Research progress in evolution of precipitated phases in Inconel 625 superalloy

Precipitation and evolution behavior of phases in Inconel 625 superalloy were reviewed, and the various types of phases in the alloy were emphatically introduced, including the γ' phase, γ″ phase, δ phase, Ni2(Cr,Mo) phase, three types of MC,M6C,M23C6 carbides and Laves phase. The precipitation and evolution behavior of phases in different forming processes, heat treatment and high temperature creep were elucidated. Further, the effects of different types of phases on the properties of the alloys were discussed. The main factors causing cracks during rapid forming and welding in Inconel 625 alloy were pointed out and it was proposed that an important development direction in the future is how to improve the thermal strength and thermal fatigue properties of the Inconel 625 alloy by selecting and controlling the phase precipitation.