Development of Structural Integrity Evaluation Technique for Weldment by AC Magnetic Method
Details
An AC magnetic testing method with a small coaxial probe was proposed to evaluate the PWHT temperature of the low alloy steel welded joints and the creep damage of the simulated HAZ specimens nondestructively. A normalized 3rd harmonic intensity of the detected signals could be used to identify the PWHT temperature after applying PWHT. Test results of creep damage measurement showed that a hysteresis was sensitive both to the microstructure change by aging and to the damage by applied stress. In order to evaluate creep damage, stress-induced damage (SID) parameter was proposed to remove aging factor of materials from HL. Creep void were observed by scanning electron microscope (SEM) for all creep damage samples of SID value under 0.8.
