In multi-pass welding, the weld metal and the associated heat-affected zone are subjected to repeated thermal cycling from successive deposition of filler metals. ... Multi-pass structural steel welds used as structural alloy in general engineering and structural applications.

What is multi pass weld important?

Multipass welding is typically used to add layers of weld to thick metal joints. This increases the strength of critical welds for applications such as pressure vessels, oil and gas midstream pipeline, shipbuilding and heavy construction.

What is a single pass weld?

[′siŋ·gəl ¦pas weld] (metallurgy) A weld made by depositing the filler metal with a single pass.