Stress Relieving

in metallurgy, the initial stage in the recovery of metals. Stress relieving is performed on deformed or irradiated metals by heating to temperatures that range from 5 to 20 percent of the melting temperature. In addition to partially relieving stress, the process redistributes dislocations and point defects, which are caused by interstitial atoms, vacancies, and interstitial compounds. Interstitial impurities and, to a lesser extent, substitutional impurities hinder stress relieving by raising the temperature requirement.

Stress relieving is accompanied by the restoration of several physical properties in the deformed metal, including electrical resistivity and density; the process exerts a weaker effect on mechanical properties. Approximately up to 70 percent of the decrease in resistivity and up to 50 percent of the density decrease that result during metal deformation are eliminated by stress relieving, but complete elimination of these decreases in physical properties is accomplished by recrystallization.