Cobalt-based alloy surfacing process optimization and surfacing material performance analysis

Abstract

In order to solve the problem of the failure of the UMCo50 process burner, the orthogonal test was used to optimize the UMCo50 cobalt-based alloy TIG surfacing process, better joint performance was obtained for welding current of 120 A, surfacing speed of 12 cm min−1, interpass temperature of 50 °C and surfacing layer of 2 ∼ 3 layers; Tungsten inert gas(TIG) welding and plasma transferred arc weld(PTAW) surfacing were used to surfacing UMCo50 welding wire and T800 cobalt-based alloy powder on UMCo50 base metal. The structure, hardness, high temperature wear resistance and heat corrosion resistance of the surfacing layer were compared. The results show that UMCo50 surfacing layers are α-Co (fcc) and ε-Co (hcp); T800 alloy surfacing layers are mainly Co3Mo2Si, CoMoSi, α-Co and ε-Co. The Laves phase in the T800 alloy surfacing layer significantly improves its hardness and high temperature wear resistance; Under the same test conditions, the heat and corrosion resistance of the UMCo50 surfacing layer is significantly better than that of the T800 surfacing layer.