Cold Stress Relieving

Cold Stress Relieving Servicesis a technique to remove or reduce the internal stresses created in a metal. These stresses may be caused in a number of ways, ranging from cold working to non-uniform cooling. Stress relieving is usually accomplished by heating a metal below the lower critical temperature and then cooling uniformly, The shaping of metal at temperatures substantially below the point of recrystallization. Cold working adds strength and hardness.

Effect of Residual Stresses:

Cold worked austenitic stainless steels will contain some 'strain induced' martensite, which, as well as making the steel partially 'ferro-magnetic', can also reduce the corrosion resistance. A highly stressed cold worked structure may also have lower general corrosion resistance than a fully softened austenitic structure. The main hazard is stress corrosion cracking (SCC), which relies on tensile stresses as part of the failure mechanism. Stress relieving removes such residual tensile stresses and so improves the SCC resistance. The other main reason for stress relieving is to provide dimensional or shape stability. The risk of distortion can be reduced during forming or machining operations by stress relieving.