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: The present invention relates to a hot dip galvanized steel sheet and a manufacturing method thereof. The hot dip galvanize steel sheet includes a steel sheet including a martensitic structure as a matrix, and a hot dip galvanized layer formed on the steel sheet. The steel sheet includes C of 0.05 wt % to 0.30 wt %, Mn of 0.5 wt % to 3.5 wt %, Si of 0.1 wt % to 0.8 wt %, Al of 0.01 wt % to 1.5 wt %, Cr of 0.01 wt % to 1.5 wt %, Mo of 0.01 wt % to 1.5 wt %, Ti of 0.001 wt % to 0.10 wt %, N of 5 ppm to 120 ppm, B of 3 ppm to 80 ppm, an impurity, and the remainder of Fe.

Abstract: A high strength steel sheet having composition includes, on a percent by mass basis, C: 0.17% to 0.73%; Si: 3.0% or less; Mn: 0.5% to 3.0%; P: 0.1% or less; S: 0.07% or less; Al: 3.0% or less; and N: 0.010% or less, satisfies Si+Al?0.7%, and the remainder includes Fe and incidental impurities, with a microstructure that has an area percentage of a total amount of lower bainite and whole martensite 10% to 90% relative to the whole steel sheet microstructure, an amount of retained austenite is 5% to 50%, an area percentage of bainitic ferrite in upper bainite is 5% or more relative to the whole steel sheet microstructure, as-quenched martensite is 75% or less of the total amount of lower bainite and whole martensite, and an area percentage of polygonal ferrite is 10% or less relative to the whole steel sheet microstructure, an average amount of C in retained austenite is 0.70% or more, and tensile strength is 980 MPa or more.

Abstract: High-Cr ferritic/martensitic steels having an improved tensile strength and creep resistance are provided, which includes 0.04˜0.13 weight % of carbon, 0.03˜0.07 weight % of silicon, 0.40˜0.50 weight % of manganese, 0.40˜0.50 weight % of nickel, 8.5˜9.5 weight % of chromium, 0.45˜0.55 weight % of molybdenum, 0.10˜0.25 weight % of vanadium, 0.02˜0.10 weight % of tantalum, 0.15˜0.25 weight % of niobium, 1.5˜3.0 weight % of tungsten, 0.05˜0.12 weight % of nitrogen, 0.004˜0.008 weight % of boron, and optionally, 0.002˜0.010 weight % of phosphorus or 0.01˜0.08 weight % of zirconium, and iron balance. By regulating the contents of alloying elements such as niobium, tantalum, tungsten, nitrogen, boron, zirconium, carbon, the high-Cr ferritic/martensitic steels with superior tensile strength and creep resistance are provided, and can be effectively used as an in-core structural material for Generation IV sodium-cooled fast reactor (SFR) which is used under high temperature and high irradiation conditions.

Abstract: A high-strength steel sheet has good ductility and stretch-flangeability and has a tensile strength (TS) of 980 MPa or more. The steel sheet contains 0.17%-0.73% C, 3.0% or less Si, 0.5%-3.0% Mn, 0.1% or less P, 0.07% or less S, 3.0% or less Al, and 0.010% or less N, in which Si+Al is 0.7% or more.

Abstract: A high strength galvanized steel sheet with excellent appearance that does not have non-uniformity of coating or coating defects or allow linear defects to occur after press forming includes a steel sheet having a ferrite single-phase structure and having a composition containing 0.0005% to 0.0040% by mass of C; 0.1% to 1.0% by mass of Si; 1.0% to 2.5% by mass of Mn; 0.01% to 0.20% by mass of P; 0.015% by mass of less of S; 0.01% to 0.10% by mass of Al; 0.0005% to 0.0070% by mass of N; 0.010% to 0.080% by mass of Ti; 0.0005% to 0.0020% by mass of B; 0.05% to 0.50% by mass of Cu; 0.03% to 0.50% by mass of Ni; and the balance of Fe and incidental impurities.

Abstract: A high-strength galvanized steel sheet has a TS of at least 590 MPa and excellent ductility and stretch flangeability and a method for manufacturing the high-strength galvanized steel sheet. The galvanized steel sheet contains, on the basis of mass percent, C: 0.05% to 0.3%, Si: 0.01% to 2.5%, Mn: 0.5% to 3.5%, P: 0.003% to 0.100% or less, S: 0.02% or less, and Al: 0.010% to 1.5%. The total of Si and Al is 0.5% to 2.5%. The remainder are iron and incidental impurities, contain 20% or more of ferrite phase, 10% or less of martensite phase, and 10% to 60% of tempered martensite, on the basis of area percent, and 3% to 10% of retained austenite phase on the basis of volume fraction. The retained austenite has an average grain size of 2.0 ?m or less.

Abstract: Steel sheets containing residual austenite of not more than 7 vol. %, crystallized and/or precipitated compounds with particle diameters of 0.01 to 5.0 ?m of 100 to 100000 particle/mm2 and C of 0.05 to 0.3 mass %, Si of not more than 3.0 mass %, Mn of 0.01 to 3.0 mass %, P of not more than 0.02 mass %, S of not more than 0.02 mass %, Al of 0.01 to 3.0 mass %, N of not more than 0.01 mass % and Mg of 0.0002 to 0.01 mass %, with the remainder comprising iron and unavoidable impurities.

Abstract: Provided are a bake hardening steel having a crystalline grain size of ASTM No. 9 or more and a method for preparing the bake hardening steel by controlling the winding, rolling and cooling conditions. The bake hardening steel includes: C:0.0016˜0.0025%, Si:0.02% or less, P:0.01˜0.05%, S:0.01% or less, sol.Al:0.08˜0.12%, N:0.0025% or less, Ti:0.003% or less, Nb:0.003˜0.011%, Mo:0.01˜0.1%, B:0.0005˜0.0015% or less, balance Fe and other inevitable impurities, wherein % is weight %, and Mn and P satisfy the relation of ?30(° C.)?803P?24.4Mn?58.

Abstract: The present invention relates to the addition of niobium to iron based glass forming alloys. More particularly, the present invention is related to changing the nature of crystallization resulting in glass formation that may remain stable at much higher temperatures, increasing the glass forming ability and increasing devitrified hardness of the nanocomposite structure.

Abstract: A cold rolled steel sheet and a hot dip galvanized steel sheet, which have high strength and elongation, such as a tensile strength of 980 MPa or more and an elongation of 28% or more, and excellent delayed fracture resistance, and manufacturing methods thereof. The cold rolled steel sheet has a composition including 0.05 to 0.3 weight percent C, 0.3 to 1.6 weight percent. Si, 4.0 to 7.0 weight percent Mn, 0.5 to 2.0 weight percent Al, 0.01 to 0.1 weight percent Cr, 0.02 to 0.1 weight percent Ni and 0.005 to 0.03 weight percent Ti, 5 to 30 ppm B, 0.01 to 0.03 weight percent Sb, 0.008 weight percent or less S, balance Fe and impurities. The hot dip galvanized steel sheet has a hot dip galvanized layer or a hot dip galvannealed layer on the cold rolled steel sheet.

Abstract: A high strength steel sheet excellent in formability which has a chemical composition in mass %: C: 0.03 to 0.20%, Si: 0.005 to 0.3%, Mn: 1.0 to 3.1%, P: 0.001 to 0.06%, S: 0.001 to 0.01%, N: 0.0005 to 0.01%, Al: 0.2 to 1.2%, Mo?0.5%, and the balance: Fe and inevitable impurities, with the proviso that the values of mass % for Si and Al satisfy the following formula (1): (0.0012×[objective value of TS]?0.29?[Si])/2.45<Al<1.5?3×[Si] . . . (1) wherein [objective value of TS] represents a design strength value for the steel sheet in an Mpa unit, and has a metal structure containing ferrite and martensite. The above high strength steel sheet is also excellent in formability and the capability of being chemically treated and that of being hot-dip zinc sheeted.

Abstract: The present invention has as its object the provision of hot rolled steel sheet (hot coil) for line pipe use in which API5L-X80 standard or better high strength and low temperature toughness and ductile fracture arrest performance are achieved and a method of production of the same. For this purpose, the hot rolled steel sheet of the present invention comprises C, Si, Mn, Al, N, Nb, Ti, Ca, V, Mo, Cr, Cu, and Ni in predetermined ranges and a balance of Fe and unavoidable impurities, in which the microstructure is a continuously cooled transformed structure, in which continuously cooled transformed structure, precipitates containing Nb have an average size of 1 to 3 nm and are included dispersed at an average density of 3 to 30×1022/m3, granular bainitic ferrite and/or quasi-polygonal ferrite are included in 50% or more in terms of fraction, furthermore, precipitates containing Ti nitrides are included, and they have an average circle equivalent diameter of 0.

Abstract: A high-strength cold-rolled steel sheet providing a product with a good surface condition after press forming, having excellent bake hardenability and anti room temperature aging property, and having a dual phase structure with a tensile strength of at least 340 MPa is provided. A high-strength cold-rolled steel sheet has a structure comprising a main phase which is a ferrite and a secondary phase which is a low temperature transformation product including a martensite and has a hardness distribution of the ferrite phase in an arbitrary cross section having a length of 10 mm in the widthwise direction of the sheet which satisfies the relationship prescribed by (Hv(max)?Hv(ave))<0.5×(Hv(ave). Hv(max) is the maximum Vickers hardness of ferrite grains in a region at a distance of from (?)t to (¼)t in the thickness direction from the surface when the thickness of the high-strength cold-rolled steel sheet is t, and Hv(ave) is the average Vickers hardness of ferrite grains in this region.

Abstract: The present application provides a high strength spring steel and a high strength spring that have superior corrosion fatigue strength. The spring steel comprises, in terms of percent by mass, 0.35-0.55% C, 1.60-3.00% Si, 0.20-1.50% Mn, 0.10-1.50% Cr and at least one element selected from 0.40-3.00% Ni, 0.05-0.50% Mo 0.05-0.50% V, the balance being at least substantially Fe and incidental elements and impurities.

Abstract: A high strength ductile steel sheet for extra deep drawing mainly used for interior or exterior plates of automobile bodies, and a method for manufacturing the same are disclosed. The steel sheet comprises, by weight %, C: 0.010% or less, Si: 0.1% or less, Mn: 0.06˜1.5%, P: 0.15% or less, S: 0.020% or less, Sol. Al: 0.10˜0.40%, N: 0.010% or less, Ti: 0.003˜0.010%, Nb: 0.003˜0.040%, B: 0.0002˜0.0020%, Mo: 0.05% or less, one or both of Sb: 0.005˜0.05% and Sn: 0.005˜0.05%, a total amount of Sb and Sn being in the range of 0.005˜0.1% when both of Sb and Sn are added to the steel sheet, and the balance of Fe and other unavoidable impurities. The steel sheet has surface agglomerates having an average diameter of 1 ?m or less, and a tensile strength of 28˜50 kgf/mm2.

Abstract: A high-strength spring steel and a spring are provided that have superior corrosion fatigue strength. The spring steel comprises, in mass percent, 0.35-0.55% C, 1.60-3.00% Si, 0.20-1.50% Mn, 0.10-1.50% Cr, and at least one of 0.40-3.00% Ni, 0.05-0.50% Mo and 0.05-0.50% V, the balance being substantially Fe and incidental elements and impurities.

Abstract: An object of the present invention is to provide at a low cost a low-alloy steel having a high strength and excellent high-pressure hydrogen environment embrittlement resistance characteristics under a high-pressure hydrogen environment. The invention is a high-strength low-alloy steel having high-pressure hydrogen environment embrittlement resistance characteristics, which has a composition comprising C: 0.10 to 0.20% by mass, Si: 0.10 to 0.40% by mass, Mn: 0.50 to 1.20% by mass, Ni: 0.75 to 1.75% by mass, Cr: 0.20 to 0.80% by mass, Cu: 0.10 to 0.50% by mass, Mo: 0.10 to 1.00% by mass, V: 0.01 to 0.10% by mass, B: 0.0005 to 0.005% by mass and N: 0.01% by mass or less, and further comprising one or two of Nb: 0.01 to 0.10% by mass and Ti: 0.005 to 0.050% by mass, with the balance consisting of Fe and unavoidable impurities.

Abstract: A high-strength non-oriented electrical steel sheet contains: by mass %, C: not less than 0.002% nor more than 0.05%; Si: not less than 2.0% nor more than 4.0%; Mn: not less than 0.05% nor more than 1.0%; N: not less than 0.002% nor more than 0.05%; and Cu: not less than 0.5% nor more than 3.0%. An Al content is 3.0% or less, and when a Nb content (%) is set to [Nb], a Zr content (%) is set to [Zr], a Ti content (%) is set to [Ti], a V content (%) is set to [V], a C content (%) is set to [C], and an N content (%) is set to [N], Formula (1) and Formula (2) are satisfied. A balance is composed of Fe and inevitable impurities, a recrystallization area ratio is 50% or more, yield stress at a tensile test is 700 MPa or more, fracture elongation is 10% or more, and an eddy current loss We10/400 (W/kg) satisfies Formula (3) in relation to a sheet thickness t (mm) of the steel sheet. 2.0×10?4?[Nb]/93+[Zr]/91+[Ti]/48+[V]/51 ??(1) 1.0×10?3?[C]/12+[N]/14?([Nb]/93+[Zr]/91+[Ti]/48+[V]/51)?3.

Abstract: An ultra-high strength steel sheet has a tensile strength of 1400 MPa or higher that can achieve both high strength and good formability and an advantageous method for manufacturing the steel sheet and includes a composition including, on a mass basis C: 0.12% or more and 0.50% or less; Si: 2.0% or less; Mn: 1.0% or more and 5.0% or less; P: 0.1% or less; S: 0.07% or less; Al: 1.0% or less; and N: 0.008% or less, with the balance Fe and incidental impurities. The steel microstructure includes, on an area ratio basis, 80% or more of autotempered martensite, less than 5% of ferrite, 10% or less of bainite, and 5% or less of retained austenite; and the mean number of precipitated iron-based carbide grains each having a size of 5 nm or more and 0.5 ?m or less and included in the autotempered martensite is 5×104 or more per 1 mm2.

Abstract: The present invention provides a spring steel that has superior hardenability, undergoes less pitting in a corrosive environment, and can achieve higher stress and toughness. More specifically, the present invention provides a high-strength and high-toughness spring steel with improved hardenability and pitting resistance, containing, in mass percent, 0.40 to 0.70% carbon, 0.05 to 0.50% silicon, 0.60 to 1.00% manganese, 1.00 to 2.00% chromium, 0.010 to 0.050% niobium, 0.005 to 0.050% aluminum, 0.0045 to 0.0100% nitrogen, 0.005 to 0.050% titanium, 0.0005 to 0.0060% boron, no more than 0.015% phosphorus and no more than 0.010% sulfur, the remainder being composed of iron and unavoidable impurities, the steel having a tensile strength of at least 1700 MPa in 400° C. tempering after quenching and a Charpy impact value of at least 40 J/cm2 for a 2 mm U-notched test piece of JIS Z 2202 and the parameter Fce being at least 1.70.

Abstract: The present invention provides high strength thick-gauge steel plate superior in weldability and having a tensile strength of 780 MPa or more and provides a method of production of the high strength thick-gauge steel plate by omitting tempering heat treatment in the production. The high strength thick-gauge steel plate of the present invention is high strength thick-gauge steel plate containing, by mass %, C: 0.030 to 0.055%, Mn: 2.4 to 3.5%, P: 0.01% or less, S: 0.0010% or less, Al: 0.06 to 0.10%, B: 0.0005 to 0.0020%, and N: 0.0015 to 0.0060%, having a weld cracking susceptibility parameter Pcm of 0.18% to 0.24%, and comprised mainly of martensite. The method of production of high strength thick-gauge steel plate of the present invention comprises heating a steel slab or cast slab having a predetermined composition of ingredients to 950 to 1100° C., rolling it at 820° C. or more, then starting accelerated cooling from 700° C. or more by a cooling rate of 8 to 80° C.

Abstract: A high strength galvanized steel sheet has a TS of 590 MPa or more and excellent processability. The component composition contains, by mass %, C: 0.05% to 0.3%, Si: 0.7% to 2.7%, Mn: 0.5% to 2.8%, P: 0.1% or lower, S: 0.01% or lower, Al: 0.1% or lower, and N: 0.008% or lower, and the balance: Fe or inevitable impurities. The microstructure contains, in terms of area ratio, ferrite phases: 30% to 90%, bainite phases: 3% to 30%, and martensite phases: 5% to 40%, in which, among the martensite phases, martensite phases having an aspect ratio of 3 or more are present in a proportion of 30% or more.

Abstract: The invention relates to an ultrahigh-strength thin steel sheet excellent in the hydrogen embrittlement resistance, the steel sheet including, by weight %, 0.10 to 0.60% of C, 1.0 to 3.0% of Si, 1.0 to 3.5% of Mn, 0.15% or less of P, 0.02% or less of S, 1.5% or less of Al, 0.003 to 2.0% of Cr, and a balance including iron and inevitable impurities; in which grains of residual austenite have an average axis ratio (major axis/minor axis) of 5 or more, the grains of the residual austenite have an average minor axis length of 1 ?m or less, and the grains of the residual austenite have a nearest-neighbor distance between the grains of 1 ?m or less.

Abstract: A high strength thin steel sheet that is mainly used for structural members and inner and outer panels for a vehicle, a galvanized steel sheet, and methods of manufacturing the same. The high strength thin steel sheet for superior press formability includes, by weight percent, 0.06 to 0.4% C, 1.0 to 5.0% Mn, 0.05 to 2.5% Si, 0.01 to 2.0% Ni, 0.02 to 2% Cu, 0.01 to 0.04% Ti, 0.05 to 2.5% Al, 0.005 to 0.1% Sb, 0.0005 to 0.004% B, 0.007% or less N, and balance Fe and inevitable impurities, and meeting relation of Ni+0.5×Mn+0.3×Cu>0.9, which is defined as Ni*, and Al/Ni*<1.3 at a same time, and relation of Ti?0.028×Al. This thin steel sheet is galvanized or galvannealed.

Abstract: The present invention provides high strength steel plate with excellent low temperature toughness, high strength steel pipe using this as a base metal, and methods of production of the same. The steel plate of the present invention contains Mo: 0.05 to 1.00% and B: 0.0003 to 0.0100%, has a Ceq of 0.30 to 0.53, has a Pcm of 0.10 to 0.20, and has a metal structure which has an area percentage of polygonal ferrite of 20 to 90% and has a balance of a hard phase comprised of one or both of bainite and martensite. To obtain this steel plate, strain-introducing rolling is performed with a start temperature of not more than Ar3+60° C., an end temperature of Ar3 or more, and a reduction ratio of 1.5 or more, then the plate is air-cooled and then acceleratedly cooled from Ar3?100° C. to Ar3?10° C. in temperature by 10° C./s or more.

Abstract: The invention is directed to providing, for application in automobiles, construction materials, household appliances and the like, high-strength sheets excellent in formability properties such as hole expansibility and ductility, and also in fatigue resistance, characterized in comprising, in specified contents expressed in mass %, C, Si, Mn, P, S, Al, N and O and a balance of iron and unavoidable impurities, and having a steel sheet structure composed mainly of ferrite and hard structures, a crystal orientation difference between some ferrite adjacent to hard structures and the hard structures of less than 9°, and a maximum tensile strength of 540 MPa or greater.

Abstract: A steel for high-strength components including bands, sheets or pipes having excellent formability and particular suitability for high-temperature coating processes above Ac3 (about 900° C.) is disclosed. The steel includes the following elements (contents in % by mass): C 0.07 to ?0.15, Al?0.05, Si?0.80, Mn 1.60 to ?2.10, P?0.020, S?0.010, Cr 0.50 to ?1.0, Mo 0.10 to ?0.30, Timin 48/14×[N], V 0.03 to ?0.12, B 0.0015 to ?0.0050, with the balance iron including usual steel-accompanying elements.

Abstract: A steel sheet having (a) a dual phase microstructure with a martensite phase and a ferrite phase and (b) a composition containing by percent weight: 0.01% to 0.2% C; 0.3% to 3% Mn; 0.05% to 2% Si; 0.1% to 2% Cr; 0.01% to 0.10% Al; and 0.0005% to 0.01% Ca, with the balance of the composition being iron and incidental ingredients. Also, the steel sheet is made by a batch annealing method, and has a tensile strength of at least approximately 400 MPa and an n-value of at least approximately 0.175.

Abstract: Provided are a high strength thin steel sheet having tensile strength of about 800 MPa or more, and a manufacturing method thereof. The thin steel sheet is mainly used for construction materials, home appliances, and automobiles. The thin steel sheet has excellent plating characteristic, welding characteristic, bending workability, and hole expansion ratio. The thin steel sheet includes, in weight %, C: 0.02-0.20%, Si: 1.5% or less, Mn: 1.5-3.0%, P: 0.001-0.10%, S: 0.010% or less, SoLAl: 0.01-0.40%, N: 0.020% or less, Cr: 0.3-1.5%, B: 0.0010-0.0060%, Sb: 0.001-0.10%, and including at least one material selected from the group consisting of Ti: 0.003-0.08%, Nb: 0.003-0.08%, and Mo: 0.003-0.08%, and includes Fe and other inevitable impurities as a remainder. Here, Si, Mn, B, Sb, P, and S meet conditions of 5<(Si/Mn+150B)/Sb<20 and C+Mn/20+Si/30+2P+4S<0.27. Also, the manufacturing method can secure workability of the thin steel sheet.

Abstract: Disclosed is a ferritic heat-resistant steel which has the following chemical composition (by weight): C: from 0.01% to less than 0.08%; Si: 0.30-1.0%; P: 0.02 or less; S: 0.010% or less; Mn: 0.2-1.2%; Ni: 0.3% or less; Cr: 8.0-11.0%; Mo: 0.1-1.2%; W: 1.0-2.5%; V: 0.10-0.30%; Nb: 0.02-0.12%; Co: 0.01-4.0%; N: 0.01-0.08%; B: not less than 0.001% and less than 0.010%; Cu: 0.3% or less; and Al: 0.010% or less, provided that the chemical composition satisfies the following equations: Mo (%)+0.5×W (%)=1.0-1.6, and C (%)+N (%)=0.02-0.15%, and which comprises a tempered martensite single-phase tissue produced by thermal refining and contains 30% by weight or less of ? ferrite.

Abstract: Disclosed is a steel plate having a specific chemical component composition. The steel plate has an F value defined by the following expression (1) and satisfying the following condition: 3.20?(F value)?4.50, has a tempered bainite microstructure having an average equivalent area diameter of grains surrounded by high-angle boundaries with a difference in orientation between two grains of 15° or more of 4 ?m or less, and has a tensile strength of 585 MPa or more: F value=9.4×[Mo]+8.1×[V]+4.7×[Cr]??(1) wherein [Mo], [V] and [Cr] represent contents (percent by mass) of Mo, V, and Cr, respectively. The steel plate having this configuration surely has satisfactory drop weight properties and high base metal toughness only by controlling the contents of necessary alloy elements.

Abstract: Embodiments of the present application are directed towards steel compositions that provide improved properties under corrosive environments. Embodiments also relate to protection on the surface of the steel, reducing the permeation of hydrogen. Good process control, in terms of heat treatment working window and resistance to surface oxidation at rolling temperature, are further provided.

Abstract: A high strength galvanized steel sheet having a TS of 780 MPa or more and exhibiting excellent stretch frangeability and bendability and a method for manufacturing the same are provided. The component composition contains C: 0.05% to 0.15%, Si: 0.8% to 2.5%, Mn: 1.5% to 3.0%, P: 0.001% to 0.05%, S: 0.0001% to 0.01%, Al: 0.001% to 0.1%, N: 0.0005% to 0.01%, Cr: 0.1% to 1.0%, Ti: 0.0005% to 0.1%, B: 0.0003% to 0.003%, and the remainder composed of iron and incidental impurities, on a percent by mass basis. The microstructure includes 30% or more of ferrite phase and 30% or more, and 70% or less of martensite phase on an areal fraction basis, wherein regarding the above-described martensite phase, the proportion of a tempered martensite phase is 20% or more relative to the whole martensite phase and the proportion of a martensite phase having a grain diameter of 1 ?m or less is 10% or less relative to the whole martensite phase.

Abstract: The invention relates to a cold-rolled and annealed steel sheet with a strength greater than 1200 MPa, the composition of which comprises, the contents being expressed by weight: 0.10%?C?0.25%, 1%?Mn?3%, Al?0.010%, Si?2.990%, S?0.015%, P?0.1%, N?0.008%, it being understood that 1%?Si+Al?3%, the composition optionally comprising: 0.05%?V?0.15%, B?0.005%, Mo?0.25%, Cr?1.65%, it being understood that Cr+3Mo?0.3%, Ti in an amount such that Ti/N?4 and Ti?0.040%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the microstructure of the steel comprising 15 to 90% bainite, the remainder consisting of martensite and residual austenite.

Abstract: A high carbon steel sheet having superior strength and ductility and a method for manufacturing the same comprising: 0.2 to 1.0 wt % carbon (C), 0 to 3.0 wt % silicon (Si), 0 to 3.0 wt % manganese (Mn), 0 to 3.0 wt % chromium (Cr), 0 to 3.0 wt % nickel (Ni), 0 to 0.5 wt % molybdenum (Mo), 0 to 3.0 wt % aluminum (Al), 0 to 0.01 wt % boron (B), 0 to 0.5 wt % titanium (Ti), and the remainder substantially being iron (Fe) and inevitable impurities. The contents of carbon, manganese, chromium, and nickel satisfy the following Equation 1, and the contents of silicon and aluminum satisfy the following Equation 2: (3.0?2.5×C)wt %?(Mn+Cr+Ni/2)?8.5 wt %—(Equation 1) Si+Al>1.0 wt % (Equation 2).

Abstract: An ultra soft high carbon hot-rolled steel sheet has excellent workability. The steel sheet is a high carbon hot-rolled steel sheet containing 0.2 to 0.7% C, and has a structure in which mean grain size of ferrite is 20 ?m or larger, the volume percentage of ferrite grains having 10 ?m or smaller size is 20% or less, mean diameter of carbide is in a range from 0.10 ?m to smaller than 2.0 ?m, the percentage of carbide grains having 5 or more of aspect ratio is 15% or less, and the contact ratio of carbide is 20% or less.

Abstract: A dual-phase steel, a flat product produced therefrom and a process for the production thereof. The dual-phase steel has, in addition to a strength of at least 950 MPa and good deformability, a surface finish which, when a simple production process is used, makes it possible for the flat product produced from this steel to be formed into a complexly formed component, such as a part of a car bodywork, in an uncoated state or in a state provided with an anti-corrosion coating. The steel according to the invention comprises 20-70% martensite, up to 8% retained austenite and the remainder ferrite and/or bainite and comprises (in % by weight): C: 0.10-0.20%, Si: 0.10-0.60%, Mn: 1.50-2.50%, Cr: 0.20-0.80%, Ti: 0.02-0.08%, B: <0.0020%, Mo: <0.25%, Al: <0.10%, P: ?0.2%, S: ?0.01%, N: ?0.012%, the remainder iron and unavoidable impurities.

Abstract: A high strength and low yield ratio steel that has excellent characteristics such as low temperature toughness, a tensile strength of approximately 600 MPa or more and a low yield ratio of 80% or less. The high strength and low yield ratio steel includes, by weight percent: C: 0.02 to 0.12%, Si: 0.01 to 0.8%, Mn: 0.3 to 2.5%, P: 0.02% or less, S: 0.01% or less, Al: 0.005 to 0.5%, Nb: 0.005 to 0.10%, B: 3 to 50 ppm, Ti: 0.005 to 0.1%, N: 15 to 150 ppm, Ca: 60 ppm or less, and the balance of be and inevitable impurities, and further includes at least one component selected from the group consisting of by weight percent: Cr: 0.05 to 1.0%, Mo: 0.01 to 1.0%, Ni: 0.01 to 2.0%, Cu: 0.01 to 1.0% and V: 0.005 to 0.3%, wherein a finish cooling temperature is limited to 500 to 600° C. after the finish-rolling process.

Abstract: The present invention provides high strength steel pipe for line pipe superior in low temperature toughness suppressed in drop of toughness of the HAZ and a method of production of the same, more particularly high strength steel plate for line pipe used as a material for high strength steel pipe for line pipe and a method of production of the same, in particular high strength steel pipe for line pipe superior in low temperature toughness characterized in that the chemical compositions of the base metal is, by mass %, C: 0.020 to 0.080%, Si: 0.01 to 0.50%, Mo: 0.01 to 0.15%, Al: 0.0005 to 0.030%, and Nb: 0.0001 to 0.030% contained in a range of C+0.25Si+0.1Mo+Al+Nb: 0.100% or less and the mixture of austenite and martensite present along prior austenite grain boundaries of the reheated part of the heat affected zone has a width of 10 ?m or less and a length of 50 ?m or less.

Abstract: In order to provide a high tensile strength steel having excellent low temperature toughness and which can withstand large heat input welding, a steel comprises, in mass percent, C: 0.01-0.10%, Si: at most 0.5%, Mn: 0.8-1.8%, P: at most 0.020%, S: at most 0.01%, Cu: 0.8-1.5%, Ni: 0.2-1.5%, Al: 0.001-0.05%, N: 0.0030-0.0080%, O: 0.0005-0.0035%, if necessary at least one of Ti: 0.005-0.03%, Nb: 0.003-0.03%, and Mo: 0.1-0.8%, and a remainder of Fe and impurities, and the N/Al ratio is 0.3-3.0.

Abstract: A cold-rolled steel sheet having superior non-ageing properties and low planar anisotropy can be produced at low cost without decreased productivity. This cold-rolled steel sheet contains, by mass, 0.010% to 0.040% carbon, 0.02% or less silicon, 1.0% to 2.5% manganese, 0.02% or less phosphorus, 0.015% or less sulfur, 0.004% or less nitrogen, and 0.020% to 0.070% aluminum, the balance being iron and incidental impurities. The steel sheet has a microstructure including a ferrite phase and a second phase. The volume percentage of the second phase is 0.2% to less than 10%. The steel sheet has an AI of 50 MPa or less, ?0.20??r?0.20, and a thickness of 0.5 mm or less.

Abstract: A high tensile strength galvanized steel sheet with excellent formability and anti-crush properties contains, in terms of % by mass, 0.05 to 0.3% of C, 0.01 to 2.5% of Si, 0.5 to 3.5% of Mn, 0.003 to 0.100% of P, 0.02% or less of S, 0.010 to 1.5% of Al, 0.007% or less of N, in addition, 0.01 to 0.2% in total of at least one element selected from Ti, Nb, and V, the remainder being Fe and unavoidable impurities, the steel sheet having a microstructure composed of, in terms of area fraction, 20 to 87% of ferrite, 3 to 10% in total of martensite and residual austenite, and 10 to 60% of tempered martensite, and a second phase composed of the martensite, residual austenite, and tempered martensite having an average crystal grain diameter of 3 ?m or less.

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: An object of the present invention is to provide at a low cost a low-alloy steel having a high strength and excellent high-pressure hydrogen environment embrittlement resistance characteristics under a high-pressure hydrogen environment. The invention is a high-strength low-alloy steel excellent in high-pressure hydrogen environment embrittlement resistance characteristics, which is characterized in that the steel has a composition comprising C: 0.10 to 0.20%, Si: 0.10 to 0.40%, Mn: 0.50 to 1.20%, Cr: 0.20 to 0.80%, Cu: 0.10 to 0.50%, Mo: 0.10 to 1.00%, V: 0.01 to 0.10%, B: 0.0005 to 0.005% and N: 0.01% or less, by mass, with the balance consisting of Fe and unavoidable impurities.

Abstract: The present invention provides a steel sheet excellent in workability, which may be used for components of an automobile or the like, and a method for producing the same. More specifically, according to one exemplary embodiment of the present invention, a steel sheet excellent in workability, including in mass, 0.08 to 0.25% C, 0.001 to 1.5% Si, 0.01 to 2.0% Mn, 0.001 to 0.06% P, at most 0.05% S, 0.001 to 0.007% N, 0.008 to 0.2% Al, at least 0.01% Fe. The steel sheet having an average r-value of at least 1.2, an r-value in the rolling direction of at least 1.3, an r-value in the direction of 45 degrees to the rolling direction of at least 0.9, and an r-value in the direction of a right angle to the rolling direction of at least 1.2.

Abstract: The invention concerns weldable steel building components whereof the chemical composition comprises, by weight: 0.10%?C?0.22%, 0.50%?Si?1.50%, AI?0.9%, 0%?Mn?3%, 0%?Ni?5%, 0%?Cr?4%, 0%?Cu?1%, 0%?Mo+W/2?1.5%, 0.0005%?B<0.010%, N?0.025%, optionally at least one element selected among V, Nb, Ta, S et Ca, in contents less than 0.3%, and/or among Ti and Zr in contents not more than 0.5%, the rest being iron and impurities resulting from preparation, the aluminium, boron, titanium and nitrogen contents, expressed in thousandths of %, of said composition further satisfying the following relationship: B??×K+0.5, (1) with K=Min (I*; J*), I*=Max (0; I) and J*=Max (0; J), I=Min (N; N?0.29(Ti?5)), J=Min {N; 0.5 (N 0.52 AI+?j(N 0.52 AI)2+283)}, the silicon and aluminium contents of the composition additionally verifying the following conditions: if C>0.145, then Si+AI<0.95 and whereof the structure is bainitic, martensitic or martensitic/bainitic and further comprises 3 to 20% of residual austenite.

Abstract: A high-strength steel sheet has a metal structure consisting of a ferrite phase in which a hard second phase is dispersed and has 3 to 30% of an area ratio of the hard second phase. In the ferrite phase, the area ratio of nanograins of which grain sizes are not more than 1.2 ?m is 15 to 90%, and dS as an average grain size of nanograins of which grain sizes are not more than 1.2 ?m and dL as an average grain size of micrograins of which grain sizes are more than 1.2 ?m satisfy an equation (dL/dS?3).

Abstract: An aspect of the present disclosure relates to an alloy composition, which may include 52 atomic percent to 68 atomic percent iron, 13 to 21 atomic percent nickel, 2 to 12 atomic percent cobalt, 10 to 19 atomic percent boron, optionally 1 to 5 atomic percent carbon, and optionally 0.3 to 16 atomic percent silicon. The alloy may include 5 to 95% by volume of one or more spinodal microconstituents, wherein the microconstituents exhibit a length scale less than 50 nm in a glass matrix.

Abstract: Ultra-high-strength linepipes having excellent low-temperature toughness manufactured by welding together the edges of steel plates comprising C of 0.03 to 0.07 mass %, Si of not more than 0.6 mass %, Mn of 1.5 to 2.5 mass %, P of not more than 0.015 mass %, S of not more than 0.003 mass %, Ni of 0.1 to 1.5 mass %, Mo of 0.15 to 0.60 mass %, Nb of 0.01 to 0.10 mass %, Ti of 0.005 to 0.030 mass %, Al of not more than 0.06 mass %, one or more of required amounts of B, N, V, Cu, Cr, Ca, REM (rare-earth metals) and Mg, with the remainder consisting of iron and unavoidable impurities and having a (Hv-ave)/(Hv-M) ratio between 0.8 and 0.9 at 2.5?P?4.0, wherein Hv-ave is the average Vickers hardness in the direction of the thickness of the base metal and Hv-M is the martensite hardness depending on C-content (Hv-M=270+1300C) and a tensile strength TS-C between 900 MPa and 1100 MPa; P=2.7C+0.4Si+Mn+0.8Cr+0.45(Ni+Cu)+(1+?)Mo?1+? (?=1 when B?3 ppm and ?=0 when B<3 ppm).