Abstract: The present disclosure relates to a high strength steel sheet having good wettability, a tensile strength of 590 MPa or more and a strength-ductility balance (TS×El) of 16,520 MPa·% or more, and a manufacturing method thereof. The high strength steel comprises, in % by weight, C: 0.03˜0.1%, Si: 0.005˜0.105%, Mn: 1.0˜3.0%, P: 0.005˜0.04%, S: 0.003% or less, N: 0.003˜0.008%, Al: 0.05˜0.4%, Mo or Cr satisfying the inequality 10?50·[Mo %]+100·[Cr %]?30, at least one of Ti: 0.005˜0.020%, V: 0.005˜0.050% and B: 0.0005˜0.0015%, and the balance of Fe and unavoidable impurities, wherein a microstructure of the steel sheet is a multi-phase structure comprising, in an area ratio of cross-sectional structure, 70% or more ferrite phase having a Vickers hardness Hv of 120˜250 and 10% or more martensite phase having a Vickers hardness Hv of 321˜555.

Abstract: A steel sheet for containers that has a hardness of 500 MPa or more and superior workability and a method for producing the steel sheet are provided. A steel containing, in percent by mass, 0.01% to 0.05% carbon, 0.04% or less silicon, 0.1% to 1.2% manganese, 0.10% or less sulfur, 0.001% to 0.100% aluminum, 0.10% or less nitrogen, and 0.0020% to 0.100% phosphorus, the balance being iron and incidental impurities, is subjected to hot rolling at a finishing temperature of (Ar3 transformation temperatute?30)° C. or more and a coiling temperature of 400° C. to 750° C., is subjected to pickling and cold rolling, is subjected to continuous annealing including overaging treatment, and is subjected to second cold rolling at a reduction rate of 20% to 50%, thus providing a high-strength steel sheet for containers that has a tensile strength of 500 MPa or more and a proof stress difference between width and rolling directions of 20 MPa or less.

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?C?0.2; 0.3?Mn?3; 0.05?Si?2; 0.2?Cr+Ni?2; 0.01?Al?0.10; 0.0005?Ca?0.01, 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 megapascals and an n-value of at least approximately 0.175.

Abstract: A method for controlling the cooling of a steel sheet characterized by controlling the end-of-cooling temperature in a cooling process from the Ae3 or above temperature of the steel sheet, during which; preliminarily obtaining enthalpies (H? and H?) of an austenite phase and ferrite phase respectively at some temperature, obtaining a gynamic enthalpy (Hsys) defined by formula (1) with an untransformed fraction (X?) of austenite in accordance with a target temperature pattern, predicting the temperature by using a gradient of this dynamic enthalpy with respect to temperature as a dynamic specific heat and controlling the cooling of the steel sheet: Hsys=H?(X?)+H?(1?X?).

Abstract: Provided are a steel sheet for an automotive muffler and a method for producing the steel sheet. The steel sheet includes 0.01% by weight or less of C, 0.1 to 0.3% by weight of Si, 0.3 to 0.5% by weight of Mn, 0.015% by weight or less of P, 0.015% or less by weight of S, 0.02 to 0.05% by weight of Al, 0.004% or less of N, 0.2 to 0.6% by weight of Cu, 0.01 to 0.04% by weight of Co, and a remainder of Fe and unavoidable impurities. The method includes 0.01% by weight or less of C, 0.1 to 0.3% by weight of Si, 0.3 to 0.5% by weight of Mn, 0.015% by weight or less of P, 0.015% or less by weight of S, 0.02 to 0.05% by weight of Al, 0.004% or less of N, 0.2 to 0.6% by weight of Cu, 0.01 to 0.

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: The present disclosure relates to a dual phase steel sheet and a method of manufacturing the same. The steel sheet comprises C: 0.05˜0.10% wt %, Si: 0.03˜0.50 wt %, Mn: 1.50˜2.00 wt %, P: greater than 0 wt %˜0.03 wt %, S: greater than 0 wt %˜0.003 wt %, Al: 0.03˜0.50 wt %, Cr: 0.1˜0.2 wt %, Mo: 0.1˜0.20 wt %, Nb: 0.02˜0.04 wt %, B: greater than 0 wt %˜0.005 wt %, N: greater than 0 wt %˜0.01 wt %, and the balance of Fe and other unavoidable impurities. To impart excellent formability, bake hardenability, dent resistance, high Ri value and plating characteristics to the steel sheet for exterior and interior panels of automobiles, the steel sheet is processed to have a dual phase structure through cold rolling, annealing, and hot-dip galvanizing.

Abstract: A cold-rolled steel sheet has a partially recrystallized grain structure with a degree of unrecrystallization of 25% to 90% and a Rockwell hardness HRB of 83 or more, the cold-rolled steel sheet containing 0.01% to 0.15% C, 0.03% or less Si, 0.10% to 0.70% Mn, 0.025% or less P, 0.025% or less S, 0.01% to 0.05% Al, and 0.008% or less N on a mass basis, the remainder being Fe and unavoidable impurities, wherein the mean diameter of ferrite is 2 to 10 ?m and these components satisfy Formula (1): (C %)+0.15×(Mn %)+0.85×(P %)?0.21, wherein (M %) represents the content (mass percent) of an element M.

Abstract: This cold-rolled steel sheet includes, in terms of mass %, C: not less than 0.05% and not more than 0.095%, Cr: not less than 0.15% and not more than 2.0%, B: not less than 0.0003% and not more than 0.01%, Si: not less than 0.3% and not more than 2.0%, Mn: not less than 1.7% and not more than 2.6%, Ti: not less than 0.005% and not more than 0.14%, P: not more than 0.03%, S: not more than 0.01%, Al: not more than 0.1%, N: less than 0.005%, O: not less than 0.0005% and not more than 0.005%, and contains as the remainder, iron and unavoidable impurities, wherein the microstructure of the steel sheet includes mainly polygonal ferrite having a crystal grain size of not more than 4 ?m, and hard microstructures of bainite and martensite, the block size of the martensite is not more than 0.9 ?m, the Cr content within the martensite is 1.1 to 1.5 times the Cr content within the polygonal ferrite, and the tensile strength is at least 880 MPa.

Abstract: A super formable high strength thin steel sheet suitable for use in various applications, e.g., automobiles, and a method for manufacturing the thin steel sheet. The thin steel sheet has a composition which comprises 0.010 wt % or less of C, 0.02 wt % or less of Si, 1.5 wt % or less of Mn, 0.03-0.15 wt % or less of P, 0.02 wt % or less of S, 0.03-0.40 wt % of Sol. Al, 0.004 wt % or less of N, 0.005-0.040 wt % of Ti, 0.002-0.020 wt % of Nb, one or both of 0.001-0.02 wt % of B and 0.005-0.02 wt % of Mo, and the balance of Fe and inevitable impurities, wherein the components P, Mn, Ti, Nb and B satisfy the relationship represented by the following Formulae 1-1 and 1-2, depending on a desired tensile strength: Formula 1-1—tensile strength: 35 kg and 40 kg grades 29.1+89.4P(%)+3.9Mn(%)?133.8Ti(%)+157.5Nb(%)+0.18[B(ppm) or Mo(%)] 15=3544.9 Formula 1-2—tensile strength: 45 kg grade 29.1+98.3P(%)+4.6 Mn(%)86.5Ti(%)62.5Nb(%)+0.

Abstract: Iron-carbon-manganese austenitic steel sheet, the chemical composition of which comprises, the contents being expressed by weight: 0.45%?C?0.75%; 15%?Mn?26%; Si?3%; Al?0.050%; S?0.030%; P?0.080%; N?0.1%; at least one metal element chosen from vanadium, titanium, niobium, chromium and molybdenum, where 0.050%?V?0.50%; 0.040%?Ti?0.50; 0.070%?Nb?0.50%; 0.070%?Cr?2%; 0.14%?Mo?2%; and, optionally, one or more elements chosen from 0.0005%?B?0.003%; Ni?1%; Cu?5%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting, the amounts of said at least one metal element in the form of precipitated carbides, nitrides or carbonitrides being: 0.030%?Vp?0.150%; 0.030%?Tip?0.130%; 0.040%?Nbp?0.220%; 0.070%?Crp?0.6%; 0.14%?Mop?0.44%.

Abstract: A hot-rolled austenitic iron/carbon/manganese steel sheet, the strength of which is greater than 1200 MPa, the product P (strength (in MPa)×elongation at break (in %)) of which is greater than 65 000 MPa % and the nominal chemical composition of which comprises, the contents being expressed by weight: 0.85%?C?1.05%; 16%?Mn?19%; Si?2%; Al?0.050%; S?0.030%; P?0.050%; N?0.1%, and, optionally, one or more elements chosen from: Cr?1%; Mo?0.40%; Ni?1%; Cu?5%; Ti?0.50%; Nb?0.50%; V?0.50%, the rest of the composition consisting of iron and inevitable impurities resulting from the smelting, the recrystallized surface fraction of said steel being equal to 100%, the surface fraction of precipitated carbides of said steel being equal to 0% and the mean grain size of said steel being less than or equal to 10 microns.

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: A method of manufacturing a cold-rolled steel sheet includes: adding, by weight %, carbon (C) 0.005% or less, nitrogen (N) 0.002 to 0.005%, manganese (Mn) 0.1 to 1.0%, phosphorous (P) 0.005 to 0.1%, niobium (Nb) 0.015 to 0.04%, silicon (Si) 0.30 or less, sulfur (S) 0.02% or less, aluminum 0.001 to 0.03%; adjusting the atomic ratio of Nb/C to 1 or more and the atomic ratio of Al/N to 0.5 to 1.5, homogenizing a steel containing iron (Fe) and elements inevitably contained in manufacturing the steel as the remainder at temperature of 1150 to 1300° C., setting the final hot-rolling temperature to 890 to 950° C. that is over an Ar3 critical point; and hot-winding the hot-rolled steel sheet and cold-rolling the hot-rolled steel sheet at 40 to 80% cold reduction ratio.

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: Disclosed is a ferritic stainless steel sheet which has excellent corrosion resistance against sulfuric acid in the high-temperature environment and shows less surface roughness at a bent part which is bent at 90° or more. Specifically disclosed is a ferritic stainless steel sheet which has the following chemical composition: C: 0.02 mass % or less, Si: 0.05 to 0.8 mass %, Mn: 0.5 mass % or less, P: 0.04 mass % or less, S: 0.010 mass % or less, Al: 0.10 mass % or less, Cr: 20 to 24 mass % Cu: 0.3 to 0.8 mass %, Ni: 0.5 mass % or less, Nb: 0.20 to 0.55 mass %, and N: 0.02 mass % or less, with the remainder being Fe and unavoidable impurities; and which has such a structure that the maximum particle diameter of an S-containing precipitate is 5 ?m or smaller.

Abstract: A steel sheet undergone precipitation strengthening and refinement in crystal grain size by containing at least one element of 0.005% to 0.05% of Nb, 0.005% to 0.05% of Ti, and 0.0005% to 0.005% of B as a chemical composition is produced through continuous annealing. A steel containing at least one element of Nb, Ti, and B is hot rolled, cooled at a cooling rate of 40° C./s or less, and coiled at 550° C. or higher to facilitate precipitation of cementite after recrystallization annealing. As a result, a steel sheet for a can having a tensile strength of 450 to 550 MPa, a total elongation of 20% or more, and a yield elongation of 5% or less is produced.

Abstract: A high strength cold-rolled steel sheet and a high strength plated steel sheet which have an excellent surface appearance required for outer panels of automobiles and which have an extremely high r value in a direction at 45° with respect to the rolling direction and which have excellent press formability and a tensile strength of at least 340 MPa and a process for their manufacture are provided. The steel sheets have a chemical composition consisting essentially of, in mass %, C: 0.0005-0.025%, Si: at most 0.2%, Mn: 0.3-2.5%, P: at most 0.15%, S: at most 0.02%, N: at most 0.006%, sol. Al: less than 0.005%, Ti: 0.005-0.05%, and Nb: 0.020-0.200% with the mass ratio (Nb/Ti) of the contents of Nb and Ti being at least 2, and a remainder of Fe and impurities, and they have an r value in a direction at 45° with respect to the rolling direction (r45) of at least 1.80 and/or a mean r value (0 of at least 1.60, and a tensile strength of at least 340 MPa.

Abstract: A high-strength steel sheet is useful for applications to automobile steel sheets and the like and has excellent deep drawability, a tensile strength (TS) of as high as 440 MPa or more, and a high r value (average r value ?1.2), and a process for producing the steel sheet. The steel sheet has a composition containing, by % by mass, 0.010 to 0.050% of C, 1.0% or less of Si, 1.0 to 3.0% of Mn, 0.005 to 0.1% of P, 0.01% or less of S, 0.005 to 0.5% of Al, 0.01% or less of N, and 0.01 to 0.3% of Nb, the Nb and C contents in steel satisfying the relation, (Nb/93)/(C/12)=0.2 to 0.7, and the balance substantially including Fe and inevitable impurities. The steel microstructure contains a ferrite phase and a martensite phase at area ratios of 50% or more and 1% or more, respectively, and the average r value is 1.2 or more.

Abstract: A low specific gravity and high strength steel sheet includes C of 0.2% to 0.8%, Mn of 2% to 10%, P of 0.02% or less, S of 0.015% or less, Al of 3% to 15%, and N of 0.01% or less. A ratio of Mn/Al is 0.4 to 1.0. Retained austenite in a structure is included in the range of 1% or more. The steel sheet further includes one or two or more elements selected from the group consisting of Si of 0.1% to 2.0%, Cr of 0.1% to 0.3%, Mo of 0.05% to 0.5%, Ni of 0.1% to 2.0%, Cu of 0.1% to 1.0%, B of 0.0005% to 0.003%, Ti of 0.01% to 0.2%, Zr of 0.005% to 0.2%, Nb of 0.005% to 0.2%, W of 0.1% to 1.0%, Sb of 0.005% to 0.2%, and Ca of 0.001% to 0.2%.

Abstract: A method, which allows high-tensile flat steel products to be manufactured with less effort, includes a steel that forms a complex phase microstructure and contains (in wt. %) C: 0.08-0.11%, Mn: 1.00-1.30%, P: ?0.030%, S: ?0.004%, Si: 0.60-0.80%, Al: ?0.05%, N: ?0.0060%, Cr: 0.30-0.80%, Ti: 0.060-0.120%, remainder iron and unavoidable impurities, being cast into a cast strip having a thickness of 1-4 mm. The cast strip is hot-rolled in-line into a hot-rolled strip having a thickness of 0.5-3.2 mm in a continuous process at a final hot-rolling temperature ranging from 900 to 1100° C., the deformation degree being greater than 20%. The hot-rolled strip is coiled at a coiling temperature ranging from 550 to 620° C., so as to obtain a hot-rolled strip, which has a minimum tensile strength Rm of 800 MPa at a minimum breaking elongation A80 of 10%.

Abstract: A bake-hardenable high-strength cold-rolled steel sheet, a hot-dipped steel sheet thereof, and a method for manufacturing the same. The steel sheet comprises 0.0016˜0.01% of C; 0.1% or less of Si; 0.2˜1.5% of Mn; 0.05˜0.15% of P; 0.01% or less of S; 0.08˜0.5% of (soluble) Al; 0.0025% or less of N; 0.003˜0.1% of Nb; 0.003% or less of Ti; 0.01˜0.4% of Mo; 0.0005˜0.005% of B; and the balance of Fe and other unavoidable impurities, in terms of weight %. The method includes the steps of heating a steel slab of the above composition to a temperature of 1,200° C. or more; and then hot rolling the steel slab with finish rolling at or above the Ar3 temperature to provide a hot rolled steel sheet; coiling the hot rolled steel sheet; cold rolling the hot rolled and coiled sheet; and continuous annealing the cold rolled sheet.

Abstract: A high-ductility, high-strength and high Mn steel strip used for steel strips of automobiles requiring superior formability and high strength, a plated steel strip produced by using the same, and a manufacturing method thereof are disclosed. The high Mn steel strip comprises, by weight %, 0.2˜1.5% of C, 10˜25% of Mn, 0.01˜3.0% of Al, 0.005˜2.0% of Si, 0.03% or less of P, 0.03% or less of S, 0.040% or less of N, and the balance of Fe and other unavoidable impurities. The high-ductility, high-strength and high Mn steel strip, and the plated steel strip produced by using the same have superior surface properties and plating characteristics.

Abstract: The invention provides a high strength cold rolled steel sheet comprising ferrite phases and second phases, in which the mean grain size of the ferrite phases is 20 ?m or less, the volume fraction of the second phase is 0.1% or more to less than 10%, the absolute value |?r| of in-plane anisotropy of r value is less than 0.15, and the thickness is 0.4 mm or more. The high strength cold rolled steel sheet of the present invention has a tensile strength of 370 to 590 MPa, and has excellent stretchability, dent resistance, surface precision, secondary working embrittlement, anti-aging, and surface appearance, therefore it is suitable for outer panels of automobile.

Abstract: The invention concerns a method for making hardenable steel plates by firing comprising: preparing a steel whereof the composition comprises, expressed in weight percent: 0.03=C=0.06, 0.50=Mn=1.10, 0.08:=Si=0.20, 0.015=Al=0.070, N=0.007, Ni=0.040, Cu=0.040, P=0.035, S=0.015, Mo=0.010, Ti=0.005; provided that it comprises boron in an amount such that 0.64=B/N=1.60 the rest consisting of iron and impurities resulting from production; casting a slab of said steel, then hot rolling of said slab to obtain a plate, the final rolling temperature being higher than the point Ar3; winding said plate at a temperature ranging between 500 and 700° C.; then cold rolling of said plate at a reduction rate ranging between 50 and 80%; continuous annealing heat treatment for a time interval less than 15 minutes; and strain hardening with a reduction rate ranging between 1.25 and 2.5%. The invention also concerns the hardenable plates and the parts obtainable therefrom.

Abstract: Disclosed herein is a Nb—Ti composite IF steel in which fine precipitates, such as CuS precipitates, having a size of 0.2 ?m or less are distributed. The distribution of fine precipitates in the Nb—Ti composite IF steel enhances the yield strength and lowers the in-plane anisotropy index. The nanometer-sized precipitates allow the formation of minute crystal grains. As a result, dissolved carbon is present in a larger amount in the crystal grain boundaries than within the crystal grains, which is advantageous in terms of room-temperature non-aging properties and bake handenability.

Abstract: A high carbon cold-rolled steel sheet having both excellent stretch-flange formability and excellent homogeneity of hardness in the sheet thickness direction is provided by a manufacturing method having the steps of: hot-rolling a steel containing 0.2 to 0.7% C by mass at finishing temperatures of (Ar3 transformation point ?20° C.) or above to prepare a hot-rolled sheet; cooling the hot-rolled sheet to temperatures of 650° C. or below at cooling rates from 60° C./s or larger to smaller than 120° C./s; coiling the hot-rolled sheet after cooling at coiling temperatures of 600° C. or below; cold-rolling the coiled hot-rolled sheet at rolling reductions of 30% or more to prepare a cold-rolled sheet; and annealing the cold-rolled sheet at annealing temperatures from 600° C. or larger to Ac1 transformation point or lower.

Abstract: The present invention provides a method for manufacturing an ultra high strength cold-rolled steel sheet, comprising the step of continuously annealing a cold-rolled steel sheet consisting essentially of, in terms of weight percentages, 0.07 to 0.15% C, 0.7 to 2% Si, 1.8 to 3% Mn, 0.02% or less P, 0.01% or less S, 0.01 to 0.1% Sol. Al, 0.005% or less N, 0.0003 to 0.003% B, and the balance being Fe, in which such continuous annealing comprises the steps of: heating the cold-rolled steel sheet at from 800° C. to 870° C. for 10 seconds or more; slowly cooling the heated steel sheet down to from 650° C. to 750° C.; rapidly cooling the slowly cooled steel sheet down to 100° C. or less at a cooling speed of over 500° C./sec; reheating the rapidly cooled steel sheet at from 325° C. to 425° C. for from 5 minutes to 20 minutes; cooling the reheated steel sheet down to room temperature; and coiling the cooled steel sheet.

Abstract: A cold rolled full hard steel strap usable in a strapping machine has a tensile strength of at least about 125.7 thousand pounds per square inch (KSI) when the strap has a width of about 0.500 inches and a thickness of 0.020 inches. The steel strap is fabricated from a coiled steel formed by hot mill rolling and reduced by cold rolling. The steel strap has a composition of approximately (in weight percent): 0.02 to 0.25 percent carbon, 0.15 to 1.50 percent manganese, 0.01 to 0.12 percent aluminum, 0.04 to 0.03 percent nitrogen, 0.04 to 0.50 percent copper, 0.03 to 0.25 percent nickel, 0.02 to 0.25 percent molybdenum, 0.03 to 0.25 percent chromium, maximum 0.05 percent phosphorous, maximum 0.05 percent sulfur, and maximum 0.25 percent silicon. A method for forming the strap also is disclosed.

Abstract: The invention relates to a production method for producing, on a production installation (1), flat products, also of a large width, from continuously cast slabs having a large or medium thickness or from thin slabs. Said production installation is comprised of a single or multiple stand blooming train (4), of a roller table (3), which is provided for conveying the rolling stock and, optionally for oscillating, of a roller table section (5) with hinged heat-insulating covering hoods. The production installation is also comprised of a straightening unit (6) for straightening the pre-strips, of an, in particular, inductive heating installation (7) for effecting the controlled heating of the pre-strips to a defined temperature over the length and width of the pre-strips, of a multiple-stand finishing train (10), of a delivery roller table with devices (11) for cooling the hot rolled strip, and of subsequently arranged coiling machines (12) for coiling the finished strip.

Abstract: A process for manufacturing a containment device including: providing steel slab including (in wt. %) C: 0.05%-0.4%; Si: ?2.0%; Mn: ?2.0%; P: ?0.1%; N: ?200 ppm; remainder iron and inevitable impurities; hot rolling the slab to steel strip after reheating the slab, or utilizing the casting heat by hot-charging the slab, or by direct rolling the slab after casting, followed by cooling the strip to coiling temperature and coiling; cold rolling the strip at between 40 and 95% thickness reduction to form cold-rolled strip; continuous annealing by reheating to temperature above Ac1, homogenising at least 5 seconds, followed by rapid cooling; producing the device. The device has steel at least 10 vol. % martensite and/or bainite and reduced properties of anisotropy. Containment device manufactured by the process and producing isolation barrier material for high temperature and/or pressure sealing for containment devices are also disclosed.

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: Disclosed is a steel sheet that exhibits an ultra-high strength after hot press forming followed by rapid cooling, and an enhanced yield strength after painting. The steel sheet has a composition comprising 0.1% to 0.5% by weight of C, 0.01% to 1.0% by weight of Si, 0.5% to 4.0% by weight of Mn, 0.1% by weight or less of P, 0.03% by weight or less of S, 0.1% by weight of soluble Al, 0.01% to 0.1% by weight of N, 0.3% by weight or less of W, and the balance Fe and other inevitable impurities. Further disclosed are a hot-pressed part made of the steel sheet and a method for manufacturing the hot-pressed part. The hot-pressed part achieves a high increment in yield strength after heat treatment for painting while ensuring an ultra-high tensile strength. Furthermore, the hot-pressed part exhibits superior adhesion to a coating layer, good surface appearance and improved corrosion resistance after painting.

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: The invention relates to a method for producing a siderurgical product made of carbon steel having a high copper content, according to which: —a liquid steel having the composition: 0.0005%?1%; 0.5?Cu?10%; 0?Mn?2%; 0?Si?5% 0?Ti?0.5%; 0?Nb?0.5%; 0?Ni?5%; 0?Al?2%, the remainder being iron and impurities, is produced;—said liquid steel is poured directly in the form of a thin strip having a thickness of no more than 10 mm;—the strip is subjected to forced cooling and/or is surrounded by a non-oxidizing atmosphere while having a temperature of more than 1000? C.; —said thin strip is hot rolled at a reduction rate of at least 10%, the temperature at the end of the rolling process being such that all of the copper is still in a solid solution in the ferrite and/or austenite matrix;—and the strip is coiled. The invention also relates to a siderurgical product obtained according to said method.

Abstract: A steel sheet for deep drawing used for automobiles, and a method for manufacturing the same are disclosed. The steel sheet comprises, by weight %, C: 0.010% or less, Si: 0.02% 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%, and the balance of Fe and other unavoidable impurities, wherein the composition of Ti, Al, B, and N satisfies the relationship: 1.0<(Ti[%]+Al[%]/16+6B[%])/3.43N[%]<4.1, and wherein the composition of Nb, Al, and C satisfies the relationship; 0.7<(Nb[%]+Al[%]/20)/7.75C[%]<3.5. The steel sheet exhibits excellent secondary work embrittlement, fatigue properties of welded joints, and an appealing plated surface as well as excellent formability.

Abstract: The present invention provide a TRIP-type composite structure steel plate of the TPF steel type in which elongation and stretch flange formability at room temperature are improved by controlling the morphology of the second-phase structure. In a composite structure sheet steel comprising 0.02 to 0.12% C, 0.5 to 2.0% Si+Al and 1.0 to 2.0% Mn, with the remainder being Fe and unavoidable impurities, and comprising 80% or more polygonal ferrite (steel structure space factor) and 1 to 7% retained austenite, with the remainder being bainite and/or martensite, wherein the elongation and stretch flange formability of the composite sheet steel are improved by reducing the number of bulky, massive second phases with an aspect ratio of 1:3 or less and a mean grain size of 0.5 ?m or more in the second phase of this composite structure, which comprises retained austenite and martensite.

Abstract: Disclosed herein is a Nb—Ti composite IF steel in which fine precipitates, such as CuS precipitates, having a size of 0.2 ?m or less are distributed. The distribution of fine precipitates in the Nb—Ti composite IF steel enhances the yield strength and lowers the in-plane anisotropy index. The nanometer-sized precipitates allow the formation of minute crystal grains. As a result, dissolved carbon is present in a larger amount in the crystal grain boundaries than within the crystal grains, which is advantageous in terms of room-temperature non-aging properties and bake hardenability.

Abstract: Disclosed herein is a Ti-based IF steel in which fine precipitates, such as CuS precipitates, having a size of 0.2 ?m or less are distributed. The distribution of fine precipitates in the Ti-based IF steel enhances the yield strength and lowers the in-plane anisotropy index. The nanometer-sized precipitates allow the formation of minute crystal grains. As a result, dissolved carbon is present in a larger amount in the crystal grain boundaries than within the crystal grains, which is advantageous in terms of room-temperature non-aging properties and bake hardenability.

Abstract: A steel having a composition, expressed in wt. %, of: 0.03?C?0.06; 0.50?Mn?1.10; 0.08?Si?0.20; 0.015?Al?0.070; N?0.007; Ni?0.040; Cu?0.040; P?0.035; S?0.015; Mo?0.008; Ti?0.005; and boron in an amount such that: 0.65?B/N?1.60, the rest of the composition consisting of iron and impurities resulting from preparation. Also a method for making steel plates having this composition, and the resulting plates, produced by the method.

Abstract: The present invention provides a process for manufacturing a steel strip with low aluminum content, which includes: hot-rolling a steel strip which includes between 0.050 and 0.080% by weight of carbon, between 0.25 and 0.40% by weight of manganese, less than 0.020% by weight of aluminum, and between 0.010 and 0.014% by weight of nitrogen, the remainder being iron and inevitable trace impurities, to form a strip; subjecting the strip to a first cold-rolling, to form a cold-rolled strip; annealing the cold-rolled strip, to form an annealed cold-rolled strip; optionally, subjecting the annealed cold-rolled strip to a secondary cold-rolling; wherein the annealing is a continuous annealing which includes: raising the temperature of the strip to a temperature higher than the temperature of onset of pearlitic transformation Ac1, holding the strip above this temperature for a duration of longer than 10 seconds, and rapidly cooling the strip to a temperature below 350° C. at a cooling rate in excess of 100° C.

Abstract: A process is provided for preparation of an aluminum-killed medium-carbon steel sheet containing by weight from 0.040 to 0.080% of carbon, from 0.35 to 0.50% of manganese, from 0.040 to 0.070% of aluminum, from 0.004 to 0.006% of nitrogen, the remainder being iron and the inevitable trace impurities, wherein the steel contains carbon in free state, a grain count per mm2 greater than 20000 and, in the aged condition, has a percentage elongation A % satisfying the relationship: (640-Rm)/10?A %?(700-Rm)/l1 where Rm is the maximum rupture strength.

Abstract: To provide a high carbon steel sheet having excellent hardenability and toughness, and low planar anisotropy of tensile properties affecting workability, and a method of producing the same. A high car steel sheet having chemical composition specified by JIS G 4051 (Carbon steels for machine structural use), JIS G 4401 (Carbon tool steels) or JIS G 4802 (Cold-rolled steel strips for springs), wherein more than 50 carbides having a diameter of 1.5 ?m or larger exist in 2500 ?m2, the ratio of number of carbides having a diameter of 0.6 ?m or less with respect to all the carbides is 80% or more, and the ?r is more than ?0.15 to less than 0.15, herein ?r=(r0+r90?2×r45)/4, and r0, r45, and r90 shows a r-value of the directions of 0° (L), 45° (S) and 90° (C) with respect to the rolling direction respectively.

Abstract: An object of the present invention is to provide a cold-rolled steel sheet and an alloyed hot-dip galvanized steel sheet in which tensile strength is effectively increased by press forming and heat treatment while maintaining excellent deep drawability in press forming. Specifically, a steel composition contains less than 0.01% of C, 0.005 to 1.0% of Si, 0.01 to 1.0% of Mn, 0.005 to 0.050% of Nb, 0.005 to 0.030% of Al, 0.005 to 0.040% of N, 0.0005 to 0.0015% of B, 0.05% or less of P, and 0.01% or less of S, the balance substantially composed of Fe, in which the following equations (1) and (2) are satisfied: N%?0.0015+14/93.Nb%+14/27.Al%+14/11.B%??(1) C%?(12/93).

Abstract: A ferritic steel sheet wherein a mean value of X-ray random intensity ratios of a group of {100}<011> to {223}<110> orientations is 3.0 or more and a mean value of X-ray random intensity ratios of three crystal orientations of {554}<225>, {111}<112>, and {111}<110> is 3.5 or less and further at least one of the r values in a rolling direction and a direction at a right angle of that is 0.7 or less.

Abstract: A material for shadow mask having the following composition of components: C?0.0008 wt %, Si?0.03 wt %, Mn:0.1 to 0.5 wt %, P?0.02 wt %, S?0.02 wt %, Al:0.01 to 0.07 wt %, N?0.0030 wt %, B: an amount satisfying the formula: 5 ppm?B?11/14×N?30 ppm, balance: Fe and inevitable impurities; a method for producing the material; a shadow mask using the material (cold rolled steel sheet); and an image receiving tube equipped with the shadow mask. The material has excellent etching characteristics, which are uniform within the same coil, and excellent press formability.

Abstract: The present invention presents a high tensile strength cold rolled steel sheet having excellent formability, impact resistance and strain age hardening characteristics, and the production thereof. As a specific means, a slab having a composition which contains, by mass %, 0.15% or less of C, 0.02% or less of Al, and 0.0050 to 0.0250% of N at N/Al of 0.3 or higher, and has N in a solid solution state at 0.0010% or more, is first hot rolled at the finish rolling delivery-side temperature of 800° C. or above, and is subsequently coiled at the coiling temperature of 750° C. or below to prepare a hot rolled plate. Then, after cold rolling, the hot rolled plate is continuously cooled at a temperature from the recrystallization temperature to 900° C. at a holding time of 10 to 120 seconds, and is cooled by primary cooling in which the hot rolled plate is cooled to 500° C. or below at a cooling rate of 10 to 300° C.

Abstract: The present invention presents a high tensile strength cold rolled steel sheet having excellent formability, impact resistance and strain age hardening characteristics, and the production thereof. As a specific means, a slab having a composition which contains, by mass %, 0.15% or less of C, 0.02% or less of Al, and 0.0050 to 0.0250% of N at N/Al of 0.3 or higher, and has N in a solid solution state at 0.0010% or more, is first hot rolled at the finish rolling delivery-side temperature of 800° C. or above, and is subsequently coiled at the coiling temperature of 750° C. or below to prepare a hot rolled plate. Then, after cold rolling, the hot rolled plate is continuously cooled at a temperature from the recrystallization temperature to 900° C. at a holding time of 10 to 120 seconds, and is cooled by primary cooling in which the hot rolled plate is cooled to 500° C. or below at a cooling rate of 10 to 300° C.

Abstract: The invention relates to a method for producing a hot strip, in particular for producing a hot strip intended for the production of a cold strip with good deep-drawing characteristics; in which a steel melt comprising (in % by weight) C:≦0.07%, Si:≦0.5%, Mn:≦2.5%, Al:≦0.1%, N:≦0.01%, P:≦0.025, B:≦0.05, if need be up to a total of 0.

Abstract: Disclosed herein are a super formable high strength thin steel sheet suitable for use in various applications, e.g., automobiles, and a method for manufacturing the thin steel sheet. The thin steel sheet has a composition which comprises 0.010 wt % or less of C, 0.02 wt % or less of Si, 1.5 wt % or less of Mn, 0.030.15 wt % or less of P, 0.02 wt % or less of S, 0.030.40 wt % of Sol. Al, 0.004 wt % or less of N, 0.0050.040 wt % of Ti, 0.0020.020 wt % of Nb, one or both of 0.0001 0.02 wt % of B and 0.0050.02 wt % of Mo, and the balance of Fe and inevitable impurities, wherein the components P. Mn, Ti, Nb and B satisfy the relationship represented by the following Formulae 1-1 and 1-2, depending on a desired tensile strength: [Formula 1-1]—tensile strength: 35 kg and 40 kg grades 29.1+89.4P(%)+3.9Mn(%)−133.8Ti(%)+157.SNb(%)+0.18[B(ppm) or Mo(%)]15=3544.9 [Formula 1-2]—tensile strength: 45 kg grade 29.1+98.3P(%)+4.