Phase relations of the Fe-Cr-Er system in the temperature range 973-1273 K were experimentally investigated using equilibrated alloys. The isothermal sections consisted of 9 single-phase regions, 16 two-phase regions, and 8 three-phase regions at 973 K and 1073 K. At 1273 K, the σ phase disappeared, and liquid appeared. All single phases had a solid solubility range that showed a downward trend with a decrease in temperature. The homogeneity range of the ErFe12-xCrx ternary compound was determined to be x = 1.8-4.5. The more accurate phase relations obtained in this work can better guide the preparation of Fe-Cr-Er alloys in actual production.
Keywords: Fe–Cr–Er system; isothermal section; oxide dispersion-strengthened steel; phase equilibria; solid solubility.