What does interpass temperature refer to in welding?

• A. The maximum heat input per inch
• B. The temperature required for bending tests
• C. The temperature that must be maintained between welding passes
• D. The ambient temperature in the shop

Answer: (C)

Interpass temperature is the temperature of the weld joint that must be maintained between welding passes. Controlling this temperature matters because it governs the cooling rate and the resulting metallurgical properties of the weld and heat-affected zone, helping to prevent cracking and excessive hardness as you add subsequent passes. This makes the temperature that must be kept between welding passes the best description. It isn’t about heat input per inch, nor a temperature for bending tests, nor the ambient shop temperature.