4140/709M40/EN19/42CrMo4/SCM440

الوصف

 ***0/**9M*0/EN*9/*2CrMo4/SCM**0

"Following quenching to hand warm, most components should be tempered between **0 C - **0 C to remove" quenching stresses in the case. This will have little effect on case hardness and will reduce the risk of grinding cracks.
Hardening
Heat to **0 oC - **5 oC, hold until temperature is uniform throughout the section, soak for *0 - *5 minutes per *5 mm section, and quench in oil, water, or polymer as required.
*Temper immediately while still hand warm.
Nitriding
***0 hardened and tempered bar can also be successfully nitrided, giving a surface hardness of up to Rc *0. Nitriding is carried out at **0 oC - **0 oC, followed by slow cooling (no quench) reducing the problem of distortion. Parts can therefore be machined to near final size, leaving a grinding allowance only. The tensile strength of the core is usually not affected since the nitriding temperature range is generally below the original tempering temperature employed.
Normalizing
Heat to **0 oC - **0 oC, hold until temperature is uniform throughout the section, soak for *0 - *5 minutes and cool in still air.
Stress Relieving
Heat to **0 oC - **0 oC, hold until temperature is uniform throughout the section, soak for 1 hour per *5 mm section, and cool in still air.
Tempering
Re-heat to **0 oC - **0 oC as required, hold until temperature is uniform throughout the section, soak for 1 hour per *5 mm of section, and cool in still air.
Notes on Heat Treatment
Heating temperatures, rate of heating and soaking times will vary due to factors such as work piece size/shape also furnace type employed, quenching medium and work piece transfer facilities etc..

Machining
***0 in the hardened and tempered as supplied condition has good to very good machinability and operations such as sawing, turning, drilling, broaching, hobbing, milling and tapping can be carried out satisfactoraly using machine manufacturers recommendations for suitable tool type - feeds and speeds.

Certificate of Quality:issued in English, in addition the normal terms, production process, the mechanical property yield strength, tensile strength, elongation and hardness, forged ratio, UT test result, Grain size, heat treatment methods and the sample of is shown on the Certificate of Quality.

 Marking:Heat No. will be cold stamped and Steel grade, diameter mm, length mm, and the manufacturer LOGO and weight kg is painted

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