Multi-layer welding technology
Multi-pass technology is a filling method where multiple weld passes are deposited on top of each other. Each pass thermally normalizes the underlying layer and improves mechanical strength.
Physical-Chemical Mechanism of Action
Multipass technology enables controlled normalization of the weld by sequentially depositing multiple weld layers. Each new layer heats the underlying layer and leads to a homogeneous structure, which increases mechanical strength.
Metallurgical Relevance & Risks in Welding
Multipass technology reduces the risk of hot cracking and burn-through, as each layer allows controlled normalization. However, inaccurate deposition or too little layer weight can lead to stress buildup, which in turn can cause cracking.
Workshop Practice & Instructions
To successfully apply multipass technology, the following steps should be observed:
• Use a welding machine with high control over layer weight and time.
• Make sure each layer is fully cooled before the next one is laid.
• Regularly check the temperature and cooling behavior of the weld.