Abstract: A ferritic stainless steel with chemical composition includes, in mass %, Cr: 10.5 to 25.0%; Al: 0.01 to 0.20%; Ti: 0.15% to 0.35%; O: 0.0001 to 0.0030%; and Mg: 0.008×[% Al] or more, in which oxysulfide-containing inclusions are present in the steel, a number ratio of the oxysulfide-containing inclusions whose minor axis is 3 ?m or more is 5 pieces/mm2 or less, and a number ratio of the oxysulfide-containing inclusions whose minor axis is 15 ?m or more is 0.05 pieces/mm2 or less. 75% or more of the inclusions whose minor axis is 3 ?m or more have an oxysulfide part whose composition satisfies formulae (1) and (2), CaO+Al2O3+MgO?90%??formula (1), Al2O3/MgO?1.25??formula (2).

Abstract: There is provided a hot-stamped member or a steel sheet for hot stamping having a chemical composition including, in mass %, C: 0.25% or more and 0.55% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.3% or more and 3.0% or less, P: 0.02% or less, S: 0.003% or less, Al: 0.005% or more and 1.0% or less, Cr: 0% or more and 1.0% or less, Mo: 0% or more and 1.0% or less, N: 0.02% or less, Ca: 0% or more and 0.0010% or less, B: 0.0005% or more and 0.01% or less, one or two or more selected from the group consisting of Ti: 0.005% or more and 0.5% or less, Nb: 0.005% or more and 0.5% or less, V: 0.005% or more and 0.5% or less, and Zr: 0.005% or more and 0.5% or less, and Ni+Cu+Sn: 0% or more and 2% or less, and a remainder consisting of Fe and impurities.

Abstract: Ferritic stainless steel securing corrosion resistance while being excellent in ridging resistance able to be stably provided, that is, ferritic stainless steel with excellent ridging resistance having a composition comprising, by mass %, C: 0.001 to 0.01%, Si: 0.3% or less, Mn: 0.3% or less, P: 0.04% or less, S: 0.01% or less, Cr: 10 to 21%, Al: 0.01 to 0.2%, Ti: 0.015 to 0.3%, O: 0.0005 to 0.0050%, N: 0.001 to 0.02%, Ca: 0.0015% or less, and Mg: 0.0003% to 0.

Abstract: Ferritic stainless steel securing corrosion resistance while being excellent in ridging resistance able to be stably provided, that is, ferritic stainless steel with excellent ridging resistance having a composition comprising, by mass %, C: 0.001 to 0.01%, Si: 0.3% or less, Mn: 0.3% or less, P: 0.04% or less, S: 0.01% or less, Cr: 10 to 21%, Al: 0.01 to 0.2%, Ti: 0.015 to 0.3%, 0: 0.0005 to 0.0050%, N: 0.001 to 0.02%, Ca: 0.0015% or less, and Mg: 0.0003% to 0.

Abstract: An environmentally friendly flux for molten steel desulfurization includes CaO and Al2O3 so that [CaO]/[Al2O3] is within a range of 1.6 to 3.0, and includes one or more alkali metal oxides of Na2O, K2O, and Li2O, and SiO2 so that [SiO2]/[R2O] is within a range of 0.1 to 3, [R2O] is within a range of 0.5 mass % to 5 mass %, and [SiO2] is within a range of 0.05 mass % to 15 mass % in a case in which the [CaO], the [Al2O3], the [SiO2], and the [R2O] represent the mass % of CaO, the mass % of Al2O3, the mass % of SiO2, and the total amount of the mass % of Na2O, the mass % of K2O, and the mass % of Li2O respectively.

Abstract: An environmentally friendly flux for molten steel desulfurization includes CaO and Al2O3 so that [CaO]/[Al2O3] is within a range of 1.6 to 3.0, and includes one or more alkali metal oxides of Na2O, K2O, and Li2O, and SiO2 so that [SiO2]/[R2O] is within a range of 0.1 to 3, [R2O] is within a range of 0.5 mass % to 5 mass %, and [SiO2] is within a range of 0.05 mass % to 15 mass % in a case in which the [CaO], the [Al2O3], the [SiO2], and the [R2O] represent the mass % of CaO, the mass % of Al2O3, the mass % of SiO2, and the total amount of the mass % of Na2O, the mass % of K2O, and the mass % of Li2O respectively.

Abstract: In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by a fluorescent X-ray analysis method using an energy dispersion type spectroscope, or by other chemical or physical measurements, to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.

Abstract: In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by dissolving the surface and extracting and filtering the inclusions to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.

Abstract: In order to quickly and economically evaluate cleanliness of a metal with high representativity when quantities, compositions, etc., of non-metallic inclusion particles existing in a metal and resulting in product defects are evaluated by a sample collected during the production process of the metal, the present invention provides an evaluation method involving the steps of levitation-melting a metal piece for a predetermined time by cold crucible levitation-melting means, discharging non-metallic inclusion particles contained in the metal piece to the surface of a molten metal, and directly analyzing a curved and non-smooth sample surface after solidification by a fluorescent X-ray analysis method using an energy dispersion type spectroscope, or by other chemical or physical measurements, to measure or analyze the quantities of elements constituting the non-metallic inclusion particles and to determine quantity of the non-metallic inclusions.