Advice for induction: 440c stainless 1

[chr10000]

I would like to receive some feedback on methods for induction heat treating 440c. I know this is a difficult procedure, but I also know it can be done. If anyone has any experience in this area I could use some advice. I am very interested in the process of preheating material prior to austenitizing. Any advice is appreciated.

 

[arunmrao]

440C is a through hardening grade material. What is your aim volume hardening or surface hardening please?

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"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr

 

[arunmrao]

Did you have any reason to select a crack prone and difficult to process alloy like 440C,especially when you are looking only for surface hardness. You could have selected 410 and had a nitride case,making life more comfortable.

_____________________________________
"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr

 

[arunmrao]

Altering the specs or change of material is not an easy one, I understand. It was only to help you appreciate the difficulties you are facing. Preheating is always advisable,as it can reduce the thermal shocks,there should be no harm doing that in my opinion.. Can you use polymer quench instead of water quenching,this can also help reduce thermal stresses,without sacrificing on your hardness. I hope this would help in reducing some of your issues.

_____________________________________
"The richer we have become materially, the poorer we have become morally and spiritually." Martin Luther King Jr

 

[TVP]

chr10000,

I agree with arunmrao on both issues, preheating and quenching. I would definitely contact Houghton, Tenaxol, etc. about your specific process. You can obtain signficant improvements in the quenching process just by adding 5-20% polymer to the water, and adjusting the flow rate and quenchant temperature.

 

[chr10000]

We use 10% ucon-b at 110f in quenchant. I have always suggested using high quench volume. What would be a satisfactory preheat temp? Is it advisable to temper freeze temper after induction. I have found some information that says to just freeze and then temper after induction and it should be sufficient. Any experience with the after induction process?