Overaging of 17-4PH 1

[HardMetal]

Do the mechanical properties of 17-4PH in the H925 condition degrade significantly if it is aged an additional 4 hours at 925F? If so, do you have any data showing how much?

Thanks.

Paul

 

[Metalguy]

They don't degrade a whole lot-only slightly. Remember, with tempering or precip. hardening, the temp. has a big effect (log.) but the time is merely linear.

I don't have actual data, but if you lose more than a few points Rc I'd be surprised.

 

[stanweld]

17-4 PH with 925 F for 4 hr preciptation hardening treatment will provide a minimum tensile strength of 170ksi-ref Vol. 2 8th Edition of Metals Handbook.

 

[stanweld]

Whoops! Misunderstood. 8hrs total time at 925F. Shouldn't be much less than 170ksia- expect approximately 165ksi min.

 

[HardMetal]

Thanks for your help. I spoke with someone from AK Steel and he said essentially the same thing, that the properties would not be significantly affected.