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US 6,358,336 B1Granted
Heat resistance Cr-Mo alloy steel
AssigneeSumitomo Metal Industries, Ltd.
InventorKaori Miyata
Life of this patent
Estimating the term…
Abstract
A heat-resistant steel contains 0.1-3 mass % of Cr and satisfies the following equation: 0.1≦Nb+Mo+V and MX-type complex precipitates formed inside microcrystalline grains contain 30 mass % or more of Mo and 7 mass % or more of Nb. Also provided is a process for producing the alloy steel product involving casting, forging, hot rolling, normalizing, optionally direct quenching, cooling at a predetermined cooling rate, and tempering.
Claims13
A Cr—Mo alloy steel consisting essentially of, on a mass % basis,
- C:
- 0.01-0.25%, Si:
- 0.01-0.7% Mn:
- 0.01-1%, P:
- 0.03% or less, S:
- 0.015% or less, Cr:
- 0.1-3%, Nb:
- 0.005-0.2%, Mo:
- 0.01-2.5%, Ca:
- 0.0001-0.01%, N:
- 0.0005-0.01%, B:
- 0.0001-0.01%, with the balance being Fe and impurities, and which satisfies the following expression:
- 0.1 < Nb + Mo
- wherein each element symbol denotes content thereof (mass %), wherein MX complex precipitates are formed inside microcrystalline grains of the steel, the M in the MX complex precipitates representing the above metallic elements, the X in the MX complex precipitates representing C and N, and the total amount of Mo in the MX complex precipitates is 30 mass % or more, and the total amount of Nb in the MX complex precipitates is 7 mass % or more.
11 more elements
A Cr—Mo alloy steel consisting essentially of, on a mass % basis,
- C:
- 0.07-0.11%, Si:
- 0.1-0.3% Mn:
- 0.2-1%, P:
- 0.03 or less S:
- 0.015 or less Cr:
- 1-1.5% (1.5% not included), Nb:
- 0.02-0.08%, Mo:
- 0.2-0.6%, Ca:
- 0.0001-0.005%, N:
- 0.002-0.01%, B:
- 0.001-0.003%,
- with the balance being Fe and impurities, and
- which satisfies the following expression:
- 0.1<Nb+Mo
- wherein each element symbol denotes content thereof (mass %),
- wherein MX complex precipitates are formed inside microcrystalline grains of the steel, the M in the MX complex precipitates representing the above metallic elements, the X in the MX complex precipitates representing C and N, and the total amount of Mo in the MX complex precipitates is 30 mass % or more, and the total amount of Nb in the MX complex precipitates is 7 mass % or more.
14 more elements
A Cr—Mo alloy steel consisting essentially of, on a mass % basis,
- C:
- 0.07-0.11%, Si:
- 0.1-0.3% Mn:
- 0.2-1%, P:
- 0.03 or less S:
- 0.015 or less Cr:
- 1-1.5% (1.5% not included), Nb:
- 0.02-0.08%, Mo:
- 0.2-0.6%, Ca:
- 0.0001-0.005%, N:
- 0.002-0.01%, B:
- 0.001-0.003%, V:
- 0.05-0.15%, Ti:
- 0.002-0.02%,
- with the balance Fe and impurities, and
- which satisfies the following expression:
- 0.1<Nb+Mo+V
- wherein each element symbol denotes content thereof (mass %),
- wherein MX complex precipitates are formed inside microcrystalline grains of the steel, the M in the MX complex precipitates representing the above metallic elements, the X in the MX complex precipitates representing C and N, and the total amount of Mo in the MX complex precipitates is 30 mass % or more, and the total amount of Nb in the MX complex precipitates is 7 mass % or more.
16 more elements
A Cr—Mo alloy steel, consisting essentially of, on a mass % basis,
- C:
- 0.07-0.11%, Si:
- 0.1-0.3% Mn:
- 0.2-1%, P:
- 0.03 or less S:
- 0.015 or less Cr:
- 1-1.5% (1.5% not included), Nb:
- 0.02-0.08%, Mo:
- 0.2-0.6%, Ca:
- 0.0001-0.005%, N:
- 0.002-0.01%, B:
- 0.001-0.003%, V:
- 0.05-0.15%,
- either one or both of 0.05 to 0.3% Ni and 0.05 to 0.3% Cu,
- with the balance Fe and impurities, and
- which satisfies the following expression:
- 0.1<Nb+Mo+V
- wherein each element symbol denotes content thereof (mass %),
- wherein MX complex precipitates are formed inside microcrystalline grains of the steel, the M in the MX complex precipitates representing the above metallic elements, the X in the MX complex precipitates representing C and N, and the total amount of Mo in the MX complex precipitates is 30 mass % or more, and the total amount of Nb in the MX complex precipitates is 7 mass % or more.
16 more elements
A Cr—Mo alloy steel which comprises, on a mass % basis,
- C:
- 0.07-0.11%, Si:
- 0.1-0.3% Mn:
- 0.2-1%, P:
- 0.03 or less S:
- 0.015 or less Cr:
- 1-1.5% (1.5% not included), Nb:
- 0.02-0.08%, Mo:
- 0.2-0.6%, Ca:
- 0.0001-0.005%, N:
- 0.002-0.01%, B:
- 0.001-0.003%, V:
- 0.05-0.15%, Ti:
- 0.002-0.02%,
- either one or both of 0.05 to 0.3% Ni and 0.05 to 0.3% Cu,
- with the balance Fe and impurities, and
- which satisfies the following expression:
- 0.1<Nb+Mo+V
- wherein each element symbol denotes content thereof (mass %),
- wherein MX complex precipitates are formed inside microcrystalline grains of the steel, the M in the MX complex precipitates representing the above metallic elements, the X in the MX complex precipitates representing C and N, and the total amount of Mo in the MX complex precipitates is 30 mass % or more, and the total amount of Nb in the MX complex precipitates is 7 mass % or more.
17 more elements
Dependencies are inferred from the claim text.