Abstract: There is provided a method for predicting the amount of corrosion in a steel including a step in which, based on a weather observation value WM at a scheduled use point M of the steel, a corrosion index Q(tMi, WM) is obtained for each past observation time tMi, extremal value statistical analysis is performed on time-series data of the corrosion index Q(tMi, WM) between observation times tM1 to tMn, and a maximal value Qmax(tFi) of the corrosion index within future evaluation periods tF1 to tFn is estimated, and a corrosion amount estimation step in which a relational expression between a measured corrosion amount obtained in a corrosion test at a test point Z and the maximum value of a corrosion index Q(tZi, WZ) obtained for each observation time tZi during a test period of the corrosion test based on a weather observation value WZ at the test point Z is obtained in advance, the maximal value Qmax(tFi) of the corrosion index estimated above is introduced into the relational expression, and an estimated value

Abstract: A martensitic stainless steel sheet for a brake disc rotor, characterized by containing predetermined components and having, in a mother phase, precipitates with a particle size of 2 ?m or less and a density of 0.01 to 20 pieces/?m2. The precipitates finely present in hot rolling and hot-rolled sheet annealing improves productivity in hardening, improves temper softening resistance of the steel sheet in use as a component, inhibits cracking in hot stamping, and inhibits reduction in high-temperature strength. Accordingly, the martensitic stainless steel sheet excellent in temper softening resistance, hardenability, formability, and high-temperature strength that is applicable to the disc rotor is provided.

Abstract: A welded structure including a base material made of duplex stainless steel and a welded portion formed by welding the base materials to each other, wherein the base material has a predetermined chemical composition, a volume fraction of a ferrite phase in a metallographic structure of a weld metal of the welded portion is 45 to 75%, a ratio of a hardness of the weld metal to a hardness of the base material is 0.80 to 1.20, and an amount of precipitates formed in the ferrite phase of the weld metal is less than 10% in area fraction.

Abstract: The present invention is a stainless steel material having antibacterial properties and antiviral properties, the stainless steel material containing a Cu-rich region 3 in which the concentration of Cu is higher than the average Cu concentration in a matrix along grain boundaries in a surface 1 of the stainless steel material and a surface layer 2 located immediately below the surface of the stainless steel material, wherein the Cu-rich region 3 has Cu grain boundary layers 6 that extend continuously at a depth of 10 ?m to 200 ?m from the surface 1 of the stainless steel material, the average number of the Cu grain boundary layers 6 is 2.0 or more per 100 ?m of a distance parallel to the surface of the stainless steel material in a cross section orthogonal to the surface of the stainless steel material.

Abstract: The present invention has as its technical problem to prevent cracking when producing a steel sheet by ferritic stainless steel sheet and provide a ferritic stainless steel sheet excellent in toughness and a part using the same. To solve this technical problem, the present invention provides steel comprised of, by mass %, C: 0.001 to 0.030%, Si: 0.01 to 1.00%, Mn: 0.01 to 1.00%, P: 0.010 to 0.050%, S: 0.0002 to 0.0100%, Cr: 10.0 to 20.0%, N: 0.001 to 0.030%, Nb: 0.10 to 0.40%, B: 0.0002 to 0.0030%, Al: 0.005 to 0.100%, and a balance of Fe and unavoidable impurities in which the amount of solute Nb being less than or equal to a smaller value of 0.20 and (Nb content-0.08) mass %.

Abstract: A high-Ni alloy having excellent weld-hot-cracking resistance includes, in mass %, Cr: 16-30%, Ni: 18-50%, Al: 0.01-1.0%, and Ti: 0.01-1.5%. In a first aspect of the invention, a relationship between number density of TiC precipitates having 1.0 ?m or more of equivalent circle diameter and Mg content in steel satisfies formula (1) below. In a second aspect of the invention, S average concentration in oxide- and sulfide-inclusions is 0.70 mass % or more. In a third aspect of the invention, mass ratios of CaO, MgO, and Al2O3 in inclusions, where O or S is detected, satisfy formula (2), the mass ratios being respectively calculated from average concentrations of Ca, Mg and Al in the inclusions, (1) number density of TiC (number of pieces/mm2)?463?9.5×Mg concentration in steel (mass ppm) and (2) [CaO?0.6×MgO] (mass %)/[CaO+MgO+Al2O3] (mass %)?0.20.

Abstract: A bar-shaped stainless steel product having a chemical composition that contains, by mass %: 0.001 to 0.030% of C; 0.01 to 4.00% of Si; 0.01 to 2.00% of Mn; 0.01 to 4.00% of Ni; 8.0 to 35.0% of Cr; 0.01 to 5.00% of Mo; 0.01 to 2.00% of Cu; 0.001 to 0.030% of N; 7.000% or less of Al; 0 to 2.00% of Ti; 0 to 2.00% of Nb; and 0 to 0.1% of B; one or more elements selected from 0.001% or more of Ti, 0.001% or more of Nb, and 0.0001% or more of B being contained, a balance consisting of Fe and impurities, an average particle size of nitrides being 10 ?m or less, and a solute N content in steel being 0.020 mass % or less.

Abstract: This titanium material is a dual phase stainless steel sheet containing an austenite and a ferrite and has a predetermined chemical composition, wherein, in a center part in a sheet thickness of a cross section in a perpendicular-to-rolling direction which is a direction perpendicular to a rolling direction on a rolled surface and a direction parallel to a sheet thickness direction, an area ratio S<001>/S<111> which is a ratio of an area proportion S<001> of a texture of a ferrite with the <001> direction oriented in the perpendicular-to-rolling direction to an area proportion S<111> of a texture of a ferrite with the <111> direction oriented in the perpendicular-to-rolling direction is 0.90 to 1.10.

Abstract: This ferritic stainless steel has a predetermined chemical composition, at least one type of oxides of oxides containing 5 mass % or more of Al and oxides containing 5 mass % or more of Si are present on the surface, and, among the oxides present on the surface, the number of oxides having a diameter D of 0.1 ?m or more and 2.0 ?m or less is 10 or more per 93 ?m2, the diameter D being represented by D=(Dmax+Dmin)/2 where Dmax is the maximum diameter of the oxide on the surface and Dmin is the minimum diameter of the oxide on the surface.

Abstract: A high-Ni alloy having excellent weld-hot-cracking resistance includes, in mass %, Cr: 16-30%, Ni: 18-50%, Al: 0.01-1.0%, and Ti: 0.01-1.5%. In a first aspect of the invention, a relationship between number density of TiC precipitates having 1.0 ?m or more of equivalent circle diameter and Mg content in steel satisfies formula (1) below. In a second aspect of the invention, S average concentration in oxide- and sulfide-inclusions is 0.70 mass % or more. In a third aspect of the invention, mass ratios of CaO, MgO, and Al2O3 in inclusions, where O or S is detected, satisfy formula (2), the mass ratios being respectively calculated from average concentrations of Ca, Mg and Al in the inclusions, (1) number density of TiC (number of pieces/mm2)?463?9.5×Mg concentration in steel (mass ppm) and (2) [CaO?0.6×MgO] (mass %)/[CaO+MgO+Al2O3] (mass %)?0.20.

Abstract: An austenitic stainless steel material consisting of, on a mass basis, 0.200% or less of C, 1.00 to 3.50% of Si, 5.00% or less of Mn, 4.00 to 10.00% of Ni, 12.00 to 18.00% of Cr, 3.500% or less of Cu, 1.00 to 5.00% of Mo, and 0.200% or less of N, a total amount of C and N is 0.100% or more, and the balance is Fe and impurities; wherein the austenitic stainless steel material has a composition having a value of Md30 of -40.0 to 0° C.; the austenitic stainless steel material has a metallographic structure comprising 25 to 35% by volume of strain-induced martensite phase; and the austenitic stainless steel material has a tensile strength (TS) of 1450 MPa or more, an elongation at break (EL) of 12.0% or more, TS x EL of 24000 or more, and a stress relaxation percentage of 1.20% or less.

Abstract: Ferritic stainless steel is characterized by including, by mass %: Cr: 12.0% to 16.0%; C: 0.020% or less; Si: 2.50% or less; Mn: 1.00% or less; P: 0.050% or less; S: 0.0030% or less; Al: 2.50% or less; N: 0.030% or less; Nb: 0.001% to 1.00%; one or more of B: 0.0200% or less, Sn: 0.20% or less, Ga: 0.0200% or less, Mg: 0.0200% or less, and Ca: 0.0100% or less; and a balance consisting of Fe and impurities, in which Expression (1) is satisfied. 10(B+Ga)+Sn+Mg+Ca>0.

Abstract: An austenitic stainless steel consists of 0.010 to 0.200% by mass of C, 2.00% by mass or less of Si, 3.00% by mass or less of Mn, 0.035% by mass or less of P, 0.0300% by mass or less of S, 6.00 to 14.00% by mass of Ni, 20.0 to 26.0% by mass of Cr, 3.00% by mass or less of Mo, 0.01 to 3.00% by mass of Cu, 1.000% by mass of less of Ti, 0.200% by mass or less of Al, 0.1000% by mass or less of Ca, 0.100 to 0.250% by mass of N, and 0.0080% by mass or less of 0, the balance being Fe and impurities.

Abstract: A ferritic stainless steel sheet is provided that has a chemical composition consisting of, in mass %, C: 0.001 to 0.020%, Si: 0.02 to 1.50%, Mn: 0.02 to 1.50%, P: 0.01 to 0.05%, S: 0.0001 to 0.01%, Cr: 10.0 to 25.0%, Ti: 0.01 to 0.30%, N: 0.001 to 0.030%, and optional elements, with the balance being Fe and unavoidable impurities, wherein: a grain size number is 6 or more; the ferritic stainless steel sheet satisfies the formulas [A+B?12.0/t], [X+Y?12.0/(t?0.3)] and [(X+Y)?(A+B)?5.0] with respect to crystal orientation intensities of a ferrite phase obtained by X-ray diffraction; and the sheet thickness is 1.0 mm or more.

Abstract: A weld structure includes a first stainless steel member and a second stainless steel member. A crevice made by welding is defined by welding an end of the first stainless steel member and a portion other than an end of the second stainless steel member. A portion close to the end of the first stainless steel member is formed as a weld metal portion by performing welding heat input on the portion close to the end of the first stainless steel member. In the crevice made by welding, a length LB from a boundary between the weld metal portion and a raw material portion to a crevice deepest portion and a crevice length LC from the crevice deepest portion to a 40 ?m-width position satisfy LC<LB.

Abstract: The stainless steel contains 0.0001 mass % or more and 0.15 mass % or less of C, 0.30 mass % or more and 2.0 mass % or less of Si, 0.1 mass % or more and 15 mass % or less of Mn, 5 mass % or more and 30 mass % or less of Ni, 0.0001 mass % or more and 0.01 mass % or less of S, 16 mass % or more and 25 mass % or less of Cr, 0 mass % or more and 5 mass % or less of Mo, 0 mass % or more and 0.005 mass % or less of Al, 0 mass % or more and 0.0010 mass % or less of Mg, 0.0010 mass % or more and 0.0060 mass % or less of 0, and 0.0001 mass % or more and 0.5 mass % or less of N, and at least includes an inclusion with an equivalent circle diameter of 5 ?m or more, having the average composition of 5 mass % or more of MnO, 20 mass % or more of Cr2O3+Al2O3, 1 mass % or more of Al2O3, and 5 mass % or less of Ca0. The number density of the inclusion having the composition is 0.5 inclusions/mm2 or less.

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: The stainless steel for metal foils includes, in mass %, 0.0001% or more and 0.15% or less of C, 0.30% or more and 2.0% or less of Si, 0.1% or more and 15% or less of Mn, 0.040% or less of P, 5% or more and 30% or less of Ni, 0.0001% or more and 0.01% or less of S, 16% or more and 25% or less of Cr, 5% or less of Mo, 0.005% or less of Al, 0.0030% or less of Ca, 0.0010% or less of Mg, 0.0010% or more and 0.0060% or less of O, and 0.0001% or more and 0.5% or less of N. The number of inclusions with a maximum equivalent circle diameter of 5 ?m or more is 0.5 inclusions/mm2 or less in a thickness of 0.010 mm or more and 0.2 mm or less.

Abstract: A bar-shaped stainless steel product contains, by mass %, 0.001 to 0.030% of C, 0.01 to 4.00% of Si, 0.01 to 2.00% of Mn, 0.01 to 4.00% of Ni, 6.0 to 35.0% of Cr, 0.01 to 5.00% of Mo, 0.01 to 2.00% of Cu, and 0.001 to 0.050% of N. In the product, an F value is 20 or less, a rolling-direction-crystal-orientation RD//<100> fraction is 0.05 or more, and preferably a rolling-direction-crystal-orientation RD//<334> fraction is 0.2 or less. The above RD//<100> fraction means an area ratio of crystal having 25 degrees or less of an orientation difference between a <100> orientation and a rolling direction, and the above RD//<334> fraction means an area ratio of crystal having 10 degrees or less of an orientation difference between a <334> orientation and a rolling direction. F value=700C+800N+20Ni+10Cu+10Mn?6.2Cr?9.2Si?9.3Mo?74.4Ti?37.2A1?3.1Nb+63.

Abstract: A stainless steel with reduced S and suppressed generation of hard inclusions. Inclusions with an equivalent circle diameter of 5 ?m or more, the number density of a first inclusion having the average composition of, in mass %, CaO: 0% or more and 15% or less, SiO2: 0% or more and 20% or less, Al2O3: 50% or more and 70% or less, and MgO: 10% or more and 40% or less is 0.5 inclusions/mm2 or less, the number density of a second inclusion having CaO: 10% or more and 70% or less, SiO2: 10% or more and 65% or less, Al2O3: 20% or less, MgO: 5% or more and 50% or less, and CaF2: 0% or more and 5% or less is 0.2 inclusions/mm2 or less, and the number density of a third inclusion having CaO: 5% or more and 40% or less, SiO2: 10% or more and 40% or less, Al2O3: 10% or more and 40% or less, MgO: 5% or more and 30% or less, and CaF2: 5% or more and 40% or less is 0.005 inclusions/mm2 or more and 0.5 inclusions/mm2 or less.