High temperature oxidation resistant austenitic steel
AssigneesSumitomo Metal Industries, Ltd., Nippon Stainless Steel Co., Ltd.
InventorsTaishi Moroishi, Hisao Fujikawa, Junichiro Murayama, Yuji Shoji
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Abstract
The present invention relates to the austenitic steel having improved resistance to oxidation at the high temperature, comprising not more than 0.10% C, 0.1-5.0% Si, not more than 3% Mn, 7-45% Ni, 15-30% Cr and sulfur content being restricted to not more than 0.003%. According to the present invention, by limiting the sulfur content in the austenitic steel to not more than 0.003%, preferably to not more than 0.0015%, the heat-resisting steel material which can show improved resistance to oxidation under severe conditions including repeated heating to high temperatures and cooling to room temperature is provided.
Claims24
An austenitic steel, said austenitic steel having improved resistance to oxidation at temperatures above 700.degree. C. and consisting essentially of the following alloying elements:
- C:
- not greater than 0.10%
- Si:
- more than 1%, but not greater than 5.0%
- Mn:
- not greater than 3.0%
- Ni:
- 7-15%
- Cr:
- 15-20%,
- the amounts of said alloying elements being adjusted to result in an austenitic microstructure, and
- a balance of iron and impurities of which sulfur is restricted to not greater than 0.003%.
An austenitic steel, said austenitic steel having improved resistance to oxidation at temperatures above 700.degree. C. and consisting essentially of the following alloying elements:
- C:
- not greater than 0.10%
- Si:
- more than 1%, but not greater than 5.0%
- Mn:
- not greater than 3.0%
- Ni:
- 10-15%
- Cr:
- 15-25%,
- the amounts of said alloying elements being adjusted to result in an austenitic microstructure, and
- a balance of iron and impurities of which sulfur is restricted to not greater than 0.003%.
An austenitic steel, said austenitic steel having improved resistance to oxidation at temperatures above 700.degree. C. and consisting essentially of the following alloying elements:
- C:
- not greater than 0.10%
- Si:
- more than 1%, but not greater than 5.0%
- Mn:
- not greater than 3.0%
- Ni:
- 15-25%
- Cr:
- 20-30%,
- the amounts of said alloying elements being adjusted to result in an austenitic microstructure, and
- a balance of iron and impurities of which sulfur is restricted to not greater than 0.003%.
An austenitic steel, said austenitic steel having improved resistance to oxidation at temperatures above 700.degree. C. and consisting essentially of the following alloying elements:
- C:
- not greater than 0.10%
- Si:
- 0.1-1.0%
- Mn:
- not greater than 3.0%
- Ni:
- 30-35%
- Cr:
- 20-25%,
- the amounts of said alloying elements being adjusted to result in an austenitic microstructure, and
- a balance of iron and impurities of which sulfur is restricted to not greater than 0.003%.
An austenitic steel, said austenitic steel having improved resistance to oxidation at temperatures above 700.degree. C. and consisting essentially of the following alloying elements:
- C:
- not greater than 0.10%
- Si:
- 0.1-1.0%
- Mn:
- not greater than 3%
- Ni:
- 7-25%
- Cr:
- 15-30%
- the amount of said alloying elements being adjusted to result in an austenitic single phase microstructure;
- and
- a balance of iron and impurities of which sulfur is restricted to not greater than 0.003%.
An austenitic steel, said austenitic steel having improved resistance to oxidation at temperatures above 700.degree. C. and consisting essentially of the following alloying elements:
- C:
- not greater than 0.10%
- Si:
- more than 1%, but not greater than 5.0%
- Mn:
- not greater than 3%
- Ni:
- 7-25%
- Cr:
- 15-30%
- Al:
- less than 0.10% as a deoxidizing agent, one or more of Ca, Mg, Y and rare earths, the total amount thereof being not greater than 0.10%,
- the amount of said alloying elements being adjusted to result in an austenitic microstructure;
- and
- a balance of iron and impurities of which sulfur is restricted to not greater than 0.003%.
Dependencies are inferred from the claim text.