Abstract: Provided are a steel having excellent rolling contact fatigue life and the manufacturing method thereof. The steel consists essentially of 0.7 to 1.1% C, 0.2 to 2.0% Si, 0.4 to 2.5% Mn, 1.6 to 4.0% Cr, 0.1% or more and less than 0.5% Mo, 0.010 to 0.050% Al, bymass, and balance of Fe and inevitable impurities, is treated by quenching and tempering, has residual cementite grain sizes ranging from 0.05 to 1.5 ?m, and has prior-austenite grain sizes of 30 ?m or smaller. When the steel is used to bearing steel, the bearing life extends even under service in more severe environments.

Abstract: A machine structural steel product having superior formability of rotary-forming, torsional properties, and quenching-crack resistance is provided which is manufactured using an electric furnace instead of a blast furnace and which removes adverse influences of tramp elements. A drive shaft having a superior static strength and fatigue strength is provided. In particular, the machine structural steel product contains: on a mass percent basis, C: 0.35% to 0.50%; Si: 0.15% or less; Mn: 0.20% to 1.1%; P: 0.02% or less; S: 0.005% to 0.035%; Cr: more than 0.1% to 0.2%; Mo: 0.05% to 0.5%; Ti: 0.01% to 0.05%; Al: 0.01% to 0.05%; N: 0.01% or less; B: 0.0005% to 0.0050%; Cu: 0.06% to 0.25%; and Ni: 0.05% to 0.2%, and in addition, the composition described above is adjusted so that an LD value represented by the following equation (1) satisfies 120 or less. LD=0.569×{7.98×(C)}1/2×(1+4.1Mn)·(1+2.83P)·(1?0.62S)·(1+0.64Si)·(1+2.33Cr)·(1+0.52Ni)·(1+3.14Mo)·(1+0.27Cu)·(1+1.5(0.9?C))}+52.

Abstract: A high-strength and high-fatigue-strength steel having a base metal strength of 1000 MPa or more and a rotating bending fatigue strength of 550 MPa or more is provided. The steel contains 0.3-0.8 percent by mass of C, 0.01-0.9 percent by mass of Si, 0.01-2.0 percent by mass of Mn, and Fe and unavoidable impurities as the remainder. The steel has a ferrite-cementite structure having a grain size of 7 ?m or less or a ferrite-cementite-pearlite structure having a grain size of 7 ?m or less. A surface metal of the steel after high-frequency induction quenching has a martensite structure having a prior austenite grain size of 12 ?m or less. Alternatively, a surface metal of the steel after nitriding has a fine structure having a ferrite grain size of 10 ?m or less.

Abstract: A long-life bearing steel for general purpose use is provided at low cost with no use of specific secondary refining process. Specifically, a bearing material having a component composition in which C: 0.95 to 1.10 mass %, Si: 0.15 to 0.70 mass %, Mn: 1.15 mass % or less, Cr: 0.90 to 1.60 mass %, and P: 0.025 mass % or less are contained, S and O, that are elements forming nonmetallic inclusions, are contained at S: 0.025 mass % or less and O: 0.0012 mass % or less, and the rest is composed of Fe and incidental impurities, wherein the maximum diameter of the oxide-based nonmetallic inclusion is more than 10 ?m, but 15 ?m or less in an inspection area: 320 mm2, the number of oxide-based nonmetallic inclusions having an equivalent circle diameter of 3 ?m or more is 250 or less in the inspection area: 320 mm2, while in the material, AlN is contained at 0.

Abstract: A case hardening bearing steel having an excellent rolling contact fatigue life in intermediate temperature, in addition, excellent toughness at room temperature is provided. Specific means for solving the problems are as follows. The composition contains, by mass percent, C of 0.15 to 0.30 mass percent, Si of 0.5 to 2.0 mass percent, Mn of 0.3 to 2.0 mass percent, Cr of 1.3 to 2.5 mass percent, Mo of 0.3 to 1.0 mass percent, and O of not more than 0.0012 mass percent in a range where (Si+Mo)?1.0 mass percent is satisfied, and contains iron and inevitable impurities as remnant; the maximum size of oxide nonmetallic inclusion is not more than 12.5 ?m when examined area is 320 mm2; number of the oxide nonmetallic inclusion having a diameter of equivalent circle of 3 ?m or more is not more than 250 when the examined area is 320 mm2; in addition, C density of an outer layer is adjusted to be in a range from 0.7 to 1.2 mass percent by carburization.

Abstract: A long-life bearing steel for general purpose use is provided at low cost with no use of specific secondary refining process. Specifically, a bearing material having a component composition in which C: 0.95 to 1.10 mass %, Si: 0.15 to 0.70 mass %, Mn: 1.15 mass % or less, Cr: 0.90 to 1.60 mass %, and P: 0.025 mass % or less are contained, S and O, that are elements forming nonmetallic inclusions, are contained at S: 0.025 mass % or less and O: 0.0012 mass % or less, and the rest is composed of Fe and incidental impurities, wherein the maximum diameter of the oxide-based nonmetallic inclusion is more than 10 &mgr;m, but 15 &mgr;m or less in an inspection area: 320 mm2, the number of oxide-based nonmetallic inclusions having an equivalent circle diameter of 3 &mgr;m or more is 250 or less in the inspection area: 320 mm2, while in the material, AlN is contained at 0.

Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree/{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the{100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.

Abstract: Electromagnetic steel sheets which contain Cr in an amount of from about 1.5 to 20% by weight and Si in an amount of from about 2.5 to 10% by weight, while having a total amount of C and N of not larger than about 100 ppm by weight, and which has a specific resistivity of not smaller than about 60 &mgr;&OHgr;·cm.

Abstract: A magnetic steel sheet used for an alternating current core, and having excellent magnetic properties in both a rolling direction, and the direction perpendicular thereto, and a method of producing the magnetic steel sheet. The magnetic steel sheet in a recrystallized cold-rolled condition is characterized in that the intensity ratio of {100}<001> orientation to random orientation is 2.0 or more, the intensity ratio of {011}<100> orientation to random orientation thereof is 2.0 to 10.0, and the intensity ratio of <001>//ND orientation to random orientation is preferably 2.0 or less. The method of producing a magnetic steel sheet includes hot-rolling a silicon steel slab so that the intensity ratio of (015)[100] orientation to random orientation of the recrystallized hot-rolled sheet is 3.0 or more.

Abstract: Electromagnetic steel sheets which contain Cr in an amount of from about 1.5 to 20% by weight and Si in an amount of from about 2.5 to 10% by weight, while having a total amount of C and N of not larger than about 100 ppm by weight, and which has a specific resistivity of not smaller than about 60 &mgr;&OHgr;·cm.

Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree/{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the{100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.

Abstract: Electromagnetic steel sheet having excellent magnetic properties and a texture gratly integrated in the {100}<001> orientation, and an uncomplicated and low cost production method; with about a 15 &mgr;&OHgr;·cm or more specific resistivity, about a 2.0 or more {100}<001> integration degree /{111}<uvw> integration degree and about a 10 &mgr;m to 500 &mgr;m grain diameter; when about 0.1 to 3.5% by weight of Si is present, the {100}<001> integration degree is about 10 or more; when about 0.2 to 1.2% by weight of P is present, the {100}<001> integration degree is about 3 or more; by applying a large reduction ratio to a steel slab in the vicinity of the final stage of hot rolling, with the hot rolling finishing temperature controlled at about 750 to 1150° C., hot rolled steel having a texture highly integrated in the {100}<001> orientation is economically produced.

Abstract: Fe—Cr—Si steel sheet having an excellent corrosion resistance and high toughness and method for manufacturing the same; the amount of Cr is about 10-30 wt %, the total amount of C and N is not more than about 100 ppm and the remainder consists of Fe and incidental impurities; when a cast piece of this steel is subjected to hot rolling to roll into a thickness of not more than about 3 mm, the hot rolled sheet can be subjected to cold rolling or to warm rolling without annealing.

Abstract: Electromagnetic steel sheets which contain Cr in an amount of from about 1.5 to 20% by weight and Si in an amount of from about 2.5 to 10% by weight, while having a total amount of C and N of not larger than about 100 ppm by weight, and which has a specific resistivity of not smaller than about 60 .mu..OMEGA..multidot.cm.

Abstract: Magnetic heat treatment of steel, characterized by transforming steel containing about 0.01 to 2.0 mass % of carbon in a magnetic field having a gradient of about 0.1 T/cm or more and about 10 T/cm or less (absolute value) at the Curie point or lower, to effectively refine the microstructure by subjecting the steel to heat treatment in a strong magnetic field having a gradient, followed by advantageously improving the mechanical properties of the steel.

Abstract: Graphite steel for a machine structural use exhibiting excellent cutting characteristic, cold forging characteristic and fatigue resistance, the graphite steel for a machine structural use containing: C: 0.1 wt % to 1.5 wt %; Si: 0.5 wt % to 2.0 wt %; Mn: 0.1 wt % to 2.0 wt %; B: 0.0003 wt % to 0.0150 wt %; Al: 0.005 wt % to 0.1 wt %; O.ltoreq.0.0030 wt %; P.ltoreq.0.020 wt %; S.ltoreq.0.035 wt %; N: 0.0015 wt % to 0.0150 wt %; and a balance consisting of Fe and unavoidable impurities, wherein substantially overall quantity of C is precipitated as graphite and size of graphite is 20 .mu.m or less.

Abstract: Graphite steel for a machine structural use exhibiting excellent cutting characteristic, cold forging characteristic and fatigue resistance, the graphite steel for a machine structural use containing: C: 0.1 wt % to 1.5 wt %; Si: 0.5 wt % to 2.0 wt %; Mn: 0.1 wt % to 2.0 wt %; B: 0.0003 wt % to 0.0150 wt %; Al: 0.005 wt % to 0.1 wt %; O.ltoreq.0.0030 wt %; P.ltoreq.0.020 wt %; S.ltoreq.0.035 wt %; N: 0.0015 wt % to 0.0150 wt %; and a balance consisting of Fe and unavoidable impurities, wherein substantially overall quantity of C is precipitated as graphite and size of graphite is 20 .mu.m or less.

Abstract: An apparatus for pulling up a single crystal according to Czochralski method is provided with a cylindrical first screen and a second screen. The first screen is arranged in the periphery of the zone of pulling up the single crystal, said screen being constituted by a heat absorbing body at the side facing a quartz crucible and by a heat insulator at the other side and being provided with respective outward and inward annular rims at the upper and lower ends thereof, the corner of said screen facing the crucible being formed in a curved or polygonal structure, and said annular rim at the lower end being positioned in the vicinity of filling the melt in the crucible. The second screen forming a parabolic shape in the section opening at its center while enclosing the crystal pulling-up zone and being provided at its upper end with an outward annular rim.

Abstract: A single crystal pulling apparatus using Czochralski method includes a first screen in the shape of a hollow round cylinder. One side of the first screen facing a quartz crucible is made of a heat absorbent material and another side of the first screen is made of a heat insulator material. The upper and lower ends of the first screen have an outwardly extending flange and an inwardly extending flange, respectively. The first screen surrounds a single crystal pulling zone such that its lower flange is positioned near a melt charged zone in the crucible. The apparatus also includes a second screen positioned inside the first screen. The vertical section of the second screen has the shape of a substantially parabola and the center of the bottom of the second screen is open and surrounds the single crystal pulling zone. The upper end of the second screen has an outwardly extending flange.