Critical crack length

Physical-Chemical Mechanism of Action

The critical crack length is the maximum crack beyond which, under load, crack propagation and brittle fracture begin. It indicates the safety margin for material stability.

Metallurgical Relevance & Welding Risks

If the crack length in the weld exceeds the critical crack length, it can become unstable under load and cause brittle fracture. This increases the risk of hot cracking and impairs the mechanical properties of the material.

Shop Practice & Action Guidelines

To minimize the critical crack length, ensure proper weld alignment, a homogeneous microstructure, and adequate cooling. Use suitable welding processes and materials to prevent cracking.