What is interpass temperature?

• A. The temperature of the shielding gas.
• B. The maximum permitted temperature of the weld area between passes.
• C. The initial temperature of the base metal before welding.
• D. The temperature of the filler metal between passes.

Answer: (B)

Interpass temperature is the maximum permitted temperature of the weld area between passes in a multi-pass weld. This limit, defined in the welding procedure and applicable codes, controls how hot the weld zone can be before starting the next pass. Keeping the interpass temperature within the specified range ensures the weld metal and heat-affected zone develop the correct microstructure, maintains intended mechanical properties, reduces residual stresses and distortion, and lowers the risk of cracking. It’s different from the shielding gas temperature, the base metal’s initial temperature, or the filler metal temperature, which are separate aspects of welding conditions.