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FORGING

EXTERNAL GUIDE

Mr. Ramaswamy

Associate vice president

BHARAT Forge LTD

Pune

INTERNAL GUIDE

Mr. Natarajan

Consultant

SPG, NTTF

Bangalore

By

S.Krishnamoorthy, 0201

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CONTENTS

• INTRODUCTION

• FORGING PROCESSES

• MATERIALS

• HAMMERS

• PRESSES

• ADVANTAGES OF FORGING

• DEFECTS IN FORGING

• APPLICATION

• SECONDARY OPERATIONS

• PRODUCT DESIGN ASPECTS

• SAFETY MEASURES

• COMPANY VISIT

• CONCLUSION

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INTRODUCTION

• By application of heat and pressure, a metal can be altered in shape permanently without rupture.

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FORGING PROCESSES

• OPEN DIE FORGING• CLOSED DIE FORGING (IMPRESSION

DIE)

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OPEN DIE PROCESS

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OPEN DIE PROCESS

• TYPES– UPSETTING– COGGING– SOLID FORGING– PIERCING, PUNCHING AND TREPANNING– RING FORGING– COMBINED PROCESSES

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OPEN DIE PROCESS

• UPSETTING

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OPEN DIE PROCESS

• COGGING

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OPEN DIE PROCESS

• SOLID FORGING– IS USED TO PRODUCE STOCK FOR FURTHER

FORGING OPERATIONS OR END PRODUCTS SUCH AS BARS OR SHAFTS

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OPEN DIE PROCESS

• PIERCING, PUNCHING AND TREPANNING

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OPEN DIE PROCESS

• RING FORGING– Slight rotation of the ring on each press stroke

reduces the ring wall uniformly and increases both the inside and outside diameters. The height of the ring remains nearly constant, but may require edging

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CLOSED DIE FORGING

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MATERIALS

• CARBON, MICRO ALLOYED AND ALLOYED STEELS

• STAINLESS STEEL• ALUMINIUM ALLOYS• COPPER BASED ALLOYS• HEAT RESISTANT ALLOYS OF IRON, Ni, Co• TITANIUM ALLOYS• MAGNESIUM ALLOYS

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HAMMERS

• BOARD HAMMERS• AIR-LIFT HAMMERS• STEAM OR AIR-POWERED HAMMERS

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PRESSES

• MECHANICAL PRESSES• SCREW PRESSES• HYDRAULIC PRESSES

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ADVANTAGES OF FORGING METALS

• GREATER STRENGTH• REDUCTION IN WEIGHT• ABILITY TO WITHSTAND UNPREDICTABLE

LOADS• MIN OF MACHINE FINISH REQUIRED• SAVINIG IN MATERIAL• ELIMINATION OF INTERNAL DEFECTS

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GRAIN FLOW

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DEFECTS

• CRACKS• TEARS• UNDERFILLING• PITTING• DENTS• LAPS

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APPLICATION

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SECONDARY OPERATIONS

• HEAT TREATING

• MACHINING

• FINISHING OPERATIONS– REMOVAL OF OXIDE SCALES– CLEANING (PICKLING, TUMBLING,

BLAST CLANING)– SHOT PEENING

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HEAT TREATING

• TO IMPROVE MECHANICAL PROPERTIES OF FORGED COMPONENTS

• UNIFORM GRAIN STRUCTURE• TO RELIEVE INTERNAL STRESSES

– ALL SEVEN GROUPS OF ALLOYS CAN BE HEAT TREATED

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MACHINING

• TO ACHIEVE FORM AND FINAL TOLERANCE

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FINISHING OPERATIONS-REMOVAL OF OXIDE SCALES

• WHY ?– DURING MACHING CUTING TOOL LIFE

REDUCES– DIE WEAR– TO FACILITATE SURFACE COATING

# STEAM OR COMPRESSED AIR

# OIL SPRAYING

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FINISHING OPERATIONS-CLEANING

• PICKLING– IMMERSED IN ACID SOLUTION– 12% TO 15% OF CONCENTRATED

SULFURIC ACID WITH WATER– IN SOME CASES ACID SOLUTION IS

HEATED– MOSTLY FOR NON FERROUS FORGINGS

(Cu, BRASS, BRONZE, Al, MONEL)

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FINISHING OPERATIONS-CLEANING

• TUMBLING

– FORGED COMPONENTS ARE ROTATED WITH LOOSE ABRASIVES TO REMOVE THE SCALE

– CARE SHOULD BE TAKEN WHEN FORGING HAVE SHARP EDGES AND SHARPLY DEFINED SECTIONS

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FINISHING OPERATIONS-CLEANING

• BLAST CLEANING– SAND, GRIT OR METALLIC SHOT ARE

MIXED WITH AIR AND FORCED AGAINST FORGINGS

– USED FOR SMALL AND MEDIUM SIZE FORGINGS

– IMPROVES SURFACE FINISH

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FINISHING OPERATIONS-SHOT PEENING

– ROUND METALLIC SHOT IS THROWN IN RELATIVELY HIGH VELOCITY

– INCREASES THE FATIGUE STRENGTH– PITTING– CRANK SHAFTS, CAM SHAFT,

CONNECTING RODS, GEARS AND SPRINGS.

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PRODUCT DESIGN OF FORGING

• CONSIDERATION FOR DESIGNING FORGED PARTS

• CONSIDERATION FOR DESIGNING FORGING DIES

• RECOMMENDED ALLOWANCES

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PRODUCT DESIGN ASPECTS A TYPICAL PART

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PRODUCT DESIGN OF FORGING

RECOMMENDATIONS :•DRAFT

7° OUTSIDE DRAFT ANGLE10° INSIDE DRAFT ANGLE

•RADII & FILLET SHOULD BE AS LARGE AS POSSIBLE•SHARP RADII SHOULD BE AVAILABLE•IN CASE OF SMALL DEPRESSION OR SMALL HOLES SHOULD BE MACHINED

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PRODUCT DESIGN OF FORGING

• AVOID DEEP IMPRESSIONS• THIN WALLED SECTIONS SHOULD BE

AVOIDED• RAPID CHANGE OF SECTIONS SHOULD BE

AVOIDED

DIE:• THE PARTING LINE SHOULD BE ARRANGED IN

ONE PLANE AS NEARLY AS POSSIBLE SO THAT EXCESS METAL OR FLASH CAN BE TRIMMED

• INSERT DESIGN

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DESIGN ASPECTS

PARTING LINE SELECTION :

– AVOIDANCE OF DEEP IMPRESSION– AVOIDANCE OF SIDE THRUST– FAVOURABLE GRAIN SIZE

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DESIGN ASPECTS

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SAFETY MEASURES

• SHIELDS, GLOVES, GOOGLES Etc.• WARNING SIGNS• OPERATOR TRAINING• SAFETY SENSORS

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COMPANY VISITED

• BHARAT FORGE LIMITED, PUNE– ONE OF THE ASIA’S BIGGEST– ALMOST ALL AUTOMOTIVE LEADERS ARE

THEIR CUSTOMERS– MANUFACTURING CRANK SHAFTS, FRONT

AXLE, REAR AXLE, CONNECTING RODS, CAM SHAFTS etc

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BHARAT FORGING LIMITED

• PRESS SHOP– CONNECTING ROD– FRONT AXLE

• DIE MANUFACTURING– MACHINES USED– DIES– LUBRICANTS

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CONNECTING ROD

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DIE FOR CONNECTING ROD

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FORGING DIE

• MATERIAL

• HARDNESS

• LIFE

• MANUFACTURING

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DIE MANUFACTURING

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DIE MANUFACTURING

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DIE MANUFACTURING

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DIE MANUFACTURING

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DIE MANUFACTURING

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DIE MANUFACTURING

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CONCLUSION

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THANK YOU