Longitudinal shrinkage
Longitudinal distortion is the shortening of a component along the weld axis due to plastic upsetting during cooling. This can lead to stresses and cracks.
Physico-Chemical Mechanism of Action
During cooling, the weld zone cools from the inside out. The outer layer cools faster than the inner one, which leads to stresses. These stresses can plastically compress the material and elongate it.
Metallurgical Relevance & Risks in Welding
Excessive longitudinal distortion can lead to stress cracks in the weld, especially if the material is not elastic enough. This can affect the strength and service life of the component.
Workshop Practice & Instructions
To minimize longitudinal distortion, control the cooling process. Use slow cooling or cooling protection agents. For particularly sensitive materials, the weld can be divided into several segments to reduce stresses.