During a typical PQR, the welding engineer or QC representative witnesses the entire process. Key checks include:
? Confirm the base material and filler metal meet the PQR specification.
? Verify that preheat and interpass temperatures are within the WPS range.
? Ensure welding parameters such as current, voltage, and travel speed are recorded accurately.
After welding, the test coupon is prepared for mechanical testing. Tension tests and guided bend tests are the most common. The results must meet the minimum tensile strength and bend requirements in Section IX, Table QW-451.1. If a test fails, the cause must be investigated before requalification.
Witnessing these tests ensures the procedure is capable of producing sound welds under controlled conditions. It also provides confidence that the procedure will perform consistently in production.
How do you document the witnessing of mechanical tests on your projects?