When we weld we generate enough heat in the welding arc to melt the filler metal and base material. Or just the base material is we are welding autogenously (as in GTAW without filler). The edges of the base material melt and combine with the filler metal to create what is called the composite zone. […]
Interpass temperature is the temperature of the base metal in and adjacent to the weld joint prior to depositing and additional pass (weld). Maintaining and measuring interpass temperature should be done carefully. Different materials require different levels of preheat and interpass temperature. For this reason it is extremely important that both prehat and interpass temperature be specified […]
