What is interpass temperature in a WPS context?

• A. The temperature maintained between successive welding passes.
• B. The ambient temperature on the shop floor.
• C. The maximum heat input.
• D. The temperature of the cooling water.

Answer: (A)

Interpass temperature is the temperature of the weld area between successive welding passes as specified in the welding procedure. It’s a control point, not the ambient shop temperature, the maximum heat input, or the cooling water temperature. The WPS uses a defined temperature range (or a maximum) to keep the weld zone within a window that supports proper fusion for the next pass, preserves the intended microstructure, and manages hydrogen content and residual stresses. If the area between passes is too cool, fusion can be inconsistent and cracking risk can rise; if it’s too hot, properties can be degraded or distortion increased. Welder or heat management steps are used to bring or maintain the weld zone within the specified interpass temperature before adding the next pass.