Microstructure and mechanical property of 12Cr oxide dispersion strengthened ferritic steel for fusion application

A 12Cr–2W oxide dispersion strengthened (ODS) ferritic steel was fabricated by mechanical alloying and hot isostatic pressing (HIP). The pre-alloyed ferritic powders were mechanical alloyed with nano-Y2O3 powders and then consolidated by HIP at 1150 °C for 3 h under pressure of 200 MPa. The tensile strength of the fabricated ODS steel reached nearly 1400 MPa at room temperature, and maintained around 400 MPa at 700 °C. Nano-oxide particles with size ranging form several nm to 20 nm were observed by TEM. The oxide particles are stable after annealing at 1100 °C for 5 h, but the size is a little increased after annealing at 1300 °C. The oxidation resistance of the 12Cr–ODS steel is rather good, only an oxide layer with thickness of 1 μm was formed on the surface after oxidation at 700 °C for 100 h in air.