Solidification hot cracking
Hot cracking during solidification occurs due to tearing of the structure in still-liquid grain boundary film zones as a result of shrinkage stresses. The susceptibility depends strongly on the impurity profile.
Physical-Chemical Action Mechanism
During solidification of steel, shrinkage stresses develop, especially in still-liquid grain boundary film zones. These stresses can tear the structure so severely that hot cracks occur.
Metallurgical Relevance & Risks in Welding
Hot cracking can lead to severe material failure and cracks in the weld. It increases susceptibility to fracture and reduces the service life of the component.
Workshop Practice & Handling Instructions
To avoid hot cracking, it is important to clean the weld carefully. Use high-quality shielding gases and ensure proper cooling of the steel after welding. The cooling rate should be set so that the structure does not cool too fast (t8/5 > 25 s).