Each pass in a multi-pass weld must:

The requirement for each pass in a multi-pass weld to fuse with the parent metal and any previous passes is crucial for ensuring the strength and integrity of the weld. This means that each layer of weld material must bond effectively to the base material as well as to the layers that have been laid down previously. This fusion is essential because it creates a continuous, strong joint without voids or defects, which could compromise the weld’s structural reliability.

Achieving a solid fusion between passes helps distribute stress throughout the entire welded joint, reducing the likelihood of failure under load. Moreover, the continuous nature of the fused material contributes to the overall durability and performance of the welded structure, making the quality of the multi-pass weld significantly better.

While complete penetration of the parent metal is important in certain welding techniques, it is not a standard requirement for each individual pass in every multi-pass application. Radiography ensures inspection quality but is not mandatory for every single pass. As for the angle of the weld passes, while it can be relevant to the weld profile, it is not as critical as the need for fusion. Thus, ensuring that each pass fuses properly is the primary concern in multi-pass welding.