Abstract: A high strength cold-rolled steel sheet has a component composition containing specific amounts of C, Si, Mn, P, S, N and Al, respectively with a remainder being iron and inevitable impurities. The steel sheet contains 95% or more of martensite in terms of area ratio, and contains 5% or less (inclusive of 0%) of residual austenite and ferrite in terms of a total area ratio. An average size of a carbide is 60 nm or less in terms of an equivalent circle diameter, and a number density of the carbide having the equivalent circle diameter of 25 nm or more is 5.0×105 pieces or less per mm2. The steel sheet has a yield strength of 1,180 MPa or more and a tensile strength of 1,470 MPa or more.

Abstract: Provided is a so-called Lundell-type generator capable of avoiding generation of eddy current in rotor iron-cores without complicated structure. The generator includes a stator, a rotary shaft, first and second rotor iron-cores, and a rotor coil. Each rotor iron-core includes a base and rotor magnetic-pole portions extending axially from the base, the rotor coil disposed on the inside thereof. Each rotor iron-core is formed of a plurality of unit plates stacked axially. The unit plates integrally include respective basal plate portions stacked to form the bases and a plurality of magnetic-pole plate portions stacked to form the rotor magnetic-pole plate portions stacked to form the rotor magnetic-pole portions.

Abstract: The present invention provides a Cu—Fe—P alloy which has a high strength, high conductivity and superior bending workability. The copper alloy comprises 0.01 to 1.0% Fe, 0.01 to 0.4% P, 0.1 to 1.0% Mg, and the remainder Cu and unavoidable impurities. The size of oxides and precipitates including Mg in the copper alloy is controlled so that the ratio of the amount of Mg measured by a specified measurement method in the extracted residue by a specified extracted residue method to the Mg content in said copper alloy is 60% or less, thus endowing the alloy with a high strength and superior bending workability.

Abstract: This high-strength steel sheet contains, in mass %, 0.05 to 0.3% of C, 1 to 3% of Si, 0.5 to 3% of Mn, up to 0.1% (inclusive of 0%) of P, up to 0.01% (inclusive of 0%) of S, 0.001 to 0.1% of Al and 0.002 to 0.03% of N with the balance consisting of iron and unavoidable impurities, and has a microstructure which comprises, in area fraction relative to the microstructure, 40 to 85% of bainitic ferrite, 5 to 20% of retained austenite (?R), 10 to 50% (in total) of martensite and ?R, and 5 to 40% of ferrite. The retained austenite (?R) has a C concentration of 0.5 to 1.0 mass %, while the quantity of ?R present in the ferrite grains is 1% or more (in area fraction) relative to the microstructure.

Abstract: A hot-dip galvanized steel sheet contains specific amounts of C, Si, Mn, P, S, Ti, Al, and N with the remainder being iron and unavoidable impurities. Bainitic ferrite, martensite, retained ?, and ferrite (?) are present each in a specific area ratio. The remainder ? has a specific C concentration. Sub-grains in the recrystallized ? and un-recrystallized ? have a specific grain diameter. The surface area ratio of ? and worked ? having a grain diameter of 5 ?m or more is 5% or less. The average particle diameter of TiC particles inside ? grains is 10 nm or less.

Abstract: In a steel sheet having a specific chemical composition and having a microstructure including ferrite that is a soft first phase by 20-50% in terms of the area ratio, the remainder being tempered martensite and/or tempered bainite that is a hard second phase, the microstructure of steel of a surface layer section of the steel sheet from the surface to the depth of 100 ?m and a center section of t/4-3t/4 (t is the sheet thickness) is controlled.

Abstract: In a high strength cold-rolled steel plate having a specific chemical composition, a soft first phase (ferrite) has an area ratio of 20-50%, the remainder being a hard second phase (tempered martensite and/or tempered bainite), among all the ferrite grains, ferrite grains that have an average grain diameter of 10-25 ?m account for a total area ratio of 80% or more, the number of the cementite grains that have an equivalent circle diameter of 0.3 ?m or more is more than 0.15 piece and 1.0 piece or less per 1 ?m2 of ferrite, and the tensile strength is 980 MPa or more.

Abstract: This hot-rolled steel sheet has a thickness of 3-20 mm and contains specific amounts of C, Si, Mn, P, S, Al and N with the balance made up of iron and unavoidable impurities. The contents of solid-solved N, C and N are within specific ranges, and bainitic ferrite having a specific average crystal grain size and pearlite have specific area occupancies in the structure, with the balance occupied by polygonal ferrite. This hot-rolled steel sheet has a specific hardness distribution in the thickness direction.

Abstract: A high-strength cold-rolled steel sheet has a chemical composition including C of 0.05% to 0.30%, Si of greater than 0% to 3.0%, Mn of 0.1% to 5.0%, P of greater than 0% to 0.1%, S of greater than 0% to 0.02%, Al of 0.01% to 1.0%, and N of greater than 0% to 0.01%, in mass percent, with the remainder including iron and inevitable impurities. The steel sheet has a microstructure containing ferrite as a soft primary phase in an area percentage of 20% to 50% with the remainder including tempered martensite and/or tempered bainite as a hard secondary phase. The ferrite grains are adapted to contain cementite particles having an appropriate size in an appropriate number density.

Abstract: A hot-rolled steel sheet having a sheet thickness of 2-10 mm and containing specific amounts of C, Mn, Al, and N with iron and unavoidable impurities. With regard to all grains existing at a position of t/4 in depth, t being sheet thickness, an area ratio of grains having a sheet-plane orientation within 10° from (123) plane is 20% or more, a total area ratio of grains having a crystal direction within 10° from <001> direction and grains having a crystal direction within 10° from <110> direction, in a rolling direction, is 25% or less, and an average grain size of all grains is 3-50 ?m.

Abstract: A hot-rolled steel sheet that: has a sheet thickness of 2-10 mm, contains specific amounts of C, Mn, Al, and N, the remainder being iron and unavoidable impurities, and contains ferrite and pearlite in a specified area ratio, the remainder being bainite. In the hot-rolled steel sheet, a number of grains having an aspect ratio of major axis to minor axis of 3 or less is 60% or more of a number of all grains and an average grain size of the all grains is from 3 to 50 ?m.

Abstract: A hot-rolled steel sheet which has a thickness of 3-20 mm and contains specific amounts of C, Si, Mn, P, S, Al and N, with the balance made up of iron and unavoidable impurities. This hot-rolled steel sheet contains a specific amount of solid-solved N, and the contents of C and N satisfy the relation 10C+N?3.0. This hot-rolled steel sheet contains bainitic ferrite and pearlite, respectively in an area ratio of 5% or more and in an area ratio of less than 20% relative to the whole structure, with the balance made up of polygonal ferrite. The average crystal grain size of the bainitic ferrite is 3-50 ?m.

Abstract: Provided is a so-called Lundell-type generator capable of avoiding generation of eddy current in rotor iron-cores without complicated structure. The generator includes a stator, a rotary shaft, first and second rotor iron-cores, and a rotor coil. Each rotor iron-core includes a base and rotor magnetic-pole portions extending axially from the base, the rotor coil disposed on the inside thereof. Each rotor iron-core is formed of a plurality of unit plates stacked axially. The unit plates integrally include respective basal plate portions stacked to form the bases and a plurality of magnetic—pole plate portions stacked to form the rotor magnetic-pole plate portions stacked to form the rotor magnetic-pole portions.

Abstract: The present invention intends a hot-rolled steel sheet with a sheet thickness in a range of 2 to 15 mm, having component composition including C: 0.3% or less by mass %, Si: 0.5% or less, Mn: in a range of 0.2 to 1%, P: 0.05% or less, S: 0.05% or less, Al: in a range of 0.01 to 0.1%, N: in a range of 0.008 to 0.025%, and the remainder being iron and unavoidable impurities. The hot-rolled steel sheet includes an amount of solute N: not less than 0.

Abstract: A high strength cold-rolled steel sheet has a component composition containing specific amounts of C, Si, Mn, P, S, N and Al, respectively with a remainder being iron and inevitable impurities. The steel sheet contains 95% or more of martensite in terms of area ratio, and contains 5% or less (inclusive of 0%) of residual austenite and ferrite in terms of a total area ratio. An average size of a carbide is 60 nm or less in terms of an equivalent circle diameter, and a number density of the carbide having the equivalent circle diameter of 25 nm or more is 5.0×105 pieces or less per mm2. The steel sheet has a yield strength of 1,180 MPa or more and a tensile strength of 1,470 MPa or more.

Abstract: Disclosed is a hot-rolled steel sheet that has a thickness of 3 to 20 mm and includes, in a chemical composition in mass percent, C of 0.3% or less (excluding 0%), Si of 0.5% or less (excluding 0%), Mn of 0.2% to 1%, P of 0.05% or less (excluding 0%), S of 0.05% or less (excluding 0%), Al of 0.01% to 0.1%, and N of 0.008% to 0.025%, with the remainder consisting of iron and inevitable impurities. A solute nitrogen content is 0.007% or more, and the carbon and nitrogen contents meet a condition as specified by 10C+N?3.0. The microstructure of the steel sheet includes pearlite of less than 20% in area percentage, with the remainder approximately consisting of ferrite. The average grain size of the ferrite is 3 to 35 ?m. The steel sheet has good cold formability during forming and still has predetermined surface hardness after forming.

Abstract: The present invention relates to a copper alloy having high strength, high electrical conductivity, and excellent bendability, the copper alloy containing, in terms of mass %, 0.4 to 4.0% of Ni; 0.05 to 1.0% of Si; and, as an element M, one member selected from 0.005 to 0.5% of P, 0.005 to 1.0% of Cr, and 0.005 to 1.0% of Ti, with the remainder being copper and inevitable impurities, in which an atom number ratio M/Si of elements M and Si contained in a precipitate having a size of 50 to 200 nm in a microstructure of the copper alloy is from 0.01 to 10 on average, the atom number ratio being measured by a field emission transmission electron microscope with a magnification of 30,000 and an energy dispersive analyzer.

Abstract: A hot-dip galvanized steel sheet contains specific amounts of C, Si, Mn, P, S, Ti, Al, and N with the remainder being iron and unavoidable impurities. Bainitic ferrite, martensite, retained ?, and ferrite (?) are present each in a specific area ratio. The remainder ? has a specific C concentration. Sub-grains in the recrystallized ? and un-recrystallized ? have a specific grain diameter. The surface area ratio of ? and worked ? having a grain diameter of 5 ?m or more is 5% or less. The average particle diameter of TiC particles inside a grains is 10 nm or less.

Abstract: In a steel sheet having a specific chemical composition and having a microstructure including ferrite that is a soft first phase by 20-50% in terms of the area ratio, the remainder being tempered martensite and/or tempered bainite that is a hard second phase, the microstructure of steel of a surface layer section of the steel sheet from the surface to the depth of 100 ?m and a center section of t/4-3t/4 (t is the sheet thickness) is controlled.

Abstract: In a high strength cold-rolled steel plate having a specific chemical composition, a soft first phase (ferrite) has an area ratio of 20-50%, the remainder being a hard second phase (tempered martensite and/or tempered bainite), among all the ferrite grains, ferrite grains that have an average grain diameter of 10-25 ?m account for a total area ratio of 80% or more, the number of the cementite grains that have an equivalent circle diameter of 0.3 ?m or more is more than 0.15 piece and 1.0 piece or less per 1 ?m2 of ferrite, and the tensile strength is 980 MPa or more.