Abstract: This torsion beam manufacturing method is a method of manufacturing a torsion beam that includes a uniformly shaped closed cross-sectional portion of which a cross section orthogonal to a longitudinal direction is a closed cross section having a substantial V-shape or a substantial U-shape at any position in the longitudinal direction, and a shape changing portion which has a connection region leading to the uniformly shaped closed cross-sectional portion and including a closed cross section having a shape different from the shape of the closed cross section of the uniformly shaped closed cross-sectional portion. The torsion beam manufacturing method includes pulling process of applying a tensile force in the longitudinal direction to at least the connection region of a torsion beam material including the uniformly shaped closed cross-sectional portion and the shape changing portion, to obtain the torsion beam.

Abstract: To provide a technique capable of preventing or suppressing fatigue failure of a vehicle underbody part material by 3DQ. A vehicle underbody part material relating to this disclosure includes: a quenched and bent steel pipe; and a plating film layer provided on a surface of the steel pipe and containing 30 mass % or more of Al and having an Al—Fe alloy existing in a surface thereof.

Abstract: A cold-rolled steel according to the present invention has a predetermined chemical composition, satisfies (5×[Si]+[Mn])/[C]>10 when [C] is the amount of C by mass %, [Si] is the amount of Si by mass %, and [Mn] is the amount of Mn by mass %, includes 40% to 95% ferrite and 5% to 60% martensite in area fraction, and optionally further includes 10% or less pearlite in area fraction, 5% or less retained austenite in volume fraction, and less than 40% bainite in area fraction. The total of the area fraction of ferrite and the area fraction of martensite is 60% or more, the hardness of martensite measured with a nanoindenter satisfies H2/H1<1.10 and ?HM<20.

Abstract: A grain-oriented electrical steel sheet includes: a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, in which a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above. When a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5 ?m toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies predetermined conditions.

Abstract: An exhaust gas treatment method includes: burning a combustible component in exhaust gas by causing the exhaust gas, which is produced in an electric furnace, to flow into a slag holding furnace and supplying oxygen-containing gas into the slag holding furnace; causing the burned exhaust gas to flow from the slag holding furnace to a suction device through an exhaust gas pipe; adjusting an internal pressure of the electric furnace by introducing external air into the exhaust gas pipe through an opening portion provided in the middle of the exhaust gas pipe; and changing an area of the opening portion depending on a variation in the internal pressure of the electric furnace by using an opening area changing unit provided in the opening portion.

Abstract: A threaded connection includes a first and a second tubular component made up one with the other. A male element of the first component includes, on its external peripheral surface, a male inner lip including an inner ring with a minimum thickness Epi and a male threaded zone. One inner end of said male threaded zone is at a non-zero axial distance (Li) from a male distal end. A female element of the second component includes, in succession over its internal peripheral surface, a female inner recess disposed facing the male inner lip and a female threaded zone, such that in the made up position of the connection, a radial clearance subsists between the male inner ring and the female inner recess and an internal seal is formed locally between the male inner lip and the female inner recess. The connection is such that 10%?Epi/Li.

Abstract: Provided is a press-formed article manufacturing method including a first step of pressing a blank with the first pressing apparatus to form a first intermediate formed article having a pair of bent portions that is bent to one side in the plate thickness direction and having a spacing between the bent portions that is narrower than the width of the top plate and equal to or more than the width of the top portion of the convex portion, and a second step of moving the second die relative to the second punch side punch with respect to the die pad and the second punch and forming a second intermediate formed article, having the standing wall formed therein, with the second die and the second punch, in a state where a portion between the bent portions is sandwiched between the die pad protruding from the second die to the second punch side punch, and the convex portion, with one side of the first intermediate formed article in the plate thickness direction as the convex portion side of the second pressing apparat

Abstract: A steel sheet of the present invention has a steel structure obtained by performing a soaking at a dual phase region temperature of Ac1 temperature or higher and lower than Ac3 temperature for a soaking time of 15 seconds or longer and 35 seconds or shorter, next, performing a primary cooling to a temperature range of 250° C. or higher and 380° C. or lower within 3 seconds at a cooling rate of 0.5 ° C./s or more and 30° C./s or less, and performing a retention in a temperature range of 260° C. or higher and 370° C. or lower for 180 seconds or longer and 540 seconds or shorter, in which a yield ratio is 65% or less and tensile strength is 590 MPa or more after the primary cooling.

Abstract: A scale composition determination device (10) determines that Fe2O3 has been generated in the outermost layer of a scale (SC) in the case where the absolute value of a difference between temperatures of a steel material SM measured by radiation thermometers (20a, 20b) is equal to or more than a predetermined temperature, and determines that Fe2O3 has not been generated in the outermost layer of the scale (SC) in the case where the absolute value of the difference between the temperatures of the steel material SM measured by the radiation thermometers (20a, 20b) is not equal to or more than the predetermined temperature.

Abstract: Provided is a mechanical joining apparatus enabling reduction of breakage of the area around a rivet of a joint obtained by riveting, the apparatus comprising a punch and die, blank holder, first power device, second power device and cooling device, wherein the first power device is configured to start supply of current through the holder and die so as to raise the temperature of the sheets before the punch drives in the rivet, the second power device is configured to start supply of current through the punch and die so as to supply current through and heat treat the rivet after the punch drives in the rivet, and the cooling device is connected to the punch and is configured to cool the rivet after the rivet is heat treated.

Abstract: The method includes treating a metal sheet having a bcc structure and a surface satisfying conditions (a) or (b), molding the metal sheet to cause plane strain tensile deformation and biaxial tensile deformation, and allowing at least one part of the metal sheet to have a sheet thickness decrease rate of from 10% to 30%. Condition (a): an area fraction of crystal grains having a crystal orientation of 15° or less relative to a (001) plane parallel to a surface of the metal sheet is from 0.20 to 0.35. Condition (b): the area fraction of crystal grains having a crystal orientation of 15° or less relative to a (001) plane parallel to a surface of the metal sheet is 0.45 or less, the average crystal grain size thereof is 15 ?m or less. The molded product satisfies conditions (a) or (b).

Abstract: The present invention provides a method of manufacturing a press-formed product. The method includes: a first process of preparing a material that is long in a first direction, and when viewed in a cross-section perpendicular to the first direction, the cross-section is a hollow cross-section that is long in a second direction perpendicular to the first direction; and a second process of bending the material in a direction intersecting the second direction when viewed from the first direction, by pressing the material along the second direction.

Abstract: A grain-oriented electrical steel sheet includes a steel layer and an insulation coating arranged in directly contact with the steel layer thereon. The steel layer includes, as a chemical composition, by mass %, 2.9 to 4.0% of Si, 2.0 to 4.0% of Mn, 0 to 0.20% of Sn, and 0 to 0.20% of Sb. In the steel layer, a silicon content and a manganese content expressed in mass % satisfy 1.2%?Si?0.5×Mn?2.0%, and a tin content and an antimony content expressed in mass % satisfy 0.005%?Sn+Sb?0.20%.

Abstract: A method for producing a metal sheet with raised lines uses a rolling mill including roll stands. In a preparing step, a grooved roll is prepared, the grooved roll including grooves. In a choosing step, a stand at least one stage before the last stand is chosen. In an incorporating step, the grooved roll is incorporated in as an upper roll of the chosen, specified stand. In a forming step, a workpiece is formed into a metal sheet with raised lines formed corresponding to the respective grooves. In the forming step, a maximum rolling reduction achieved by rolls of the specified stand is set to a provisional value that is lower than a required value. After the leading edge of the workpiece reaches the stand next to the specified stand, the maximum rolling reduction of the specified stand is changed to the required value.

Abstract: An electrical steel sheet (1) includes a base material (2) of electrical steel, and an insulating film (3) formed on a surface of the base material (2). Three conditions (1.8?3[Fe]/[P]+?nM[M]/[P]?3.6, 0.6??nM[M]/[P]?2.4, and 0.6?3[Fe]/[P]?2.4) are satisfied in a region of 50 area % or more of a cross section parallel to a thickness direction of the insulating film. [Fe] denotes a proportion (atom %) of Fe, [P] denotes a proportion (atom %) of P, [M] denotes a proportion (atom %) of each of Al, Zn, Mg and Ca, and nM denotes a valence of each of Al, Zn, Mg and Ca.

Abstract: A shape measurement apparatus includes: a linear light source that includes a superluminescent diode and applies linear light spreading in a width direction of the strip-shaped body to a surface of the strip-shaped body; a screen on which reflected light of the linear light off the surface of the strip-shaped body is projected; an area camera that captures an image of the reflected light of the linear light projected on the screen; and an arithmetic processing apparatus that calculates the surface shape of the strip-shaped body using the captured image of the reflected light of the linear light captured by the area camera.

Abstract: There is provided a power supply device that supplies an output current to an electric processing device which performs electric processing on workpieces. The device includes: a first power supply; a magnetic energy recovery switch that receives a current supplied from the first power supply, and converts the received current into the output current; and a control unit that controls the magnetic energy recovery switch such that an electric current frequency of the output current includes a first electric current frequency and a second electric current frequency which are different from each other within a one-time electric processing time using the electric processing device.

Abstract: A structural member for automobiles to be disclosed includes a press formed product. The press formed product includes two vertical wall sections and a top plate section that joins the two vertical wall sections to each other. At least part of the top plate section is provided with a protruding section that is a steel sheet extending from the top plate section and so folded over against itself as to protrude. The protruding section protrudes from the top plate section toward the interior of the press formed product and extends along the longitudinal direction of the press formed product. With the thus configured structural member, a structural member for automobiles that has a good characteristic in a three-point bending test is provided.

Abstract: A rolled wire rod for spring steel contains, as a chemical composition, by mass %: C: 0.42% to 0.60%; Si: 0.90% to 3.00%; Mn: 0.10% to 1.50%; Cr: 0.10% to 1.50%; B: 0.0010% to 0.0060%; N: 0.0010% to 0.0070%; Mo: 0% to 1.00%; V: 0% to 1.00%; Ni: 0% to 1.00%; Cu: 0% to 0.50%; Al: 0% to 0.100%; Ti: 0% to 0.100%; Nb: 0% to 0.100%; P: limited to less than 0.020%; S: limited to less than 0.020%; and a remainder including Fe and impurities, the carbon equivalent (Ceq) is 0.75% to 1.00%, the area fraction of tempered martensite and bainite included in a microstructure is 90% or greater, the tensile strength is 1,350 MPa or less, and the reduction of area is 40% or greater.

Abstract: A steel sheet for hot stamping includes a steel structure represented by an area fraction of bainite, fresh martensite and tempered martensite: 80% or more in total, and a product of a number density (pieces/?m2) of carbides and a proportion of carbides precipitated into prior austenite grains in carbides: 0.50 or more.