Residual Stress in a Nitronic 60 Forging
Residual Stress in a Nitronic 60 Forging
(OP)
I believe I may have a residual stress problem with a forging which becomes apparent only after stress is applied to it and it yields more than anticipated. The material is Nitronic 60 (UNS S21800). Standard practice after forging is solution anneal at 1850°F for a few hours then rapid quench.
I have a couple other theories too, but was hoping I could get some guidance on measuring and/or eliminating the stress without redesigning the part.
Can I heat to part below it's solutionizing temperature for a longer duration and let it furnace cool? Can I put the part on a vibration table used for welding stress relief?
Any clues would be appreciated.
I have a couple other theories too, but was hoping I could get some guidance on measuring and/or eliminating the stress without redesigning the part.
Can I heat to part below it's solutionizing temperature for a longer duration and let it furnace cool? Can I put the part on a vibration table used for welding stress relief?
Any clues would be appreciated.





RE: Residual Stress in a Nitronic 60 Forging
How did you confirm that it yields more than anticipated? Did you conduct actual tensile testing? Strain gage?
RE: Residual Stress in a Nitronic 60 Forging
Can Nitronic 60 store residual stress? That's question 1. Question 2 is how can I get rid of it?
RE: Residual Stress in a Nitronic 60 Forging
To answer your questions;
1) Yes, residual stress can be introduced in a material after solution treatment by any of the methods I listed above.
2).You can remove the residual stress by thermal treatment - lower temperature stress relief (800 deg F) based on 1 hour per inch of thickness) or during subsequent machining steps as material is removed, residual stress is altered.
RE: Residual Stress in a Nitronic 60 Forging
RE: Residual Stress in a Nitronic 60 Forging
I would conduct a thermal stress relief (as mentioned above) on several forgings, prior to machining, and see if this solves your problem.
RE: Residual Stress in a Nitronic 60 Forging