Phosphorus Segregation Banding
Phosphorus segregation banding results from string-like concentration differences of phosphorus in rolled steel. This leads to anisotropic mechanical properties and a drop in toughness transverse to the rolling direction.
Physical-Chemical Mechanism of Action
In rolled steel, string-like concentration differences of phosphorus develop. During rolling, phosphorus segregates to surfaces and in certain directions, resulting in a streak pattern.
Metallurgical Relevance & Welding Risks
These phosphorus segregation streaks can lead to anisotropic mechanical properties. The toughness of the steel drops significantly transverse to the rolling direction, increasing the risk of cracks and fractures under mechanical load. Weld defects such as hot cracks or grain coarsening can occur.
Workshop Practice & Action Guidelines
To minimize phosphorus segregation streak formation, pay attention to the correct rolling direction and a homogeneous weld pool. When welding, it is important to run the weld in line with the rolling direction to reduce the risk of cracks. Use suitable welding methods with controlled cooling and regularly check the mechanical properties of the material.