Microstructures and properties of P92 welding joint obtained by CMT+P welding

Welding method and characteristics of cold metal transfer + pulse welding (CMT+P) were introduced. P92 steel was butt joined by the CMT+P process, while microstructures and mechanical properties of welding joints were analyzed and compared to those of TIG+SMAW joints. The results showed that the microstructures in both of the welding joints were tempered martensite after welding and heat treatment. The martensite lath of the CMT+P joint was smaller. Heat affected zone of the CMT+P joint with the equiaxed grains was relatively narrower. High temperature creep performances of the CMT+P joints were relatively better. The tensile strength of the CMT+P joint was superior to that of parent metal, while the impact toughness of the CMT+P joint was corresponded with that of the TIG+SMAW joint. Therefore, the CMT+P welding process can be thought as a new choice to weld P92 steel.