What does the term "interpass temperature" refer to in welding?

The term "interpass temperature" refers specifically to the temperature of the weld metal between successive welding passes. It is a critical aspect of the welding process, as maintaining the appropriate interpass temperature can significantly affect the mechanical properties and integrity of the weld.

During multi-pass welding, each layer of weld metal must cool and solidify before the next pass is applied. If this temperature is too low, it can lead to undesirable effects such as cracking or insufficient fusion between passes. Conversely, if it is too high, it can degrade the microstructure of the weld or cause issues such as distortion.

Maintaining the interpass temperature within specified limits helps ensure that the welding process achieves the desired strengths and properties needed for the materials being joined. By watching the interpass temperature carefully, welders can produce a more reliable and durable weld.