Boron Segregation Coefficient
The boron segregation coefficient indicates how boron distributes between liquid and solid steel. A high value leads to better segregation.
Physico-Chemical Effect Mechanism
During solidification, boron is transformed from liquid to solid steel. The boron segregation coefficient describes how well boron partitions between these two phases. A high coefficient means that boron is better transferred to the solid phase.
Metallurgical Relevance & Welding Risks
A too high boron segregation coefficient can lead to uneven segregation. This can cause local hardness variations and an increased risk of cracks in the weld. Conversely, a low coefficient may mean that boron is not sufficiently transferred to the solid phase, affecting segregation.
Shop Practice & Instructions
To ensure optimal segregation, the boron segregation coefficient should be in the range of 0.5 to 1. A coefficient above 1 can lead to uneven distribution and increased crack risk. A value below 0.5 may mean insufficient segregation. It is important to control the boron content and melting time to keep the coefficient in the desired range.