Corrosion resistant, high strength alloy and a method for manufacturing the same
AssigneeHitachi, Ltd.
InventorsRyo Ishibashi, Yasuhisa Aono
Life of this patent
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Abstract
A corrosion resistant, high strength austenitic stainless steel consisting of 1.0% or less of Si, 2.0% or less of Mn, 0.5% or less of O, 7 to 30% of Ni, 14 to 26% of Cr, 0.3% or less of combination of C and N, at least one element selected from the group consisting of 1.0% or less of Ti, 2.0% or less of Zr and 2.0% or less of Nb, and the balance consisting of Fe and unavoidable impurities, the percentage being given in weight basis; said steel containing carbonitride with a grain size of several to 100 nm dispersed therein; said steel having an average crystal grain size of 1 μm or less; and said steel containing 90% by volume or more of austenite phase; is excellent in strength and corrosion resistance.
Claims12
A corrosion resistant, high strength austenitic stainless steel consisting of 1.0% or less of Si, 2.0% or less of Mn, 0.5% or less of O, 7 to 30% of Ni, 14 to 26% of Cr, 0.3% or less of combination of C and N, at least one element selected from the group consisting of 1.0% or less of Ti, 2.0% or less of Zr and 2.0% or less of Nb, and the balance consisting of Fe and unavoidable impurities, the percentage being given in weight basis;
- said steel containing carbonitride with a grain size of several to 100 nm dispersed therein;
- said steel having an average crystal grain size of 1 μm or less;
- and said steel containing 90% by volume or more of austenite phase.
A corrosion resistant, high strength austenitic stainless steel consisting of 1.0% or less of Si, 2.0% or less of Mn, 0.5% or less of O, 7 to 30% of Ni, 14 to 26% of Cr, 3% or less of Mo, 0.3% or less of combination of C and N, at least one element selected from the group consisting of 1.0% or less of Ti, 2.0% or less of Zr and 2.0% or less of Nb, and the balance consisting of Fe and unavoidable impurities, the percentage being given in weight basis;
- said steel containing carbonitride with a grain size of several to 100 nm dispersed therein;
- said steel having an average crystal grain size of 1 μm or less;
- and said steel containing 90% by volume or more of austenite phase.
A method for manufacturing a corrosion resistant, high strength austenitic stainless steel, which comprises the steps of:
- providing a mechanically milled powder with an average crystal grain size of 200 nm or less consisting of 1.0% or less of Si, 2.0% or less of Mn, 0.5% or less of 0, 7 to 30% of Ni, 14 to 26% of Cr, 0.3% or less of combination of C and N, at least one element selected from the group consisting of 1.0% or less of Ti, 2.0% or less of Zr and 2.0% or less of Nb, and the balance consisting of Fe and unavoidable impurities, the percentage being given in weight basis;
- and subjecting said mechanically processed powder to a process selected from the group consisting of:
- (a) consolidating the mechanically milled powder at 700 to 900° C., and
- (b) consolidating the mechanically milled powder at 700 to 900° C. to obtain a consolidated material and thermomechanically treating the consolidated material.
A method for manufacturing a corrosion resistant, high strength austenitic stainless steel, which comprises the steps of:
- providing a mechanically milled powder with an average crystal grain size of 200 nm or less consisting of 1.0% or less of Si, 2.0% or less of Mn, 0.5% or less of O, 7 to 30% of Ni, 14 to 26% of Cr, 3% or less of Mo, 0.3% or less of combination of C and N, at least one element selected from the group consisting of 1.0% or less of Ti, 2.0% or less of Zr and 2.0% or less of Nb, and the balance consisting of Fe and unavoidable impurities, the percentage being given in weight basis;
- and subjecting said mechanically milled powder to a process selected from the group consisting of:
- (a) consolidating the mechanically milled powder at 700 to 900° C., and
- (b) consolidating the mechanically milled powder at 700 to 900° C. to obtain a consolidated material and thermomechanically treating the consolidated material.
Dependencies are inferred from the claim text.