) must be made.

♦♦ Are there documented efforts to eliminate the need for reprocessing? Cause of reprocessing should be analyzed using basic quality and problem solving tools (including statistical

methods and verification of upstream system controls) refer to sections IV and V.



0 There are major deficiencies in processing, handling, storage, and packaging. There is no

systematic approach for improving these functions. 1 There are two or more significant discrepancies in either processing, handling, storage, or

packaging. 2 There are two or more significant discrepancies in either handling, storage, or packaging. 3 There are two or more significant discrepancies in processing or packaging. 4 There is a significant discrepancy in either processing, handling, storage, or packaging. 5 While processing, handling, storage, and packaging are generally satisfactory, there are corrective

actions required in one of these areas. 6 Processing, handling, storage, and packaging are generally satisfactory. 7 Heat treat processing, packaging, storage and handling are fully satisfactory. 8 Heat treat processing, packaging, storage and handling are fully satisfactory and fully meet the

requirements of MF1750 or EU 1750A. 9 Heat treat processing, packaging, storage, and handling meet all of the concerns listed on the next

page. 10 The plant has several documented examples of process packaging, storage and handling that have

resulted in measurable quality and heat treat improvements. 19. Are heat treat processing, handling, storage and packaging adequate to preserve product quality? (QS-

9000, Element 4.15)(Section III)(W-HTX, 1.7, 2.4, 3.4) During the review of the heat treater's process, attention should be paid to product handling.* The product, where appropriate, should be protected against damage and contamination.* Storage areas for incoming, in-process and finished products should be reviewed to determine if any conditions exist which could affect product quality. Packaging should be reviewed for adequacy.

Seek answers to the following concerns: • bar coding requirements • design of the containers and conveyor system which will reduce part entrapment. • cleanliness of containers. • loading of containers: • condition of the containers/baskets and conveyors. • damaging the product, during heat treatment and packaging. • potential for mixing of non-heat treated vs. heat treated product. • general cleanliness of the shop. • status identification of containers throughout the processing cycle. • foreign material in containers Note: It is essential that every container being used for transfer and/or transportation of parts should

have status identified. IF containers with parts and "NO STATUS IDENTIFICATION TAG" are found during the audit the maximum score allocation should be "4."



0 The heat treater's plant cleanliness, housekeeping or working conditions are totally inappropriate

for quality processing of the parts. 1 to 2 Specific aspects of the plant's cleanliness, housekeeping or working conditions pose a major risk,

but some plans have been made to resolve it. 3 to 4 Plans have been implemented and appear to be effective. However, several specific concerns still

remain. 5 to 6 Cleanliness, housekeeping and working conditions generally support high quality (5), but minor

quality related concerns still remain.(6) 7 to 8 Heat treater's systems promote high quality, (7) and specific examples of improvements have

resulted in measurable quality improvements (8). 9 to 10 The heat treater has a unique concept in place which promotes employee and management

participation in maintaining cleanliness, housekeeping and good working conditions. 20. Are plant cleanliness, housekeeping, environmental, and working conditions conducive to quality

improvement? (QS-9000, Element 4.9),(Section II) This question seeks information on the suitability of the heat treater's plant for the commodity and processes

involved. Is it reasonable to expect high quality and continuous improvement from these facilities? ♦♦ Are there working conditions that could be detrimental to quality improvement? Review heat treater's housekeeping procedure with emphasis on potential major risk areas, such as, but not limited to: • Miscellaneous loose parts and unidentified containers/baskets around processing equipment. • Cleaning sequence of Austenitizing/Tempering furnaces for loose parts which may have fallen off the

conveying system. • Dredging sequence for the quench tanks to remove scale and loose parts. • Flash and fire point checks of quench oil to safeguard against contamination which could create fire

hazards. Oil spill around quench tanks. • Condition of area around shot blast and storage of incoming and quarantined parts which could affect

product quality. • Overall plant lighting (especially at the mechanical and the visual inspection areas), floor markings,

identified utility lines and work area identification signs. • Inadequate storage facilities which could affect product quality. ♦♦ Could product quality be affected by plant environment? • Does the facility meets the OSHA, state and/or appropriate country's standards? Verify.


GLOSSARY

Allotropy The reversible phenomenon by which certain metals may exist in more than one crystal structure. If not reversible, the phenomenon is termed "polymorphism." Annealing Heating to and holding at a suitable temperature and then cooling at a suitable rate, for such purposes as reducing hardness, improving machinability, facilitating cold working, producing a desired microstructure, or obtaining desired mechanical, physical or other properties. When applied to ferrous alloys, the term "annealing," without qualification, implies full annealing. When applied to nonferrous alloys, the term "annealing" implies a heat treatment designed to soften a cold worked structure by recrystallization or subsequent grain growth or to soften an age-hardened alloy by causing a nearly complete precipitation of the second phase in relatively coarse form. Austempering Quenching a ferrous alloy from a temperature above the transformation range, in a medium having a rate of heat abstraction high enough to prevent the formation of high-temperature transformation products, and then holding the alloy, until transformation is complete, at a Temperatures lower than those where very fine pearlite forms and higher than that where martensite begins to form on cooling. Its appearance is feathery if formed in the upper part of the temperature range; acicular, resembling tempered martensite, if formed in the lower part. Black Annealing Box annealing or pot annealing ferrous alloy sheet, strip or wire. (See box annealing.) Black Light Electromagnetic radiation not visible to the human eye. The portion of the spectrum generally used in fluorescent inspection falls in the ultraviolet region between 3300 and 4000 A, with the peak at 3650 A. Blank Carburizing Simulating the carburizing operation without introducing carbon. This is usually accomplished by using an inert material in place of the carburizing agent, or by applying a suitable protective coating to the ferrous alloy. Blue Brittleness Brittleness exhibited by some steels after being heated to some temperature within the range of 300 to 650 F, and more especially if the steel is worked at the elevated temperature. Killed steels are virtually free of this kind of brittleness. Box Annealing Annealing a metal or alloy in a sealed container under conditions that minimize oxidation. In box annealing a ferrous alloy, the charge is usually heated slowly to a temperature below the transformation range, but sometimes above or within it, and is then cooled slowly; this process is also called "close annealing" or "pot annealing." (See black annealing.) Brale A diamond penetrator of specified sphero-conical shape used with a Rockwell hardness tester for hard metals. This penetrator is used for the A, C, D and N scales. Brinell Hardness Test A test for determining the hardness of a material by forcing a hard steel or carbide ball of specified diameter into it under a specified load. The result is expressed as the Brinell hardness number, which is the value obtained by dividing the applied load in kilograms by the surface area of the resulting impression in square millimeters. Brazing Joining metals by flowing a thin layer, capillary thickness, of nonferrous filler metal into the space between them. Brazing temperatures are in excess of 800°F. Carbide A compound of carbon with one or more metallic elements.


Carbonitriding Introducing carbon and nitrogen into a solid ferrous alloy by holding above Ac1, in an atmosphere that contains suitable gases such as hydrocarbons, carbon monoxide and ammonia The carbonitrided alloy is usually quench hardened. Carburizing Introducing carbon into a solid ferrous alloy by holding above Ac, in contact with a suitable carbonaceous material, which may be a solid, liquid or gas. The carburized alloy is usually quench hardened. Case In a ferrous alloy, the outer portion that has been made harder than the inner portion, or core, by case hardening. Case Hardening Hardening a ferrous alloy so that the outer portion, or case, is made substantially harder than the inner portion, or core. Typical processes used for case hardening are carburizing, cyaniding, carbonitriding, nitriding, induction hardening and flame hardening. Cementite A compound of iron and carbon, known chemically as iron carbide and having the approximate chemical formula Fe3C. It is characterized by an orthorhombic crystal structure. When it occurs as a phase in steel, the chemical composition will be altered by the presence of manganese and other carbide-forming elements. Critical Characteristics (CC) Product and/or process requirements that affect compliance with government regulation or safe vehicle/product function which can include dimension, specification, tests, processes, assembly sequences, tooling, joints, torque's, welds, attachments, component usage's, etc. Critical Characteristics must be documented on a Control Plan along with their specific controls. Critical Cooling Rate The minimum rate of continuous cooling just sufficient to prevent undesired transformations. For steel, the slowest rate at which it can be cooled from above the upper critical temperature to prevent the decomposition of austenite at any temperature above the Ms. Critical Point (1) The temperature or pressure at which a change in crystal structure, phase or physical properties occurs. Same as transformation temperature. (2) In the equilibrium diagram, that specific value of composition, temperature and pressure, or combinations thereof, at which the phases of a heterogeneous system are in equilibrium Critical Ranges (Critical Temperature Ranges) Synonymous with transformation ranges. which is preferred. Cryogenic/Deep Freeze (Cold Treatment, Sub-Zero Treatment) A heat treat process which converts unstable retained Austenite into stable untempered Martensite. Deep Freeze is usually performed at -100�F to 150�F in dry ice mixed with alcohol or mechanical refrigeration. Deep freezing is actually an extension of quenching. In some instances, the Mf (Martensite finish) temperature may be well below room temperature which favors the retention of large amounts of unstable, soft retained Austenite - deep freeze transforms Austenite to stable, hard Martensite. Retained Austenite in a finished part can cause dimensional instability and/or excessive residual stress or cracking. Decarburization The loss of carbon from the surface of a ferrous alloy as a result of heating in a medium that reacts with the carbon at the surface. Deep Etching Severe etching of a metallic surface for examination at a magnification of ten diameters or less to reveal gross features such as segregation, cracks, porosity or grain flow. Dendrite A crystal that has a tree-like branching pattern, being most evident in cast metals slowly cooled through the solidification range. Direct Quenching Quenching carburized parts directly from the carburizing operation. Dye Penetrant Penetrant with dye added to make it more readily visible under normal lighting conditions.


Eddy-current Testing Nondestructive testing method in which eddy-current flow is induced in the test object. Changes in the flow caused by variations in the object are reflected into a nearby coil or coils for subsequent analysis by suitable instrumentation and techniques. Eutectic/Eutectoid (1) An isothermal reversible reaction in which a liquid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectic/eutectoid point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectic/eutectoid reaction. Ferrite A solid solution of one or more elements in body-centered cubic iron. Unless otherwise designated (for instance, as chromium ferrite), the solute is generally assumed to be carbon. On some equilibrium diagrams there are two ferrite regions separated by an austenite area. The lower area is alpha ferrite; the upper, delta ferrite. If there is no designation, alpha ferrite is assumed. File Hardness Hardness as determined by the use of a file of standardized hardness on the assumption that a material which cannot be cut with the file is as hard as, or harder than, the file. Files covering a range of harnesses may be employed. Flame Annealing Annealing in which the heat is applied directly by a flame. Flame Hardening Quench hardening in which the heat is applied directly by a flame. Free Ferrite Ferrite that is structurally separate and distinct, as may be formed without the simultaneous formation of carbide when cooling hypoeutectoid austenite into the critical temperature range. Also proeutectoid ferrite. Full Annealing Annealing a ferrous alloy by austenitizing and then cooling slowly through the transformation range. The austenitizing temperature for hypoeutectoid steel is usually above Ac3; and for hypereutectoid steel, usually between Ac and AcS Gas Cyaniding A misnomer for carbonitriding. GR & R Gage Repeatability and Reproducibility Grain An individual crystal in a poly-crystalline metal or alloy. Hardenability In a ferrous alloy, the property that determines the depth and distribution of hardness induced by quenching. (See jominy test.) Hardening Increasing the hardness by suitable treatment, usually involving heating and cooling. When applicable, the following more specific terms should be used: age hardening, case hardening, flame hardening, induction hardening, precipitation hardening,, quench hardening and through hardening. Heat Check A pattern of parallel surface cracks that are formed by alternate rapid heating and cooling of the extreme surface metal, sometimes found on forging dies and piercing punches. There may be two sets of parallel cracks, one set perpendicular to the other. Heat Treatment Heating and cooling a solid metal or alloy in such a way as to obtain desired conditions or properties. Heating for the sole purpose of hot working is excluded from the meaning of this definition. High Impact Characteristic (HIC)—Product and/or process characteristics that, when outside of the specification tolerance, severely affect subsequent manufacturing operations or customer satisfaction; the product or process is not, however, unsafe. Hypereutectic Alloy Any binary alloy whose composition lies to the right of the eutectic on an equilibrium diagram, and which contains some eutectic structure.


Hypoeutectic Alloy Any binary alloy whose composition lies to the left of the eutectic on an equilibrium diagram, and which contains some eutectic structure. I and MR Individual and Moving Range Impact Test A test to determine the behavior of materials when subjected to high rates of loading, usually in bending, tension or torsion. The quantity measured is the energy absorbed in breaking the specimen by a single blow, as in the Charpy or Izod tests. lnduction Hardening Quench hardening in which the heat is generated by electrical induction. lnterrupted Quenching Quenching in which the metal object being quenched is removed from the quenching medium while the object is at a temperature substantially higher than that of the quenching medium. (See also time quenching.) lsothermal Annealing Austenitizing a ferrous alloy and then cooling to and holding at a temperature at which austenite transforms to a relatively soft ferrite carbide aggregate. Isothermal Transformation—A change in phase at any constant temperature. Izod Test A pendulum type of single-blow impact test in which the specimen, usually notched, is fixed at one end and broken by a falling pendulum. The energy absorbed, as measured by the subsequent rise of the pendulum, is a measure of impact strength or notch toughness. Jominy Test The Jominy test is used for determining end-quench hardenability. It consists in water quenching, under closely-controlled conditions, one end of a 1-in. diameter specimen of the steel under test and measuring the degree of hardness at regular distances from the quenched end along the side. Liquidus In a constitution or equilibrium diagram, the locus of points representing the temperatures at which the various compositions in the system begin to freeze on cooling or to finish melting on heating. MA & MR Moving Average and Moving Range Macrostructure The structure of metals as revealed by examination of the etched surface of a polished specimen at a magnification not exceeding ten diameters. Magnetic-particle Inspection A nondestructive method of inspection for determining the existence and extent of possible defects in ferromagnetic materials. Finely divided magnetic particles, applied to the magnetized part, are attracted to and outline the pattern of any magnetic-leakage fields created by discontinuities. Martempering Quenching an austenitized ferrous alloy in a medium at a temperature in the upper part of the martensite range, or slightly above that range, and holding it in the medium until the temperature throughout the alloy is substantially uniform. The alloy is then allowed to cool in air through the martensite range. Martensite Martensite is a microconstituent or structure in quenched steel characterized by an acicular or needle-lie pattern on the surface of polish. It has the maximum hardness of any of the structures resulting from the decomposition products of austenite. Metallograph An optical instrument designed for both visual observation and photomicrography of prepared surfaces of opaque materials at magnifications ranging from about 25 to about 1500 diameters. The instrument consists of a high-intensity illuminating source, a microscope and a camera bellows. On some instruments provisions are made for examination of specimen surfaces with polarized light, phase contrast, oblique illumination, dark-field illumination and customary bright-field illumination. Microhardness The hardness of microscopic areas or of the individual microconstituents in a metal, as measured by such means as Tukon, Knoop or scratch methods.


Nitriding Introducing nitrogen into a solid ferrous alloy by holding at a suitable temperature (below Ac, for ferritic steels) in contact with a nitrogenous material, usually ammonia or molten cyanide of appropriate composition. Quenching is not required to produce a hard case. Normalizing Heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range. Optical Pyrometer An instrument for measuring the temperature of heated material by comparing the intensity of light emitted with a known intensity of an incandescent lamp filament. Overheating Heating a metal or alloy to such a high temperature that its properties are impaired. When the original properties cannot be restored by further heat treating, by mechanical working or by a combination of working and heat treating, the overheating is known as burning. Pearlite A lamellar aggregate of ferrite and cementite, often occurring in steel and cast iron. Peening Mechanical working of metal by hammer blows or shot impingement. Penetrant Inspection A method of nondestructive testing for determining the existence and extent of discontinuities that are open to the surface in the part being inspected. The indications are made visible through the use of a dye or fluorescent chemical in the liquid employed as the inspection medium. Precipitation Heat Treatment Artificial aging in which a constituent precipitates from a supersaturated solid solution. (See artificial aging, interrupted aging and progressive aging.) Quench Hardening Hardening a ferrous alloy by austenitizing and then cooling rapidly enough so that some or all of the austenite transforms to martensite. The austenitizing temperature for hypoeutectoid steels is usually above Ac3 and for hypereutectoid steels usually between Acl and Acz n,. Quenching Rapid cooling When applicable, the following more specific terms should be used: direct quenching, jog quenching, hot quenching, interrupted quenching, selective quenching, spray quenching and time quenching. Quench Time In resistance welding, the time from the finish of the weld to the beginning of temper. Also called chill time. Recrystallization Annealing Annealing cold worked metal to produce a new grain structure without phase change. Recrystallization Temperature The approximate minimum temperature at which complete recrystallization of a cold worked metal occurs within a specified time. RSIR Routine Sample Inspection Report Seam (1) On the surface of metal, an unwelded fold or lap which appears as a crack, usually resulting from a defect obtained in casting or in working (2) Mechanical or welded joints. Significant Characteristics (SC) Product and/or process and/or test requirements which are important for customer satisfaction and for which Quality Planning actions must be documented on a Control Plan along with their specific controls. Sintering Heating a mass of fine particles for a prolonged time below the melting point, usually to cause agglomeration. Solid Solution A single solid homogeneous crystalline phase containing two or more chemical species.


Solidus In a constitution or equilibrium diagram, the locus of points representing the temperatures at which various compositions finish freezing on cooling or begin to melt on heating. Solution Heat Treatment Heating an alloy to a suitable temperature, holding at that temperature long enough to allow one or more constituents to enter into solid solution, and then cooling rapidly enough to hold the constituents in solution. The alloy is left in a supersaturated, unstable state and may subsequently exhibit quench aging. Special Characteristics Product and/or process characteristics that affect vehicle safety, compliance with government regulations or customer satisfaction. For Special Characteristics, manufacturing processes must be controlled to ensure products will meet all engineering requirements. Spheroid An aggregate of iron or alloy carbides of essentially spherical shape dispersed through-out a matrix of ferrite. Spheroidizing Heating and cooling to produce a spherodial or globular form of carbide in steel. Strain Hardening An increase in hardness and strength caused by plastic deformation at temperatures lower than the recrystallization range. Stress Relieving Heating to a suitable temperature, holding long enough to reduce residual stresses and then cooling slowly enough to minimize the development of new residual stresses. Superficial Rockwell Hardness Test Form of Rockwell hardness test using relatively light loads which produce minimum penetration. Used for determining surface hardness or hardness of thin sections or small parts, or where large hardness impression might be harmful. Temper In heat treatment, reheating hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing the hardness and increasing the toughness. The process also is sometimes applied to normalized steel. Tempering Reheating a quench-hardened or normalized ferrous alloy to a temperature below the transformation range and then cooling at any rate desired. Thermocouple A device for measuring temperatures, consisting of two dissimilar metals which produce an electromotive force roughly proportional to the temperature difference between their hot and cold junction ends. Toughness Ability of a metal to absorb energy and deform plastically before fracturing. It is usually measured by the energy absorbed in a notch impact test, but the area under the stress-strain curve in tensile testing is also a measure of toughness. Transformation Ranges (Transformation Temperature Ranges) Those ranges of temperature within which austenite forms during heating and transforms during cooling. The two ranges are distinct, sometimes overlapping but never coinciding. The limiting temperatures of the ranges depend on the composition of the alloy and on the rate of change of temperature, particularly during cooling. (See transformation temperature.) T5 Artificially Aged Only (Aluminum) T6 Solution Heat Treated and Then Artificially Aged (Aluminum) T7 Solution Heat Treatment and Stabilization (Aluminum) Transformation Temperature The temperature at which a change in phase occurs. The term is sometimes used to denote the limiting temperature of a transformation range. The following symbols are used for iron and steels:


Accm In hypereutectoid steel, the temperature at which the solution of cementite in austenite is completed during heating.

Ac1 The temperature at which austenite begins to form during heating. Ac3 The temperature at which transformation of ferrite to austenite is completed during heating. Ac4 The temperature at which austenite transforms to delta ferrite during heating. Aecm, Ael, Ae3, Ae4 The temperatures of phase changes at equilibrium. Arcm In hypereutectoid steel, the temperature at which precipitation of cementite starts during

cooling. Arl The temperature at which transformation of austenite to ferrite or to ferrite plus cementite is

completed during cooling. Ar3 The temperature at which austenite begins to transform to ferrite during cooling. Ar4 The temperature at which delta ferrite transforms to austenite during cooling. Ms The temperature at which transformation of austenite to martensite starts during cooling. Mf The temperature at which martensite formation finishes during cooling. NOTE All these changes except the formation of martensite occur at lower temperatures during cooling

than during heating, and depend on the rate of change of temperature. X bar R Mean (Average) Value and Range

HEAT TREAT SYSTEM SURVEY REPORT

A. General Information

Division Survey No Date

H.T. Supplier Name____________________________ Supplier Code________________________________ Plant________________________________________ Address_____________________________________ City_________________________________________ State/Country and Postal Code__________________ Phone No. (area code)_________________________ Quality Manager______________________________ Ford Engineer________________________________

(If part is outsoursed for heat treat) Heat Treat Service Provided To: ____________________________________________ Address_____________________________________ City_________________________________________ State/Country and Post Code___________________ Phone No. (area Code)_________________________ Quality Manager______________________________

Supplier in Conformance with Ford Heat Treat System Survey yes_____ No____ Corrective action required yes_____ No____ Purchasing assistance required yes_____ No____ Supplier acknowledgement signature

Survey representative signature(s)

B. HEAT TREAT PROCESSES AVAILABLE AT THIS LOCATION Annealing Carburizing ___Ferritic Nitro ___Cryogenic Treating ___Bright ___Fluid Bed Carburizing (Deep Freeze) ___Full ___Gas ___Homogenize ___Ion Tool Steel Treating Brazing ___Isothermal ___Pack ___Fluid Bed ___Dip ___Local (Flame, ___Salt ___Furnace ___Furnace Induction) ___Vacuum ___Salt ___Torch ___Spheroidize ___Carbon ___Vacuum ___Vacuum Restoration Hardening Nitriding High Speed Steel ___Marquenching/ ___Conductive ___Fluid Bed Treating Martempering ___Flame ___Gas ___Fluid Bed ___Press Quenching ___Furnace ___Ion ___Furnace ___Induction ___Salt ___Salt ___Steam Treating ___Induction-Atmosphere ___Vacuum ___Neutral Salts ___Sintering ___Precipitation ___Straightening ___Tufftriding ___Temper/Stress Relief ___Vacuum Carbonitriding Aluminium/Nonferrous ___Fluid Bed ___T-5 ___Normalize ___Gas ___T-6 ___Salt ___Solution ___Tufftriding ___Austempering ___Recrystallize ___Vacuum ___Carbo Austempering

HEAT TREAT SYSTEM SURVEY REPORT

C. FORD PARTS, PROCESS AND SPECIFICATION LIST: Part Name Part Number Material Process Hardness (Surf/Core) Case Depth (Effectiv/Total) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

D. HEAT TREAT EQUIPMENT AND CONTROLS LIST Furnace Temperature Instrumentation ___Flow Meters ___Atmosphere ___Controlling ___Electric ___Indicating ___Mixing Valves ___Fluidized Bed ___Recording ___Gas/Oil Fired Atmospheres Controls ___Salt Bath ___Infrared Monitoring ___Vacuum Thermocouple Controlling ___Test Pyrometer ___Resistance Wire Test Atmospheres ___Test Thermocouple ___Oxygen (O2) Probe ___Ammonia (NH3) (Standard) ___Other ___Dissociated ___Primary Standard Ammonia Thermocouple Other ___Generators ___Flame Units (List) ___Endothermic ___Induction Units ___Exothermic ___Nitrogen ___Other

E. TYPE OF QUENCH SYSTEMS AVAILABLE: ___Oil ___Salt (%) ___Synthetic (%) ___Water ___Caustic (%) ___Other (List)

F. INSPECTION/TEST EQUIPMENT AVAILABLE: ___Emission Spectrometer ___Cut-off Equipment (abrasive wheel, bandsaw, etc.) ___Carbon/Sulfur Analyser ___Metallographic Sample Preparation ___Hardness Testers ___Metallograph ___Vickers ___Scanning Electron Microscope (SEM) ___Brinnel ___Eddy Current ___Rockwell ___Gas Chromatography ___Rockwell Superficial ___Quenchometer ___Microhardness (Tukon/Vickers) ___Fluorscope ___Magnetic Penetrant Inspection ___Ultra Sound ___Liquid Penetrant Inspection ___Other ___Mechanical Test Equipment

HEAT TREAT SYSTEM SURVEY REPORT Heat Treating Facility Name______________________________________________ Assign a rating for each element based on the Heat Treat System Survey Scoring Guidelines

Rating

A. PLANNING FOR QUALITY

1. Is the responsibility for quality planning of heat treat processes clearly defined? Assess the adequacy of the heat treater’s quality planning effort. Identify the key contact personnel/department for quality planning and quality concern recognition. Include names, department names, and phone numbers.

2. Are Failure Mode and Effects Analysis (FMEA) and Control Plans used as a basis for establishing

quality programs for heat treat processes? • Does the heat treater use analysis processes to determine special characteristics and process

parameters? • Is the customer/end user of the heat treated product brought into the quality planning

process? 3. Does the heat treater have available and use a procedure for reviewing part design and heat treat

process changes prior to implementation? • Are FMEAs and Control Plans reviewed and updated as part of the procedure? • Is customer approval obtained prior to implementing changes? • Is there a procedure for updating operator instructions and visual aids for process and product

changes? TOTAL PLANNING FOR QUALITY (total points available =30)

B. STATISTICAL METHODS

4. Is statistical Process Control (SPC) utilized for special product characteristics and process parameters?

• How are the special characteristics chosen? Describe the SPC methods used. Are they appropriate to the factors being controlled?

• Evaluate the heat treater’s reaction to out-of-control conditions. Is the reaction as specified in the Control Plan? What is the role of the operator?

• Evaluate the heat treater’s application of SPC, based on the evidence of the control charts, process logs and other appropriate documentation.

5. Are process verification/capability studies conducted on new product characteristics and heat treat

process parameters? 6. Are statistical control charts being used effectively to monitor the process? Do control charts indicate that the statistical control has been achieved and that process capability

has been demonstrated? • In all cases where process capability has not been demonstrated, is there a plan to improve

the process? Is appropriate interim action being taken to prevent shipment of non-conforming parts?

7. Does the heat treater have a definite program to bring about continual improvement in quality and

productivity? • Describe the program. Indicate the tools being used for continual improvement.

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Rating

8. Does the heat treater have an effective system for ensuring the quality of incoming products and

services? How is SPC encouraged at Tier 1 and Tier 2 suppliers. • Assess the adequacy of the heat treater's control on the quality of the services it receives.

TOTAL STATISTICAL METHODS (total points available = 50) C. GENERAL 9. Are process/product monitoring and control functions and responsibilities clearly defined? Indicate which plant activities conduct process/product monitoring and control. • Assess the adequacy of the heat treater's control program. 10. Are written procedures defining quality-related functions available? • Are these procedures appropriate to and adequate for the heat treater's operations? • Are the procedures implemented as written? • Is there a review process to verify implementation? • Is there an adequate procedure for reacting to ES, ES-M, product qualification and test

failures? 11. Are written process monitoring and control instructions available for incoming, in-process,

laboratory, dimensional inspection and outgoing auditing? • Are all Special characteristics and Process Parameters included, particularly those affecting

function and durability? • Are Special characteristics and related operations identified? • Are sample sizes and frequencies adequate? • Is appropriate statistical analysis specified? 12. Are appropriate process monitors, thermocouple and inspection/test equipment available to

facilitate process control? 13. Does the heat treater have an effective preventive maintenance program for heat treat process

equipment, thermocouple and process monitoring equipment? • Do records indicate that process monitors, thermocouples and inspection test equipment are

periodically inspected and calibrated? • Does the heat treater perform furnace temperature uniformity surveys (thermal profiles)? • Assess the adequacy of the heat treater's preventive maintenance program and its

effectiveness. 14. What controls does the heat treater use to indicate the processing and inspection status of

products throughout the heat treating system. • Are effective controls in place to provide accurate part processing information throughout

processing storage, packaging and shipping? • Are controls adequate to prevent movement of nonconforming rejected in-process products

into the production system? 15. Does the heat treater have complete records supporting Production Part Approval (PPAP)

certification? • When required, has product engineering approval of Product/Process Control Plan, samples

And test equipment been documented?

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Rating

16. Does the heat treater react appropriately to customer concerns? • Are in-house and customer quality concerns effectively communicated to all members of the

organization? • Are nonconforming parts returned by customers analyzed? Is the root cause of failure

determined,verified and corrective action taken? • Is a disciplined method of problem solving, e.g., the Eight Discipline format, utilized?

TOTAL GENERAL (Total points available = 80) D. IN-PROCESS AND OUTGOING 17. Are process monitoring and inspection/tests performed according to the instruction sheet? • Are there adequate records of inspection and tests? 18. Are documented heat treat reject, reprocessing or scrap procedures available? • Are reprocessed parts audited for conformance to all customers requirements? • Assess the adequacy of the procedures. 19. Are heat treat processing, handling, storage and packaging adequate to preserve product

quality? • Assess the heat treater's furnace loading system, in-process handling and shipping process

for any cause of concerns. 20. Are plant cleanliness, housekeeping, environmental, and working conditions conducive to Quality

improvements? • Are there working conditions that could be detrimental to quality improvement? • Could product quality be affected by plant environment?

TOTAL IN-PROCESS AND OUTGOING (Total points available = 40)

TOTAL RATING POINTS FROM ELEMENTS 1-20 (Maximum = 200 points)

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Conformance to QS-9000, Heat Treat System Survey Scoring Guidelines and W-HTX requires at least a ‘7’ rating on each individual element and at least a ‘160’ overall System Survey Rating. Suppliers should provide improvement action plans for all areas with a rating below ‘7’ within 60 days.

SurveyScoringGuidelines W-HTX 2000

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