Microstructure and Tensile Properties of 9Cr Oxide Dispersion Strengthened Steel Prepared at Different Ball Milling Time Intervals

Fe-9Cr-1.5W-0.3Ti-0.3Y alloy powder was prepared by atomization method and then was subjected to ball milling for different time intervals. 9Cr oxide dispersion strengthened (ODS) steel was prepared by hot isostatic pressing with the alloy powder as raw materials. The microstructure and tensile properties of the 9Cr-ODS steel were studied. The results show that the atomized alloy powder was a regular spherical α-Fe alloy powder with average particle size of 47.83 μm and grain size of about 20 μm. After ball milling for 20 h, the average particle size and grain size of the alloy powder decreased significantly to 30.50 μm and 12 nm, respectively. With the extension of milling time, the grain size of 9Cr-ODS steel decreased and the content of precipitated phase increased. Prolonging ball milling time was beneficial to improve the room temperature and high temperature tensile strength of the 9Cr-ODS steel, but not conducive to improving the high temperature toughness.