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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
