Abstract: In this paper, the effect of carbon migration on creep properties of Cr5Mo dissimilar welded joints with Ni-based (Inconel 182) and Cr23Ni13 (A302) austenitic weld metal was investigated. Carbon migration near the weld metal/ferritic steel interface of Cr5Mo dissimilar welded joints was analyzed by aging method. Local creep deformations of the dissimilar welded joints were measured by a long-term local creep deformation measuring technique. The creep rupture testing was performed for Cr5Mo dissimilar welded joints with Inconel 182 and A302 weld metal. The research results show that the maximum creep strain rate occurs in the decarburized zone located on heat affect zone (HAZ) of Cr5Mo ferritic steel. The creep rupture life of Cr5Mo dissimilar welded joints with A302 weld metal decreases due to carbon migration and is about 50％ of that welded with Inconel 182 weld metal.

Key words: dissimilar welded joint, carbon imgration, creep rupture