Abstract: Provided is a martensitic stainless-steel sheet having a reduced anisotropy in workability and fatigue resistance which are attributable to oxide based inclusions. A martensitic stainless-steel sheet which has a steel composition that contains, in terms of mass %, 0.030 to 0.300% C, 0.20 to 2.50% Si, 0.15 to 4.00% Mn, 0.01 to 1.00% Ni, 11.00 to 15.00% Cr, 0.001 to 0.100% N, 0.0001 to 0.0350% Al, 0 to 0.50% V, 0 to 0.50% Nb, 0 to 0.50% Ti, 0 to 0.020% B, and a balance of Fe and unavoidable impurities, and that has a value of ?max, determined by the following equation (1), of 80.0 or greater, and in which oxide based inclusions are observed in the metallographic structure, the oxide based inclusions having a converted composition comprising up to 30 mass % or less Al2O3, 20 to 60 mass % SiO2, and 15 to 70 mass % MnO.

Abstract: In an austenitic stainless steel sheet, the arithmetic average roughness Ra is 0.2 ?m or more and 1.2 ?m or less. In addition, the dull pattern transfer rate on the steel sheet surface is 15% or more and 70% or less. Furthermore, micropits with a depth of 0.5 ?m or more and an open area of 10 ?m2 or more which are formed on the steel sheet surface have an existing density of 10.0 or less per 0.01 mm2 and an open area ratio of 1.0% or less. In addition, a film formed on the steel sheet surface is constituted from an oxide containing SiO2 as a main constituent, which oxide contains at least Si, N, Al, Mn, Cr, Fe, Nb, Ti and O as film-forming elements other than C, wherein the Si content is 10 at % or more, and the N content is 10 at % or less.

Abstract: A hot rolled austenitic stainless steel sheet contains 0.030 to 0.300% of C, from 0.30 to 3.20% of Si, from 0.90 to 17.00% of Mn, from 1.00 to 8.00% of Ni, from 14.00 to 19.00% of Cr, from 0.50 to 3.50% of Cu, from 0.045 to 0.250% of N, from 0.0001 to 0.0300% of Al, from 0 to 0.50% of V, from 0 to 0.50% of Nb, from 0 to 0.30% of Ti, and from 0 to 0.010% of B, all in terms of percentage by mass, with the balance of Fe and unavoidable impurities, has a converted average composition of an oxide based inclusion that contains 30% by mass or less of Al2O3, 60% by mass or less of SiO2, and 15% by mass or more of MnO, and satisfies MnO3—3SiO2+110. Anisotropy of workability and fatigue resistance characteristics caused by an oxide based inclusion is decreased.

Abstract: In a ferritic stainless steel sheet, the arithmetic average roughness Ra is 0.2 ?m or more and 1.2 ?m or less. In addition, the dull pattern transfer rate on the steel sheet surface is 15% or more and 70% or less. Furthermore, micropits with a depth of 0.5 ?m or more and an open area of 10 ?m2 or more which are formed on the steel sheet surface have an existing density of 10.0 or less per 0.01 mm2 and an open area ratio of 1.0% or less. In addition, a film formed on the steel sheet surface is constituted from an oxide containing SiO2 as a main constituent, which oxide contains at least Si, N, Al, Mn, Cr, Fe, Nb, Ti and O as film-forming elements other than C, wherein the Si content is 10 at % or more, and the N content is 10 at % or less.

Abstract: A method of manufacturing an austenitic stainless steel, being dissolved and refined, by providing Si from 0.2 to 2.0% by mass, Mn from 0.3 to 5.0% by mass, S at 0.007% by mass or less, Ni from 7.0 to 15.0% by mass, Cr from 15.0 to 20.0% by mass, Al at 0.005% by mass or less, Ca at 0.002% by mass or less, Mg at 0.001% by mass or less, and 0 from 0.002 to 0.0065% by mass and setting a ratio, during refining, of CaO/SiO2 in a slag between 1.0 and 2.5. The remainder comprises Fe and unavoidable impurities, and a mass ratio indicated by (Mn+Si)/Al among Mn, Si, and Al is 200 or more. An oxide-based nonmetallic inclusion comprises MnO—SiO2—Al2O3—CaO, where Al2O3 is 30% by mass or less, Cr2O3 is 5% by mass or less, and MgO is 10% by mass or less, and a sulfide-based nonmetallic inclusion is CaS whose maximum area is 100 ?m2 or less.

Abstract: A hot rolled austenitic stainless steel sheet contains 0.030 to 0.300% of C, from 0.30 to 3.20% of Si, from 0.90 to 17.00% of Mn, from 1.00 to 8.00% of Ni, from 14.00 to 19.00% of Cr, from 0.50 to 3.50% of Cu, from 0.045 to 0.250% of N, from 0.0001 to 0.0300% of Al, from 0 to 0.50% of V, from 0 to 0.50% of Nb, from 0 to 0.30% of Ti, and from 0 to 0.010% of B, all in terms of percentage by mass, with the balance of Fe and unavoidable impurities, has a converted average composition of an oxide based inclusion that contains 30% by mass or less of Al2O3, 60% by mass or less of SiO2, and 15% by mass or more of MnO, and satisfies MnO3-3SiO2+110. Anisotropy of workability and fatigue resistance characteristics caused by an oxide based inclusion is decreased.

Abstract: Provided is a martensitic stainless-steel sheet having a reduced anisotropy in workability and fatigue resistance which are attributable to oxide based inclusions. A martensitic stainless-steel sheet which has a steel composition that contains, in terms of mass %, 0.030 to 0.300% C, 0.20 to 2.50% Si, 0.15 to 4.00% Mn, 0.01 to 1.00% Ni, 11.00 to 15.00% Cr, 0.001 to 0.100% N, 0.0001 to 0.0350% Al, 0 to 0.50% V, 0 to 0.50% Nb, 0 to 0.50% Ti, 0 to 0.020% B, and a balance of Fe and unavoidable impurities, and that has a value of ?max, determined by the following equation (1), of 80.0 or greater, and in which oxide based inclusions are observed in the metallographic structure, the oxide based inclusions having a converted composition comprising up to 30 mass % or less Al2O3, 20 to 60 mass % SiO2, and 15 to 70 mass % MnO.

Abstract: A stainless steel plate is manufactured by performing temper rolling using a dull roller after the finish cold rolling and bright annealing. The stainless steel plate has an arithmetic mean roughness Ra of 0.2 to 1.2 ?m in a direction perpendicular to the rolling direction of the steel plate surface. Furthermore, the stainless steel plate has a transfer ratio of 15 to 70% which is an area ratio of a portion onto which a dull pattern is transferred relative to the steel plate surface. In addition, the micro-pits being formed in the steel plate surface, having a depth of 0.5 ?m or more, and having an opening area of 10 ?m2 or more, have an existing density in the steel plate surface of 10.0 or less per 0.01 mm2, and an opening area ratio in the steel plate surface of 1.0% or less.

Abstract: Provided is an austenitic stainless steel having excellent surface glossiness. The austenitic stainless steel contains, on the basis of percent by mass, Si from 0.2 to 2.0%, Mn from 0.3 to 5.0%, S at 0.007% or less, Ni from 7.0 to 15.0%, Cr from 15.0 to 20.0%, Al at 0.005% or less, Ca at 0.002% or less, Mg at 0.001% or less, and O from 0.002 to 0.01%, wherein the remainder comprises Fe and unavoidable impurities. The value of (Mn+Si)/Al among Mn, Si, and Al is 200 or more. The oxide-based nonmetallic inclusion consists mainly of MnO—SiO2—Al2O3—CaO, where Al2O3 is 30% by mass or less, Cr2O3 is 5% by mass or less, and MgO is 10% by mass or less. Ina sulfide-based nonmetallic inclusion, the maximum area of one sulfide is 100 ?m2 or less.

Abstract: A stainless steel plate is manufactured by performing temper rolling using a dull roller after the finish cold rolling and bright annealing. The stainless steel plate has an arithmetic mean roughness Ra of 0.2 to 1.2 ?m in a direction perpendicular to the rolling direction of the steel plate surface. Furthermore, the stainless steel plate has a transfer ratio of 15 to 70% which is an area ratio of a portion onto which a dull pattern is transferred relative to the steel plate surface. In addition, the micro-pits being formed in the steel plate surface, having a depth of 0.5 ?m or more, and having an opening area of 10 ?m2 or more, have an existing density in the steel plate surface of 10.0 or less per 0.01 mm2, and an opening area ratio in the steel plate surface of 1.0% or less.

Abstract: High-rigidity stainless steel sheet is provided for CPU socket frames or retention covers that are lower in cost and have a better fastening performance compared to conventional ones. The stainless steel sheet has a Young's modulus ET in the T direction that is 210 GPa or above, an 0.2% yield strength ?0.2L in the L direction that is from 500 to 900 MPa, and an 0.2% yield strength ?0.02T in the T direction that is from 600 to 900 MPa, with the L direction being steel sheet rolling direction and the T direction being a direction perpendicular to the rolling direction (that is, a direction perpendicular to both the rolling direction and the sheet thickness direction). In the stainless steel sheet, the relationship between the Young's modulus EL (GPa) in the L direction and the Young's modulus ET (GPa) in the T direction is preferably EL?ET?15.

Abstract: A new austenitic stainless steel containing approximately 0.1-1.0 mass % of Si and not more than approximately 0.003 mass % of Al. Nonmetallic inclusions dispersed in a steel matrix are converted to MnO—SiO2—Al2O3 containing not less than approximately 15 mass % of SiO2 and not more than approximately 40 mass % of Al2O3. During steel making, molten steel is covered with basic slag and heavily deoxidized with a Si alloy whose Al content is controlled to not more than approximately 1.0 mass % in a vacuum or non-oxidizing atmosphere. The austenitic stainless steel sheet can be formed to an objective shape without the occurrence of cracking due to its decrease in susceptibility to cracking and its good formability.

Abstract: High-rigidity stainless steel sheet is provided for CPU socket frames or retention covers that are lower in cost and have a better fastening performance compared to conventional ones. The stainless steel sheet has a Young's modulus ET in the T direction that is 210 GPa or above, an 0.2% yield strength ?0.2L in the L direction that is from 500 to 900 MPa, and an 0.2% yield strength ?0.2T in the T direction that is from 600 to 900 MPa, with the L direction being steel sheet rolling direction and the T direction being a direction perpendicular to the rolling direction (that is, a direction perpendicular to both the rolling direction and the sheet thickness direction). In the stainless steel sheet, the relationship between the Young's modulus EL (GPa) in the L direction and the Young's modulus ET (GPa) in the T direction is preferably EL?ET?15.

Abstract: A stainless steel sheet has a chemical composition consisting of 0.15 mass % or less of C, 1.0 mass % or less of Si, 1.0 mass % or less of Mn, 0.005 mass % or less of S, 10-20 mass % of Cr, 0.5 mass % or less of Ni, 0.001-0.05 mass % of Al, optionally one or more of 0.5-2.0 mass % of Mo, 0.5-3.0 mass % of Cu and 0.05-1.0 mass % of Nb, and the balance being Fe except inevitable impurities. It is strengthened by a work-hardened ferritic structure, wherein Al2O3 and/or Al2O3.MgO inclusions of 10 ?m or less in size are distributed with cleanliness of 0.06% or less. It is useful as lightweight material for parts and structural members of home electric appliances, office automation devices and so on, due to excellent bendability in addition to high yield strength of 700 N/mm2 or more.

Abstract: A new austenitic stainless steel containing approximately 0.1-1.0 mass % of Si and not more than approximately 0.003 mass % of Al. Nonmetallic inclusions dispersed in a steel matrix are converted to MnO—SiO2—Al2O3 containing not less than approximately 15 mass % of SiO2 and not more than approximately 40 mass % of Al2O3. During steel making, molten steel is covered with basic slag and heavily deoxidized with a Si alloy whose Al content is controlled to not more than approximately 1.0 mass % in a vacuum or non-oxidizing atmosphere. The austenitic stainless steel sheet can be formed to an objective shape without the occurrence of cracking due to its decrease in susceptibility to cracking and its good formability.

Abstract: A new austenitic stainless steel containing approximately 0.1-1.0 mass % of Si and not more than approximately 0.003 mass % of Al. Nonmetallic inclusions dispersed in a steel matrix are converted to MnO—SiO2—Al2O3 containing not less than approximately 15 mass % of SiO2 and not more than approximately 40 mass % of Al2O3. During steel making, molten steel is covered with basic slag and heavily deoxidized with a Si alloy whose Al content is controlled to not more than approximately 1.0 mass % in a vacuum or non-oxidizing atmosphere. The austenitic stainless steel sheet can be formed to an objective shape without the occurrence of cracking due to its decrease in susceptibility to cracking and its good formability.

Abstract: A new soft stainless steel sheet has an austenite-stability index Md30 controlled in a range of −120 to −10 and a stacking fault formability index SFI controlled not less than 30, and involves precipitates whose Cu concentration is controlled not more than 1.0%, so as to maintain concentration of dissolved Cu at 1-5%. The stainless steel sheet preferably contains up to 0.06%(C+N), up to 2.0% Si, up to 5% Mn, 15-20% Cr, 5-9% Ni, 1.0-4.0% Cu, up to 0.003% Al, up to 0.005% S, and optionally one or more of up to 0.5% Ti, up to 0.5% Nb, up to 0.5% Zr, up to 0.5% V, up to 3.0% Mo, up to 0.03% B, up to 0.02% REM (rare earth metals) and up to 0.03% Ca. The stainless steel sheet can be plastically deformed to an objective shape without any cracks even at a part heavily-worked part by multi-stage deep drawing or compression deforming. Md30(° C.)=551−462(C+N)−9.2Si−8.1Mn−29(Ni+Cu)−13.7Cr−18.5Mo SFI(mJ/m2)=2.2Ni+6Cu−1.

Abstract: A new soft stainless steel sheet has an austenite-stability index Md30 controlled in a range of −120 to −10 and a stacking fault formability index SFI controlled not less than 30, and involves precipitates whose Cu concentration is controlled not more than 1.0%, so as to maintain concentration of dissolved Cu at 1-5%. The stainless steel sheet preferably contains up to 0.06%(C+N), up to 2.0% Si, up to 5% Mn, 15-20% Cr, 5-9% Ni, 1.0-4.0% Cu, up to 0.003% Al, up to 0.005% S, and optionally one or more of up to 0.5% Y, up to 0.5% Nb, up to 0.5% Zr, up to 0.5% V, up to 3.0% Mo, up to 0.03% B, up to 0.02% REM (rare earth metals) and up to 0.03% Ca. The stainless steel sheet can be plastically deformed to an objective shape without any cracks even at a part heavily-worked part by multi-stage deep drawing or compression deforming.

Abstract: A new austenitic stainless steel contains 0.1-1.0 mass % of Si and not more than 0.003 mass % of Al. Nonmetallic inclusion dispersed in a steel matrix is converted to MnO—SiO2—Al2O3 containing not less than 15 mass % of SiO2 and not more than 40 mass % of Al2O3. During steel making, molten steel is covered with basic slag and strongly deoxidized with a Si alloy whose Al content is controlled not more than 1.0 mass % in a vacuum or non-oxidizing atmosphere. The austenitic stainless steel sheet can be formed to an objective shape without occurrence of cracking due to its less crack-sensitivity and good formability.