A common oversight in production welding is the failure to monitor interpass temperature consistently, especially during multi-pass welds. Shops often rely on a single preheat reading and assume interpass stays within limits. However, heat buildup from consecutive passes can push temperatures above the specified maximum, particularly in thick sections or when using high deposition rates.
Key points to remember:
• Always measure interpass temperature at the start of each pass, not just preheat.
• Use contact thermocouples or infrared pyrometers calibrated for the material.
• Record interpass temperatures on the WPS or production log for traceability.
• If the maximum is exceeded, allow the weld to cool to the specified range before continuing.
Auditors and inspectors routinely check interpass temperature records. A gap in monitoring can lead to NCRs and costly rework.
How do you ensure interpass temperature compliance on your site?
Source: ISO 13916, 2017