Abstract: A component of an air-hardenable steel composed of (contents in mass %): C<0.20; Al<0.08; Si<1.00; Mn 1.20 to <2.50; P<0.020; S<0.015; N<0.0150; Cr 0.30 to <1.5; Mo 0.10 to <0.80; Ti 0.010 to <0.050; V 0.03 to <0.20; B 0.0015 to <0.0060, with the remainder being iron including the usual elements present in steel, is produced by heating a hot- or cold-rolled steel sheet or steel tube section to a temperature of ?blank=800 to 1050° C. and then forming the sheet or tube into a component in a forming tool. After removal from the tool, the component is cooled down in air while the component still has a temperature above ?removal=200° C. and below 800° C. The component achieves the required mechanical properties during air-cooling.

Abstract: A high strength steel plate containing 0.02 to 0.08% C, by mass, and has substantially a two phase microstructure of ferrite and bainite. The ferrite contains precipitates having a particle size of 30 nm or smaller grain size. The steel plate has a yield strength of 448 MPa or higher. A method for manufacturing the high strength steel plate which comprises hot rolling, accelerated cooling and reheating. The accelerated cooling is conducted down to a temperature of 300 to 600° C. at a cooling rate of 5° C./s or higher. The reheating is conducted up to a temperature of 550 to 700° C. at a heating rate of 0.5° C./s or higher.

Abstract: A press-hardened component and a method for producing press-hardened components, in particular a bodywork component, from a semi-finished product made from unhardened, hot-formable steel sheet. Various process steps are carried out in the process. A component blank is formed from the semi-finished product by a cold-forming process, in particular a drawing process. The component blank is trimmed at the margin side to a margin contour which approximately corresponds to the component to be produced. The trimmed component blank is heated and press-hardened in a hot-forming tool, and then the press-hardened component blank is covered with a corrosion-prevention layer in a coating step.

Abstract: A method of designing low cost, high strength, high toughness martensitic steel uses mathematical modeling to define optimum low cost chemical compositions, the content of retained austenite, and critical temperatures; melting an ingot, processing same, making steel articles, and heat treating the articles using the critical temperatures and the content of retained austenite. The new steel comprises, by weight, about 0.3-0.45% of C; at most 2.5% of Cr; at most 1.0% of Mo; at most 3.50% of Ni; about 0.3 to 1.5% of Mn; about 0.1-1.3% of Si; about 0.1-1.0% of Cu; Cu being less than Si; about 0.1 to 1.0% of V+Ti+Nb; at most 0.25% of Al; the sum of alloying elements being less than about 11.5%; the balance being essentially Fe and incidental impurities. Procedures of melting, processing and heat treatment using the mathematical model are disclosed.

Abstract: The present invention provides high strength thin-gauge steel sheet with excellent elongation and hole expandability having a tensile strength of 500 MPa or more and a method of production of high strength thin-gauge steel sheet with excellent elongation and hole expandability enabling production of this on an industrial scale, that is, high strength thin-gauge steel sheet comprised of, by mass %, C: 0.03 to 0.25%, Si: 0.013 to 0.299%, Mn: 0.8 to 3.1%, P?0.02%, S?0.02%, Al?2.0%, N?0.01%, and a balance of Fe and unavoidable impurities and having a microstructure comprised of ferrite with an area fraction of 10 to 85% and residual austenite with a volume fraction of 1 to 10%, an area fraction of 10% to 60% of tempered martensite, and a balance of bainite.

Abstract: A method for manufacturing an axle is provided. The method includes heating a billet at a heating station to a predetermined temperature, forging the heated billet at a forging station to form an axle, and machining the axle at a machining station to form a machined axle. A product is automatically transported to and from each station using a product transport system, wherein the product includes the billet, the axle and the machined axle.

Abstract: A steel part having a long rolling contact fatigue life and capable of further increasing the life of a bearing under severer using condition than usual conditions. The steel part includes steel having a composition containing 0.7% by mass to 1.1% by mass of C, 0.5% by mass to 2.0% by mass of Si, 0.4% by mass to 2.5% by mass of Mn, 1.6% by mass to 5.0% by mass of Cr, 0.1% by mass to less than 0.5% by mass of Mo, 0.010% by mass to 0.050% by mass of Al, less than 0.0015% by mass of Sb as an impurity, and the balance composed of Fe and inevitable impurities, the steel being hardened and tempered. In the steel structure of a portion from the surface to a depth of 5 mm, residual cementite has a grain diameter of 0.05 to 1.5 ?m, prior austenite has a grain diameter of 30 ?m or less, and the ratio by volume of the residual austenite is less than 25%.

Abstract: The subject of the invention is a process for manufacturing a part made of steel having a multiphase microstructure, said microstructure comprising ferrite and being homogeneous in each of the regions of said part, which process comprises the steps consisting in: cutting a blank from a strip of steel, the composition of which is typical of that of steels having a multiphase microstructure; said blank is heated so as to reach a soak temperature Ts above Ac1 but below Ac3 and held at this soak temperature Ts for a soak time ts adjusted so that the steel, after the blank has been heated, has an austenite content equal to or greater than 25% by area; said heated blank is transferred into a forming tool so as to hot-form said part; and said part is cooled within the tool at a cooling rate V such that the microstructure of the steel, after the part has been cooled, is a multiphase microstructure, said microstructure comprising ferrite and being homogeneous in each of the regions of said part.

Abstract: The invention relates to a method of and a plant for making hot-rolled strips of cast metal, wherein the cast strip is subjected as a rough strip to at least a first step for momogenizing the grain structure in a protective gas and the cast strip is then subjected to at least a further heat-treatment step before it is rolled to reduce its thickness. After the thickness reduction the cast strip is subjected to a second step of homogenization or recrystallization of its grain structure before finally the strip is passed to a cutter and a finished rolled hot piece is severed from the following strip.

Abstract: The present invention provides an abrasion resistant steel having a hardness of HB400 to HB520, having little change of hardness during long term use, and superior in toughness, characterized by containing, by mass %, C: 0.21% to 0.30%, Si: 0.30 to 1.00%, Mn: 0.32 to 0.70%, P: 0.02% or less, S: 0.01% or less, Cr: 0.1 to 2.0%, Mo: 0.1 to 1.0%, B: 0.0003 to 0.0030%, Al: 0.01 to 0.1%, and N: 0.01% or less, further containing one or more of V: 0.01 to 0.1%, Nb: 0.005 to 0.05%, Ti: 0.005 to 0.03%, Ca: 0.0005 to 0.05%, Mg: 0.0005 to 0.05%, and REM: 0.001 to 0.

Abstract: The present invention provides a fire resistant steel material excellent in high temperature strength, toughness, and reheating embrittlement resistance containing, by mass %, C: 0.001% to 0.030%, Si: 0.05% to 0.50%, Mn: 0.4% to 2.0%, Nb: 0.03% to 0.50%, Ti: 0.005% to less than 0.040%, N: 0.0001% to less than 0.0050%, and Al: 0.005% to 0.030%, limiting P: 0.03% or, less and S: 0.02% or less, satisfying C—Nb/7.74?0.005 and 2?Ti/N?12, and having a balance of Fe and unavoidable impurities and, further, a process for production of a fire resistant material comprising heating a steel slab comprised of this chemical composition to 1100 to 1350° C. and hot rolling it by a cumulative reduction rate at 1000° C. or less of 30% or more.

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: In a method of manufacturing a high tensile strength thick steel plate, a steel slab contains 0.03-0.055% of C, 3.0-3.5% of Mn, and 0.002-0.10% of Al, the amount of Mo is limited to 0.03% or less, the amount of Si is limited to 0.09% or less, the amount of V is limited to 0.01% or less, the amount of Ti is limited to 0.003% or less, the amount of B is limited to 0.0003% or less, and of which Pcm value representing a weld cracking parameter is fallen within the range of 0.20-0.24% and DI value representing a hardenability index is fallen within the range of 1.00-2.60, is heated to 950-1100° C. The steel slab is subjected to a rolling process with a cumulative draft of 70-90% when a temperature is in a range of 850° C. or more, and then, the steel slab is subjected to a rolling process at 780° C. or higher with a cumulative draft of 10-40% when a temperature is in a range of 780-830° C., and subsequently, accelerated cooling at a cooling rate of 8-80° C./sec is started from 700° C.

Abstract: A high-strength hot-rolled steel sheet containing C: 0.05 to 0.15%, Si: no more than 1.50% (excluding 0%), Mn: 0.5 to 2.5%, P: no more than 0.035% (excluding 0%), S: no more than 0.01% (including 0%), Al: 0.02 to 0.15%, and Ti: 0.05 to 0.2%, which is characterized in that its metallographic structure is composed of 60 to 95 vol % of bainite and solid solution-hardened or precipitation-hardened ferrite (or ferrite and martensite) and its fracture appearance transition temperature (vTrs) is no higher than 0° C. as obtained by impact tests. (% in terms of % by weight).

Abstract: A martensitic stainless steel pipe, which comprises specified quantities of C, Si, Mn, P, S, Cr, Ni, Al, N, Cu, Ti, V, Mo, Nb, B and Ca, and the balance being Fe and impurities, has satisfactory toughness at a high strength of 650 MPa or more by yield strength and also excellent hot workability. Therefore, it can be used as a high-strength martensitic stainless steel pipe for carbon dioxide gas corrosion resistant use, to be used in oil and/or gas well environments containing no hydrogen sulfide but carbon dioxide gas. This high-strength martensitic stainless steel pipe is an inexpensive martensitic stainless steel pipe, which does not require an addition of large quantities of expensive elements such as Ni and Mo, and moreover does not require the control of the content of P to a value less than 0.010% by mass.

Abstract: A transformation toughened, high-strength steel alloy useful in plate steel applications achieves extreme fracture toughness (Cv & gt; 80 ft-lbs corresponding to KId & equals; 200 ksi.in½) at strength levels of 150-180 ksi yield strength, is weldable and formable. The alloy is characterized by dispersed austenite stabilization for transformation toughening to a weldable, bainitic plate steel and is strengthened by precipitation of M2C carbides in combination with copper and nickel. The desired microstructure is a matrix containing a bainite-martensite mix, BCC copper and M2C carbide particles for strengthening with a fine dispersion of optimum stability austenite for transformation toughening. The bainite-martensite mix is formed by air-cooling from solution treatment temperature and subsequent aging at secondary hardening temperatures to precipitate the toughening and strengthening dispersions.

Abstract: The present invention provides a tool steel containing, by mass percent, 0.55 to 0.85% of C, 0.20 to 2.50% of Si, 0.30 to 1.20% of Mn, 0.50% or less of Cu, 0.01 to 0.50% of Ni, 6.00 to 9.00% of Cr, 0.1 to 2.00% of Mo+0.5 W, and 0.01 to 0.40% of V, with the balance of Fe and inevitable impurities, in which, when an area rate of a coarse carbide having a circle equivalent diameter of 2 ?m or more in a cross section parallel to a forging direction is represented by L(%) and an area rate of the coarse carbide in a cross section perpendicular to the forging direction is represented by T(%), the area rate L is 0.001% or more, the area rate T is 0.001% or more, and the ratio L/T is within a range from 0.90 to 3.00. The tool steel of the invention exhibits an isotropic size change in quenching and tempering.

Abstract: An iron alloy according to the present invention comprises: Al in an amount of from 3 to 5.5%; Mn in an amount from 0.2 to 6%; and the balance being iron (Fe), and inevitable impurities and/or a modifying element; when the entirety is taken as 100%. Since a high damping factor is obtainable at a low-strain amplitude, this iron alloy demonstrates a stable damping property even in a high-temperature region. Moreover, since the alloying elements are Al and Mn alone, and since their contents are less, the iron alloy according to the present invention is low in cost.

Abstract: Disclosed are a weldable steel of high strength and high toughness and a method of producing members of machine parts. The steel consists essentially of, by weight %, C: 0.10-0.16%, Si: 0.05-0.50%, Mn: 1.3-2.3%, Cu: up to 0.5%, Ni: up to 0.5%, Cr: up to 0.5%, Mo: up to 0.3% and Ti: 0.025-0.035%, and the balance of Fe and inevitable impurities, and satisfying the condition that the weld-cracking susceptibility, Pcm, defined by the formula 1A below is less than 0.35, and the condition that the manganese equivalent, Mneq, defined by the formula 2A below is larger than 2.0.

Abstract: A steel tie rod end includes a shaft portion and first and second fitting portions. A minimum area portion having a small radially cross-sectional area is provided for the shaft portion, and 90% or above of a steel structure of the minimum area portion is formed of martensite or tempered martensite. The surface hardness of the minimum area portion and the average hardness of the radial cross section of the minimum area portion are 600 Hv or below, and the average hardness of the radial cross section of the first fitting portion and the average hardness of the radial cross section of the second fitting portion are 300 Hv or below. A method of manufacturing a steel tie rod end includes a quenching process of heating only a prospective shaft portion by high frequency to an austenitizing temperature and then rapidly cooling the prospective shaft portion by water or cooling medium.

Abstract: The present invention is: a pearlitic steel rail excellent in wear resistance and ductility, characterized in that, in a steel rail having pearlite structure containing, in mass, 0.65 to 1.40% C, the number of the pearlite blocks having grain sizes in the range from 1 to 15 ?m is 200 or more per 0.2 mm2 of an observation field at least in a part of the region down to a depth of 10 mm from the surface of the corners and top of the head portion; and a method for producing a pearlitic steel rail excellent in wear resistance and ductility, characterized by, in the hot rolling of said steel rail, applying finish rolling so that the temperature of the rail surface may be in the range from 850° C. to 1,000° C. and the sectional area reduction ratio at the final pass may be 6% or more, and then applying accelerated cooling to the head portion of said rail at a cooling rate in the range from 1 to 30° C./sec. from the austenite temperature range to at least 550° C.

Abstract: The present invention provides a steel plate that exhibits excellent low-temperature toughness in a base material and a weld heat-affected zone and has small strength anisotropy, wherein the steel includes, by mass, C: 0.04%-0.10%; Si: 0.02%-0.40%; Mn: 0.5%-1.0%; P: 0.0010%-0.0100%; S: 0.0001%-0.0050%; Ni: 2.0%-4.5%; Cr: 0.1%-1.0%; Mo: 0.1%-0.6%; V: 0.005%-0.1%; Al: 0.01%-0.08%; and N: 0.0001%-0.0070%, with the balance including Fe and inevitable impurities, a Ni segregation ratio at a portion located at one-fourth of a thickness of the steel plate in a steel-plate thickness direction from a surface of the steel plate is 1.3 or lower, a degree of flatness of a prior austenite grain is in a range from 1.05 to 3.0, an effective diameter of crystal grain is 10 ?m or lower, and a Vickers hardness number is in a range of 265 HV to 310 HV.

Abstract: An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

Abstract: A thick-walled seamless steel pipe for line pipe which has a high strength and improved toughness and corrosion resistance in spite of the thick wall and which is suitable for use as a riser and flow line has a chemical composition comprising, in mass percent, C: 0.02-0.08%, Si: at most 0.5%, Mn: 1.5-3.0%, Al: 0.001-0.10%, Mo: greater than 0.4%-1.2%, N: 0.002-0.015%, at least one of Ca and REM in a total amount of 0.0002-0.007%, and a remainder of Fe and impurities, with the impurities having the content of P: at most 0.05%, S: at most 0.005%, and O: at most 0.005%, the chemical composition satisfying the inequality: 0.8?[Mn]×[Mo]?2.6, wherein [Mn] and [Mo] are the numbers equivalent to the contents of Mn and Mo, respectively, in mass percent.

Abstract: A method of production of 780 MPa class high strength steel plate excellent low temperature toughness comprising heating a steel slab of containing, by mass %, C: 0.06 to 0.15%, Si: 0.05 to 0.35%, Mn: 0.60 to 2.00%, P: 0.015% or less, S: 0.015% or less, Cu: 0.1 to 0.5%, Ni: 0.1 to 1.5%, Cr: 0.05 to 0.8%, Mo: 0.05 to 0.6%, Nb: less than 0.005%, V: 0.005 to 0.060%, Ti: less than 0.003%, Al: 0.02 to 0.10%, B: 0.0005 to 0.003%, and N: 0.002 to 0.006% to 1050° C. to 1200° C. in temperature, hot rolling ending at 870° C. or more, waiting for 10 seconds to 90 seconds, then cooling from 840° C. or more in temperature by a 5° C./s or more cooling rate to 200° C., then tempering at 450° C. to 650° C. in temperature for 20 minutes to 60 minutes.

Abstract: The present invention provides an ultra soft high carbon hot-rolled steel sheet. The ultra soft high carbon hot-rolled steel sheet contains 0.2% to 0.7% of C, 0.01% to 1.0% of Si, 0.1% to 1.0% of Mn, 0.03% or less of P, 0.035% or less of S, 0.08% or less of Al, 0.01% or less of N, and the balance being Fe and incidental impurities and further contains 0.0010% to 0.0050% of B and 0.05% to 0.30% of Cr in some cases. In the texture of the steel sheet, an average ferrite grain diameter is 20 ?m or more, a volume ratio of ferrite grains having a grain diameter of 10 ?m or more is 80% or more, and an average carbide grain diameter is in the range of 0.10 to less than 2.0 ?m. In addition, the steel sheet is manufactured by the steps, after rough rolling, performing finish rolling at a reduction ratio of 10% or more and at a finish temperature of (Ar3?20° C.) or more in a final pass, then performing first cooling within 2 seconds after the finish rolling to a cooling stop temperature of 600° C.

Abstract: Method of heat treating cultivating disc, coulter or grain drill blades made from heat quenched boron steels, such that they can be re-edged and re-sharpened using rollers, and yet retain excellent toughness, hardness and wear characteristics. The invention also includes the cultivating disc, coulter or grain drill blades made from boron steel, which have been heat treated according to the inventive method, such that can be re-edged or sharpened using pinch rollers. The cultivating blades are especially useful in the dry, sandy soils such as found in the wheat growing regions extending from central Kansas down into Texas.

Abstract: To provide a non-aging steel sheet for vitreous enameling, the steel sheet being excellent in resistance to bubbles and black spots, without the employment of decarbonization and denitrification annealing that raises the cost of production and also without the addition of expensive elements such as Nb, Ti, etc. that raise the cost of alloys. The steel sheet comprises, in mass, to C: 0.0050% or less, Si: 0.50% or less, Mn: 0.005 to 1.0%, P: 10×(B?11/14×N) to 0.10%, S: 0.080% or less, Al: 0.050% or less, N: 0.0005 to 0.020%, B: 0.60×N to 0.020%, and O: 0.002 to 0.0800%, and the shape of B nitrides is controlled mainly by adjusting hot-rolling conditions.

Abstract: Disclosed is a hot rolled steel sheet in which it includes a steel having a chemical composition of 0.03 to 0.10% (the percent hereinafter representing % by mass) of C, 0.2 to 2.0% of Si, 0.5 to 2.5% of Mn, 0.02 to 0.10% of Al, 0.2 to 1.5% of Cr, 0.1 to 0.5% of Mo, and the residue of iron and inevitable contaminants, and in this steel sheet, at least 80% by area in longitudinal cross section has a martensitic structure. As a consequence, a high strength hot rolled steel sheet having a tensile strength of the level as high as 980 MPa or higher simultaneously with an excellent forming workability, and in particular, excellent stretch flangeability is provided at a relatively low cost.

Abstract: A high-strength forged part is disclosed which comprises a base phase structure, comprising 30% or more of ferrite in terms of a space factor, and a second phase structure, comprising bainite and/or martensite, and retained austenite having an average gain diameter of 5 ?m or less and a content represented by 50X[C]<[V?R]<150x[C], wherein [V?R] represents a space factor of the retained austenite (?R) and [C] represents the mass % of C in the forged part. Furthermore, a high-strength forged part is disclosed which comprises a base phase structure, comprising 50% or more of tempered bainite or tempered martensite in terms of a space factor, and a second phase structure, comprising martensite and 3% to 30% retained austenite in terms of a space factor, wherein the portion of the retained austenite and martensite having an aspect ratio of 2 or less is 25% or less in terms of a space factor.

Abstract: This invention provides a high-strength hot-rolled steel sheet having strength of at least 980 N/mm2 at a sheet thickness of from about 1.0 to about 6.0 mm and excellent in hole expandability, ductility and ability of phosphate coating, which steel sheet is directed to automotive suspension components that are subjected to pressing. The high-strength hot-rolled steel sheet contains, in terms of a mass %, C: 0.01 to 0.09%, Si: 0.05 to 1.5%, Mn: 0.5 to 3.2%, Al: 0.003 to 1.5%, P: 0.03% or below, S: 0.005% or below, Ti: 0.10 to 0.25%, Nb: 0.01 to 0.05% and the balance consisting of iron and unavoidable impurities; satisfies all of the following formulas <1> to <3>: 0.9?48/12×C/Ti<1.7??<1> 50,227×C?4,479×Mn>?9,860??<2> 811×C+135×Mn+602×Ti+794×Nb>465??<3>, and has strength of at least 980 N/mm2.

Abstract: The present invention provides a fine grain surface layer steel part having a high proof strength ratio equal to or higher than that of conventional quenched and tempered materials, that is, a fine grain surface layer steel part containing, by mass %, C: 0.45% to 0.70%, Nb: 0.01% to 0.60%, Si: 0.10% to 1.50%, Mn: 0.40% to 2.0%, P: 0.10% or less, S: 0.001% to 0.15%, and N: 0.003% to 0.025% and having a balance of Fe and unavoidable impurities, where the surface layer and inside at all or part of the part have structures of different average particle sizes of ferrite crystal grains surrounded by high angle grain boundaries of a misorientation angle of 15 degrees or more and a method of production of that part comprising warm forging locations where strength is required to a predetermined shape at 1000° C. to 800° C. during which working so as to give an equivalent strain of 1.5 or more.

Abstract: Disclosed is an efficient heat treatment method which can be performed in a short time. Specifically disclosed is a method for heat-treating a steel material wherein a plastically deformed steel work is introduced into a heat treatment furnace when the work still retains the heat applied thereto during the plastic deformation, then the work is heated preferably at a heating rate of 15-50 DEG C./min and held at a temperature between Ac1 and Ac3 for 10 minutes or less, and then the work is slowly cooled at a cooling rate of 5-45 DEG C./min. This heat treatment method enables to easily produce a steel material having a uniform metal structure by simple facilities.

Abstract: A high speed tool steel, which is high in impact value and free from variations in tool performance, comprising, by mass %, of: 0.4?C?0.9; Si?1.0; Mn?1.0; 4?Cr?6; 1.6-6 in total of either or both of W and Mo in the form of (½W+Mo) wherein W?3; 0.5-3 in total of either or both of V and Nb in the form of (V+Nb); wherein carbides dispersed in the matrix of the tool steel have an average grain size of ?0.5 ?m and a dispersion density of particles of the carbides is of ?80×103 particles/mm2.

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).

Abstract: The present invention provides high temperature strength and fire-resistant steel superior in weld joint reheat embrittlement resistance and toughness which is produced using steel of a room temperature strength of the 400 to 600N/mm2 class containing as main ingredients C: 0.010% to less than 0.05%, Si: 0.01 to 0.50%, Mn: 0.80 to 2.00%, Cr: 0.50% to less than 2.00%, V: 0.03 to 0.30%, Nb: 0.01 to 0.10%, N: 0.001 to 0.010%, and Al: 0.005 to 0.10%, limiting the contents of Ni, Cu, Mo, and B, and satisfying the relationship of 4Cr[%]-5Mo[%]-10Ni[%]-2Cu[%]-Mn[%]>0.

Abstract: A method for producing a plate of steel which is resistant to abrasion and whose chemical composition includes, by weight: 0.24%?C<0.35%; 0%?Si?2%; 0%?Al?2%; 0.5%?Si+Al?2%; 0%?Mn?2.5% 0%?Ni?5%; 0%?Cr?<5% 0%?Mo?1%; 0%?W?2%; 0.1%?Mo+W/2?1%; 0%?B?0.02%; 0%?Ti?1.1%; 0%?Zr?2.2%; 0.35%<Ti+Zr/2?1.1%; 0%?S?0.15%; N<0.03%, optionally up to 1.5% of copper; optionally at least one element selected from Nb, Ta and V at contents such that Nb/2 +Ta/4+V?0.5%; optionally at least one element selected from among Se, Te, Ca, Bi, Pb at contents which are less than or equal to 0.1%; and the balance being iron and impurities resulting from the production operation. The chemical composition further complying with the following relationships: C*=C?Ti/4?Zr/8+7×N/8?0.095% and 1.05×Mn+0.54×Ni+0.50×Cr+0.3×(Mo+W/2)1/2+K>1.8 with: K=0.5 if B?0.0005% and K=0 if B<0.0005%.

Abstract: The invention relates to ultrahigh strength hot-rolled steel having a chemical composition consisting of, by weight: 0.05%?C?0.1% 0.7%?Mn?1.1% 0.5%?Cr?1.0% 0.05%?Si?0.3% 0.05%?Ti?0.1% Al?0.07% S?0.03% P?0.05% the remainder comprising iron and impurities resulting from the production thereof. Moreover, the inventive steel has a bainitic-martensitic structure which can contain up to 5% ferrite. The invention also relates to a method of producing bands of said steel.

Abstract: A steel plate for linepipes having ultra-high strength and excellent low temperature toughness, and a method for manufacturing the same are disclosed. The steel plate has a strength of 930 MPa or more and excellent toughness even with much smaller amounts of alloying elements than that of conventional steel plates, and a method for manufacturing the same. The steel includes by weight %: 0.03˜0.10% C; 0˜0.6% Si; 1.6-2.1% Mn; 0˜1.0% Cu; 0-1.0% Ni; 0.02-0.06% Nb; 0-0.1% V; 0.1-0.5% Mo; 0-1.0% Cr; 0.005-0.03% Ti; 0.01-0.06% Al; 0.0005-0.0025% B; 0.001-0.006% N; 0-0.006% Ca; 0.02% or less P; 0.005% or less S; and the balance Fe and unavoidable impurities. The microstructure includes at least about 75 area percent of a mixture of bainitic ferrite and acicular ferrite.

Abstract: The invention relates to a method for transforming steel blanks. The invention in particular relates to a method for transforming a steel blank comprising kneading in order to obtain very good mechanical properties. The obtained products may notably be used for forming a pressure device component.

Abstract: UHC lightweight structural steel with improved scaling resistance, comprising the composition in % by weight C: 1 to 1.6, Al: 5 to 10, Cr: 0.5 to 3, Si: 0.1 to 2.8, the remainder iron and customary impurities accompanying steel, and a method for producing components hot-formed from this in air, wherein hot-forming temperatures of from 800 to 1050° C. are used, depending on the Si content.

Abstract: The present invention provides a method for manufacturing high tensile strength steel plate having 570 MPa (N/mm2) or larger tensile strength and having also extremely superior balance of strength and toughness both before PWHT and after PWHT to that of the conventional steel plates, by specifically specifying the temperature-rising rate at the plate thickness center portion of a quenched and tempered material during tempering, and to be concrete, the method has the steps of: casting a steel consisting essentially of 0.02 to 0.18% C, 0.05 to 0.5% Si, 0.5 to 2.0% Mn, 0.005 to 0.1% Al, 0.0005 to 0.008% N, 0.03% or less P, 0.

Abstract: A galvanized steel sheet having (a) a dual phase microstructure with a martensite phase and a ferrite phase and (b) a composition containing by percent weight: carbon in a range from about 0.01% to about 0.18%; manganese in a range from about 0.2% to about 3%; silicon ? about 1.2%; aluminum in a range from about 0.01% to about 0.1%; one or both of chromium and nickel in a range from about 0.1% to about 3.5%; calcium in a range from about 0.0003% to about 0.01%; phosphorus ? about 0.01%; sulfur ? about 0.03%; nitrogen ? about 0.02%; molybdenum ? about 1%; copper ? about 0.8%; one or more of niobium, titanium, and vanadium ? about 1%; and boron ? about 0.006% by weight; and with the balance of the composition being iron and incidental ingredients. In one embodiment, the steel sheet is both galvanized and galvannealed.

Abstract: A steel sheet contains, in terms of percent by mass, C: 0.01 to 0.2%, Si: 2.0% or less, and Mn: 3.0% or less and has a martensite phase as dominant phase and ferrite with a grain size of 20 ?m or less as a second phase. The ferrite is contained in area ratio of 1% to 30% and the amount of solute carbon being 0.01 percent by mass of more. The steel sheet can provide a hot-rolled steel sheet suitable for automobile steel sheet, i.e., has excellent press workability and excellent strain aging property whereby the tensile strength significantly increases by heat treatment at about the same temperature as typical baking process after the press-working. Moreover, hardening of the ferrite phase improves the fatigue strength after the strain aging.

Abstract: A process for hot stamping a steel component is described. The hot stamping process enables the formation of one or more regions of the component to exhibit specific physical properties different than other regions of the component. The various processes are particularly well suited for forming a variety of automobile structural members.

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: The invention relates to a method for producing quenched components consisting of sheet steel, comprising the following steps: a) shaped parts are formed from sheet steel; b) the end of the shaped part is cut and the sheet steel is optionally punched or provided with a desired hole pattern prior to, during, or after the forming of the shaped part; c) at least some sections of the shaped part are subsequently heated to a temperature that permits the steel material to austenitize; and d) the component is then transferred to a quenching die, where it is subjected to a quenching process, during which the component is cooled and thus quenched by the contact of the quenching die with some sections of the component and the compression of said sections. The invention is characterised in that the component is supported by the quenching die in the vicinity of the positive radii and that some sections of said component are clamped in a secure manner without distortion in the vicinity of the cut edges.

Abstract: A hot press-formed member having stable strength and toughness is manufactured from a high strength steel sheet by hot press forming. In the cooling stage during hot press forming, the cooling rate is at least the critical cooling rate until the Ms point is reached and it is then in the range of 25-150° C./s in the temperature range from the Ms point to 200° C. The Vickers hardness of the hot pressed member is less than the value of (maximum quenching hardness—10) and at least the value of (maximum quenching hardness—100).

Abstract: Disclosed is a dual-phase steel sheet having low yield ratio, excellent in the balance for strength-elongation and for strength-stretch flange formability, and also excellent in bake hardening property containing (on the mass % basis). C: 0.01-0.20%, Si: 0.5% or less, Mn: 0.5-3%, sol.Al: 0.06% or less (inclusive 0%), P: 0.15% or less (exclusive 0%), and S: 0.02% or less (inclusive 0?), and in which the matrix phase contains tempered martensite; tempered martensite and ferrite; tempered bainite; or tempered bainite and ferrite, and the second phase comprises 1 to 30% of martensite at an area ratio based on the entire structure.

Abstract: In a method of making a hardened sheet metal part, a blank is cut to form a region defined by at least one cutting edge having a cutting depth which is smaller than a material thickness of the blank. The blank is subjected to a hot forming step and at least in one area is allowed to harden. After the hot forming step, the region is pushed along the cutting edge.