Stress relieving is applied to both ferrous and non-ferrous alloys and is intended to remove internal residual stresses generated by prior manufacturing processes such as machining, cold rolling, and welding. Without it, subsequent processing may give rise to unacceptable distortion and/or the material can suffer from service problems such as stress corrosion cracking. The treatment is not intended to produce significant changes in material structures or mechanical properties and is therefore normally restricted to relatively low temperatures.
Non-ferrous alloys are stress relieved at a wide variety of temperatures related to alloy type and condition. Alloys that have been age-hardened are restricted to stress relieving temperatures below the ageing temperature.