Enhanced strength and high temperature resistance of 25Cr20Ni ODS austenitic alloy through thermo-mechanical treatment and addition of Mo

A Mo alloyed Oxide Dispersion Strengthened (ODS) austenitic alloy with a design composition of Fe-25Cr-20Ni-2Mo-0.35Y(2)O(3)-0.5Ti was fabricated by the process of mechanical alloying and the hot isostatic press. The ODS alloy shows very fine grains with an average size of 300 nm and homogeneously dispersed ultrafine Y2Ti2O7 particles with sizes between several nm to tens nm. The effects of plastic deformation combined with annealing on the tensile property were investigated. The treatments of forging, rolling and annealing can balance the strength and plasticity of the alloy effectively. The microstructure and the mechanical property of the Mo alloyed ODS austenitic alloy were compared with a similar ODS austenitic steel without Mo. The addition of Mo shows almost no influence on the microstructure, while can improve the tensile strength obviously, especially at the high temperature of 700 degrees C.