Fatigue Crack Inspection, Weld Repair and Post-Repair Fatigue Behavior of Stainless Steel Welded Components

摘要

Fatigue damage caused by cyclic loading can limit structural functions and durability and lead to collapse. Fatigue crack detection and timely repair are desirable for prevention of failure. In this study, eleven I-shaped AL-6XN superaustenitic stainless steel welded specimens with attachments on flanges were selected from previous fatigue tests. The welded attachment details were examined by a nondestructive eddy current procedure to establish information on fatigue crack size. Based on the crack information, weld repair procedures were developed and repairs were made using GTA remelt, grinding plus reweld, and major repair. Weld treatment such as air hammer peening (AHP) and ultrasonic impact (UIT) was also .applied to slightly cracked details to evaluate their effect on suppressing crack growth. Fatigue testing was carried out on the repaired specimens. This paper reports the fatigue crack measurements, weld repair procedures and fatigue test results.