Heat treat 8620 with Carburizing

[yshgao]

Hi there,

If we want to harden 8620 with carburizing, Please advise if the following forming, heat treatment and hardening process correct:

1) forming to near net shape (cold or hot)
2) stress relief or normalizing to release the residual stress
3) machining to the expected dimension and surface finished
4) carburizing for the surface hardening. The surface hardening is the last step.

 

[arunmrao]

Do not complete finish machine. Leave some stock 0.2mm atleast. Finish your carburizing and hardening treatment. Finally finish grind the part to drawing dimension.

Also do you need the complete part to be case hardened or a selective region to be done?


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[TVP]

As stated by arunmrao, the desired sequence is forming--> normalizing (if necessary) --> rough machining --> carburizing --> grinding or other finishing.

 

[PeterCharles]

It depends on your component and final application. For us final grinding is an unnecessary expense. We either machine from stock bar and do a one shot case hardening process, or forge and control cool, machine, then one shot case hardening. There is a small amount of distortion on the forged component, but the end accuracy is "fit for purpose". (the market won't stand finish grinding)