Effect of the mu-phase on the properties of superhigh-temperature deformable nickel alloy KhN60KVYuMB

One of the requirements imposed on high-temperature nickel alloys for long-term operation under high temperatures and stresses is structural stability, which ensures constant properties during operation of parts. It is known that the main strengthening phase of nickel alloys is a gamma'-phase of the type (Ni, Cr)(3)(Al, N) or (Ni, Cr)(3)(Al, Ti, Nb), which may amount to 50% in deformable nickel alloys. In addition, these alloys contain a certain amount of carbides, borides, and carbonitrides (up to 3 wt. %). An increase in the content of alloying elements in high-temperature alloys may cause formation of undesirable TCP-phases in their structure. For example, at high contents of molybdenum and tungsten a thin lamellar mu-phase (Ni, Co, Fe)(7)(Mo, W)(6) is segregated. The authors investigated the effect of the mu-phase on the set of chemical properties of industrial alloy KhN60KVYuMB (pressed rods 105 mm in diameter).