1984 Volume 70 Issue 2 Pages 232-237
To determine experimentally the solubility of a tungsten-rich bcc α2 phase in a nickel-rich fcc γ phase in a Ni-Cr-W-Mo quaternary system, four Ni-Cr-W-Mo alloys with 0.03wt pct carbon, whose compositions were in a γ+α2 phase field, were equilibrated at 1 000, 1 100, 1 200, and 1 300°C for 8 000, 4 500, 100, and 100h, respectively. Chemical compositions of the constituent phases were determined by means of electron microprobe analysis. Tie-lines between γ and α2 phases and γ/(γ+α2)/α2 phase boundaries were constructed in four isothermal sections of the Ni-Cr-W-Mo quaternary equilibrium phase diagram. The solubility of α2 in γ decreased with decreasing temperatures. Precipitation of carbides such as M6C and M12C at lower temperatures apparently lead to further decrease in the α2 solubility.