Grain Boundary Segregation
The enrichment of impurity elements at grain boundaries leads to a reduction in cohesion and can cause intergranular fractures.
Physical-Chemical Mechanism of Action
During welding, certain impurity elements (like silicon or nickel) can concentrate at grain boundaries. This concentration enrichment can strengthen the atomic bonding between crystals and reduce the cohesion of the structure.
Metallurgical Relevance & Risks in Welding
Increased cohesion at grain boundaries can lead to intergranular fractures, especially under high stresses or mechanical loads. This can impair the strength and service life of the weld.
Workshop Practice & Action Guidelines
To avoid grain boundary enrichment, pay attention to correct melting time and temperature. Use suitable protective measures or impurity elements in the weld. For highly stressed applications, stabilizing the structure through mechanical treatments like peening or rolling can be helpful.