Phosphorus segregation band formation

Physical-Chemical Mechanism

During cooling of a metal, a gradient in phosphorus concentration forms. This creates banded structures, so-called segregation bands. Phosphorus reacts with the metal and locally alters its properties.

Metallurgical Relevance & Welding Risks

Phosphorus segregation bands can cause local ductility differences, affecting the toughness of the weld. These differences make the weld prone to cracking and deformation under mechanical stress.

Shop Practice & Guidelines

To avoid phosphorus segregation bands, ensure homogeneous solidification. This can be achieved through controlled cooling routines. Use sufficient heat input and ensure uniform cooling behavior during welding.