Magnetic and Mechanical Properties of a Cold-Rolled Isotropic Fe–30Cr–20Co–2Mo Powder Alloy

Abstract—The magnetic characteristics and compressive mechanical properties of a hard magnetic isotropic Fe–30Cr–20Co–2Mo powder alloy subjected to cold rolling to a rolling reduction of 30–70% and subsequent multistage heat treatment, namely, annealing at 630°C and two-stage cooling, are studied. At all rolling reductions, the alloy is shown to have a single-phase structure, i.e., only an α-phase solid solution with a bcc structure is detected. The magnetic properties of the alloy decrease as the preliminary rolling reduction increases. The highest magnetic properties are observed at a rolling reduction of 30%; these are Br = 0.91 T, Hc = 46.2 kA/m, and (BH)max = 17.4 kJ/m3. After heat treatment, the yield stress $$\sigma _{{0.2}}^{{\text{c}}}$$ of the alloy increases by more than 1.7 times, namely, to 1650–1800 MPa, whereas the compressive strength $$\sigma _{{\text{u}}}^{{\text{c}}}$$ increases to ~2200 MPa. In this case, the alloy retains its plasticity at all rolling reductions, i.e., failure occurs at a strain εc = 14–16%.