Dispersion strengthened austenitic stainless steel article, method for manufacturing same and product made of same

A method for manufacturing a dispersion strengthened austenitic stainless steel article, wherein the stainless steel article has a chemical composition comprising:

• 16 mass % or more and 26 mass % or less of Cr;
• 8 mass % or more and 22 mass % or less of Ni;
• 0.005 mass % or more and 0.08 mass % or less of C;
• 0.002 mass % or more and 0.1 mass % or less of N;
• 0.02 mass % or more and 0.4 mass % or less of O;
• at least one of 0.2 mass % or more and 2.8 mass % or less of Zr, 0.4 mass % or more and 5 mass % or less of Ta, and 0.2 mass % or more and 2.6 mass % or less of Ti;
• and a balance being Fe and inevitable impurities,
• wherein the Zr component, the Ta component, and the Ti component form inclusion particles in combination with the C component, the N component, and the O component, and
• wherein the stainless steel article has an average grain size of 1 μm or less and a maximum grain size of 5 μm or less, the method comprising:
• an alloy powder synthesizing step of synthesizing an alloy powder having the chemical composition by mechanical alloying or mechanical milling;
• a powder grading step of grading the alloy powder to a grain size of 0.3 mm or more and 3 mm or less to prepare a graded powder;
• and
• a heating solidification molding step of solidification molding the graded powder at a temperature of 750° C. or more and 1100° C. or less to manufacture a solidification molded body.