Stress ReliefThermal stress relief involves heating a material to a suitable elevated temperature, holding at that temperature for a set period of time, followed by slow cooling. Its purpose is to allow residual stresses created by welding operations or due to cold working to reduce. In so doing it also helps to restore mechanical properties, particularly toughness and ductility. The heating and cooling cycle must be carried out steadily and evenly as fast cooling could result in regeneration of residual stresses. Higher temperature heat treatments, such as annealing or tempering will also induce stress relief. Stress relief may also be carried out by application of certain mechanical methods. These involve use of overloading or peening to reduce or redistribute stresses but these are less frequently applied than thermal treatments.
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