Macroscopic Residual Stresses
Residual stresses of the first kind are homogeneous stresses that extend over the entire component and can lead to distortion.
Physico-chemical mechanism of action
Residual stresses of the first kind arise from uneven thermal expansion or mechanical loading of a material. They are uniformly distributed and result in a constant stress state over the entire component.
Metallurgical relevance & risks in welding
These stresses can lead to distortion during machining or to cracking if too high. They also affect the strength and toughness of the material. During welding, the microstructure can be altered, increasing residual stresses.
Workshop practice & action instructions
To minimize residual stresses of the first kind, it is important to ensure uniform heating and cooling of the component. Avoid rapid cooling or uneven loading. During welding, the weld should be positioned so that it does not run in the direction of the stresses. For heavily loaded parts, continuous monitoring of the temperature profile is required.