Microstructure and tensile properties of a 14Cr ODS ferritic steel

The excellent mechanical performance of oxide dispersion strengthened (ODS) steels is attributed to the highly dispersed and extremely stable oxide particles with diameters of a few nanometers. Studies were made to determine the microstructure and tensile properties of a 14Cr ODS ferritic steel with the nominal composition of Fe-14Cr-2W-0.3Ti-0.2V-0.07Ta-0.3Y2O3 produced by Hot Isostatic Pressing (HIP) in this work. Through the microstructure investigations, numerous nanoparticles with the average size of 5 nm was found to be located at the grain boundaries and inside the grains, and the average grain size was identified to be approximately 300 nm. The as-HIPed ODS steel proved to have excellent ductility at room temperature by tensile test, which is due to the bimodal structure with uniformly distributed nanoparticles and the addition of vanadium and tantalum.