Numerical simulation of the effect of low-temperature transformation expansion on residual stress in cold cracking test specimens of different restraint factors

Abstract

Ni-Cr based high-strength weld metals have been developed to reduce preheating processes. In the development process of a welding wire, the evaluation of cold cracking resistance is important. In this study, the effect of low-temperature transformation expansion on the residual stress reduction of welds with different restraint factors in cold cracking test specimens was examined by numerical simulation. The results indicated that the weld metal with low-temperature transformation expansion exhibits the effect of residual stress reduction at a high restraint factor. The reduction decreased for a low restraint factor. Even if the restraint factor changes, the distribution of the restraint factor in the Y-groove weld cracking test is different from that in the H-type restrained weld cracking test. Distributions of residual stresses at the weld root in cold cracking in the Y-groove test and the H-type test have different tendencies. Thus, the difference should be considered when conducting the cold cracking test.