Which statement about interpass temperature is true?

• A. It defines the maximum shielding gas flow.
• B. It sets the minimum allowable temperature of the weld area.
• C. It defines the maximum permissible temperature of the weld area between passes.
• D. It indicates the ambient temperature of the work area.

Answer: (C)

Interpass temperature is the temperature the weld area is allowed to reach between successive passes. Controlling this temperature helps maintain proper metallurgy and minimize issues like hydrogen-induced cracking on susceptible steels. The correct statement is that it defines the maximum permissible temperature between passes, because the weld area must not exceed a specified ceiling between passes to ensure continued proper fusion and weld integrity. It isn’t about shielding gas flow, ambient work-area temperature, or a minimum allowable temperature.