A PQR/WPS essential variable using FCAW will not require requalification if what occurs?

In the context of the AWS D1.1 Structural Welding Code, understanding essential variables is crucial for ensuring quality and consistency in welding procedures. For a Procedure Qualification Record (PQR) and Welding Procedure Specification (WPS), certain changes can mandate requalification, depending on the nature and extent of those changes.

When an increase in travel speed by 25% occurs, it does not require requalification because the essential variables related to travel speed are less critical compared to other factors that affect the chemical and mechanical properties of the weld. Travel speed influences the heat input and the cooling rates of the weld but does not inherently alter the fundamental qualities of the welding process itself.

In contrast, changes such as a decrease in amperage by 10%, a change in filler material, or altering the welding position from flat to overhead are considered significant enough to necessitate requalification due to their potential impact on the weld properties. For instance, a different filler material can change the way the weld interacts with the base metals, potentially affecting its strength, permeability, or corrosion resistance. Similarly, altering the welding position can also lead to changes in the heat distribution and the dynamics of the weld pool.

Overall, an increase in travel speed by 25% does not directly imply