What can trigger the necessity for requalification of a welding procedure specification (WPS)?

A change in parent material can indeed trigger the necessity for requalification of a welding procedure specification (WPS). The parent material refers to the base metal that is being welded. Different materials may have varying mechanical properties, chemical compositions, and physical characteristics, which can significantly affect the welding process, the characteristics of the weld, and the final quality of the weld joint.

When the parent material changes, it is essential to re-evaluate the welding parameters, techniques, and processes to ensure that the welds meet the required standards and performance criteria. This includes assessing how the new material will respond to the welding process and whether it will achieve the desired strength, ductility, and resistance to defects such as cracks or porosity.

Factors such as the need for different filler materials, adjustments in heat input, or changes in preheating and post-weld heat treatment may arise from the new material’s unique properties, making requalification not just advisable but necessary to ensure safety and compliance with applicable standards.