Effects of processing condition on the microstructural and tensile properties of 14Cr-based oxide dispersion strengthened alloys

Eight different oxide dispersion strengthened (ODS) steels were manufactured to investigate the influence of several processing parameters including milling temperature, rotation speed, and consolidation temperature. Microstructural evolution and resulting mechanical properties were then characterized for the different manufacturing processes. As milling temperature decreases, microstructures become finer and room temperature tensile strength increases. Lowering the consolidation temperature induces an increase in tensile strength with a decrease of ductility. The microstructure becomes homogeneous as the tensile strength increases when the milling speed increases from 100 rpm to 250 rpm. However, the improvement seems to be less effective than the adoption of a cryomilling technique. Porosity development was considerably dependent not only on consolidation condition but also on powder quality after mechanical alloying.