Shaft Heat Treatment 1

[1366060]

Greeting !

I take following part to heat treatment lab, for hardening as per description on the following drawing. they say this part should hardened using induction method, and in induction method we cannot give this part hardness more than 50 HRC. and also the hardening depth would be limited to 2.5 mm.

does any body have any idea of best heat treatment practice for this part?

I would appreciate any comment.

 

[AidanMc]

What material is the part made from?

Aidan McAllister
Metallurgical Engineer

 

[1366060]

Dear AidanMc

sorry I forgot to mention material spec.
Material is 1.7225(42CrMo4)
total weight : 89.5 Kg

 

[EdStainless]

At 40 C you will never get that hardness even as quenched.
It looks like the call out is for the surface hardness of one end of the part.
This must require a surface treatment such as carburizing in order to achieve that.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[dbooker630]

You should be able to induction harden to achieve hardness over 50 HRC. The question is what prior treatment has the part received. If it has not been normalized or quench & tempered before induction hardening, you will have trouble with induction hardening response, the microstructure will be inconsistent.

 

[1366060]

Dear dbooker630

Thank you for your valuable reply

actually, the designer of the part have specified the material specification as 1.7225(42CrMo4)+QT on the drawing.

so it seems situation you described is true. and we need to first QT the part and then induction harden it.

just one question, wouldn't it be problematic if I QT the machined part?
I have now finished machining and just Hardening is required.

any comment would really be appreciated.

 

[dbooker630]

You will first have to determine your required core hardness after quench and temper, this will determine your tempering temperature after oil quenching. You may want to measure some of the critical dimensions to note what size changes you have after Q & T. If no green size changes are needed then you can induction harden and repeat the size studies.

 

[1366060]

Thank you dbooker630

all is clear now. I really appreciate your valuable comments.


Best regards.