the effect of heat treatment on the … · • aar m 201-05 specification ... tensile strength...

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THE EFFECT OF HEAT TREATMENT ON THE MECHANICAL PROPERTIES

AND MACHINABILITY OF AAR GRADE E STEEL

ABDUL RAZAK ESAKJEE (Pr. Eng.) 16 MARCH 2017

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OVERVIEW

• INTRODUCTION

• OBJECTIVE

• MATERIAL CHARCTERIZATION

• EXPERIMENTAL WORK

• EXPERIMENTAL RESULTS

• DISCUSSION

• CONCLUSION

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INTRODUCTION

• USED IN THE RAIL INDUSTRY

• COUPLERS, DRAWBARS, KNUCKLES, YOKES, LOCKS, FOLLOWER BLOCKS,

STRIKER CASTING

• TYPICALLY SAND CASTING

• ANNUAL NEW BUILD OF 1 500 FREIGHT WAGONS

• EXISTING FLEET OF 75 000 FREIGHT WAGONS

• VOLUMES JUSTIFY EFFICIENCY IMPROVEMENT

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OBJECTIVE

• INVESTIGATE EFFECT OF HEAT TREATMENT ON MECHANICAL

PROPERTIES

• INVESTIGATE EFFEECT OF HEAT TREATMENT ON MACHINABILITY

• OPTIMISE PRODUCTION PROCESS

• IMPROVE PRODUCTION EFFICIENCY

• REDUCE PRODUCTION COSTS

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MATERIAL CHARACTERIZATION

• AAR M 201-05 SPECIFICATION

ELEMENT MAX. CHEMICAL COMPOSITION (wt%)

Carbon (C) 0.32

Manganese (Mn) 1.85

Phosphorus (P) 0.04

Sulphur (S) 0.04

Silicon (Si) 1.5

AAR GRADE E MINIMUM REQUIREMENTS

Tensile Strength (MPa) 827 Min.

Yield Strength (MPa) 690 Min.

% Elongation 14 Min.

% Reduction of Area 30 Min.

Hardness (HB10/3000) 241-311

Charpy Impact Test (J) at -40°C 27 Min.

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EXPERIMENTAL WORK

• SAMPLE PREPARATION

• HEAT TREATMENT

• MICROSTRUCTURAL ANALYSIS

• MECHANICAL PROPERTIES TEST

• MACHINABILITY TESTS

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MICROSTRUCTURAL ANALYSIS

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MECHANICAL PROPERTIES

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MACHINABILITY- TOOL WEAR

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MACHINABILITY- CUTTING FORCE

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MACHINABILITY- SURFACE ROUGHNESS

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MACHINABILITY- POWER CONSUMPTION

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DISCUSSION

• EFFECT OF HEAT TREATMENT ON THE MICROSTRUCTURE

• EFFECT OF HEAT TREATMENT ON THE MECHANICAL PROPERTIES

• EFFECT OF HEAT TREATMENT ON THE MACHINABILITY

• Tool Wear

• Cutting Force

• Surface Roughness

• Power Consumption

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CONCLUSION

• EXPERIMENTAL WORK CONDUCTED WITH THE AIM OF EVALUATING THE

EFFECT OF HEAT TREATMENT ON THE MICROSCTRUCTURAL FORMATION,

MECHANICAL PROPERTIES AND MACHINABILITY OF AAR GRADE E STEEL

• CONCERNING MECHANICAL PROPERTIES

• CONCERNING MACHINABILITY

Thank you