Stress relieving on SS316

[dogbural]

Hi,

If the extruded SS 316 tube is stress relieved at the following condition, can we expect to have any hardness change?
- furnace @980 deg Celsius for 20 hours
- cool by air

 

[weldstan]

Yes, but why for 20 hrs?

 

[EdStainless]

From that temp you would need to heat quickly and cool quickly.
My guess is that 20min would be long enough.
And yes, you may see a change in properties.
It depends on how the original material was cooled and handled.
If it was quenched from above 960C then I would expect no change.
If it slow cooled, you are actually hurting the material by not going hotter (1060C min) for full solution anneal.
If it had much cold work done to it, then you will recover ductility and reduce the yield strength.