To determine the cause of the failure of the fusion line of boiler heat transfer tube dissimilar metal welds (DMW), which is a common problem worldwide because the failure mechanism has not been elucidated, Mitsubishi Heavy Industries Group (MHI Group) carried out research on the extraction of factors that influence failure and the proposal of a failure mechanism using metallurgical investigation and creep analysis by FEM (Finite Element Method). In addition, based on the proposed failure mechanism, we developed maintenance techniques against the failure of the fusion line of heat transfer tube low alloy steel DMW.
