Weld Metal Solidification Crack
A hot crack occurs when the weld metal cools too quickly and forms glass-hard phases. This leads to fracture points.
Physical-Chemical Action Mechanism
During cooling of weld metal, glass-hard crystalline phases such as martensite form at high temperatures if cooling is too fast. These phases are susceptible to cracking and fracturing.
Metallurgical Relevance & Risks in Welding
Hot cracking can lead to severe material failure, especially under mechanical stress. This can result in component failure or machine deflection. The service life and reliability of the weld metal are impaired.
Workshop Practice & Handling Instructions
To avoid hot cracks, controlled cooling is essential. Use a slow cooling throttle or a heat exchanger to regulate the cooling rate. Pay attention to correct welding parameters like temperature and time. For heavy materials or high stresses, careful planning of the cooling method is especially important.