Tension Test Acceptance Criteria for Welding Procedure Qualification per ASME IX;
To qualify the welding procedure according to the ASME Section IX, the mechanical properties of the test coupon must be tested. Tension Test, which is the test of the strength of the weld by The principle of ASME is that Weld Metal must be stronger than or equal to the strength of Base Metal. Therefore, the result of the Tension Test will have Acceptance Criteria as follows.
- The workpiece is torn/break at Base Metal:
- Ultimate Tensile Strength (UTS) or Failure Stress of the workpiece must be greater than 95% of Minimum Specified Tensile Strength (SMTS *) of Base Metal
Note: The Min Specified T.S follows the standard ASTM, Not Actual mentions in MTC.
- The workpiece is torn/break at the Weld Metal:
- Ultimate Tensile Strength or Failure Stress of Weld Metal must be equal to SMTS of Base Metal.
- In the case of Dissimilar Weld or Base Metal having unequal SMTS, Weld Metal ‘s Ultimate Tensile Strength or Failure Stress must be equal to SMTS of Base Metal with less strength ( lower SMTS ).
* SMTS of Base Material can be found in Table QW-422 in ASME Section IX.
Example of Tension Test Results Evaluation for Welding Procedure Qualification per ASME IX;
Example of evaluating the Tension Test for the Qualify Welding Procedure according to the ASME Section IX. The Tension Test results are recorded in the PQR.