Abstract: A steel for induction hardening according to the present invention includes a chemical composition consisting of, in mass percent: C: 0.53 to less than 0.58%, Si: 0.70 to 1.40%, Mn: 0.20 to 1.40%, P: less than 0.020%, S: less than 0.020%, Al: 0.005 to 0.060%, N: 0.0020 to 0.0080%, O: 0.0015% or less, B: 0.0003 to 0.0040%, Ti: 0.010 to 0.050%, and Ca: 0.0005 to 0.005%, with the balance being Fe and impurities, and satisfies Formulae (1) to (3). The steel microstructure is made up of ferrite and pearlite. A ratio of a number of composite inclusions is 20% or more. C+Si/7+Mn/5+Cr/9+Mo/2.5?0.98??(1) C+Si/10+Mn/20+Cr/25?0.70??(2) Cr/Si?0.

Abstract: A steel sheet has a specific chemical composition and has a structure represented by, by area ratio, ferrite: 5 to 95%, and bainite: 5 to 95%. When a region that is surrounded by a grain boundary having a misorientation of 15° or more and has a circle-equivalent diameter of 0.3 ?m or more is defined as a crystal grain, the proportion of crystal grains each having an intragranular misorientation of 5 to 14° to all crystal grains is 20 to 100% by area ratio. Hard crystal grains A in which precipitates or clusters with a maximum diameter of 8 nm or less are dispersed in the crystal grains with a number density of 1×1016 to 1×1019 pieces/cm3 and soft crystal grains B in which precipitates or clusters with a maximum diameter of 8 nm or less are dispersed in the crystal grains with a number density of 1×1015 pieces/cm3 or less are contained, and the volume % of the hard crystal grains A/(the volume % of the hard crystal grains A +the volume % of the soft crystal grains B) is 0.1 to 0.9.

Abstract: Rolled wire rod effectively suppressing fracturing at the time of cold forging and excellent in hydrogen embrittlement resistance after quenching and tempering following spheroidization annealing even without spheroidization annealing before cold forging or even if shortening the time period of spheroidization annealing is provided wherein it has a predetermined composition and wherein if the contents of Ti, N, and S (mass %) are respectively [Ti], [N], and [S], if [S]?0.0010, [Ti] is (4.5×[S]+3.4×[N]) or more and (0.008+3.4×[N]) or less, while if [S]?0.0010, [Ti] is (4.5×[S]+3.4×[N]) or more and (8.0×[S]+3.4×[N]) or less, the internal structure is a mixed structure of ferrite and pearlite with an area rate of a ferrite fraction of 40% or more, and a mean area of sulfides present in a range from a surface to a D/8 position is 6 ?m2 or less in the case of a diameter of D (mm) in a cross-section at a plane including the axial direction, and a mean aspect ratio of the sulfides is 5 or less.

Abstract: A steel sheet according to an aspect of the present invention has a chemical composition within a predetermined range; in which a metallographic structure at a thickness ¼ portion includes, by unit area %, ferrite: 10% or more and less than 50%, granular bainite: 5% or more and less than 50%, and martensite: 20% or more and less than 60%; in the metallographic structure at the thickness ¼ portion, a total of upper bainite, lower bainite, residual austenite, and pearlite is 0% or more and less than 15% by unit area %; at the thickness ¼ portion, a product of an area ratio Vm of the martensite and an average hardness Hv of the martensite is 12,000 to 34,000; and a tensile strength is 980 MPa or higher.

Abstract: Provided is a chemical treatment steel sheet including a steel sheet; a composite coated layer which is formed on at least one surface of the steel sheet, and contains 2 to 200 mg/m2 of Ni in terms of an amount of metal Ni and 0.1 to 10 g/m2 of Sn in terms of an amount of metal Sn, and in which an island-shaped Sn coated layer is formed on an Fe—Ni—Sn alloy layer; and a chemical treatment layer that is formed on the composite coated layer, and contains a 0.01 to 0.1 mg/m2 of Zr compounds in terms of an amount of metal Zr and 0.01 to 5 mg/m2 of phosphate compounds in terms of an amount of P.

Abstract: A steel sheet has a specific chemical composition and has a structure represented by, by area ratio, ferrite: 30 to 95%, and bainite: 5 to 70%. When a region that is surrounded by a grain boundary having a misorientation of 15° or more and has a circle-equivalent diameter of 0.3 ?m or more is defined as a crystal grain, the proportion of crystal grains each having an intragranular misorientation of 5 to 14° to all crystal grains is 20 to 100% by area ratio. An average aspect ratio of ellipses equivalent to the crystal grains is 5 or less. An average distribution density of the total of Ti-based carbides and Nb-based carbides each having a grain size of 20 nm or more on ferrite grain boundaries is 10 carbides/?m or less.

Abstract: A titanium sheet having a sheet thickness of 0.2 mm or less and including a hardened layer on a surface, the titanium sheet including a chemical composition containing, in mass percent: Fe: 0.001 to 0.08%; and O: 0.03 to 0.08%, wherein a grain size satisfies following Formulas (1) to (3), a thickness of the hardened layer is 0.1 to 2.0 ?m. The titanium sheet has both a sufficient strength and an excellent workability. Formulas (1) to (3) are dave?2.5 (1), t/dave?3.0 (2), and t/dmax—1.5 (3), where, in Formulas (1) to (3), t denotes the sheet thickness (?m), dave denotes an average grain size (?m), and dmax denotes a maximum grain size (?m).

Abstract: Provided are: a metalworking oil composition having excellent workability and rust inhibiting performance, which is prepared by blending (A) at least one carboxylate selected from a polyhydric alcohol ester of a monocarboxylic acid and a monohydric alcohol ester of a polycarboxylic acid, (B) a phosphorus-containing compound, and (C) a rust inhibitor, wherein the monocarboxylic acid has 9 or more and 21 or less carbon atoms, and the content of the carboxylate is 0.6% by mass or more based on the total amount of the composition; and a metalworking method using the composition.

Abstract: A steel plate according to an aspect of the present invention has a predetermined chemical composition, an index Q obtained by Equation (1) is 0.00 or more, a carbon equivalent Ceq (%) obtained by Equation (2) is less than 0.800%, a ratio of a difference between a hardness at a surface layer portion and a hardness at a thickness center portion to the hardness at the surface layer portion at a room temperature is 15.0% or less, the hardness at the suffice layer portion at a room temperature is 400 or more in terms of Vickers hardness, and a steel thickness is 40 or more. Q=0.18?1.3(logT)+0.75(2.7×[C]+[Mn]+0.45×[Ni]+0.

Abstract: A non-oriented electrical steel sheet has a predetermined chemical composition, and when an average value of Mn concentrations in a range from a surface of a base iron to a position where a depth from the surface of the base iron is 2 ?m is set to [Mn2], and an Mn concentration at a position where a depth from the surface of the base iron is 10 ?m is set to [Mn10], the base iron satisfies the following expression 1. 0.1?[Mn2]/[Mn10]?0.

Abstract: Provided is a carbonitrided bearing part which has high hardenability and toughness, and is excellent in wear resistance and surface-originated flaking life. A carbonitrided bearing part of the present embodiment has a chemical composition containing, in mass %, C: 0.15 to 0.45%, Si: not more than 0.50%, Mn: 0.40 to 1.50%, P: not more than 0.015%, S: not more than 0.005%, Cr: 0.30 to 2.0%, Mo: 0.10 to 0.35%, V: 0.20 to 0.40%, Al: 0.005 to 0.10%, N: not more than 0.030%, and O: not more than 0.0015%, with the balance being Fe and impurities, and satisfying Formulae (1) and (2). At surface, C concentration is 0.7 to 1.2%, N concentration is 0.15 to 0.6%, and Rockwell hardness HRC is 58 to 65. 1.20<0.4Cr+0.4Mo+4.5V<2.60??(1) 2.7C+0.4Si+Mn+0.8Cr+Mo+V>2.

Abstract: An objective of the present invention is to provide a threaded connection for pipe or tube having an excellent anti-misalignment property and an appropriate shouldering torque, and further having excellent corrosion resistance and an excellent adhesiveness of a solid lubricant coating, and to provide a method of producing the threaded connection for pipe or tube. The threaded connection for pipe or tube according to the present embodiment includes a pin and a box. The pin and the box have contact surfaces including thread portions and unthreaded metal contact portions. The threaded connection for pipe or tube comprises an alloy plating layer consisting of a Zn—Ni alloy on the contact surface of at least one of the pin and the box, a phosphating layer, and a solid lubricant coating. These are stacked in an order of the alloy plating layer, phosphating layer, and the solid lubricant coating, from a contact surface side.

Abstract: In a metal coated steel sheet, a chemical composition contains, in mass %, at least C: 0.03% to 0.70%, Si: 0.25% to 2.50%, Mn: 1.00% to 5.00%, P: 0.100% or less, S: 0.010% or less, sol. Al: 0.001% to 2.500, N: 0.020% or less, and a balance composed of iron and impurities, a metal structure contains greater than 5.0 vol % of retained austenite and greater than 5.0 vol % of tempered martensite, and satisfies a C content in the retained austenite being 0.85 mass % or more.

Abstract: An electric resistance welded steel pipe for a torsion beam, in which a base metal portion includes, in terms of % by mass, 0.04 to 0.12% of C, 0.03 to 1.20% of Si, 0.30 to 2.50% of Mn, 0.08 to 0.24% of Ti, 0.005 to 0.500% of Al, 0.01 to 0.06% of Nb, and 0.0005 to 0.0100% of N, a balance including Fe and impurities, wherein Vc90, defined by the following Formulae (i) and (ii), is 200 or more, a mass ratio of Ti content to C content is from 0.85 to 5.00, an areal ratio of ferrite is 80% or more, an average crystal grain size of ferrite crystal grains is 10 ?m or less, and an average aspect ratio of ferrite crystal grains is 2.0 or less, in a metallographic microstructure of a central portion in a wall thickness direction of the base metal portion; log Vc90=2.94?0.75(?a?1)??Formula (i); ?a=2.7C+0.4Si+Mn+0.45Ni+0.8Cr+Mo??Formula (ii).

Abstract: A manufacturing method of a steel component includes: heating a steel sheet in a carburizing atmosphere to form a carburized layer on a surface of the steel sheet, the steel sheet having: a chemical composition represented by: in mass %, C: 0.0005 to 0.1%; Si: 0.01 to 2.0%; Mn: 0.05 to 3.0%; Al: 0.9% or less; P: 0.05% or less; S: 0.01% or less; Ti: 0.0 to 0.2%; Nb: 0.0 to 0.1%; Cr: 0 to 2%; Mo: 0.0 to 0.2%; B: 0.000 to 0.005%; and the balance: Fe and impurities; and a steel structure represented by ferrite with an area fraction of 70% or more; and forming the steel sheet by using metal dies, and performing quenching on the steel sheet in a state of housing the steel sheet in the metal dies to transform the carburized layer into martensite and make a part of the steel sheet on the further inside than the carburized layer to be a steel structure represented by ferrite with an area fraction of 50% or more.

Abstract: An evaluation method of a plastic material includes: a first shearing process of performing simple shearing deformation with respect to a first plastic sheet; a second shearing process of performing simple shearing deformation with respect to a second plastic sheet; a first partial stress-strain curve data obtaining process of obtaining first partial stress-strain curve data; a second partial stress-strain curve data obtaining process of obtaining second partial stress-strain curve data; and a synthesized stress-strain curve data obtaining process of obtaining synthesized stress-strain curve data based on the first partial stress-strain curve data and the second partial stress-strain curve data.

Abstract: A non-oriented magnetic steel sheet includes a specific chemical composition represented by, in mass %: Si: 3.0% to 3.6%; Al: 0.50% to 1.25%; Mn: 0.5% to 1.5%; Sb or Sn or both of them: [Sb]+[Sn]/2 is 0.0025% to 0.05% where [Sb] denotes an Sb content and [Sn] denotes an Sn content; P: 0.010% to 0.150%; Ni: 0.010% to 0.200%; C: 0.0010% to 0.0040%; and others. The thickness of the non-oriented magnetic steel sheet is 0.15 mm to 0.30 mm. the non-oriented magnetic steel sheet includes magnetic properties represented by, where t denotes a thickness (mm) of the non-oriented magnetic steel sheet: a magnetic flux density B50: “0.2×t+1.52” T or more; a magnetic flux density difference ?B50: 0.08 T or less; core loss W10/50: 0.95 W/kg or less; and core loss W10/400: “20×t+7.5” W/kg or less. A ratio of a number of intergranular carbides precipitated in grains relative to a sum of the number of the intergranular carbides and a number of grain boundary carbides precipitated on grain boundaries is 0.50 or less.

Abstract: A high-strength hot-dip galvanized steel sheet containing a main component, the steel sheet having at least 40 wt. % of ferrite as a main phase in terms of the volumetric ratio, and 8-60% inclusive of residual austenite, the remaining structure comprising one or more of bainite, martensite, or pearlite. Austenite particles within a range where the average residual stress (sigmaR) thereof satisfies the expression ?400 MPa<=sigmaR<=200 MPa (formula (1)) are present in an amount of 50% or more in the hot-dip galvanized steel sheet. The surface of the steel sheet has a hot-dip galvanized layer containing less than 7 wt. % of Fe, the remainder comprising Zn, Al and inevitable impurities.

Abstract: An amount of wear of a railroad vehicle wheel flange online while traveling in a curved section is directly measured. A laser rangefinder 3 is installed on an outer track side in a rounded curve section of a railroad track. When a railroad vehicle travels through the rounded curve section, the laser rangefinder 3 measures a distance to a front rim surface of a wheel on an outer track side of a wheelset in a forward direction of travel of a bogie forming a vehicle. The amount of wheel flange wear is obtained by comparing this measured distance with a previous measurement of the measured distance. It is then possible to control the amount of wheel flange wear when traveling in a curved section, thus making it possible to quickly find wheels having flange wear that has exceeded a control range and ensure safety during travel of the railroad vehicle.

Abstract: A spring steel includes a predetermined chemical composition and a composite inclusion having a maximum diameter of 2 ?m or more that TiN is adhered to an inclusion containing REM, O and Al, in which the number of the composite inclusion is 0.004 pieces/mm2 to 10 pieces/mm2, the maximum diameter of the composite inclusion is 40 ?m or less, the sum of the number density of an alumina cluster having the maximum diameter of 10 ?m or more, MnS having the maximum diameter of 10 ?m or more and TiN having the maximum diameter of 1 ?m to 10 pieces/mm2.