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-0.4Y(2)O(3) (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 mu m) and nanometer grains was formed. Through aging treatment, epsilon-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. (C) 2011 Elsevier B.V. All rights reserved.