Solidification microsegregation
Solidification microsegregation is a chemical concentration shift at the microscopic level between dendrite arms due to delayed diffusion. It causes local property differences and can lead to cracking.
Physicochemical mechanism of action
Solidification microsegregation occurs when, during the welding process, chemical elements such as carbon or silicon do not diffuse uniformly between dendrite arms. This leads to uneven concentrations in different areas of the weld.
Metallurgical relevance & welding risks
These microsegregations can cause local property differences, such as varying hardness or toughness. They increase susceptibility to cracking and hot cracking, especially when the material is under mechanical stress.
Shop practice & instructions
To minimize solidification microsegregation, it is important to ensure optimal welding speed and a suitable weld pool. Weld durability can be improved by careful cooling and the use of stable filler materials.