Abstract: A steel bar for hot forging according to the present disclosure has a chemical composition consisting of, in mass percent, C: 0.05 to 0.40%, Si: 0.05 to 0.50%, Mn: 1.51 to 3.50%, P: 0.010 to 0.100%, S: 0.30% or less, Cr: 0.05 to 2.50%, V: 0.10 to 0.75%, Ti: 0.005% to 0.250%, Al: 0.005 to 0.060%, and N: 0.002 to 0.020%, with the balance being Fe and impurities, and satisfying Formula (1). A number density of TiNs having a circle equivalent diameter of not less than 20 ?m in steel is 0.3 to 4.0/mm2: 0.48?C+0.11Mn+0.08Cr+0.75V+0.20Mo?1.50??(1) where, symbols of elements in Formula are to be substituted by contents of corresponding elements (in mass percent).

Abstract: The present invention provides steel sheet excellent in cold formability and ductility after heat treatment and a method for production thereof. The steel sheet of the present invention is steel sheet which has a chemical composition containing, by mass %, C: 0.10 to 0.40%, Si: 0.30 to 1.00%, Mn: 0.30 to 1.00%, Al: 0.001 to 0.10%, P: 0.0001 to 0.02%, and S: 0.0001 to 0.01% and having a balance of Fe and impurities, which steel sheet characterized in that a ratio (B/A) of the number of carbides at the ferrite grain boundaries (B) to the number of carbides inside the ferrite grains (A) is over 1, a ferrite grain size is 5 ?m to 50 ?m, an average grain size of carbides is 0.4 ?m to 2.0 ?m, a pearlite area ratio is 6% or less, and a Vicker's hardness is 120 HV to 170 HV.

Abstract: A process for producing a spring or torsion bar from a steel wire by hot forming may involve providing a steel wire; thermomechanically forming the steel wire; cooling the steel wire thermomechanically; cutting the steel wire to length to give rods; heating the rods; hot forming the rods; and tempering the rods to give a spring or torsion bar, comprising quenching the rods to give a spring or torsion bar to a first cooling temperature, reheating the spring or torsion bar to a first annealing temperature, and cooling the spring or rod to a second cooling temperature. Further, in some examples, the cooling of the steel wire may be cooled to a temperature below a minimum recrystallization temperature such that at least a partly ferritic-pearlitic structure is established in the steel wire.

Abstract: A wire rod for a steel cord has a wire diameter R of 3.5 mm to 8.0 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 50 ?m to 0.20×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 even after a finish drawing process and cracking or the like caused by a delamination phenomenon can be prevented.

Abstract: A steel wire according to an aspect of the present invention includes a predetermined chemical composition, in which a wire diameter R of the steel wire is 1.0 mm to 3.5 mm, a soft portion is formed along an outer circumference of the steel wire, the Vickers hardness of the soft portion is lower than that of a position of the steel wire at a depth of ¼ of the wire diameter R by Hv 30 or higher, the thickness of the soft portion is 5 ?m to 0.1×R mm, the metallographic structure of a center portion of the steel wire contains 95% to 100% of pearlite by area %, the average lamellar spacing of pearlite in a portion from a surface of the steel wire to a depth of 5 ?m is less than that of pearlite at the center of the steel wire, the difference between the average lamellar spacing of pearlite in the portion from the surface of the steel wire to the depth of 5 ?m and the average lamellar spacing of pearlite at the center of the steel wire is 3 nm to 60 nm, and the tensile strength is 1100 MPa or higher.

Abstract: A wire-form spray material, in particular for arc wire spraying, essentially comprising iron. The spray material is formed at least with carbon as a microalloy such that upon solidification of the spray material a fine pearlitic, bainitic, martensitic structure arises in which finely dispersed nitrides are present.

Abstract: A chisel includes an elongate shank portion composed of a first steel, and a working end portion composed of a second steel that is different than the first steel. The working end portion is joined to the shank and configured to chisel a workpiece. The joined shank portion and working end portion has been heat treated to cause the first steel of the shank portion to adopt a first microstructure comprising bainite, the second steel of the working end portion to adopt a second microstructure comprising martensite, and the working end portion to have a greater hardness than the shank portion.

Abstract: Provided is a high-carbon steel wire which gives steel wires having high strength and has excellent suitability for wiredrawing and which after being wiredrawn, has excellent fatigue properties. The high-carbon steel wire has an adequately regulated chemical composition and has a pearlite structure in an areal proportion of 90% or more. In 2,000 ?m2 of the pearlite structure, the number of BN compound grains having an equivalent-circle diameter of 100 nm or more but less than 1,000 nm is 100 or less (including 0) and the number of BN compound grains having an equivalent-circle diameter of 1,000 nm or more is 10 or less (including 0).

Abstract: A method of manufacturing a steel wire material that contains 0.05%-1.2% C (“%” means “% by mass,” same hereinafter for chemical components.), 0.01%-0.7% Si, 0.1%-1.5% Mn, 0.02% max. P (not including 0%), 0.02% max. S (not including 0%), and 0.005% max. N (not including 0%), with the remainder being iron and unavoidable impurities. The steel wire material has a scale 6.0-20 ?m thick and holes of an equivalent circle diameter of 1 ?m max. in said scale that occupy 10% by area max. Said scale does not detach in the cooling process after hot rolling or during storage or transportation but can readily detach during mechanical descaling.

Abstract: Disclosed is a spring steel wire rod that comprises C in a range of 0.35 to 0.65% (mass %, the same applies to respective elements described hereinafter), Si in a range of 1.4 to 2.2%, Mn in a range of 0.10 to 1.0%, Cr in a range of 0.1 to 2.0%, P not more than 0.025% (0% excluded), and S not more than 0.025% (0% excluded), balance comprising iron, and unavoidable impurities, wherein an average grain size Dc of a central part of the steel wire rod is not more than 80 ?m while an average grain size Ds of a surface layer part of the steel wire rod is not less than 3.0 ?m.

Abstract: This case hardening steel has a chemical composition including, by mass %: C: 0.1 to 0.6%; Si: 0.02 to 1.5%; Mn: 0.3 to 1.8%; P: 0.025% or less; S: 0.001 to 0.15%; Al: over 0.05 to 1.0%; Ti: 0.05 to 0.2%; N: 0.01% or less; and O: 0.0025% or less, and further including, by mass %, one or more of Cr: 0.4 to 2.0%, Mo: 0.02 to 1.5%, Ni: 0.1 to 3.5%, V: 0.02 to 0.5%, and B: 0.0002 to 0.005%, and the balance consisting of iron and unavoidable impurities.

Abstract: A reduced nickel-chromium alloy component having by weight about 0.38% to about 0.43% C, about 0.15% to about 0.30% Si, about 1.00% to about 1.25% Mn, about 0.75% to about 0.90% Ni, about 1.00% to about 1.30% Cr, about 0.25% to about 0.35% Mo, about 0.05% to about 0.12% V, up to about 0.015% S, up to about 0.015% P, up to about 0.15% Cu, and balance iron and incidental impurities. The component has a hardenability corresponding to an ideal diameter of greater than about 10 inches.

Abstract: Fatigue damage resistant metal or metal alloy wires have a submicron-scale or nanograin microstructure that demonstrates improved fatigue damage resistance properties, and methods for manufacturing such wires. The present method may be used to form a wire having a nanograin microstructure characterized by a mean grain size that is 500 nm or less, in which the wire demonstrates improved fatigue damage resistance. Wire manufactured in accordance with the present process may show improvement in one or more other material properties, such as ultimate strength, unloading plateau strength, permanent set, ductility, and recoverable strain, for example. Wire manufactured in accordance with the present process is suitable for use in a medical device, or other high end application.

Abstract: The present invention relates to a wire rod used in bolts for automobile engines, for example, and more specifically to a wire rod having an improved resistance to hydrogen delayed fracture, to a manufacturing method for same, to a bolt using same and a method for manufacturing the bolt. Provided are a high strength wire rod having a superior resistance to hydrogen delayed fracture and a method for manufacturing same, a high strength bolt using the wire rod and a method for manufacturing same, wherein. the wire rod comprises, 0.3-0.7 wt % C, 0.05-2.0 wt % Si, 0.7-1.5 wt % Mn, 0.01-0.1 wt % Ni, and 30-70 ppm La, and the remainder thereof is comprised by Fe and inevitable impurities.

Abstract: High modulus turbine shafts and high modulus cylindrical articles are described as are the process parameters for producing these shafts and cylindrical articles. The shafts/articles have a high Young's modulus as a result of having high modulus <111> crystal texture along the longitudinal axis of the shaft/article. The shafts are produced from directionally solidified seeded <111> single crystal cylinders that are axisymmetrically hot worked before a limited recrystallization process is carried out at a temperature below the recrystallization temperature of the alloy. The disclosed process produces an intense singular <111> texture and results in shaft or cylindrical article with a Young's modulus that is at least 40% greater than that of conventional nickel or iron alloys or conventional steels.

Abstract: A bead wire has a composition of Mn: 5-35 at % and Al: 5-20 at % and the remainder being Fe and inevitable impurities, in which a steel structure is an austenite single-phase structure, and achieves weight reduction and high ductility without reducing strength.

Abstract: Provided is a wire rod having high strength and high toughness, which suppresses the generation of surface oxide and has superior surface properties through uniform oxide formation, and to a method for manufacturing same. For this purpose, a wire rod comprising 0.005˜ to 0.02 wt. % of Sb, having superior surface properties, high strength and high toughness, and a method for manufacturing same are provided.

Abstract: The present invention provides a wire rod with a composition at least including: C: 0.95-1.30 mass %; Si: 0.1-1.5 mass %; Mn: 0.1-1.0 mass %; Al: 0-0.1 mass %; Ti: 0-0.1 mass %; P: 0-0.02 mass %; S: 0-0.02 mass %; N: 10-50 ppm; O: 10-40 ppm; and a balance including Fe and inevitable impurities, wherein 97% or more of an area in a cross-section perpendicular to the longitudinal direction of the wire rod is occupied by a pearlite, and 0.5% or less of an area in a central area in the cross-section and 0.5% or less of an area in a first surface layer area in the cross-section are occupied by a pro-eutectoid cementite.

Abstract: A wire rod and steel wire having superior magnetic characteristics and a method for manufacturing same, wherein the wire rod and the steel wire can be used in transformers, vehicles, electric or electronic products, or the like which require low iron loss and high permeability. Provided are a wire rod and steel wire having superior magnetic characteristics and a method for manufacturing same, wherein the wire rod or the steel wire comprises, by wt %, 0.03 to 0.05% of C, 3.0 to 5.0% of Si, 0.1 to 2.0% of Mn, 0.02 to 0.08% of Al, 0.0015 to 0.0030% of N, and the remainder being Fe and unavoidable impurities. The wire rod and steel wire having directional properties may be provided by a general manufacturing process without using expensive alloying elements and without having to add a manufacturing facility.

Abstract: Provided is a wire rod for use in mechanical structure connections, vehicle components, or the like, and more particularly, to a wire rod which has superior toughness without being subjected to a heat treatment, and the strength of which is ensured through a cold-drawing process. Tot his end, provided are a high-toughness cold-drawn non-heat-treated wire rod and a method for manufacturing the same, wherein the wire rod comprises in % by weight: 0.2 to 0.3% of carbon (C), 0.1 to 0.2% of silicon (Si), 2.5 to 4.0% of manganese (Mn), 0.035% or less (but not 0%) of phosphorus (P), 0.04% or less (but not 0%) of sulfur (S), the remainder being iron (Fe) and unavoidable impurities.

Abstract: The present invention provides a wire rod with a composition at least including: C: 0.95-1.30 mass %; Si: 0.1-1.5 mass %; Mn: 0.1-1.0 mass %; Al: 0-0.1 mass %; Ti: 0-0.1 mass %; P: 0-0.02 mass %; S: 0-0.02 mass %; N: 10-50 ppm; O: 10-40 ppm; and a balance including Fe and inevitable impurities, wherein 97% or more of an area in a cross-section perpendicular to the longitudinal direction of the wire rod is occupied by a pearlite, and 0.5% or less of an area in a central area in the cross-section and 0.5% or less of an area in a first surface layer area in the cross-section are occupied by a pro-eutectoid cementite.

Abstract: A high carbon steel wire material which is made of high carbon steel as a raw material for wire products such as steel cords, bead wires, PC steel wires and spring steel, allows for these wire products to be manufactured efficiently at a high wire drawing rate and has excellent wire drawability and a manufacturing process thereof. This high carbon steel wire material is made of a steel material having specific contents of C, Si, Mn, P, S, N, Al and O, and the Bcc-Fe crystal grains of its metal structure have an average crystal grain diameter (Dave) of 20 ?m or less and a maximum crystal grain diameter (Dmax) of 120 ?m or less, preferably an area ratio of crystal grains having a diameter of 80 ?m or more of 40% or less, an average sub grain diameter (dave) of 10 ?m or less, a maximum sub grain diameter (dmax) of 50 ?m or less and a (Dave/dave) ratio of the average crystal grain diameter (Dave) to the average sub grain diameter (dave) of 4.5 or less.

Abstract: This invention relates to an ultra-high-strength steel bar and to a method of manufacturing the same, in which the steel bar includes C: 0.05 to 0.45 wt %, Si: 0.10 to 0.35 wt %, Mn: 0.1 to 0.85 wt %, Cr: 0.6 to 1.20 wt %, and Mo: 0.05 to 0.35 wt %, with the remainder being Fe, wherein a martensite structure is formed at a surface layer and a fine ferrite structure is formed at a center layer.

Abstract: The present invention relates to a pre-heat treatment steel wire with high strength for a cold forging which is used as a material for an engine, chassy and parts (bolts and shafts) of a steering device. The method includes: cold drawing of a wire rod containing 0.15-0.40 wt % of C, less than 1.5 wt % of Si, 0.30-2.0 wt % of Mn, less than 0.03 wt % of P, less than 0.03 wt % of S and the remainder including Fe and unavoidable impurities; rapidly heating the cold drawn wire rod in a series of high frequency induction heating devices over Ac3 transformation point for 30-90 seconds and maintaining such a heated state; rapidly cooling the wire rod in the heated state by water or oil; executing a tempering process by heating the wire rod to 500° C.

Abstract: Provided is an ultra-fine grained, high-strength, high-toughness carbon steel wire rod manufactured through control of a microstructure by process control without addition of relatively expensive alloying elements. More particularly, the material provided is an ultra-fine grained, high-strength, high-toughness carbon steel wire rod having a microstructure including a ferrite structure having an area fraction of 60% or more and a cementite structure as a remainder, wherein an average grain diameter of ferrite grains is 15 ?m or less. Also provided is a method of manufacturing the wire rod.

Abstract: The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is hot rolled, the hot-rolled steel is coiled in a specified temperature range, and the coiled steel is subjected to patenting at a predetermined cooling rate, thereby affording a high-carbon steel wire excellent in workability. It is high-strength steel wire excellent in drawability comprising a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and having a pearlite block size of not less than 20 ?m and not greater than 45 ?m. The invention also provides a high-carbon steel wire excellent in ductility, which is manufactured by subjecting the wire rod to intermediate patenting and cold drawing and has a tensile strength of 2800 MPa or greater.

Abstract: Provided are a high-strength, high-manganese steel wire rod having excellent cold heading quality and not requiring spheroidizing and quenching-tempering treatments during manufacturing a bolt and a method of manufacturing a bolt using the steel wire rod. The method of manufacturing a steel wire rod includes heating a steel containing 12 to 25 wt % of Mn within a temperature range of 1100° C. to 1250° C., hot rolling the heated steel within a temperature range of 700° C. to 1100° C., and cooling the hot rolled steel to a temperature of 200° C. or less and cold caliber rolling or drawing to manufacture a steel wire rod.

Abstract: The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is heated in a specified temperature range to conduct post-reaustenization patenting and thereby obtain a high-carbon steel wire excellent in ductility that has a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and whose fracture reduction of area RA satisfies Expressions (1), (2) and (3) below: RA?RAmin??(1), where RAmin=a?b×pearlite block size (?m), a=?0.0001187×TS (MPa)2+0.31814×TS (MPa)?151.32??(2) b=0.0007445×TS (MPa)?0.3753??(3).

Abstract: A wire rod which is mainly composed of pearlite and has an area fraction of 5% or less of a non-pearlite structure composed of pro-eutectoid ferrite, degenerate-pearlite or bainite in a section, or has an area fraction of 10% or less of a non-pearlite structure in a portion from the surface to a depth of 100 ?m.

Abstract: Provided are a high-strength, high-toughness steel wire rod and a method of manufacturing the same. The steel wire rod has a composition including 0.07 wt % to 0.14 wt % of aluminum (Al) and nitrogen (N) wherein Al:N (where Al and N denote wt % of each element) is in a range of 15:1 to 25:1. Since a steel wire rod having sufficient strength and toughness improvement effects can be obtained with a simple alloy component, a steel wire rod capable of allowing processing such as cold forging to be performed without an additional heat treatment may be provided.

Abstract: The present invention provides a wire rod with a composition at least including: C: 0.95-1.30 mass %; Si: 0.1-1.5 mass %; Mn: 0.1-1.0 mass %; Al: 0-0.1 mass %; Ti: 0-0.1 mass %; P: 0-0.02 mass %; S: 0-0.02 mass %; N: 10-50 ppm; O: 10-40 ppm; and a balance including Fe and inevitable impurities, wherein 97% or more of an area in a cross-section perpendicular to the longitudinal direction of the wire rod is occupied by a pearlite, and 0.5% or less of an area in a central area in the cross-section and 0.5% or less of an area in a first surface layer area in the cross-section are occupied by a pro-eutectoid cementite.

Abstract: A wire rod or a steel wire of a bamboo nano-structure, whose mean grain diameter in a C-direction section is 200 nm or smaller, is prepared by applying a hot or warm working and additionally applying a cold working to a steel and next, by performing a forging, by a tool or a die such as cold pressure production, to a section, of a desired, limited site, other than a section parallel to an L-direction, an equiaxed nano-structure, whose mean grain diameter is 200 nm or smaller, is formed in this site. As a typical example of a formed article, there is enumerated a high strength micro screw in which a shaft outer diameter is 1.6 mm or smaller, a surface layer part of a head part recess has equiaxed nano-structure and a hardness Hv?300, and a screw main body portion has bamboo nano-structure and a hardness Hv?250.

Abstract: A high-carbon steel wire rod of high ductility for steel cord and the like is provided that experiences little breakage during drawing. The high-carbon steel wire rod of high ductility is a high-carbon steel wire rod fabricated by hot rolling that that has a carbon content of 0.7 mass % or greater, wherein 95% or greater of the wire rod metallographic structure is pearlite structure and the maximum pearlite block size of pearlite at the core of the hot-rolled wire rod is 65 ?m or less. The high-carbon steel wire rod of high ductility has a tensile strength in a range of {248+980×(C mass %)}±40 MPa} and a reduction of area of {72.8?40×(C mass %) %} or greater. The high-carbon steel wire rod of high ductility is characterized in that the average pearlite block size at the core of the hot-rolled wire rod constituted by ferrite grain boundaries of an orientation difference of 9 degrees or greater as measured with an EBSP analyzer is 10 ?m or greater and 30 ?m or less.

Abstract: A steel wire for a cold-formed spring according to the present invention contains a prescribed chemical component composition, wherein: a martensitic transformation start temperature MS1 shown by the following expression (1) is in the range from 280° C. to 380° C.; the austenite grain size number N of austenite grains is No. 12 or more; the grain boundary share of carbide precipitated along the austenite grain boundaries is 50% or less; the amount of retained austenite after austenitized and tempered is 20 vol. % or less; and the tensile strength is 2,000 MPa or more; MS1=550?361[C]?39[Mn]?20[Cr]??(1), where [C], [Mn] and [Cr] represent the contents (mass %) of C, Mn and Cr, respectively. Such a steel wire can: secure hot-rolling formability and subsequent drawability while aiming at higher strength and higher stress; moreover exhibit excellent corrosion resistance; and obtain a spring (mainly a suspension spring for an automobile) excellent also in fatigue strength which is a basic required characteristic.

Abstract: In an antibacterial stainless steel wire and its manufacturing method, a wire drawing process, a cold working process, or a solution treatment integrated with an ageing treatment are used for making a precipitation of copper into an independent phase and in a granular form uniformly distributed in a stainless steel substrate, such that the stainless steel wire has an antibacterial effect.

Abstract: The present invention provides a steel wire, including chemical components of: C: 0.7-1.2 mass %; Si: 0.05-2.0 mass %; and Mn: 0.2-2.0 mass %, with a balance including Fe and inevitable impurities, in which the steel wire has a pearlite structure, the average C concentration at a center portion of a ferrite phase in an outermost layer of the steel wire is 0.2 mass % or lower, and a residual compressive stress in the longitudinal direction of the steel wire in the outermost layer is 600 MPa or more.

Abstract: This case hardening steel has a chemical composition including, by mass %: C: 0.1 to 0.6%; Si: 0.02 to 1.5%; Mn: 0.3 to 1.8%; P: 0.025% or less; S: 0.001 to 0.15%; Al: over 0.05 to 1.0%; Ti: 0.05 to 0.2%; N: 0.01% or less; and O: 0.0025% or less, and further including, by mass %, one or more of Cr: 0.4 to 2.0%, Mo: 0.02 to 1.5%, Ni: 0.1 to 3.5%, V: 0.02 to 0.5%, and B: 0.0002 to 0.005%, and the balance consisting of iron and unavoidable impurities.

Abstract: The purposes of the present inventions are to provide a raw material for shot-peening materials wherein breaking a wire is prevented in obtaining a finished wire to improve the productivity, to provide a finished wire and a method of manufacturing shot-peening materials by which productivity is improved, and to provide shot-peening materials that are manufactured by that method. The finished wire, of which the area of carbides with a particle size of 2 ?m or less is 80% or more of the total area, is manufactured by the steps of wiredrawing a raw material to obtain a wire, and repeatedly annealing and cold-drawing the wire. The raw material for the shot-peening materials comprises, by mass %, 0.95-1.10% carbon, 0.15-0.30% silicon, 0.40% or less manganese, 0.020% or less phosphorus, 0.010% or less sulfur, 1.40-1.60% chromium, 0.0015% or less oxygen, and the remaining materials of iron and unavoidable impurities. The method of manufacturing the shot-peening materials uses that raw material.

Abstract: The invention relates to a method for the thermomechanical treatment of steel. According to said method, the parent material is heated to a temperature in excess of the re-crystallization temperature, the structure is austenitized, held at an equalized temperature and then formed and subsequently quenched to form martensite and tempered. Round steel bars, whose re-crystallization temperature is adjusted over the bar length in a compensation furnace, constitute the parent material. The round steel bars are subsequently re-modeled by cross-rolling, remaining substantially straight and after the critical deformation degree has been exceeded are subjected to dynamic re-crystallization processes. The round steel bars are then subjected to a post-heating process above the Ac3 temperature, in order to undergo a complete static re-crystallization and finally are quenched from the austenitic state to form martensite and tempered.

Abstract: There are provided a wire rod for drawing having superior strength and ductility and a method for manufacturing the same. The wire rod for drawing comprises, by weight: carbon (C): 0.87 to 1.0%, manganese (Mn): 0.1 to 0.60%, silicon (Si): 0.3 to 1.0%, sulfur (S): 0.010% or less (excluding 0%), phosphorus (P): 0.011% or less (excluding 0%), chromium (Cr): 0.1 to 0.5%, nitrogen (N): 0.007% or less (excluding 0%), and the balance of iron (Fe) and other inevitable impurities, wherein the sum of the Si and Cr contents satisfies the following equation: 0.6?Si+Cr?1.2 (the contents of Si and Cr is represented by ‘% by weight’), and the wire rod has a pearlite structure.

Abstract: In a double-sided engagement silent chain having inner link plates with inwardly protruding teeth, outermost link plates with outwardly protruding teeth, and outer link plates with outwardly protruding teeth, adjacent the outermost link plates, the plates are composed of a bainite and martensite mixed plate material. The bainite mixing ratio in the outermost link plates is higher than the bainite mixing ratio of the inner link plates and the adjacent outer link plates. The martensite mixing ratio of the inner link plates and of the adjacent outer link plates is higher than the martensite mixing ratio in the outermost link plates. The heights of the backs of the outermost link plates, measured from the tooth gap bottoms, are greater than the corresponding heights of the backs of the inner link plates, and may be equal to or greater than the heights of the backs of the adjacent outer tooth plates.

Abstract: Provided is a steel wire rod for a high strength and high toughness spring having excellent cold workability, the steel wire rod having a composition comprising: in weight %, C: 0.4 to 0.7%, Si: 1.5 to 3.5%, Mn: 0.3 to 1.0%, Cr: 0.01 to 1.5%, Ni: 0.01 to 1.0%, Cu: 0.01 to 1.0%, B: 0.005 to 0.02%, Al: 0.1% or less, O: 0.0020% or less, P: 0.02% or less, S: 0.02% or less, N: 0.02% or less, remainder Fe, and other unavoidable impurities, having a microstructure formed of ferrite and pearlite, and in which a prior (before cooling) austenite grain size is 8 ?m or less.

Abstract: The present invention inexpensively provides with high productivity and good yield a steel rod superior in drawability and a steel wire superior in twistability using the same as a material, that is, draws a high strength steel rod superior in ductility where the chemical components contain C: 0.80 to 1.20%, Si: 0.1 to 1.5%, Mn: 0.1 to 1.0%, Al: 0.01% or less, Ti: 0.01% or less, one or both of W: 0.005 to 0.2% and Mo: 0.003 to 0.

Abstract: A method for making a strain aging resistant steel comprises adding boron to the steel, wherein substantially all of the boron in the steel forms boron nitride. A method for making steel comprises adding a nitride-forming element to the steel to lower the free nitrogen content of the steel to a free nitrogen content specification. A high-carbon steel contains boron nitride, wherein the free nitrogen content of the steel is less than 80 ppm. A strain aging resistant steel wherein the carbon content of the steel is between about 0.54 percent and about 0.75 percent.

Abstract: There are provided an excellent cold-workability exhibiting high-strength steel wire or steel bar, or high-strength shaped article and a process for producing them. In particular, there is provided a process comprising carrying out hot working at 350 to 800° C. of a steel ingot, cast slab, steel slab or steel semifinished product having a C content of not greater than the solid solution limit of carbon of ferrite phase at Ae1 point and not greater than 0.010 mass % and being free of any cementite, or having a C content of >0.01 to 0.45 mass % to thereby obtain a material whose average crystal grain diameter in a cross section perpendicular to the longitudinal direction is ?3 ?m, and thereafter carrying out cold working of the material to thereby attain formation of a ferrite structure whose average crystal grain diameter in a cross section perpendicular to the longitudinal direction is ?500 nm.

Abstract: The invention provides wire rod excellent in drawability and steel wire made from the wire rod as starting material with high productivity at good yield and low cost. A hard steel wire rod of a specified composition is hot rolled, the hot-rolled steel is coiled in a specified temperature range, and the coiled steel is subjected to patenting at a predetermined cooling rate, thereby affording a high-carbon steel wire excellent in workability. It is high-strength steel wire excellent in drawability comprising a pearlite structure of an area ratio of 97% or greater and the balance of non-pearlite structures including bainite, degenerate-pearlite and pro-eutectoid ferrite and having a pearlite block size of not less than 20 ?m and not greater than 45 ?m. The invention also provides a high-carbon steel wire excellent in ductility, which is manufactured by subjecting the wire rod to intermediate patenting and cold drawing and has a tensile strength of 2800 MPa or greater.

Abstract: A bead wire has a composition of Mn: 5-35 at % and Al: 5-20 at % and the reminder being Fe and inevitable impurities, in which a steel structure is an austenite single-phase structure, and achieves weight reduction and high ductility without reducing strength.

Abstract: A process for manufacturing plated-steel armor wires intended for reinforcement of flexible tubular pipes for transporting hydrocarbons, comprising a plating coating is intimately bonded, by high pressure, to a core made of hardenable steel with moderate mechanical properties, and then the plated wire obtained undergoes a rapid high-temperature hardening step followed by a tempering step.

Abstract: Disclosed is a hard-drawn spring which exhibits fatigue strength and sag resistance equal or superior to springs produced using an oil-tempered wire. The hard-drawn spring is produced using a steel wire containing 0.5 to 0.7 mass % of C, 1.0 to 1.95 mass % of Si, 0.5 to 1.5 mass % of Mn and 0.5 to 1.5 mass % of Cr, with the balance being Fe and inevitable impurities. In the steel wire, the number of carbides having circle-equivalent diameters of 0.1 ?m or more is 5 particles/100 ?m2 or less.

Abstract: A wire rod which is mainly composed of pearlite and has an area fraction of 5% or less of a non-pearlite structure composed of pro-eutectoid ferrite, degenerate-pearlite or bainite in a section, or has an area fraction of 10% or less of a non-pearlite structure in a portion from the surface to a depth of 100 ?m.