Which method is often employed to relieve residual stresses in welded components?

Normalizing is a heat treatment process frequently used to relieve residual stresses in welded components. When welding occurs, the rapid heating and cooling can lead to the formation of residual stresses due to thermal expansion and contraction. Normalizing involves heating the welded component to a temperature typically above its critical range and then allowing it to cool in air. This process not only redistributes the residual stresses but also refines the grain structure of the material, ultimately enhancing its mechanical properties.

The effectiveness of normalizing in stress relief lies in its ability to achieve a more uniform microstructure, thereby reducing the internal stresses that could lead to warping or failure during service. It's a controlled method that can significantly improve the integrity and performance of welded parts.

In contrast, quenching, which involves rapid cooling from a high temperature, can actually increase stresses in a component, especially if it's not followed by tempering. Tempering, on the other hand, is used primarily to reduce brittleness in hardened steels and does not serve the purpose of stress relief as effectively as normalizing does. Meanwhile, shot peening is a surface treatment method that induces compressive stresses on the surface of a material, which can help improve fatigue life but does not directly relieve residual stresses within the bulk of a weld