Hot rolled plate or forging of an austenitic steel
AssigneeArcelorMittal
InventorsBernard Bonnefois, Amelie Fanica, Lionel Coudreuse, Tassa Oriana, Johannes Cornelis Van Wortel
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Abstract
A hot rolled plate or forging of an austenitic steel not susceptible to relaxation cracking is provided. The hot rolled plate or austenitic steel includes a composition having in percentages by weight: 0.019%≤C≤0.030%, 0.5%≤Mn≤2%, 0.1%≤Si≤0.75%, Al≤0.25%, 18%≤Cr≤25%, 14%≤Ni≤17%, 1.5%≤Mo≤3%, 0.001%≤B≤0.008%, 0.25%≤V≤0.35%, 0.23%≤N≤0.27%, the balance being iron and unavoidable impurities, Ni(eq.)≥1.11 Cr(eq.)−8.24, Cr(eq)=Cr+Mo+1.5Si+5V+3Al+0.02, Ni(eq)=Ni+30C+x(N−0.045)+0.87; x=30 for N≤0.2, x=22 for 0.2<N≤0.25, x=20 for 0.25<N≤0.35.
Claims22
A hot rolled plate or forging of an austenitic steel non-susceptible to relaxation cracking, with composition comprising, in percentages by weight:
- 0.019%≤C≤0.030%
- 0.5%≤Mn≤3%
- 0.1%≤Si≤0.75%
- Al≤0.25%
- 18%≤Cr≤25%
- 12%≤Ni≤20%
- 1.5%≤Mo≤3%
- 0.001%≤B≤0.008%
- 0.25%≤V≤0.35%
- 0.23%≤N≤0.27%,
- the balance being iron and unavoidable impurities, and wherein:
- Ni(eq.)≥1.11 Cr(eq.)−8.24, wherein:
- Cr(eq)=Cr+Mo+1.5Si+5V+3Al+0.02
- Ni(eq)=Ni+30C+x(N−0.045)+0.87 wherein:
- x=22 for 0.23%≤N≤0.25%
- x=20 for 0.25%<N≤0.27%;
- and
- a fully austenitic structure.
A hot rolled plate or forging of an austenitic steel non-susceptible to relaxation cracking, with composition comprising, in percentages by weight:
- 0.019%≤C≤0.030%
- 0.5%≤Mn≤3%
- 0.1%≤Si≤0.75%
- Al≤0.25%
- 18%≤Cr≤25%
- 14%≤Ni≤17%
- 1.5%≤Mo≤3%
- 0.001%≤B≤0.008%
- 0.25%≤V≤0.35%
- 0.23%≤N≤0.27%,
- the balance being iron and unavoidable impurities, and wherein:
- Ni(eq.)≥1.11Cr(eq.)−8.24, wherein:
- Cr(eq)=Cr+Mo+1.5Si+5V+3Al+0.02
- Ni(eq)=Ni+30C+x(N−0.045)+0.87 wherein:
- x=22 for 0.23%≤N≤0.25%
- x=20 for 0.25%<N≤0.27%.
A hot rolled plate or forging of an austenitic steel non-susceptible to relaxation cracking, with composition comprising, in percentages by weight:
- 0.019%≤C≤0.030%
- 0.5%≤Mn≤3%
- 0.1%≤Si≤0.75%
- Al≤0.25%
- 18%≤Cr≤25%
- 14%≤Ni≤17%
- 1.5%≤Mo≤3%
- 0.001%≤B≤0.008%
- 0.25%≤V≤0.35%
- 0.23%≤N≤0.27%,
- the balance being iron and unavoidable impurities, and wherein:
- Ni(eq.)≥1.11 Cr(eq.)−8.24, wherein:
- Cr(eq)=Cr+Mo+1.5Si+5V+3Al+0.02
- Ni(eq)=Ni+30C+x(N−0.045)+0.87 wherein:
- x=22 for 0.23%≤N≤0.25%
- x=20 for 0.25%<N≤0.27%;
- and
- the hot rolled plate or forging being non-susceptible to stress relaxation cracking at temperatures from 550 to 750° C.
Dependencies are inferred from the claim text.