Block welding sequence
Block welding is a welding sequence where thick cross-sections are built up in separate blocks. It controls heat concentration and prevents residual stresses.
Physicochemical Mechanism of Action
In block welding, the melting process is carried out in multiple phases, with each block welded and cooled individually. This reduces localized heat concentration and prevents uncontrolled growth of residual stresses.
Metallurgical Relevance & Welding Risks
If block welding is not performed correctly, residual stresses can occur, leading to cracking and distortion. Uneven cooling or too fast a melting phase can alter the microstructure and impair mechanical properties.
Workshop Practice & Action Guidelines
To perform block welding successfully, follow these steps:
1. Divide the steel to be welded into equal-sized blocks.
2. Weld each block individually and allow it to cool after each phase.
3. Use a controlled heat source to regulate temperature during the melting process.
4. Ensure each block cools evenly to avoid residual stresses.