Surface Deformation Hardening
Surface strain hardening is a targeted cold working of the part surface through mechanical processing, which increases dislocation density and raises the yield strength in the outermost layer.
Physical-Chemical Mechanism of Action
Surface layer work hardening changes the surface microstructure of a metal through mechanical processing. This deformation leads to an increased dislocation density and the formation of dislocations, which increase the hardness of the material.
Metallurgical Relevance & Risks in Welding
The increased surface hardness can cause difficulties when welding. The material becomes harder to melt and there is a higher risk of cracks or hot cracks, especially if the weld seam is not cooled properly. Additionally, the hardness can reduce the service life of the components.
Workshop Practice & Action Instructions
To minimize the negative effects of surface layer work hardening, it is important to carry out careful pre-treatment. This can, for example, involve chemical surface treatment or special weld preparation equipment. During actual welding, ensure the seam is cooled slowly and controllably to avoid cracks or hot cracks.