Microstructures and mechanical properties of Fe–14Cr–3W–Ti–Y2O3 steel with 1 wt.% Cu addition fabricated by a new method

Effect of 1 wt.% copper addition on microstructures and mechanical properties of Fe–14Cr–3W–0.4Ti–0.4Y2O3 (wt.%) alloy has been investigated. Mechanically alloyed powders and pre-alloyed powders were blended and consolidated by hot extrusion. A bimodal grain structure with large grains (10–20 μm) and nanometer grains was formed. Through aging treatment, ε-Cu phase with face cubic centered lattice structure precipitated from the supersaturated solid solution. After aging for 6 h, the microhardness reached a peak value of HV326, which was attributed to precipitation of copper-rich phase. The alloy exhibited a high strength due to the strengthening of both copper-rich precipitates and Y–Ti–O nanoclusters, and an excellent ductility due to its bimodal structure.