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Stress relieving on SS316
- Thread starter dogbural
- Start date
EdStainless
Materials
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.
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.
- Thread starter
- #4
Supplier actually confirmed the process as below
Placing the SS tubes for 3 hours (this is a stage where the temperature ramps up to 980 deg)
Open the furnace and cool it down for 17 hours
I have not checked with raw material supplier as to how they do quenching.
It seems believe or not, the hardness was measured higher after stress relieving. Please note that we just compared different samples as we did not measure the hardness before and after the relieving.
Is it worthwhile to do mechanical property testing to see the samples are actually still okay?
Placing the SS tubes for 3 hours (this is a stage where the temperature ramps up to 980 deg)
Open the furnace and cool it down for 17 hours
I have not checked with raw material supplier as to how they do quenching.
It seems believe or not, the hardness was measured higher after stress relieving. Please note that we just compared different samples as we did not measure the hardness before and after the relieving.
Is it worthwhile to do mechanical property testing to see the samples are actually still okay?
EdStainless
Materials
If they slow cooled enough to form carbides and/or intermetallics in the structure, then the hardness should go up.
And corrosion resistance and ductility both go down.
And corrosion resistance and ductility both go down.
- Thread starter
- #6
EdStainless
Materials
How heavy is the wall of the tube?
Is the material 316L?
If so, then charge into a hot furnace, once everything stabilizes give it another 15min, pull it out and force cool it with fans.
You want to be under 800F (~450C) within a few minutes.
If it was well annealed to start with then this is all that you need.
If it was 'process annealed' originally then I would raise the temp and do a real anneal at 1075-1100C.
Is the material 316L?
If so, then charge into a hot furnace, once everything stabilizes give it another 15min, pull it out and force cool it with fans.
You want to be under 800F (~450C) within a few minutes.
If it was well annealed to start with then this is all that you need.
If it was 'process annealed' originally then I would raise the temp and do a real anneal at 1075-1100C.
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