Segregation
Segregation is an uneven distribution of alloying elements in the metal, formed during solidification. It leads to an irregular crystal structure and can cause loss of toughness, embrittlement, and porosity.
Physical-Chemical Mechanism of Action
Segregation occurs when alloying elements or accompanying substances have different solubilities in the melt. During solidification, these elements cannot be distributed uniformly, forming non-uniform regions in the metal.
Metallurgical Relevance & Risks in Welding
Segregation can lead to loss of toughness because the irregular crystal structure impairs the mobility of atoms. It also increases the risk of embrittlement and porosity, which reduces the strength and service life of the metal.
Workshop Practice & Action Instructions
To minimize segregation, use as homogeneous alloys as possible during manufacturing and welding. With fine-tuned melt process control and uniform cooling, the formation of segregation can be reduced.