Effects of High Toughness and Welding Residual Stress for Unstable Fracture Prevention

Unstable fractures generally occur in brittle materials under low-temperature service conditions. Toughness and welding residual stress are the main factors that should be evaluated when defining a brittle crack propagation path. In this study, a rainbow welding technique was proposed and confirmed as being significantly useful in preventing unstable fractures in weld joints. The residual compressive stress in the crack front was particularly useful for decreasing the possibility of brittle fracture. The objective was to examine the effect of high welding consumable toughness welding residual stress, especially for avoiding brittle fracture through welding residual compressive stress.