The effects of Si content in ERNiMo-2 deposited metals on deformation and fracture behavior during creep process

The microalloying of suitable elements could play a multiplier role in regulating properties of alloys. In this paper, the ERNiMo-2 deposited metals with different Si content were prepared. The influence of Si element on carbide evolution in as-weld and after creep state ERNiMo-2 deposited metals was investigated. The investigation in this paper showed that the Si addition could obviously influence the carbides, which could be categorized into eutectic carbides, nano-carbides, and grain boundary carbides, in as-weld state deposited metals and its evolution during creep, and therefore affects the creep elongation of the deposited metals. The nano-carbides distributed as islands reduced the minimum creep rate and caused the local strain concentration near the grain boundary which led to the crack of the 0 Si sample at low deformation. Due to the uniform distribution of strain and the continuous distribution of grain boundary carbides, the Si-containing samples have higher creep elongation. This research is of great value for adjusting the composition of ERNiMo-2 welding wire and improving the design of the creep performance of welded parts.