Fracture Toughness and Fatigue Crack Initiation Tests of Welded Precipitation-Hardening Stainless Steel

摘要

An analysis of a welded stainless steel box beam that experienced a structuralfailure during fatigue testing is described. Cracks initiated at notches caused by partial penetration welds and grew to a length of several centimeters in about 100 load cycles. The objective of this report is to describe the characterization of fracture toughness and fatigue crack initiation for the precipitation-hardening stainless steels used for the welds and parent plate of the beam. Three-point bend specimens were used to measure both fatigue crack initiation life and the J-integral fracture toughness of the parent plate and weld-metal in various conditions. The notch fatigue analysis method of Barsom and Rolfe was used to analyze the crack initiation test results. The crack was lengthened, side notches were added, and JIc tests were performed using ASTM Method E-813 with a modified load-line displacement unloading-compliance procedure to measure crack growth. (rrh)