Abstract: A stainless steel having a low surface contact resistance for fuel cell separators is provided. The stainless steel has a Cr content of 16 to 40 mass % or more. The stainless steel includes a region having a fine textured structure on its surface, and the area percentage of the region is 50% or more, preferably 80% or more. The region having a fine textured structure is a region which has a structure having depressed portions and raised portions at an average interval between depressed portions or raised portions of 20 nm or more and 150 nm or less when observed with a scanning electron microscope.

Abstract: A stainless steel having a low surface contact resistance for fuel cell separators is provided. The stainless steel has a Cr content of 16 to 40 mass % or more. The stainless steel includes a region having a fine textured structure on its surface, and the area percentage of the region is 50% or more, preferably 80% or more. The region having a fine textured structure is a region which has a structure having depressed portions and raised portions at an average interval between depressed portions or raised portions of 20 nm or more and 150 nm or less when observed with a scanning electron microscope.

Abstract: A stainless steel having a low surface contact resistance for fuel cell separators is provided. The stainless steel has a Cr content of 16 to 40 mass % or more. The stainless steel includes a region having a fine textured structure on its surface, and the area percentage of the region is 50% or more, preferably 80% or more. The region having a fine textured structure is a region which has a structure having depressed portions and raised portions at an average interval between depressed portions or raised portions of 20 nm or more and 150 nm or less when observed with a scanning electron microscope.

Abstract: A grain oriented electrical steel sheet includes forsterite film on a surface of base steel sheet; and a sulfur-concentrated portion in at least one of the forsterite film and an interface between the forsterite film and the base steel sheet by a presence ratio expressed as area-occupying ratio of the S-concentrated portion, of at least 2%, per 10000 ?m2 of the surface of the base steel sheet, which has been subjected to magnetic domain refinement treatment by electron beam irradiation.

Abstract: A grain oriented electrical steel sheet includes forsterite film on a surface of base steel sheet; and an aluminum-concentrated portion in at least one of the forsterite film and an interface between the forsterite film and the base steel sheet by a presence ratio expressed as area-occupying ratio of the Al-concentrated portion, of at least 5%, per 10000 ?m2 of the surface of the base steel sheet, which has been subjected to magnetic domain refinement treatment by electron beam irradiation.

Abstract: A grain oriented electrical steel sheet has a total length of cracks in a film on a steel sheet surface, of 20 ?m or less per 10000 ?m2 of the film, wherein magnetic domain refinement interval in a rolling direction of the steel sheet, provided in magnetic domain refinement through substantially linear introduction of thermal strain from one side of the steel sheet corresponding to a winding outer peripheral side of a coiled steel sheet at a stage of final annealing in a direction intersecting the rolling direction; and deflection of 3 mm or less per unit length: 500 mm in the rolling direction of the steel sheet.

Abstract: A stainless steel for a fuel cell having good corrosion resistance throughout a wide potential range and a method for producing the same are provided. In particular, a coating having an intensity ratio [(OO/OH)/(Cr/Fe)] of 1.0 or more determined by X-ray photoelectron spectroscopy analysis is formed by performing an anodic electrolyzation treatment on a surface of a stainless steel in an electrolyte solution, the stainless steel containing 16% by mass or more of Cr and preferably having a composition that includes, in terms of percent by mass, C: 0.03% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.03% or less, Cr: 20 to 40%, at least one selected from Nb, Ti, and Zr, in total: 1.0% or less, and the balance being Fe and unavoidable impurities.

Abstract: An iron powder for dust cores is provided which can be formed into a dust core having a high resistivity and having a low iron loss without degrading the mechanical strength. The iron powder for dust cores includes an iron powder and an oxide film on the surface thereof, wherein the oxide film is composed of a Si-based oxide in which the ratio of Si to Fe satisfies Si/Fe?0.8 on an atomic number basis.

Abstract: It is an object to provide a surface-treated steel sheet which contains no Cr, which is excellent in wet resin adhesion, and which can be used as an alternative to a conventional tin-free steel sheet and to provide a resin-coated steel sheet produced by coating the surface-treated steel sheet with resin. A surface-treated steel sheet including an adhesive layer which is disposed on at least one surface of the steel sheet and which contains Ti and at least one selected from the group consisting of Co, Fe, Ni, V, Cu, Mn, and Zn, the ratio of the total amount of Co, Fe, Ni, V, Cu, Mn, and Zn to the amount of Ti contained therein being 0.01 to ten on a mass basis, and a method for producing the surface-treated steel sheet.

Abstract: A stainless steel having a low surface contact resistance for fuel cell separators is provided. The stainless steel has a Cr content of 16 to 40 mass % or more. The stainless steel includes a region having a fine textured structure on its surface, and the area percentage of the region is 50% or more, preferably 80% or more. The region having a fine textured structure is a region which has a structure having depressed portions and raised portions at an average interval between depressed portions or raised portions of 20 nm or more and 150 nm or less when observed with a scanning electron microscope.

Abstract: Stainless steel for fuel cell separators are provided which exhibit stable contact resistance characteristics and excellent practical utility. The stainless steel contains not less than 16 mass % of Cr. When the surface configuration of the stainless steel is analyzed with a scanning electron microscope at a spatial resolution of not more than 0.1 ?m, the surface modulus is not less than 1.02. Preferably, the chemical composition further includes C: not more than 0.03%, Si: not more than 1.0%, Mn: not more than 1.0%, S: not more than 0.01%, P: not more than 0.05%, Al: not more than 0.20%, N: not more than 0.03%, Cr: 16 to 40%, and one or more of Ni: not more than 20%, Cu: not more than 0.6% and Mo: not more than 2.5%, the balance being Fe and inevitable impurities.

Abstract: Stainless steel for fuel cell separators contains C: ?0.03%, Si: ?1.0%, Mn: ?1.0%, S: ?0.01%, P: ?0.05%, Al: ?0.20%, N: ?0.03%, Cr: 16 to 40%, and one or more of Ni: ?20%, Cu: ?0.6% and Mo: ?2.5%, the balance being Fe and inevitable impurities. According to X-ray photoelectron spectroscopy, the surface of the stainless steel contains fluorine and provides a 3.0 or higher ratio of the total of atomic concentrations of Cr and Fe in other than the metallic forms calculated from data resulting from the separation of peaks of Cr and Fe into metallic peaks and peaks other than the metallic peaks to the total of atomic concentrations of Cr and Fe in the metallic forms calculated from data resulting from the separation of peaks of Cr and Fe into metallic peaks and peaks other than the metallic peaks.

Abstract: A grain oriented electrical steel sheet includes forsterite film on a surface of base steel sheet and a selenium-concentrated portion in at least one of the forsterite film and an interface between the forsterite film and the base steel sheet by a presence ratio expressed as area-occupying ratio of the Se-concentrated portion, of at least 2%, per 10000 ?m2 of the surface of the base steel sheet, which has been subjected to magnetic domain refinement treatment by electron beam irradiation.

Abstract: A grain oriented electrical steel sheet has a total length of cracks in a film on a steel sheet surface, of 20 ?m or less per 10000 ?m2 of the film, wherein magnetic domain refinement interval in a rolling direction of the steel sheet, provided in magnetic domain refinement through substantially linear introduction of thermal strain from one side of the steel sheet corresponding to a winding outer peripheral side of a coiled steel sheet at a stage of final annealing in a direction intersecting the rolling direction; and deflection of 3 mm or less per unit length: 500 mm in the rolling direction of the steel sheet.

Abstract: A stainless steel for a fuel cell having good corrosion resistance throughout a wide potential range and a method for producing the same are provided. In particular, a coating having an intensity ratio [(OO/OH)/(Cr/Fe)] of 1.0 or more determined by X-ray photoelectron spectroscopy analysis is formed by performing an anodic electrolyzation treatment on a surface of a stainless steel in an electrolyte solution, the stainless steel containing 16% by mass or more of Cr and preferably having a composition that includes, in terms of percent by mass, C: 0.03% or less, Si: 1.0% or less, Mn: 1.0% or less, S: 0.01% or less, P: 0.05% or less, Al: 0.20% or less, N: 0.03% or less, Cr: 20 to 40%, at least one selected from Nb, Ti, and Zr, in total: 1.0% or less, and the balance being Fe and unavoidable impurities.

Abstract: A tin-plated steel sheet includes a plating layer containing tin on at least one surface of a steel sheet, and a chemical conversion coating containing P and tin on the plating layer is provided. In the steel sheet, a coated amount of the chemical conversion coating per surface is 1.0 to 50 mg/m2 in terms of P, an atomic ratio Sn/P obtained from the intensity of a P2p peak and that of a Sn3d peak is 1.0 to 1.5, the intensities being measured at the surface using an x-ray photoelectron spectroscopic method, and an atomic ratio O/P obtained from the intensity of the P2p peak and that of an O1s peak is 4.0 to 9.0. The phosphoric acid-based chemical conversion coating of the tin-plated steel sheet can suppress degradation in performance, which is caused by the growth of a tin oxide layer on the surface, instead of a conventional chromate coating.

Abstract: It is an object to provide a surface-treated steel sheet which contains no Cr, which is excellent in wet resin adhesion, and which can be used as an alternative to a conventional tin-free steel sheet and to provide a resin-coated steel sheet produced by coating the surface-treated steel sheet with resin. A surface-treated steel sheet including an adhesive layer which is disposed on at least one surface of the steel sheet and which contains Ti and at least one selected from the group consisting of Co, Fe, Ni, V, Cu, Mn, and Zn, the ratio of the total amount of Co, Fe, Ni, V, Cu, Mn, and Zn to the amount of Ti contained therein being 0.01 to ten on a mass basis, and a method for producing the surface-treated steel sheet.

Abstract: Since a surface of an iron powder is covered with an oxide film composed of a Si-based oxide in which the ratio of Si to Fe satisfies Si/Fe?0.8 on an atomic number basis, an iron powder for dust cores is provided which can be formed into a dust core having a high resistivity and hence having a low iron loss without degrading the mechanical strength.

Abstract: A brake disk including, by mass, 0.1% or less of C, 1.0% or less of Si, 2.0% or less of Mn, 10.5% to 15.0% of Cr, 2.0% or less of Ni, greater than 0.5% to 4.0% of Cu, 0.02% to 0.3% of Nb, and 0.1% or less of N and further including N, Nb, Cr. Si, Ni, Mn, Mo, and Cu, the remainder being Fe and unavoidable impurities, such that the following inequalities are satisfied: 5Cr+10Si+15Mo+30Nb?9Ni?5Mn?3Cu?225N?270C<45??(1) 0.03?{C+N?(13/93)Nb}?0.09??(2) and having a martensitic structure having prior-austenite grains with an average diameter of 8 ?m or more, a hardness of 32 to 38 HRC, and high temper softening resistance.

Abstract: A tin-plated steel sheet includes a plating layer containing tin on at least one surface of a steel sheet, and a chemical conversion coating containing P and tin on the plating layer is provided. In the steel sheet, a coated amount of the chemical conversion coating per surface is 1.0 to 50 mg/m2 in terms of P, an atomic ratio Sn/P obtained from the intensity of a P2p peak and that of a Sn3d peak is 1.0 to 1.5, the intensities being measured at the surface using an x-ray photoelectron spectroscopic method, and an atomic ratio O/P obtained from the intensity of the P2p peak and that of an O1s peak is 4.0 to 9.0. The phosphoric acid-based chemical conversion coating of the tin-plated steel sheet can suppress degradation in performance, which is caused by the growth of a tin oxide layer on the surface, instead of a conventional chromate coating.