Regaining surface finishing after hardening stainless steel

[bamek]

Hi!
My name is Daniel and I work at a mechanical workshop in Norway.

We are going to machine some stainless steel parts that will require hardening afterwards.
The parts are going to be hardened in an oven at 600 degrees celcius for 4 hours and then air cooled. This procedure is given in the suppliers data sheet.

Because i'm new in the game of hardening stainless steel, I wonder how the surface finish will turn out? And -if it turns out bad, how can we regain it? I was thinking about treating it with some kind of acid, but i don't know if it will work.

Best Regards
Daniel

[Kelly_Bramble]

Welcome to Engineers Edge!

I've only had one cup of coffee but - 600 Deg. C for four hours then air cooled seems like a stress relieving or normalizing process rather than a case or material hardening process..

I do not believe there will be a notable change in effective surface roughness after this process.

[bamek]

I know, i found it kind of odd as well.

But the data sheet (which is given by one of the largest specialist on stainless steel) clearly states that this procedure will give a hardness of 40-43 HRC. It also states that this steel can not be stress relieved like other types of steel, since heating it only will result in increased hardness.

[PinkertonD]

How big is the item being machined and hardened? You can get thin (0.002") stainless sheet (24" x 100') for wrapping items prior to heat treatment to prevent surface damage. Search on some of the Engineering supply sites for

Stainless steel foil

[RWOLFEJR]

What is this S.S. material? Are you sure that you're not looking at a tempering temperature when you say 600C? If surface finish and maybe more importantly, size, is critical then maybe you should consider leaving stock and adding a finish machine cut after heat treat to the process?

[bamek]

Well, we are machining 3000 of these in round one. Because of this we want a production line that is as simple as possible. Using google i found that the english term for the heat treatment is precipitation hardening. While reading a bit about it I found that this is a treatment that can be used on certain types of stainless steel.

I was on contact with the manufacturer and they said that we might get a slightly blue color to the finish, wich doesn't really matter. Thank you guys for the help!