Stress Relief Article
Stress Relief Article
(OP)
Daniel Herring, aka "The Heat Treat Doctor" had an article in the latest issue of Industrial Heating about stress relief. One of his points was that for a stress relief heat treatment to be successful, the parts must not be rapidly cooled. "Rapid cooling will only serve to re-introduce stess, and this is the most common mistake made in stress-relief operations." Having never heard anything like this, I am skeptical. I am of the impression that once the part is at a temperature sufficient to reduce the material's yield strength, stress relief happens via a creep mechanism and subsequent cooling rate has no effect on the stress outcome. What do you guys think?





RE: Stress Relief Article
RE: Stress Relief Article
Basically, the concern is to avoid harmful thermal gradients to the component. The 800 deg F limitation has been established by experience and means that once the part falls below 800 deg F, one can cool the part in air or moving without a specified cooling rate.
Would I use a quenching medium to cool the part from 799 deg F to ambient temperature, no, because you still have thermal gradients upon cooling. Part geometry will influence how quickly one can cool from 800 deg F without introducing harmful thermal gradients.
RE: Stress Relief Article
RE: Stress Relief Article
RE: Stress Relief Article
RE: Stress Relief Article