Abstract: [Object] To provide a nitrided plate part that exhibits fatigue strength equivalent to or better than that of a carburized member, and a method for producing the same. [Solution] Provided is a nitrided plate part having predetermined components and structure. Nitrogen average content in a range in which a distance from a sheared end face of the part toward an interior of the nitrided plate part in a sheared end face normal direction is equal to or greater than 0.05 mm and equal to or less than 0.10 mm is equal to or greater than 0.4000% and equal to or less than 1.2000% in mass %, and minimum nitrogen content in a range in which the distance is equal to or greater than 0.015 mm and equal to or less than 0.200 mm is 0.0600% or more. After uncoiling a steel sheet coil, stretch and compressive deformation in a range of equal to or greater than 0.03% and equal to or less than 3.00% in amount of plastic strain are alternately applied to a surface layer of a steel sheet.

Abstract: A hot stamping steel material, which secures good hydrogen embrittlement resistance even when the steel sheet after hot stamping is subjected to processing leading to remaining of stress, such as piercing and which is easily practicable, wherein the steel sheet has the chemical composition of: C: 0.18 to 0.26%; Si: more than 0.02% and not more than 0.05%; Mn: 1.0 to 1.5%; P: 0.03% or less; S: 0.02% or less; Al: 0.001 to 0.5%; N: 0.1% or less;O: 0.001 to 0.02%; Cr: 0 to 2.0%; Mo: 0 to 1.0%; V: 0 to 0.5%; W: 0 to 0.5%; Ni: 0 to 5.0%; B: 0 to 0.01%; Ti: 0 to 0.5%; Nb: 0 to 0.5%; Cu: 0 to 1.0%; and balance: Fe and impurities, in terms of % by mass, the concentration of a Mn-containing inclusion is not less than 0.010% by mass and less than 0.25% by mass, and the number ratio of a Mn oxide to the inclusion having a maximum length of 1.0 to 4.0 pm is 10.0% or more.

Abstract: A filament for a high strength steel cord has a wire diameter R of 0.1 mm to 0.4 mm, and includes, in a chemical composition, by mass %: C: 0.70% to 1.20%; Si: 0.15% to 0.60%; Mn: 0.10% to 1.00%; N: 0.0010% to 0.0050%; Al: more than 0% and 0.0100% or less; and a remainder of Fe and impurities, in which a surface part and a central part are included, a thickness of the surface part is 0.01×R to 0.10×R, the central part includes a pearlite structure in a proportion of 95% to 100% by area %, a C content of the surface part is 40% to 95% of a C content of the central part, and a ratio of a thickness of a lamellar cementite at a center of the thickness of the surface part to a thickness of a lamellar cementite in the central part is 95% or less, whereby high strength and workability can be achieved and cracking or the like caused by a delamination phenomenon can be prevented.

Abstract: The present invention is a secondary cooling method and a secondary cooling device for a casting product casted in a continuous casting machine, the continuous casting machine including, in a secondary cooling zone below a mold, a plurality of pairs of support rolls that support the casting product from both sides of the casting product in a thickness direction, a cooling device being disposed between support rolls adjacent to each other along a casting direction of the continuous casting machine, the cooling device including a coolant pipe that supplies a coolant, and a coolant guide plate with a flat plate shape for spreading the coolant on the casting product, the coolant guide plate being disposed parallel to and spaced in a perpendicular direction from a surface of the casting product.

Abstract: The transverse flux induction heating device is allows an alternating magnetic field to intersect the sheet face of a conductive sheet which is conveyed in one direction, thereby inductively heating the conductive sheet. The transverse flux induction heating device includes a heating coil disposed such that a coil face faces the sheet face of the conductive sheet; a core around which the heating coil is coiled; a shielding plate formed of a conductor and disposed between the core and a side end portion in the direction perpendicular to a conveyance direction of the conductive sheet; and a non-conductive 10 soft magnetic material which is attached to the shielding plate, wherein the shielding plate is interposed between the core and the non-conductive soft magnetic material.

Abstract: The present invention adopts a hot rolled bar or hot rolled wire rod including a chemical composition including, by mass %, C: 0.05 to 0.30%, Si: 0.30 to 0.60%, Mn: 0.40 to 1.0%, S: 0.008 to less than 0.040%, Cr: 1.60 to 2.00%, Mo: 0.1% or less, Al: 0.025 to 0.05%, N: 0.010 to 0.025%, Ti: 0.003% or less, Bi: 0.0001 to 0.0050%, and a remainder including Fe and impurities, in which amounts of P and O in the impurities are respectively P: 0.025% or less and O: 0.002% or less; in which a microstructure includes ferrite-pearlite or ferrite-pearlite-bainite, and an Expression (1) is satisfied. 1.70?Cr+2×Mo?2.

Abstract: A soft nitrided induction hardened steel part which is excellent in bearing fatigue strength comprised of a predetermined chemical composition wherein a dissolved N concentration from the surface to 0.2 mm depth is 0.05 to 1.50%, a Vicker's hardness from the surface to 0.2 mm depth after tempering at 300° C. is HV 600 or more, and t/r?0.35 when an effective hardened layer depth “t” is 0.5 mm or more and a radius of a breakage risk site or half of the thickness is “r” (mm).

Abstract: A piercing plug of the present invention includes: a plug body; a Ni—Cr layer formed on a surface of the plug body; and a sprayed coating formed on a surface of the Ni—Cr layer. The plug body contains, by mass %, 20 to 30% of Cr, 30 to 55% of Ni, 0.005 to 0.5% of C, 0.1 to 1.0% of Si, 0.2 to 1.5% of Mn, and at least one of Mo and W which satisfy a following conditional expression (A), and remainder including Fe and impurities. 1.5%?Mo+0.5W?8.

Abstract: A composition for solid coating formation, includes a mixed solvent including water and a dipolar aprotic solvent, a powdery organic resin which is partially soluble at least in the dipolar aprotic solvent. The powdery organic resin is dissolved or dispersed in the mixed solvent.

Abstract: A steel according to an aspect of the present invention has a chemical composition within a predetermined range, in which a hardenability index Ceq ranges from greater than 7.5 to smaller than 44.0, an AlN precipitation index IAlN ranges from greater than 0.00030 to smaller than 0.00110, a metallographic structure includes ferrite ranging from 85 to 100 area %, an average distance between sulfides, which are observed in a cross section parallel to a rolling direction of the steel and have an equivalent circle diameter ranging from 1 ?m or greater to smaller than 2 ?m, is shorter than 30.0 ?m, and a presence density of the sulfides, which are observed in the cross section parallel to the rolling direction of the steel and have an equivalent circle diameter ranging from 1 ?m or greater to smaller than 2 ?m, is 300 pieces/mm2 or more.

Abstract: Provided is a method for manufacturing a round billet of Ni-containing high alloy including steps of continuously casting a molten steel by using a casting mold, thereby obtaining a rectangular billet, and shaping the rectangular billet into round billet by forging/rolling, wherein the casting mold has a shape such that a w/h ratio between long side length (w) and short side length (h) of a cross section of the rectangular billet perpendicular to the casting direction of rectangular billet is 1.0 to 2.0, the chemical composition of molten steel is, by mass %: C: 0.005 to 0.250%, Si: 0.05 to 2.00%, Mn: 0.05 to 3.00%, P: 0.04% or less, S: 0.004% or less, Cu: 0.01 to 3.00%, Cr: 10 to 35%, Ni: 10 to 80%, Mo: 1.5 to 10.0%, Al: 0.001 to 0.300%, N: 0.001 to 0.300%, W: 0.00 to 6.00%, Ti: 0.00 to 2.00%, and the balance: Fe and impurities.

Abstract: A method for manufacturing a forged steel roll comprises: casting, by the ESR method, a steel ingot which contains, by mass %, C: 0.3% or more, Si: 0.2% or more, Cr: 2.0-13.0% and Mo: 0.2% or more, and further contains Bi at 10-100 ppm by mass; and forging the steel ingot to manufacture the roll. According to this method, since freckle defects can be sealed near the center of the steel ingot, the roll can be stably used over a long period of time.

Abstract: A method of reheating a rail weld zone after rails were welded, a distance C between a reheating region P of a rail web portion 2 and a welding center Q is set to more than or equal to 0.2 times and less than or equal to three times a HAZ length Lh of the rail weld zone. A length B of the reheating region P may be more than or equal to 0.5 times and less than or equal to five times the HAZ length Lh of the rail weld zone. A height A of the reheating region P may be more than or equal to 0.2 times a height Hw of the rail web portion 2. A temperature Th reached in a reheating process at a center of the reheating region P may be higher than or equal to 400° C. and lower than or equal to 750° C.

Abstract: A roughly shaped material for a rolling bearing of the present invention is produced by forging a steel composed of a high-carbon chrome bearing steel containing 0.7 mass % to 1.2 mass % of a carbon, and 0.8 mass % to 1.8 mass % of a chromium to a predetermined shape while heating the steel to a forging temperature in a range of (Ae1 point+25° C.) to (Ae1 point+105° C.), cooling a forged article to a temperature of Ae1 point or lower, and performing an annealing in which the forged article that is obtained is heated to a soaking temperature in a range of (Ae1 point+25° C.) to (Ae1 point+85° C.), the forged article is retained for 0.5 hours or longer, and the forged article is cooled down to 700° C. or lower at a cooling rate of 0.30° C./s or slower.

Abstract: Provided is a steel material shearing method that enables highly productive and low-cost production of a steel material with a sheared surface having excellent hydrogen embrittlement resistance, fatigue strength, and stretch flangeability. The shearing method comprises making a clearance between a die and a punch 5 to 80% of a sheet thickness of a workpiece, shearing the workpiece using the punch, and, by utilizing a punched material punched out by the punch, pressing an end face of the punched out material against the sheared surface of the worked material on the die to produce a steel sheet with a sheared edge having excellent hydrogen embrittlement resistance and fatigue strength.

Abstract: A seamless steel pipe has a carbon equivalent Ceq of 0.50% to 0.58%, and contains specified carbides containing Mo at a ratio of 50 mass % or more, V, and at least one selected from the group consisting of Ti and Nb, and having a size of 20 nm or more.

Abstract: A steel bar according to one embodiment of the present invention includes predetermined chemical composition, wherein a quenching deflection in a cross section is 1.5 mm or less, wherein ?max and ?min is 1.5 mm or less, wherein a structure in a surface layer area includes 10 area % or less of ferrite and a remainder including one or more selected from a group consisting of a bainite and a martensite, wherein an average value of the grain size of a bcc phase in the surface layer area is 1.0 to 10.0 ?m, wherein an average value of the grain size of the bcc phase in a center area is 1.0 to 15.0 ?m, wherein a hardness of a region of which a depth from the surface is 50 ?m is Hv200 to Hv500, and wherein a total decarburized layer thickness DM-T is 0.20 mm or less.

Abstract: The present invention provides a method for inspecting a crankshaft, which enables accurate detection of defects which occur partially in the crankshaft, such as underfills and dent flaws, by discriminating these defects from bending and torsion over an entire length of the crankshaft.

Abstract: A grain-oriented magnetic steel sheet includes grooves each of which extends in a direction intersecting a transportation direction, the grooves being formed at predetermined pitches PL in the transportation direction by laser beam irradiation, in which a relationship between a standard deviation value D and the pitch PL satisfies the following expression (1), the standard deviation value D being a standard deviation of distances between a linear approximation line, which is obtained from a center line of each of the grooves in a groove width direction by a least-squares method, and respective positions on the center line, and an average angle formed between tangent lines of the respective positions on the center line and a direction perpendicular to the transportation direction is more than 0° to 30°. [Expression 1] 0.

Abstract: The present invention provides spring steel used for spring steel wire achieving both high strength and cold coilability and spring steel wire, that is, spring steel containing, by mass %, C: 0.45 to 0.70%, Si: 1.0 to 3.0%, Mn: 0.05 to 2.0%, P: 0.015% or less, S: 0.015% or less, N: 0.0015 to 0.0200%, and t-O: 0.0002 to 0.01 and further limiting Al?0.01% and Ti?0.003%. Further, it is characterized by satisfying the following regarding the cementite-based spherical carbides present at an observed plane, an occupied area ratio of grains with a circle equivalent diameter of 0.2 ?m or more of 7% or less, a density of presence of grains with a circle equivalent diameter of 0.2 to 3 ?m of 1/?m2 or less, and a density of presence of grains with a circle equivalent diameter 3 ?m or more of 0.