Training Module for Testing

8/6/2019 Training Module for Testing

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QA&C / Plate & Coil Mill Division

Training Module - Q uality Assurance & ControlQ uality Assurance & Control

WELCOME

MATERIALMATERIAL TESTINGTESTING


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OBJ ECTIVEOBJ ECTIVE

Objective of this Module to understand the Imp ortance andProcedure of Various Material Testing which are done in house forMechanical Pro p erties, Che m ical Pro p erties & for Microstructure

evaluation of S teel.I n this Module a brief discussion is done on the Mechanical p ro p ertiesof S teel.


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MATERI AL TESTINGMATERI AL TESTING

To know the Pro p erties of m aterial we do the Material Testing.

I n S teel we do the following Testing to know the MaterialPro p erties:

1. Mechanical Pro p erties i.e., S trength, Hardness, Toughness,fatigue etc.

2. Microstructure i.e., structure, grain size, inclusion etc.

3. Che m ical Pro p erties i.e., % of alloying ele m ents p resents insteel.


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MECHANI CAL P ROP ERTIES

S trength For m ability Rigidity Toughness Durability

Tensile % elongation Modulus of Impact Hardness Yield % reduction elasticity strength WearShear in area Modulus of Notch resistanceCreep Bending rigidity sensitivity FatigueFlexural radius Bulk modulus etc StrengthStress rupture etc. Flexural etc.etc. Modulus

etc.



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1. ELASTI CITY 7 . TOUGHNESS

2. PLA STI CITY 8 . STI FFNESS

3. STRENGT H 9. RESI LIEN CE

4 . DUC TI LITY 10. MALL E AB I LITY

5 . HA RDNESS 11. FA TIG UE

6 . B RITT LENESS 12. C REE P


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1. ELASTI CITY : I t is defined as non- p er m anent defor m ation. I t isability of m aterial to resu m e its original size and

sha p e, after the force is re m oved.2. PLASTI CITY : I t is defined as p er m anent defor m ation. I t is the

ability of m aterial to be p er m anently defor m edwithout fracture even after the re m oval of force.

3 . STRENGT H: S trength m ay defined as the ca p acity of m etal towithstand load.

4 . DUC TI LITY : I t is the ability of m aterial to be p er m anentlydefor m ed without breaking when a force isa pp lied.

5 . HARDNESS : Hardness of m aterial is defined as the resistanceof m aterial to scratch, wear or p enetration of itssurface by harder bodies.

6 . BRITT LENESS : The p ro p erty fracturing a m aterial withoutwarning or a pp reciable defor m ation is calledbrittleness.



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7 . TOUGHNESS : Toughness is the p ro p erty of m aterial whichenables m aterial to be twisted, bent or stretched

under a high stress before ru p ture.

8 . STI FFNESS : S tiffness is the p ro p erty of m aterial which enablesm aterial to resist defor m ation.

9. RESI LIEN CE: Resilience is the ca p acity of a m aterial to absorb

or store energy , or to resist shock and i mp act.

10. MALL E AB I LITY : Malleability is the p ro p erty of m aterial of gettingp er m anently defor m ed by co mp ression withoutru p ture.

11. FA TIG UE: The failure of m etal under alternating stresses isknown as fatigue failure.

12. C REE P: A ti m e de p endent, p er m anent defor m ation at highte mp eratures, occurring at constant load orconstant stress.



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To know the Mechanical Pro p erties of steel we do the following Testing:

1. Tensile testing

2. Hardness Testing

3. Imp act Testing

4 . Dro p -Weight Wear and Tear Test

5 . Bend Test


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LIST OF TESTING EQUI PM ENTS AT PLATE & CO I L MI LLLIST OF TESTING EQUI PM ENTS AT PLATE & CO I L MI LL

S .N.

N AME OFFAC I LITY /MACH INE MAKE CAPAC ITY

1UNIVERSAL TENSILE TESTING

MACHINE WITH ROBOT ZWICK ROELL, GERMANY 1200 KN

2 IMPACT TESTING MACHINE TINUS OLSEN,USA 542 JOULES

3 MICRO & MACRO VICKERSHARDNESS TESTER ZWICK ROELL,UK

Test Forces : 0 .1 , 0 .5, 1 , 3, 5, 10 , 3 0 kgf Test Scales : HV 0 .1 , HV0 .5, HV1 , HV3, HV5,

HV10 , HV30 and Knoop scales

4 PROFILE PROJECTOR MITUTOYO, JAPANMAGNIFICATION :10X & 50X

X Y RANGE : 50 x50 MM ANGLE RANGE :0 to 36 0

5 DROP WEIGHT TEAR TESTER ZWICK ROELL, GERMANY 80000 JOULES

6 BEND TEST MACHINE MICRO CONTROL SYSTEM 1 50 TON

7 OPTICAL EMISSIONSPECTROMETER SHIMADZU , JAPAN

2 8 Analytical Channels withLow Nitrogen Channel

8 OX YGEN/HYDROGEN

DETECTORLECO CORP.,USA OX YGEN & HYDROGEN DETECTION

9

METALLURGICAL MICROSCOPE OLYMPUS, JAPAN MAGNIFICATION :1 500X

ANALYZER & CAMERA GRAIN SIZE, INCLUSION RATING, MICRO STRUCTURE

ANALYSIS

10STERIO ZOOM MICROSCOPE

WITH ILLUMUNATION &SWIVAL

OLYMPUS, JAPAN SURFACE INSPECTION & MACRO PHOTOGRAPHY


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1. TENSI LE TESTINGUNIVERS AL TENSI LE TESTING MACHINE WIT H ROBO T,MAKE- ZW ICK ROELL, GERMANY, CAPACITY-1 200 KN


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1. TENSI LE TESTINGRECTANGULAR TENSION TEST SPECIMEN


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1. TENSI LE TESTING

TerminologyTerminology

Ulti m ate Tensile S trengthTheThe ultimate tensile strengthultimate tensile strength ( U TS) is the maximum resistance to fracture.(U TS) is the maximum resistance to fracture. It It is equivalent to the maximum load that can be carried by one square inch of is equivalent to the maximum load that can be carried by one square inch of crosscross--sectional area when the load is applied as simple tensionsectional area when the load is applied as simple tension

Elongation A measurement of ductility expressed in terms of the stretch having occurred A measurement of ductility expressed in terms of the stretch having occurredover a given length on a standard tensile specimen at time of fracture, usuallyover a given length on a standard tensile specimen at time of fracture, usuallybased upon an original length of 2 inches.based upon an original length of 2 inches.

Yield S trengthThe stress beyond which stainless steel undergoes important permanent flowThe stress beyond which stainless steel undergoes important permanent flow commonly specified as that stress producing a 0 .2 % offset from the linearcommonly specified as that stress producing a 0 .2 % offset from the linearportion of the stressportion of the stress- -strain curve.strain curve.

Yield PointLoad at which aLoad at which a material deforms permanently without increase in the load.deforms permanently without increase in the load.


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The Strength of a material when it is called upon to withstand loads whichproduce a tensile stress in it, is defined as the tensile strength of material.

1. TENSI LE TESTING


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The Tensile Strength or ultimate tensile strength (UTS) is the maximum loaddivided by the original cross-sectional area of the specimen.

1. TENSI LE TESTING


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2. HA RDNESS TESTING

Hardness is the property of a material that enables it to resist plastic deformation,penetration, indentation and scratching.These tests are commonly used in industry and research work because theyprovide an easy and reliable method for evaluating the effect of hot and coldworking processes and heat treatments, upon the basic properties of metals.

There are number of arbitrary definitions of hardness, on the basis of whichhardness testing method is selected. Some of these are:

1 . Resistance to permanent indentation under static or dynamic loads Indentation Hardness.

2 . Energy absorption under impact load Rebound hardness.3. Resistance of scratching Scratch Hardness.4. Resistance to abrasion - Wear Hardness.

In the Industry, the Indentation Hardness is most commonly used. In themetallurgical sense, it has become a practice to understand hardness as theindentation hardness only, unless otherwise specified.


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IN DENT ATI ON HARDNESS

The a m ount of resistance offered by a m etal for indentation orp enetration is defined as the I ndentation Hardness.

I n I ndustry, so m e hardness test are used as described under:

1. Brinell Hardness Test.

2. Rockwell Hardness Test.

3. Vicker Hardness Test.


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1. B RINE LL HARDNESS TEST

Brinell hardness testing machine uses a hardened steel ball of diameter 10mm+/-0.0045mm and the load is 3000kg for hard material, 1500kg for

intermediate hardness and 500kg for soft materials. Applying the load on the steel bal for 15 seconds, the load is removed and theindentation made is measured. The surface area of the indentation id dependentupon the depth of penetration. The load applied (in kgf) divided by the sphericalarea of indentation (in square millimeter) is taken as the Brinell HardnessNumber.

Brinell Hardness Test is best for measuring hardness of gray iron castingconsisting of soft flake graphite, iron and hard iron carbide.


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2. ROCKW ELL HARDNESS TEST2. ROCKW ELL HARDNESS TEST

Rockwell Hardness tester is developed with the depth of penetration as thecriterion for the hardness of the metal.The machine is a direct type. The dial consists of two pointers. The small pointer which is situated in the top left quarter of the dial proper indicates the applicationof the minor load of 10 kgf. The anvil with the specimen placed on it is turnedslowly so as to lift it upward. The small pointer starts to move once the specimentouches the indenter. The anvil is lifted up until the pointer comes to the stipulated

position. Viz., until it comes up to the black dot. Thos indicates that the minor loadof 10kgfs is acting upon the indenter.The dial is then turned to the required position i.e., the zero on the C-scale. Themajor load is applied by pressing the hand lever.The major load of 60,100 and 150kg are used. The common indenters employedin the Rockwell hardness tester are a 1/16 hardened steel ball and a diamond

cone. When the former is employed, the major load is maintained at 100kgf andthe hardness value read on the B-scale.The B-scale is suitable to test plain carbon steels and common non-ferrous metalsand alloys like copper, brasses, bronze etc.For testing very hard materials like hardened steel, diamond indenter is employed.The major load consists of 1540kgf. The hardness is read on C-scale.


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Advantages of the process:The process is relatively fast.The hardness is directly read on the dial.There is greater latitude for soft to hard materials.A small indentation is left on the objects.Use of initial minor loads avoids the errors arising out of the uneven surfaceof the metal, and machine and table errors.

Disadvantages of the process:The scale range is contracted.The use of more than one scale to express the hardness.Difficulty to readily convert the Rockwell hardness values either into Brinell or

Vickers.Errors are likely to be induced when the work is large and overhangs.

2. ROCKW ELL HARDNESS TEST2. ROCKW ELL HARDNESS TEST


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3. VICKER HR AD NESS TEST3. VICKER HR AD NESS TESTMI CRO & MAC RO VICKERS HARDNESS TESTER , ZW I CK ROELL, UK


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3. VICKER HR AD NESS TEST3. VICKER HR AD NESS TEST

The Vickers hardness test uses a square-base diamond pyramid as theindenter. The included angle between opposite faces of the pyramid is 1 36 .Because of the shape of the indentation diameter, this is frequently called thediamond-pyramid hardness test. The diamond-pyramid hardness number(DPH), or Vickers hardness number (VHN, or VPH) is defined as the loaddivided by the surface area of the indentation. In practice, this area iscalculated from microscopic measurements of the length of the diagonals of the impression. The DPH may be determined from the following equation:


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The Vickers hardness test has received fairly wide for research work because itprovides a continuous scale of hardness, for a given load, from very soft metalswith a DPH of 5 to extremely hard materials with a DPH of 1500.

The loads ordinarily used with this test range from 1 to 120kg, depending uponhardness of metal to be tested. In spite of these advantages, the Vickers

hardness test has not been widely accepted for routine testing because it isslow, requires careful surface preparation of the specimen, and allows greater chance for personal error in the determination of the diagonal length.

3. VICKER HR AD NESS TEST3. VICKER HR AD NESS TEST


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I MPAC T TESTI MPAC T TEST

I MPAC T TESTING MACHINE , TIN US OLSEN , US A , 54 2 JOUL ES


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A simple tensile test does not reveal the brittle nature of the metals, and if only

the tensile test data are relied upon the and the object put into use, failure iscertain. It is therefore, necessary to test the specimen under shock or suddenloading condition.

Strength data are mostly academic. In actual use and practice, we rarely comeacross the ideal case of gradually applied loads. When we sit on chair, ourweight of few kilograms is applied to the chair, suddenly. When an electric

motor is put on, the shaft takes a sudden torque of the full r.p.m., being at zero r.p.m. just before. Many instances can be cited when loads at=re borneby engineering components suddenly.

There are four types of impact tests. They are:1 . Izod2 . Charpy3. Fremont,and4. Amsler.

Of the above, the first and second are commonly employed.These machines are standardized in all respects, including the specimen to beused in them.


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The principle employed in all impact testing procedures is that a materialabsorbs a certain amount of energy before it breaks. The quantity of energythus absorbed is characteristic of the physical nature of the material. If it isbrittle, it breaks rapidly, i.e., absorbs a lesser quantity of energy, and if tough, it needs more energy in order to fracture.

The methods of testing are also very similar. A swinging hammeris made to strike the specimen held firmly in a vice. The hammer breaks thespecimen on accounts of it potential energy. The height of rise of thehammer on the other side indicates the residual energy of the hammer. Theenergy actually absorbed by the specimen in order to fracture is given by thedifference between initial and final energies of the hammer.


The standard specimen for Impact test is asquare rod of 10 mm side. There is a 2 mmdeep, 45 notch made at a distance of 2 8 mmfrom the end of the specimen. The root of thenotch is finished with a 0 .2 5mm radius.


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The actual testing procedure as follows:

1 . The pendulum weight is brought up and clamped.2 . The specimen is fixed in the vice.3. The scale is adjusted to read zero.4. The pendulum weight is released from the clamp.5. The energy absorbed by the specimen is read on the scale to give the

impact strength of the material.

The Impact strength, as explained above is the energy absorbed by thematerial. It is expressed in ft.lbs., or kilogram force metres.


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DROP W EIG HT TE AR TESTDROP W EIG HT TE AR TEST

DROP W EIG HT TE AR TESTER , ZW I CK ROELL, GER MANY, 8 0000 JOUL ES


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The drop weight tear test (DWTT) has been in use for over 40 years now, as apractical laboratory-scale way of ensuring that steel used in the manufacture of line-pipe is not subject to brittle failure when in service.

Drop weight and dynamic tear tests are widely used in the steel industryto determine material characteristics such as fracture resistance, transitiontemperature ranges and suitability of use of a steel for a specific application.During these tests the specimens are cooled or heated over a range of temperatures in order to determine the highest temperatures at which the samplefractures. Below this Nil-Ductility Transition temperature the material willconsistently fracture, but above the material does not.

The American Petroleum Institute (API) 5L test standard is used to determinethe fracture ductility of metal line pipe. Specimens are cut from sections of pipe,

soaked at a prescribed temperature and tested within 10 seconds. ASTM E 436,similar to API-5L, is used to establish the temperature range over which ferriticsteels undergo a fracture mode transition from ductile to brittle. In both standardsa determination regarding ductile to brittle behavior is based upon visualinspection of the specimens in conjunction with, at times, a calculation todetermine the percentage of shear seen the materials fracture.


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Shear area is calculated by the for m ula:

T = Thickness of the sa mp le in mm T = Thickness of the sa mp le in mm


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BEND TESTBEND TEST

Specimen prior to test Specimen after test


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BEND TESTBEND TEST

This is a simple test which indicates the behavior of the metal under bendingloads. The metal piece under test is fixed in a vice vertically and bentthrough an angle of 90.

Some designers specify that the bending should be continued further. In suchcases, the sheet is taken of the vice and hammered so as to double it. Thusit is bent through an angle of 180.

Reversed Bend Test: This is a more drastic test than the bend test. Thespecimen, after being bent, is straightened and again bent in the oppositedirection. Instead of performing the test with a vice and hammer, if it isconducted in a sheet metal press, the magnitude of the bending load canalso be measured.

The above test serve only as guides, in addition to the conventional tensile test

data regarding the percentage elongation. The ease with which the sheet or plate is bent or reverse bent gives us an idea about the work-hardeningtendency of the metal, in addition to its formability.


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PRODUC T SPECI FI CATI ONSPRODUC T SPECI FI CATI ONSUSED AT PLATE & CO I L MI LLSUSED AT PLATE & CO I L MI LLS

1. API 5L 2. ASTM A36 3. IS 2062 4. EN 10025RE QU IRED TESTING AS PER STANDARDS

1 . API 5L TENSILE ASTM A37 0

DW TT API RP 5L3 IMPACT ASTM A37 0 H ARDNESS ASTM E9 2

CH EMICAL ASTM A751 MICRO ASTM E11 2

BEND (S U PPLEMENTARY)

2. ASTM A36 TENSILE ASTM A37 0

CH

EMICAL ASTM A751 IMPACT ASTM A673

(S U PPLEMENTARY)

3 . IS 20 62

TENSILE IS 16 08

IMPACT IS 1757 BEND IS 1599 CH EMICAL IS 228

4 . EN 1 002 5 TENSILE EN1 002

IMPACT EN 1 00 45 CH EMICAL ISO 14 28 4


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S AMPL ING LOCATI ONS AMPL ING LOCATI ONSa mp ling Location m eans fro m where we can take sa mp le to p erfor m the testing fro m the p late:

1 . API 5L 2. ASTM A36

TT ( Transverse tensile test) taken atlocations B, C, F, or GCI L (Char p y i mp act longitudinal)taken at any location, A through H


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S AMPL ING LOCATI ONS AMPL ING LOCATI ONSa mp ling Location m eans fro m where we can take sa mp le to p erfor m the testing fro m the p late:

3 . IS 20 62 4 . EN 1 002 5


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REQUIRE MENTS OF S AMPL E PO SITI ON IN DI FFERENT GR AD ES

FOR DI FFERENT TESTS


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S AMPL E SI ZE

AP I 5 L1 6 0 mm x 7 00 mm (for Transverse Sa mp les)3 5 0 mm x 7 00 mm (for Transverse/Longitudinal Sa mp les)

ASTM A3 67 0 mm x 4 00 mm ( Nor m al case)

2 5 0 mm x 4 00 mm ( I n case of Imp act require m ent )

EN 1002 52 5 0 mm x 55 0 mm

IS 20 6 22 5 0 mm x 55 0 mm


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MI CROMI CRO--STR UCTURESTR UCTURE

1. Metallogra p hy

Metallogra p hy is the science and art of p re p aring a m etal surface form icrostructual analysis of features by grinding, p olishing and etching.

A syste m atic m ethod to exa m ine m icrostructure of m aterials ( m ainlym etallic m aterials).


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1. Metallogra p hy

Most engineering alloys are polycrystalline. This means that each piece of ametal is made up of a large number of tiny crystals, or grains, each havinga regular crystal structure (for example, FCC, BCC, or HCP)

Materials specialists are interested to see the grain boundaries in order toestimate the grain sizes. The average grain size in metals is usually in theorder of several to tens of micrometers, which can be measured only bythe use of an optical or light microscope

Microstructure: It is the geometric arrangement of grains and the different phases present in a material

Grain Boundaries: It is the interface between two grains in a polycrystallinematerial where the crystal is disordered due to rapid change in crystallographicdirections



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1. Metallogra p hy

Wh y Metallograp h y ?To Study and characterization of materialsTo Ensure the correlation between properties and structureTo Predict properties of materialsTo Design alloys with new propertiesTo Check if the material has been correctly processed

Requirements of Sample for Success Metallograp h y:Be flat and free from imperfectionsStable mountingNo chippingFree of all debrisIdeally smooth and flawless.

U ses of Metallograp h y:Shows grain size, inclusions, impuritiesQuality control in metal processingFailure analysisResearch studies

Alloy development



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1. Metallogra p hy

S te p s in m etallogra p hic sa mp le p re p aration:1 . Sectioning2 . Mounting3. Grinding Rough & Fine4. Polishing Rough & Fine5. Etching



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1. Sectioning

Why sectioning?

1 . Size limitation of specimen to be examined under optical microscope.

2 . To select a small area for microscopic examination from a large sample.

Abrasive Cutting is the most common sectioning method. Theabrasive cut-off disc is usuallymade by silicon carbideparticles, or diamond particles(called Diamond saws).


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2. Mounting


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2. MountingMounting is required when Sample is small or oddly shaped to be handled.When the sample edge area needs is to be examined.

Why m ounting ?

Small samples are at times difficult to hold safely during grinding and polishingoperations, and their shape may not be suitable for observation on a flat surface.

They are therefore mounted inside a polymer block or mount.

Cold m ounting can be done using two component resins (epoxies) as liquid tostart with but which set solid shortly after mixing.It requires very simple facilities consisting of a cylindrical ring which serves as amould and a flat piece which serves as the base of the mould.

The sample is placed on the flat piece within the mould and the mixture poured inand allowed to set. Cold mounting takes few minutes to hours to complete

Hot- m ounting: the sample is surrounded by an organic polymeric powder(Bakelite) which melts under the influence of heat (about 200 0 C). Pressure isalso applied by a piston, ensuring a high quality mould free of porosity and withintimate contact between the sample and the polymer


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3. Grinding

Grinding removes the damages on the surface produced by sectioning At the end of grinding phase, the only grinding marks present must be from

the last grinding stepSuch marks will be removed by polishing

Grinding m aterials: Abrasive papers (coated with silicon carbide grits)Commonly, a series of abrasive papers are used, from coarse to fine one

Grit sequence: 120 -, 2 40 -, 3 20 -, 4 00 -, & 600 -mesh

Grinding is done using rotating discs covered with silicon carbide paper andwaterThere are a number of grades of paper,with 120 , 1 80 , 2 40 , 4 00 , 600 , grains of

silicon carbide per square inch 120 graderepresents the coarsest particles and thisis the grade to begin the grinding operation. Always light pressure is applied at the centreof the sample


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3. Grinding

Grinding is continued until all the blemishes have been removed, the samplesurface is flat, and all the scratches are in a single orientation

The sample is washed with water and moved to the next grade, orienting thescratches from the previous grade normal to the rotation direction. This makesit easy to see when the coarser scratches have all been removed

After the final grinding operation on 600 paper, the sample is washed in

water followed by alcohol wash and dried before moving to the polishersArtifact structure from improper grinding

Surface deformation fromimproper grinding shouldbe avoid, otherwise themicrostructure may beobscured as shown below


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4 . Polishing


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4 . Polishing

After being ground to a 600-grit finish, the sample is polished to produce a flatand scratch-free surface with high reflectivity.

Coarse polis h ing:abrasives in the range of 30 ~ 3 m using diamond grits of several micrometers

Fine polis h ing:abrasives in the range of 1 m using diamond grits of 1 m, followed by 0.3 ~

0.05 m alumina slurries.

The polishers consist of rotating discs covered with soft cloth impregnated witha pre-prepared slurry of hard powdery alumina particles (Al2O3), the size rangesfrom 0.5 to 0.03 m

Begin with the coarse slurry and continue polishing until the grinding scratcheshave been removed


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Polishing sequence

4 . Polishing


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4 . Polishing

Artifacts fro m imp ro p er p olishing

Polishing should produce a scratch-free surface. Excessive pressure may causeartifact of second phase particles as shown below.


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4 . Polishing

It is of vital importance that the sample is thoroughly cleaned using soapy water,followed by alcohol, and dried before moving onto the final stage.

Any contamination of the final polishing disc will make it impossible to achieve asatisfactory polish.

Examining the specimen in the microscope after polishing should reveal mirror like surface.


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5 . EtchingWhat is Etching ?Etching is controlled corrosion process resulting from electrolytic action between

surface areas of different potential.Etching reveals the microstructure of a material by selective dissolution of thematerial from the surface.

The p ur p ose of etching is two-fold.

1 . Grinding and polishing operations produce a highly deformed, thin layer on thesurface which is removed chemically during etching.

2 .To attack the surface with preference for those sites with the highest energy,leading to surface relief which allows different crystal orientations, grainboundaries, precipitates, phases and defects to be distinguished in reflected light microscopy.

Using chemical to dissolve selectively the surface of materials in order to revealthe inhomogeneous nature in microscopic scale.


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Etchant SampleNital (2 ml HNO3 + 98 ml ethanol) Steels and cast irons

Picral (10 g Picric acid + 100 ml ethanol) Carbon & low alloy steels

Nital (2 ml HNO3 + 98 ml ethanol) Steels and cast irons

Picral (10 g Picric acid + 100 ml ethanol) Carbon & low alloy steels

Vilella (1 g Picric acid + 5 ml HCl + 100 mlethanol)

High carbon & high alloy steels

Vilella (1 g Picric acid + 5 ml HCl + 100 mlethanol)

High carbon & high alloy steels

5 . Etching5 . Etching

Different Kind of Etchant used for Steel :


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Microsco p ic Exa m inationMicrosco p ic Exa m ination

Crystallites (grains) and grain boundaries. Vary considerably in size. Can bequite large

Crystallites (grains) can be quite small (mm or less) necessary to observewith a microscope.

Microsco p ic techniques:

Optical microscopy is used to obtain an enlarged image of a small object.

In general, a microscope consists of a light source, a condenser, an objective,and an ocular or eyepiece.

The scope of optical microscope is limited by the wavelengths of the light used

and by the materials available for manufacturing the lenses.


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Microsco p ic Exa m inationMicrosco p ic Exa m inationOp tical Microsco p e


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Microsco p ic Exa m inationMicrosco p ic Exa m ination

Deter m ination of the Grain S ize according to A STM E 112

Standard ASTM Grain Size

N = 2 n -1 , n = ASTM grain size number


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IN CLUSI ONIN CLUSI ONInclusion distribution form different API 5L X65 steels


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MI CROSTR UCTUREMI CROSTR UCTURE

200 XGR AIN SI ZE : 7 .7 0PE ARLITE : 22. 58 %

200 XGR AIN SI ZE 8 .3 8PE ARLITE 1 5 .3 7 %


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SPECTROMETERSPECTROMETEROP TI CAL EMISSI ON SPECTROMETER , SHI MADZU, JAPA N


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Training Module for Testing

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