Mechanical Residual Stresses
Mechanical residual stresses develop from uneven plastic deformation in parts and persist. They affect mechanical properties and can cause cracking.
Physico-chemical mechanism of action
Mechanical residual stresses occur when different parts of a component are plastically deformed to different degrees. This can happen due to uneven stresses or temperature differences during manufacturing or machining. The deformations create stress zones inside the material.
Metallurgical relevance & risks when welding
These stresses can lead to cracking and fracture, especially when combined with external service loads. They reduce the strength and mechanical properties of the material. Welding can add more stress to the material, leading to further cracking or distortion.
Workshop practice & instructions for action
To minimize mechanical residual stresses, components should be loaded and processed evenly. In welding, it's important to control temperatures and times to avoid uneven deformation. Using stress measurement tools can help identify and reduce existing stresses.