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Unformatted text preview: • • • • • Tempering Annealing Stress Relieving Normalizing Quenching • Reheating a Hardened Material
– Increases Ductility and Toughness • Three Components
– Temperature – Time – Cooling Rate • Heating and holding a suitable temperature followed by an appropriate cooling rate.
– Quenching has to occur – Produces desirable changes in the material properties or microstructure • Relieves stresses that remain locked in a structure as a consequence of a manufacturing sequence – Welding – Cutting with a torch – Machining • Both Thermal and Microstructure point of view
• Heating then cooled in still or slightly agitated air • Rapid cooling of steel from an elevated temperature
– Typical Quenching techniques
• • • Water Oil Air • What is the hardness required?
– Refer to Heat Treater’s Guide • How Deep do You Need the Treatment?
– Case – Through • What type of Heat Treatment is required?
– Tempering, Annealing, Stress-Relief, Normalizing, Quenching • Turn On Furnace • Set To Appropriate Temperature
– Determine from references • Place Metal In Furnace When Up to Temperature
– Leave for determined time • Remove and Immediately Quench
– Quench in appropriate fluid
• Oil, Water, Air • Re-Set Furnace Temperature (Tempering) • Place Metal Back in Furnace (Tempering)
– Leave for determined time • Remove and Cool at Designated Rate (Tempering) • Establish the type of steel that will be used • Determine the desired properties
• Case/Through • Choose the proper quenching technique • Metals Handbook Desk Edition, Second Edition.
– JR Davis, Davis and Associates, 1998, ASM International • Steel Aluminum Stock List and Reference Book, Reference
– Jorgensen Steel, Earle M. Jorgensen Co., 1998. (Section S.) ...
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