Annealing and stress relieving are not the same heat treatment. Annealing is performed at a higher temperature and the component is furance cooled. Stress relieving is performed at a lower temperature and the component can be air cooled.
I would suggest you look these terms up on the internet for more information.
patprimmer;
Yes indeed. They have posted a thread in another forum concerning cast iron and spheriodal cast iron and heat treatment. So, I believe this post was related.
Knowing that I agree but it would be really nice if the OP confirmed it, along with convincing us it is not a student homework post as it is a VERY elementary question. Of course there is one good explanation why a real working engineer might ask such an elementary question, but I would really like to hear from the OP in that regard.
Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
The problem is the terms "annealing" and "stress reliving" describe the desired result of the heat treatment, not the heat treatment itself. For one particular metal, a particular cycle could be considered an annealing cycle, while for another, the same heat treatment could be considered a stress reliving cycle. Still another, it could result in hardening of the material.
Stress relieving as the name implies relies on a combination of heat and stress to produce solid diffusion that results in elastic stresses being relieved. Typically, depending on the state of stress these temperatures are well under the annealing temperature. For instance, I've been able to stress relieve fine wire at 375C in order to straighten it while the typical full annealing temperature was over 300C higher. Keep in mind that during stress relieving you will get some recovery, and in age hardening systems you can get a precipitation reaction depending on the kinetics.
Yes, cracks are excellent at relieving stresses! Several years ago, a crack developed in my windshield after a rock hit it. Everybody pointed out that I had a crack, but I saw it as a stress relief.
