Microstructure and Tensile Property Analysis of 22Cr-3Al Oxide Dispersion Strengthened Steel Obtained Through the STARS Route

Oxide dispersion strengthened (ODS) ferritic steels are the candidate structural materials for the advanced nuclear reactors due to their excellent swelling resistance and creep strength. Herein, a 22Cr-3Al ODS steel was prepared through the surface treatment of gas atomized powder, followed by reactive synthesis route and hot isostatic pressing without the mechanical alloying step. As a result, the metastable Fe and Cr oxides formed on the powder surface and promoted the precipitation of Y-Al-O particles at the grain boundaries of the as-hot isostatic pressed steel. In addition, the dispersed oxides with an average size of 97 nm at grain boundaries ensured that the average ultimate tensile strength of the 22Cr-3Al ODS steel is 797 MPa at room temperature.