In-situ cracking for nondestructive inspection process validation
ork at the Idaho National Engineering and Environmental Laboratory (INEEL) includes efforts to weld steel storage containers. Producing repeatable high quality welds and assuring weld quality is paramount to this work. The nondestructive examination (NDE) method used to measure weld quality is the magnetic particle testing (MT) process since the containers are fabricated from mild steel.
A paradox occurred during the initial mockup welding and inspection system demonstrations. Since the welding was flawless, the semi-automatic remote MT system had no defects to find. The MT system was calibrated, as per the welding code, with calibration blocks, but it never demonstrated that it worked during the demonstration because of the flawless welds. To validate the MT system during the mockup welding demonstration, in-situ defects were artificially generated. Two-in. (5.1-cm) long copper wire segments were placed into the weld groove joint and consumed into the weld metal during welding. This in-situ crack generation technique provided physical defects for the inspector/regulator to observe, which then validated the inspection system.
KeywordsWelding Weld Metal Weld Quality Inspection System Practical Failure Analysis Volume
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