Ultrasonic Inspection and Fatigue Evaluation of Critical Pore Size in Welds

摘要

Controlled amounts of weld porosity were introduced into double-vee butt weld joints of low-alloy, high strength structural steel using a gas metal arc weld method. The weld zones were inspected radiographically and ultrasonically to detect and classify porosity severity. Subsequent uniaxial fatigue tests indicated that mean fatigue life of 'water clear' weld was superior to the mean fatigue life of weldments of all pore sizes. Fracture toughness (KIC) as measured by Charpy impact under dynamic loading was noted to improve with weld specimens containing fine pores (0.024 inch diameter and under).