Optimal Chemical Composition in Fe-Cr-Ni Alloys for Ultra Grain Refining by Reversion from Deformation Induced Martensite.

摘要: A thermomechanical treatment, which applies reversion from deformation induced martensite (α') to ultra grain refining of austenite (γ), was proposed for metastable austenitic stainless steels. To determine optimal steels the effect chamical composition on γ-α' transformation behavior during cold rolling and α'-γ by successive annealing investigated in Fe-Cr-Ni ternary alloys. An fine γ structure obtained when satisfied following three compositional conditions:(1) Metastable should be almost completely transformed α' at room temperature. The amount 90% can estimated Ni equivalent (Ni+0.35Cr). For with less than 16.0 mass%, over 90 vol% transforms temperature.(2) Most must revert again relatively low temperatures where growth is difficult occur. When Cr (Cr-1.2Ni) 4.0 most reverts through 873K-0.6ks annealing. Retained 10 vol%.(3) Ms temperature reversed below (Ni+0.65Cr) more 19.7 stable alloys satisfy these conditions, an might α'. example, grains 0.5μm were observed a 15.5%Cr-10%Ni steel subjected subsequent