Stress relieving 17-4 and 13-8 round bars

[SeymourDumore]

Guys

I have a family of parts that need to be made from 17-4 and 13-8 bar
For all intents and purposes, the part is 4.5 x 2.5 x .350 thick, with multiple cross sections getting milled down to .062 and .093 thickness.
I am all but certain that this thing will turn into a potato chip just by waving the blueprint in front of it.
So, the question I have: is it possible to successfully stress relieve both of these materials?
I know of 1018, 321SS, Inco 625 and 718 is very compliant for the process, but have no idea about 17-4 and 13-8.

Thank You

 

[LOTT]

What does the final condition need to be? H900?

 

[SeymourDumore]

The final condition is H1050.
That said, after just weeding through the revisions, all of the parts are now AMS5629 ( 13-8 ), Cond H1050, no more 17-4.

 

[Triaged]

What condition will you be doing your machining in? Solution treated? Finish machine after finish age? Or all machining after finish age? Aged it's some hard stuff.

Edit: I was wrong. At H1050 it isn't that hard. It's the lower temps that are hard.

 

[SeymourDumore]

Good question, which would have been my next.
I don't have a problem with roughing to near-net first and finish after H/T, but if the thing cannot be un-stressed before the roughing, then I am out right from the get-go.

 

[Orange Vise]

No need for additional stress relief.

Heat treat (age harden) it first. Condition A is around HRC 25-30 and H1050 is around HRC 35. Practically no difference in machinability, except for tapping.

It's nothing like 1018. Solution annealing is done at high temp, near 2000F, effectively a stress relieving process on its own. Followed by 4 hours at 1050F, it's about as good as it's gonna get.

If I were stress relieving 1018, the only difference is that I would furnace cool rather than air cool. The benefits would be marginal.

 

[mhajicek]

It cuts better in the hardened state, and is very stable.

 

[SeymourDumore]

No need for additional stress relief.

Heat treat (age harden) it first. Condition A is around HRC 25-30 and H1050 is around HRC 35. Practically no difference in machinability, except for tapping.

It cuts better in the hardened state, and is very stable.

So getting it into H1050 first is almost like stress relief?

(I'm just quoting a large lot, large enough to eat a lot of shit if it doesn't work... )

 

[LOTT]

On some parts we machine, weld, then heat treat, and others heat treat then machine (all H900). The finish is nicer when stock is prehardened, but our shapes aren't prone to warping so I don't have good data other than to say it can work either way.

 

[Nate8409]

Would this family of parts be for a company in NH?

 

[rjwalker1973]

I would heattreat it first like was said earlier. I usually prefer turning pre hardened SS.

 

[SeymourDumore]

Would this family of parts be for a company in NH?

In short, No!