| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 148645000 | With flattening, straightening, or tensioning by external force | 74 |
| 20080251167 | Bake-Hardenable Cold Rolled Steel Sheet With Superior Strength, Galvannealed Steel Sheet Using the Cold Rolled Steel Sheet and Method for Manufacturing the Cold Rolled Steel Sheet - A cold-rolled steel sheet for outer panels and the like of an automobile body, a galvannealed steel sheet using the cold-rolled steel sheet, and a method for manufacturing the same are disclosed. It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing. The cold-rolled steel sheet and the galvannealed steel sheet produced using the cold-rolled steel sheet have the superior bake hardenability, aging resistance at room temperature, and secondary work embrittlement resistance. | 10-16-2008 |
| 20090025838 | COLD-ROLLED STEEL SHEET, METHOD OF PRODUCING THE SAME, BATTERY, AND METHOD OF PRODUCING THE SAME - A cold-rolled steel sheet has a composition containing, by mass percent, 0.0040% or less of C, 0.02% or less of Si, 0.14% to 0.25% of Mn, 0.020% or less of P, 0.015% or less of S, 0.0040% or less of N, 0.020% to 0.070% of Al, 0.005% to 0.030% of Nb, 0.005% to 0.030% of Ti, (0.0003% to 0.0010% of the equivalent amount of solid solution B (from which the amount of B forming BN has been subtracted)), and the balance composed of Fe and inevitable impurities, wherein even when the rolling reduction of cold rolling is 85% or less, the average grain size of a ferrite structure is reliably 12.0 μm or less, and the relationship −0.20≦Δr≦0.20 can be reliably satisfied and which has an excellent earing property. | 01-29-2009 |
| 20090101248 | Grain-Oriented Electrical Steel Sheet and Process for Producing the Same - The present invention provides a grain-oriented electrical steel sheet produced by a method for promoting secondary recrystallization without an inhibitor, the grain-oriented electrical steel sheet including 2.0% or more and 4.5% or less of Si and 0.01% or more and 0.5% or less of Mn on a mass % basis, wherein the number of oxide particles having a diameter of 1 to 3 μm among that (oxide particles) of containing Ca and/or Mg is 400 or less per unit area (1 cm | 04-23-2009 |
| 20090107591 | High-Tensile Steel Plate of Low Acoustic Anisotropy and High Weldability Having Yield Stress of 450 MPa or Greater and Tensile Strength of 570 MPa or Greater, and Process for Producing the Same - A high-tensile steel plate of low acoustic anisotropy and high weldability having yield stress of 450 MPa or greater and tensile strength of 570 MPa or greater and a process for producing the steel plate are provided. The steel has an Si content of 0.10% or less, thereby achieving a volume ratio of island martensite of 3% or less, contains Nb≧0.025% and Ti≧0.005% so as to satisfy 0.045%≦[Nb]+2×[Ti]≦0.105%, contains Nb, Ti, C and N in ranges such that the value of A=([Nb]+2×[Ti])×([C]+[N]×12/14) is 0.0022 to 0.0055, and has a steel structure wherein bainite volume ratio is 30% or more and pearlite volume ratio is less than 5%. | 04-30-2009 |
| 20090250146 | High Strength Thick-Gauge Electric-Resistance Welded Steel Pipe Excellent in Hardenability, Hot Workability and Fatigue Strength and Method of Production of the Same - The present invention provides high strength thick-gauge electric-resistance welded steel pipe excellent in hardenability, hot workability, and fatigue strength and a method of production of the same, that is, thick-gauge electric-resistance welded steel pipe containing, by mass %, C: 0.25 to 0.4%, Si: 0.01 to 0.50%, Mn: 0.8 to 1.5%, P: 0.05% or less, S: 0.05% or less, Al: 0.05% or less, Ti: 0.005 to 0.05%, B: 0.0005 to 0.01%, N: 0.001 to 0.05%, and a balance of Fe and unavoidable impurities, having a critical cooling rate V | 10-08-2009 |
| 20090250147 | Dr Steel Sheet and Manufacturing Method Thereof - This DR steel sheet includes the following steel components: C: 0.02 to 0.06 mass %, Si: equal to or less than 0.03 mass %, Mn: 0.05 to 0.5 mass %, P: equal to or less than 0.02 mass %, S: equal to or less than 0.02 mass %, Al: 0.02 to 0.10 mass %, and N: 0.008 to 0.015 mass %. The amount of solute N (Ntotal−NasAlN) in the steel sheet containing a residual iron and inevitable impurities, is equal to or more than 0.006%; and the total stretchability in a rolling direction after aging is equal to or more than 10%, total stretchability in a sheet width direction after aging is equal to or more than 5%, and an average Lankford value after aging is equal to or less than 1.0. | 10-08-2009 |
| 20090308504 | STEEL SHEET EXCELLENT IN FINE BLANKING PERFORMANCE AND MANUFACTURING METHOD OF THE SAME - A steel sheet excellent in FB performance and also excellent in fabrication performance after FB working and a manufacturing method of the same are provided. The steel sheet is a steel sheet having a composition containing from 0.1 to 0.5% of C, not more than 0.5% of Si and from 0.2 to 1.5% of Mn in terms of % by mass, with P and S being adjusted at proper ranges and having a structure having a ferrite having an average grain size of more than 10 μm and less than 20 μm and a cementite present in the ferrite grain having an average particle size of from 0.3 to 1.5 μm. In this way, the steel sheet becomes a steel sheet excellent in FB performance, mold life and performance (side bend elongation) after FB working. | 12-17-2009 |
| 20100037995 | HIGH-STRENGTH STEEL SHEET SUPERIOR IN FORMABILITY - Disclosed is a high-strength steel sheet which has a predetermined component composition, structurally has a ferrite matrix structure and bainitic and martensitic second phase structures, and has a ferrite fraction of from 50 to 86 percent by area, a bainite fraction of from 10 to 30 percent by area, and a martensite fraction of from 4 to 20 percent by area, relative to the entire structure, in which the bainite area fraction is larger than the martensite area fraction, the ferrite has an average grain size of 2.0 to 5.0 μm, and the ratio of the average ferrite hardness (Hv) to the tensile strength (MPa) of the steel sheet is equal to or more than 0.25. The steel sheet excels both in TS-EL balance and TS-λ balance at high strengths on the order of 590 to 780 MPa. | 02-18-2010 |
| 20100059150 | High Toughness Abrasion Resistant Steel with Little Change in Hardness During use and Method of Production of same - 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 0.1%, having a balance of Fe, and furthermore having an ingredient with an M value defined by the following formula (1) of −10 to 16: | 03-11-2010 |
| 20100089505 | METHOD FOR MANUFACTURING HOT-ROLLED SHEET HAVING FINE-GRAINED FERRITE, AND HOT-ROLLED SHEET - The present invention provides a method for manufacturing the hot-rolled sheet, which includes: a step A including a first rolling in which a steel sheet containing 0.04-0.20% C, 0.01-2.0% Si, 0.5-3.0% Mn by mass, and the reminder being Fe and inevitable impurities, is rolled by successive multi-pass rolling at a total rolling reduction of 80% or more while keeping the steel sheet at temperatures not lower than the para-equilibrium transformation temperature Ae3; a step B including a second rolling in which a single-pass rolling is carried out at a rolling reduction of 30-55% when an entry side temperature is not lower than the para-equilibrium transformation temperature Ae3; a step C including a third rolling in which a single-pass rolling is carried out at a rolling reduction of 35-70% when an entry side temperature is set within a predetermined range; and a step D in which within 0.2 seconds after the third rolling, the rolled sheet is cooled at a cooling rate of 600 degree C./sec or higher to a temperature not higher than {(the para-equilibrium transformation temperature Ae3)−130 degree C.}, in the step C, the third rolling being carried out: within 0.6 seconds after the second rolling when the predetermined temperature range is {(the para-equilibrium transformation temperature Ae3)−60 degree C.} or more and below {(the para-equilibrium transformation temperature Ae3)−30 degree C.}; within 0.5 seconds after the second rolling when the predetermined temperature range is {(the para-equilibrium transformation temperature Ae3)−30 degree C.} or more and below {(the para-equilibrium transformation temperature Ae3)−5 degree C.}; and within 0.3 seconds after the second rolling when the predetermined temperature range is {(the para-equilibrium transformation temperature Ae3)−5 degree C.} or more and below {(the para-equilibrium transformation temperature Ae3)+20 degree C.}. | 04-15-2010 |
| 20100139820 | WEAR-RESISTANT STEEL PLATE HAVING EXCELLENT WEAR RESISTANCE AT HIGH TEMPERATURES AND EXCELLENT BENDING WORKABILITY AND METHOD FOR MANUFACTURING THE SAME - This wear-resistant steel plate includes, in terms of mass %, C: not less than 0.13% and not more than 0.18%, Si: not less than 0.5% but less than 1.0%, Mn: not less than 0.2% and not more than 0.8%, P: not more than 0.020%, S: not more than 0.010%, Cr: not less than 0.5% and not more than 2.0%, Mo: not less than 0.03% and not more than 0.30%, Nb: more than 0.03% but not more than 0.10%, Al: not less than 0.01% and not more than 0.20%, B: not less than 0.0005% and not more than 0.0030%, and N: not more than 0.010%, with a remainder being Fe and unavoidable impurities, wherein an element composition is such that HI is 0.7 or greater and Ceq exceeds 0.50, and an HB value (Brinell hardness) at 25° C. is not less than 360 and not more than 440. | 06-10-2010 |
| 20100206440 | METHOD OF PRODUCTION OF 780 MPA CLASS HIGH STRENGTH STEEL PLATE EXCELLENT IN LOW TEMPERATURE TOUGHNESS - 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. | 08-19-2010 |
| 20100218859 | HIGH CARBON STEEL SHEET SUPERIOR IN FATIUGUE LIFEAND MANUFACTURING METHOD THEREOF - The present invention relates to a high carbon steel sheet that is superior in fatigue life and a method of manufacturing the high carbon steel sheet. The high carbon steel sheet includes about 0.75 wt % to about 0.95 wt % of carbon, smaller than about 1.8 wt % of silicon, about 0.1 wt % to about 1.5 wt % of manganese, about 0.1 wt %˜1.0 wt % of chromium, smaller than about 0.02 wt % of phosphorus, smaller than about 0.02 wt % of sulfur, a residual amount of iron, and inevitable impurities. A layer interval between laminar carbides included in the high carbon steel sheet is smaller than about 0.5 μm. The high carbon steel sheet may include a fine pearlite having a lamellar structure. The fine pearlite included in the high carbon steel sheet may have a volume percentage of larger than about 90%. A ratio of length to width of the lamellar structure may be larger than about 10:1. | 09-02-2010 |
| 20100230016 | HIGH-STRENGTH STEEL PLATE AND PRODUCING METHOD THEREFOR - A high-strength steel plate includes the following composition: 0.18 to 0.23 mass % of C; 0.1 to 0.5 mass % of Si; 1.0 to 2.0 mass % of Mn; 0.020 mass % or less of P; 0.010 mass % or less of S; 0.5 to 3.0 mass % of Ni; 0.003 to 0.10 mass % of Nb; 0.05 to 0.15 mass % of Al; 0.0003 to 0.0030 mass % of B; 0.006 mass % or less of N; and a balance composed of Fe and inevitable impurities. A weld crack sensitivity index Pcm of the high-strength steel plate is 0.36 mass % or less. The A | 09-16-2010 |
| 20100236672 | HIGH TENSILE STEEL FOR DEEP DRAWING AND MANUFACTURING METHOD THEREOF - There are provided a steel for deep drawing, and a method for manufacturing the steel and a high pressure container. The steel for deep drawing includes, by weight: C: 0.25 to 0.40%, Si: 0.15 to 0.40%, Mn: 0.4 to 1.0%, Al: 0.001 to 0.05%, Cr: 0.8 to 1.2%, Mo: 0.15 to 0.8%, Ni: 1.0% or less, P: 0.015% or less, S: 0.015% or less, Ca: 0.0005 to 0.002%, Ti: 0.005 to 0.025%, B: 0.0005 to 0.0020% and the balance of Fe and inevitable impurities, wherein a microstructure of the steel has a triphase structure of ferrite, bainite and martensite. The steel for deep drawing may be useful to further improve the strength without the deterioration of the toughness by adding a trace of Ti and B, compared to the conventional steels having a strength of approximately 1100 MPa. Also, the a method for manufacturing a steel may be useful to save the manufacturing cost and time by significantly curtailing time used in the spheroidization heat treatment during the deep drawing process, and to manufacture a steel for deep drawing that is used for a low-temperature, high-pressure container having a tensile strength of approximately 1200 Mpa by reducing a depth of the softening layer to prevent the deterioration in strength of the steel. | 09-23-2010 |
| 20100258219 | High-Strength Steel Sheet with Excellent Low Temperature Toughness and Manufacturing Method Thereof - There is provided a high-strength steel plate having acicular ferrite and bainite as a main microstructure and an austenite/martensite (M & A) as a second phase under the control of a cooling rate above the austenite transformation temperature. The high-strength steel plate comprises: carbon (C): 0.03 to 0.10 wt %, silicon (Si): 0.1 to 0.4 wt %, manganese (Mn): 1.8 wt % or less, nickel (Ni): 1.0 wt % or less, titanium (Ti): 0.005 to 0.03 wt %, niobium (Nb): 0.02 to 0.10 wt %, aluminum (Al): 0.01 to 0.05 wt %, calcium (Ca): 0.006 wt % or less, nitrogen (N): 0.001 to 0.006 wt %, phosphorus (P): 0.02 wt % or less, sulfur (S): 0.005 wt % or less, and the balance of iron (Fe) and other inevitable impurities. The method for manufacturing a high-strength steel plate may be useful to economically and effectively manufacture a high strength steel, which is able to secure excellent properties such as high strength and high toughness since the acicular ferrite and bainite may be effectively formed without adding expensive elements such as molybdenum (Mo). | 10-14-2010 |
| 20100263773 | HIGH STRENGTH AND LOW YIELD RATIO STEEL FOR STRUCTURE HAVING EXCELLENT LOW TEMPERATURE TOUGHNESS - 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. The high strength and low yield ratio steel satisfying characteristics such as low temperature toughness, brittle crack arrestability and low yield ratio, and the manufacturing method thereof may be provided. | 10-21-2010 |
| 20100269962 | METHOD FOR MANUFACTURING SUPER STRONG STEEL BODY FOR MANUFACTURE OF PRODUCTS WITH COMPLICATED SHAPE - The present invention relates to a method of manufacturing ultra-high strength steel products and, more particularly, to a method of manufacturing ultra-high strength steel products suitable for production of articles having a complicated shape or a high processing depth. The method includes preparing a steel sheet by blanking the steel sheet having hardenability to form a rough shape of a final product, cold-pressing the steel sheet to form a 50˜80% shape of the final product, precisely trimming the cold-formed steel sheet along a contour line corresponding to an outer contour of the final product, and hot-pressing the trimmed product to form the remaining 20˜50% shape of the final product and quenching simultaneous with hot-pressing, after heating the trimmed product to an austenite region of 700° C. or more. | 10-28-2010 |
| 20100326572 | METHOD FOR PRODUCING LOW YIELD STRENGTH COLD ROLLED STEEL SHEET EXCELLENT IN UNIFORMITY - A method produces a high-strength cold-rolled steel sheet includes hot-rolling and cold-rolling steel having a composition which contains, by % by mass, over 0.01% to less than 0.08% of C, 0.2% or less of Si, 0.8% to less than 1.7% of Mn, 0.03% or less of P, 0.02% or less of S, 0.3% or less of sol. Al, 0.01% or less of N, and over 0.4% to 2% of Cr, and which satisfies 1.9<[Mneq]<3 and 0.34≦[% Cr]/[% Mn], the balance being composed of iron and inevitable impurities; heating at an average heating rate of less than 3° C./sec in a temperature range of 680° C. to 740° C.; annealing at an annealing temperature of over 740° C. to less than 820° C.; cooling at an average cooling rate of 2 to 30° C./sec in a temperature range of the annealing temperature to 650° C.; cooling at an average cooling rate of 10° C./sec or more in the temperature range of 650° C. to Tc° C. | 12-30-2010 |
| 20110030857 | HIGH STRENGTH THIN STEEL SHEET FOR THE SUPERIOR PRESS FORMABILITY AND SURFACE QUALITY AND GALVANIZED STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME - 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. | 02-10-2011 |
| 20110041965 | HIGH STRENGTH THICK-GAUGE STEEL PLATE SUPERIOR IN WELDABILITY AND HAVING TENSILE STRENGTH OF 780 MPA OR MORE AND METHOD OF PRODUCTION OF SAME - 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. | 02-24-2011 |
| 20110048589 | HIGH-STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME - 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 μm or less and included in the autotempered martensite is 5×10 | 03-03-2011 |
| 20110067788 | PROCESSES FOR REDUCING FLATNESS DEVIATIONS IN ALLOY ARTICLES - A process for reducing flatness deviations in an alloy article is disclosed. | 03-24-2011 |
| 20110108169 | STEEL WITH HIGH PROPERTIES FOR SOLID PARTS - High-strength steel of which the chemical composition comprises, by weight:
| 05-12-2011 |
| 20110120600 | COLD-ROLLED STEEL SHEET, METHOD FOR MANUFACTURING THE SAME, AND BACKLIGHT CHASSIS - A cold-rolled steel sheet includes, on a percent by mass basis: C: 0.0010% to 0.0030%, Si: 0.05% or less, Mn: 0.1% to 0.3%, P: 0.05% or less, S: 0.02% or less, Al: 0.02% to 0.10%, N: 0.005% or less, and Nb: 0.010% to 0.030% and the remainder composed of Fe and incidental impurities, wherein r values in a rolling direction and a direction perpendicular to the rolling direction are within a range of 1.0 to 1.6, and a mean value El | 05-26-2011 |
| 20110168304 | METHOD FOR MANUFACTURING HIGH STRENGTH STEEL PLATE - 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. | 07-14-2011 |
| 20110192508 | MAGNETOSTRICTIVE MATERIAL AND PREPARATION METHOD THEREOF - The present invention relates to a Fe—Ga—Al-based magnetostrictive thin-sheet material and a process for preparation thereof. The raw materials used for production of the thin-sheet material is composed of the components according to the general Formula, Fe | 08-11-2011 |
| 20110226393 | HOT-PRESSED STEEL PLATE MEMBER AND MANUFACTURING METHOD THEREFOR - Disclosed are a high-strength, high-toughness hot- pressed steel plate member and a manufacturing method therefor. A specified hot-press process is performed on a steel plate member that, with respect to the chemical composition of the steel plate, includes: 0.15 to 0.4 wt % of C; 1.0 to 5.0 wt % of Mn or of a total of Mn and at least one of Cr, Mo, Cu, and Ni; 0.02 to 2.0 wt % of at least any one of Si and Al; and the remainder being Fe and unavoidable impurities, thus providing the physical properties of a martensite phase average grain diameter of 5 μm or less and a tensile strength of 1200 MPa or higher. | 09-22-2011 |
| 20110253271 | HIGH-STRENGTH STEEL PLATE AND PRODUCING METHOD THEREFOR - A high-strength steel plate includes the following composition: 0.18 to 0.23 mass % of C; 0.1 to 0.5 mass % of Si; 1.0 to 2.0 mass % of Mn; 0.020 mass % or less of P; 0.010 mass % or less of S; greater than 0.5 mass % and equal to or less than 3.0 mass % of Cu, 0.25 to 2.0 mass % of Ni; 0.003 to 0.10 mass % of Nb; 0.05 to 0.15 mass % of Al; 0.0003 to 0.0030 mass % of B; 0.006 mass % or less of N; and a balance composed of Fe and inevitable impurities. A weld crack sensitivity index Pcm of the high-strength steel plate is calculated by | 10-20-2011 |
| 20110259483 | Fine Spheroidized Steel Sheet with Excellent Heat Treatment Characteristic and Method for Manufacturing the Same - A method for manufacturing a fine spheroidized steel sheet having an excellent heat treatment characteristic, the method including: i) manufacturing a high carbon slab that is formed of 0.3 to 1.0 wt % C, 0.1 to 1.2 wt % Mn, 0 to 0.4 wt % Si, 0.01 to 0.1 wt % Al, 0 to 0.01 wt % S, and balance Fe and an inevitably added impurity as residuals; ii) reheating the slab to a temperature of Ar3 transformation point or more; iii) roughing rolling the slab, and manufacturing a thin plate by performing finish rolling in an austenite region; iv) cooling the thin plate at a cooling speed of 50 to 300° C./sec; v) finishing the cooling of the thin plate at a temperature region of 400 to 650° C. and maintaining the temperature; vi) winding the thin plate at a temperature region of 450 to 700° C.; vii) performing cold rolling at a reduction ratio of 30% or more; and viii) spheroidizing annealing the cold rolled thin plate. | 10-27-2011 |
| 20110303330 | Steel sheet heating device, method for producing press-formed part, and press-formed part - It is provided a steel sheet heating device that heats a flat steel sheet, including: a hot plate having a flat heating surface brought into close contact with the steel sheet; and a plurality of heating equipment able to heat a plurality of heating regions, formed by dividing the heating surface of the hot plate into a plurality of sections, to different heating temperatures at the same time, wherein the steel sheet is heated to different temperatures at various portions based on the heating temperatures of the plurality of heating regions of the heating surface, at the same time through a single heating treatment. | 12-15-2011 |
| 20120024435 | METHOD AND DEVICE FOR CONTROLLED STRAIGHTENING AND COOLING OF A WIDE METAL STRIP, ESPECIALLY A STEEL STRIP OR SHEET METAL, RUNNING OUT OF A HOT ROLLED STRIP ROLLING MILL - A method and device for controlled straightening and cooling of a wide metal strip, especially a steel strip or sheet metal, running out of a hot rolled strip rolling mill, using pinching rollers arranged in the moving direction of the strip behind vertical double rollers, said pinching rollers producing a tensile stress acting in a longitudinal direction. According to the invention, the range of use of conventional sheet metal cooling systems can be extended to obtain a more even surface of said steel strip with an increased cooling effect. This is achieved by displacing the metal strip or sheet metal between a pre-straightening machine and splash cooling facility in defined conditions of tensile stress by adjusting the tensile stress and by cooling said strip or sheet metal inside said splash cooling facility between successive pairs of pinching rollers and by additionally controlling the tensile stress. | 02-02-2012 |
| 20120067469 | VERY THIN STEEL SHEET AND PRODUCTION METHOD THEREOF - The present invention provides a very thin steel sheet and production method thereof that, in a very thin steel sheet of 0.4 mm or less thickness, enable production at low addition of special elements, simultaneous achievement of both good workability and anti-aging property, and stable passing of even wide coil in a continuous annealing process, which very thin steel sheet and production method. | 03-22-2012 |
| 20120118443 | NON-HEAT TREATED ROLLED STEEL AND DRAWN WIRE ROD WITH EXCELLENT TOUGHNESS, AND METHOD FOR MANUFACTURING THE SAME - There is provided a rolled steel with excellent toughness, a drawn wire rod prepared by drawing the rolled steel, and a method for manufacturing the same, in which even if a heating step is omitted, the toughness of the steel can be improved by securing a degenerated pearlite structure in an internal structure of the rolled steel by controlling a content of Mn among components and cooling conditions, and then preventing C diffusion. The rolled steel according to the present invention includes C: 0.15˜0.30%, Si: 0.1˜0.2%, Mn: 1.8˜3.0%, P: 0.035% or less, S: 0.040% or less, the remainder Fe, and other inevitable impurites, as a percentage of weight, in which the microstucture of the rolled steel is composed of ferrite and pearlite including cementite with 150 nm or less of thickness. | 05-17-2012 |
| 20120138198 | BAKE-HARDENABLE COLD ROLLED STEEL SHEET WITH SUPERIOR STRENGTH, GALVANNEALED STEEL SHEET USING THE COLD ROLLED STEEL AND METHOD FOR MANUFACTURING THE COLD ROLLED STEEL SHEET - It is an object of the present invention to provide a high strength cold-rolled steel sheet, which has superior bake hardenability, aging resistance at room temperature and secondary work embrittlement resistance, and a method for manufacturing the same. The steel sheet has a grain size of ASTM No. of 9 or more after annealing, a BH of 30 MPa or more, an AI of 30 MPa or less, and a tensile strength of 340˜390 MPa through appropriate control of solute elements in steel by addition of a small amount of Ti, addition of Al and Mo, and control of manufacturing conditions, and refinement of crystal grains after annealing. The cold-rolled steel sheet and the galvannealed steel sheet produced using the cold-rolled steel sheet have the superior bake hardenability, aging resistance at room temperature, and secondary work embrittlement resistance. | 06-07-2012 |
| 20120175028 | HIGH STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME - A high strength steel sheet has a tensile strength of 980 MPa or higher includes a composition including, on a mass% basis, C: 0.1% or more and 0.3% or less, Si: 2.0% or less, Mn: 0.5% or more and 3.0% 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 being Fe and incidental impurities, wherein a steel micro-structure includes, on an area ratio basis, martensite: 50% or more, ferrite: 50% or less, bainite: 10% or less, and retained austenite: 10% or less; and the full-width at half maximum in a frequency distribution of nano-hardness, which is obtained by measuring a hardness distribution of the martensite, is 2.0 GPa or more. | 07-12-2012 |
| 20120241057 | LOW YIELD RATIO, HIGH STRENGTH AND HIGH TOUGHNESS STEEL PLATE AND METHOD FOR MANUFACTURING THE SAME - Provided is a low yield ratio, high strength and high toughness steel plate having excellent strain ageing resistance equivalent to API 5L X70 Grade or lower and a method for manufacturing the same. The steel plate has a metallographic microstructure that is a three-phase microstructure consisting of bainite, M-A constituent, and quasi-polygonal ferrite, the area fraction of the bainite being 5% to 70%, the area fraction of the M-A constituent being 3% to 20%, the remainder being the quasi-polygonal ferrite, the equivalent circle diameter of the M-A constituent being 3.0 μm or less. The steel plate has a yield ratio of 85% or less and a Charpy impact test absorbed energy of 200 J or more at −30° C. before or after being subjected to strain ageing treatment at a temperature of 250° C. or lower for 30 minutes or less. | 09-27-2012 |
| 20120267015 | Non-Oriented Electrical Steel Sheet Having Superior Magnetic Properties and a Production Method Therefor - Provided are: a non-oriented electrical steel sheet having outstanding magnetic properties and comprising, as percentages by weight, from 1.0 to 3.0% of Al, from 0.5 to 2.5% of Si, from 0.5 to 2.0% of Mn, from 0.001 to 0.004% of N, from 0.0005 to 0.004% of S and a balance of Fe and other unavoidably incorporated impurities, wherein the Al, Mn, N and S are included so as to satisfy the compositional formulae {[Al]+[Mn]}≦3.5, 0.002≦{[N]+[S]}≦0.006, 300≦{([Al]+[Mn])/([N]+[S])}≦1,400; and a production method therefor. By optimising the Al, Si, Mn, N and S added components in this way, the distribution density of coarse inclusions is increased, thereby making it possible to improve crystal-grain growth properties and domain wall mobility and so produce the highest grade of non-oriented electrical steel sheet having superior magnetic properties, low hardness, and superior customer workability and productivity. | 10-25-2012 |
| 20120312433 | HIGH-STRENGTH STEEL SHEET EXCELLENT IN WORKABILITY AND COLD BRITTLENESS RESISTANCE, AND MANUFACTURING METHOD THEREOF - The invention relates to a steel sheet having a tensile strength of 1180 MPa or more, which excels in workability and cold brittleness resistance. The high-strength steel sheet contains 0.10% to 0.30% of C, 1.40% to 3.0% of Si, 0.5% to 3.0% of Mn, 0.1% or less of P, 0.05% or less of S, 0.005% to 0.20% of Al, 0.01% or less of N, 0.01% or less of O, as well as Fe and inevitable impurities. The steel sheet has: (i) a ferrite volume fraction of 5% to 35% and a bainitic ferrite and/or tempered martensite volume fraction of 60% or more; (ii) a MA constituent volume fraction of 6% or less (excluding 0%); and (iii) a retained austenite volume fraction of 5% or more. | 12-13-2012 |
| 20130000798 | STEEL MATERIAL EXCELLENT IN RESISTANCE OF DUCTILE CRACK INITIATION FROM WELDED HEAT AFFECTED ZONE AND BASE MATERIAL AND METHOD FOR MANUFACTURING THE SAME - A steel material has a composition of C: 0.02 to 0.2%, Si: 0.01 to 0.5%, Mn: 0.5 to 2.5%, P: 0.05% or lower, S: 0.05% or lower, Al: 0.1% or lower, and N: 0.01% or lower and, as required, one or two or more elements selected from Cu: 0.01 to 2%, Ni: 0.01 to 5%, Cr: 0.01 to 3%, Mo: 0.01 to 2%, Nb: 0.1% or lower, V: 0.1% or lower, Ti: 0.1% or lower, B: 0.01% or lower, Ca: 0.01% or lower, and REM: 0.1% or lower in terms of % by mass, and the balance Fe with inevitable impurities, in which the microstructure at the ¼ position of the plate thickness contains ferrite and a hard phase, the area fraction of the hard phase is 50 to 90%, and the average aspect ratio of the ferrite is 1.5 or more. | 01-03-2013 |
| 20130037182 | MECHANICAL PART MADE OF STEEL HAVING HIGH PROPERTIES AND PROCESS FOR MANUFACTURING SAME - A mechanical steel part in steel with high characteristics, characterized in that its composition, comprising in weight percentages, is 0.05%≦C≦0.25%; 1.2%≦Mn≦2%; 1%≦Cr≦2.5%; wherein the contents of C, Mn and Cr are such that (830-270C %-90 Mn %-70Cr %)≦560; 0| 02-14-2013 | |
| 20130042950 | HOT ROLLING MILL AND METHOD FOR HOT ROLLING A METAL STRIP OR SHEET - A method for hot rolling a metal strip or metal sheet, wherein 1. | 02-21-2013 |
| 20130074996 | METHOD FOR MANUFACTURING GRAIN ORIENTED ELECTRICAL STEEL SHEET - A method includes preparing a steel slab in which contents of inhibitor components have been reduced, i.e. content of Al: 100 ppm or less, and contents of N, S and Se: 50 ppm, respectively; subjecting the steel slab to hot rolling and then either a single cold rolling process or two or more cold rolling processes interposing intermediate annealing(s) therebetween to obtain a steel sheet having the final sheet thickness; and subjecting the steel sheet to primary recrystallization annealing and then secondary recrystallization annealing. The primary recrystallization annealing includes heating the steel sheet to temperature equal to or higher than 700° C. at a heating rate of at least 150° C./s, cooling the steel sheet to a temperature range of 700° C. or lower, and then heating the steel sheet to soaking temperature at the average heating rate not exceeding 40° C./s in a subsequent heating zone. | 03-28-2013 |
| 20130098515 | MULTI-PHASE HOT-ROLLED STEEL SHEET HAVING IMPROVED DYNAMIC STRENGTH AND A METHOD FOR ITS MANUFACTURE - A multi-phase hot-rolled steel sheet having improved strength in an intermediate strain rate region has a chemical composition comprising, in mass percent, C: 0.07-0.2%, Si+Al: 0.3-1.5%, Mn: 1.0-3.0%, P: at most 0.02%, S: at most 0.005%, Cr: 0.1-0.5%, N: 0.001-0.008%, at least one of Ti: 0.002-0.05% and Nb: 0.002-0.05%, and a remainder of Fe and impurities. The area fraction of ferrite is 7-35%, the grain diameter of ferrite is in the range of 0.5-3.0 μm, and the nanohardness of ferrite is in the range of 3.5-4.5 GPa. A second phase which is the remainder other than ferrite contains martensite and bainitic ferrite and/or bainite. The average nanohardness of the second phase is 5-12 GPa, and the second phase contains a high-hardness phase of 8-12 GPa with an area fraction of 5-35% based on the overall structure. | 04-25-2013 |
| 20130133792 | HIGH-STRENGTH COLD ROLLED SHEET HAVING EXCELLENT FORMABILITY AND CRASHWORTHINESS AND METHOD FOR MANUFACTURING THE SAME - A high-strength cold rolled steel sheet has excellent formability and crashworthiness and includes, on a mass % basis, C: 0.05 to 0.3%, Si: 0.3 to 2.5%. Mn: 0.5 to 3.5%, P: 0.003 to 0.100%, 5: 0.02% or less, Al: 0.010 to 0.5%, the balance being iron and unavoidable impurities, the high-strength cold rolled steel sheet having a microstructure including 20% or more of ferrite on an area fraction basis, 10 to 60% of tempered martensite on an area fraction basis, 0 to 10% of martensite on an area fraction basis, and 3 to 15% of retained austenite on a volume fraction basis. | 05-30-2013 |
| 20130146187 | METHOD OF PRODUCING NON-ORIENTED ELECTRICAL STEEL SHEET - Disclosed is a method for producing a non-oriented magnetic steel sheet, wherein a steel slab that consists of 0.01-0.1 mass % of C, 4 mass % or less of Si, 0.05-3 mass % of Mn, 3 mass % or less of Al, 0.005 mass % or less of S, 0.005 mass % or less of N and the balance made up of Fe and unavoidable impurities is subjected to hot rolling, cold rolling and final annealing. By carrying out the final annealing, while setting the average heating rate during the heating to 100° C./sec or more and setting the soaking temperature within the temperature range of 750-1100° C., a non-oriented magnetic steel sheet that has extremely increased magnetic flux density in the rolling direction of the steel sheet is advantageously produced. | 06-13-2013 |
| 20130153096 | HIGH-YIELD-RATIO AND HIGH-STRENGTH STEEL SHEET EXCELLENT IN WORKABILITY - Provided is a steel sheet having a tensile strength of 980 MPa or more and exhibiting a high yield ratio and an excellent workability. The steel sheet includes C, Si, Mn, B, at least one of Ti, Nb and V, P, S, Al and N, the content by percentage of each of which is in a specified range. The metal structure thereof includes bainite, and martensite and may include ferrite. The proportion by area of bainite in the entire metal structure is 42 to 85%, that of martensite is 15 to 50%, that of ferrite is 5% or less, and that of entire microstructure of the balance other than bainite, martensite and ferrite is 3% or less thereof. Furthermore, bainite has an average crystal grain diameter of 7 μm or less. | 06-20-2013 |
| 20130160907 | HIGH STRENGTH COLD ROLLED STEEL SHEET HAVING EXCELLENT STRETCH FLANGEABILITY AND METHOD FOR MANUFACTURING THE SAME - A steel is subjected to a hot rolling step, a cold rolling step, and an annealing step having a maximum achieving temperature: 800° C. to 900° C., two-step heating, and two-step cooling. The two-step heating includes first-step heating to (maximum achieving temperature—(10° C. to 50° C.)) at an average temperature raising rate: 0.5° C. to 5.0° C./s and second-step heating in which the temperature raising time from that temperature range to the maximum achieving temperature is specified to be 30 to 150 s. Two-step cooling includes first-step cooling to cool from the maximum achieving temperature at a cooling rate of 10° C. to 40° C./s and second-step cooling to cool to a temperature range of 400° C. to 500° C. at a cooling rate of 0.2 to 0.8 times the first-step cooling rate for a cooling time of 0.2 to 0.8 times the total cooling time. | 06-27-2013 |
| 20130167987 | Low Iron Loss High Strength Non-Oriented Electromagnetic Steel Sheet and Method for Manufacturing Same - Provided is a low iron loss high strength non-oriented electromagnetic steel sheet and a method for manufacturing the same. The method comprises hot-rolling a slab comprising 0.005 weight % or less of C, 4.0 weight % or less of Si, 0.1 weight % or less of P, 0.03 weight % or less of S, 0.1 to 2.0 weight % of Mn, 0.3 to 2.0 weight % of Al, 0.003 weight % or less of N, 0.005 weight % or less of Ti, the remainder being Fe and unavoidable impurities, cold-rolling the slab, and finally annealing the slab such that the fractional area of the non-recrystallization tissue at the cross sectional surface of the steel sheet is 50% or lower (not including 0%). | 07-04-2013 |
| 20130180634 | Grain-Oriented Electric Steel Sheet Having Superior Magnetic Property and Method for Manufacturing Same - Provided is a grain-oriented electric steel sheet and a method for manufacturing same, the steel sheet having superior magnetic properties. The method comprises heating a slab comprising 2.0 to 4.5 weight % of Si, 0.001 to 0.10 weight % of C, 0.010 weight % or lower of Al, 0.08 weight % or lower of Mn, 0.005 weight % or lower of N, 0.002 to 0.050 weight % of S, the remainder being Fe and other unavoidable impurities, performing hot-rolling of the heated slab, performing cold-rolling one time or two or more times including an intermediate annealing, performing decarbonization and re-crystallizing annealing, and performing secondary re-crystallizing annealing. | 07-18-2013 |
| 20130248060 | STRAIN AGING HARDENING TYPE STEEL SHEET EXCELLENT IN AGING RESISTANCE, AND MANUFACTURING METHOD THEREOF - A strain aging hardening type steel sheet excellent in aging resistance, and manufacturing method thereof, said steel sheet comprises: in mass %, C: 0.0010 to 0.010%; Si: 0.005 to 1.0%; Mn: 0.08 to 1.0%; P: 0.003 to 0.10%; S: 0.0005 to 0.020%; Al: 0.010 to 0.10%; Cr: 0.005 to 0.20%; Mo: 0.005 to 0.20%; Ti: 0.002 to 0.10%; Nb: 0.002 to 0.10%; N: 0.001 to 0.005%; and a balance being composed of Fe and inevitable impurities, in which a ferrite fraction is 98% or more, an average grain diameter of ferrite is 5 to 30 μm, a minimum value of dislocation density in a portion having a ½ thickness of a sheet thickness and a minimum value of dislocation density in a surface layer portion are each 5×10 | 09-26-2013 |
| 20130263981 | METHOD OF PRODUCING NON-ORIENTED ELECTRICAL STEEL SHEET - A non-oriented electrical steel sheet having a high magnetic flux density in a rolling direction of the steel sheet is produced by hot rolling a raw steel material including C: not more than 0.03 mass %, Si: not more than 4 mass %, Mn: 0.03˜3 mass %, Al: not more than 3 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass % and the balance being Fe and inevitable impurities, and then cold rolling and finishing annealing to produce a non-oriented electrical steel sheet, characterized in that a crystal grain size before the cold rolling is rendered into not more than 100 μM and the finishing annealing is conducted by rapidly heating up to a temperature exceeding recrystallization temperature at an average temperature rising rate of not less than 100° C./sec. | 10-10-2013 |
| 20130284324 | Steel Sheet for an Oil Sand Slurry Pipe Having Excellent Abrasion Resistance, Corrosion Resistance, and Low-Temperature Toughness and Method for Manufacturing Same - Provided is a steel sheet for an oil sand slurry pipe having excellent abrasion resistance, corrosion resistance, and low-temperature toughness including 0.2 wt % to 0.35 wt % of carbon (C), 0.1 wt % to 0.5 wt % of silicon (Si), 0.5 wt % to 1.8 wt % of manganese (Mn), 0.1 wt % to 0.6 wt % of nickel (Ni), 0.005 wt % to 0.05 wt % of niobium (Nb), 0.005 wt % to 0.02 wt % of titanium (Ti), 0.03 wt % or less of phosphorous (P), 0.03 wt % or less of sulfur (S), 0.05 wt % or less (excluding 0 wt %) of aluminum (Al), 0.01 wt % or less (excluding 0 wt %) of nitrogen (N), and iron (Fe) as well as other unavoidable impurities as a remainder. | 10-31-2013 |
| 20140090755 | ABRASION RESISTANT STEEL PLATE OR STEEL SHEET EXCELLENT IN RESISTANCE TO STRESS CORROSION CRACKING AND METHOD FOR MANUFACTURING THE SAME - Provided is an abrasion resistant steel plate or steel sheet, suitable for use in construction machines, industrial machines, and the like, and a method for manufacturing the same. A steel plate or steel sheet has a composition containing 0.20% to 0.27% C, 0.05% to 1.0% Si, 0.30% to 0.90% Mn, P, S, 0.005% to 0.025% Nb, 0.008% to 0.020% Ti, 0.1% or less Al, and 0.0010% to 0.0060% N on a mass % basis, the composition further containing one or more of Cr, Mo, W, and B, the composition containing one or more of Cu, Ni, V, an REM, Ca, and Mg as required, the remainder being Fe and inevitable impurities. After being heated, a semi-finished product having the steel composition is hot-rolled and is subjected to reheat-quenching or direct quenching. | 04-03-2014 |
| 20140096875 | ABRASION RESISTANT STEEL PLATE OR STEEL SHEET EXCELLENT IN RESISTANCE TO STRESS CORROSION CRACKING AND METHOD FOR MANUFACTURING THE SAME - An abrasion resistant steel plate or steel sheet suitable for use in construction machines, industrial machines, and the like and a method for manufacturing the same. In particular, a steel plate or steel sheet has a composition containing 0.20% to 0.30% C, 0.05% to 1.0% Si, 0.40% to 1.20% Mn, P, S, 0.1% or less Al, 0.01% or less N, and 0.0003% to 0.0030% B on a mass basis, the composition further containing one or more of Cr, Mo, and W, the composition further containing one or more of Nb, Ti, Cu, Ni, V, an REM, Ca, and Mg as required, the remainder being Fe and inevitable impurities. A semi-finished product having the above steel composition is heated, hot rolling is performed, air cooling is performed, reheating is performed, and accelerated cooling is then performed or accelerated cooling is performed immediately after hot rolling. | 04-10-2014 |
| 20140144559 | METHOD FOR PRODUCTION OF MARTENSITIC STEEL HAVING A VERY HIGH YIELD POINT AND SHEET OR PART THUS OBTAINED - The present invention provides a method for the fabrication of a martensitic steel sheet with a yield stress greater than 1300 MPa. The method includes the steps of obtaining a semi-finished steel product, the composition of which includes, whereby the contents are expressed in percent by weight: 0.15%≦C≦0.40%, 1.5%≦Mn≦3%, 0.005%≦Si≦2%, 0.005%≦Al≦0.1%, S≦0.05%, P≦0.1%, 0.025%≦Nb≦0.1%, and optionally: 0.01%≦Ti≦0.1%, 0%≦Cr≦4%, 0%≦Mo≦2%, 0.0005%≦B≦0.005%, 0.0005%≦Ca≦0.005%. The remainder of the composition is iron and the inevitable impurities resulting from processing. The semi-finished product is reheated to a temperature T | 05-29-2014 |
| 20140158259 | Method of Manufacturing a Steel Plate for Linepipe having Ultra-High Strength and Excellent Low Temperature Toughness - 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. | 06-12-2014 |
| 20140246131 | HIGH-TENSILE STEEL PLATE GIVING WELDING HEAT-AFFECTED ZONE WITH EXCELLENT LOW-TEMPERATURE TOUGHNESS, AND PROCESS FOR PRODUCING SAME - A high-tensile steel plate has a chemical composition containing, by mass, specific amounts of C, Mn, Si, P, S, Al, Ni, B, N, one or more elements selected from Cr, Mo, V, Cu, Ti, and Ca as needed, Ceq≦0.80, and a center-segregation zone hardness index HCS satisfying 5.5[C] | 09-04-2014 |
| 20140251514 | GRAIN-ORIENTED ELECTRICAL STEEL SHEET AND METHOD OF PRODUCING THE SAME (AS AMENDED) - In a method of producing a grain-oriented electrical steel sheet by hot rolling a steel slab comprising C: 0.001˜0.10 mass %, Si: 1.0˜5.0 mass %, Mn: 0.01˜1.0 mass %, one or two of S and Se: 0.01˜0.05 mass % in total, sol. Al: 0.003˜0.050 mass % and N: 0.001˜0.020 mass %, cold rolling, subjecting to primary recrystallization annealing, applying an annealing separator and finally subjecting to final annealing, the primary recrystallization annealing is conducted so as to control a heating rate S1 between 500 and 600° C. to not less than 100° C./s and a heating rate S2 between 600 and 700° C. to not less than 30° C./s but not more than 0.6×S1, and as a main ingredient of the annealing separator is used MgO having an expected value μ(A) of citric acid activity distribution of 3.5˜3.8, a cumulative frequency F of 25˜45% when an activity A is not less than 4.0. | 09-11-2014 |
| 20140261919 | LOW CARBON-HIGH MANGANESE STEEL AND MANUFACTURING PROCESS THEREOF - A low carbon-high manganese steel sheet and process for manufacturing the sheet is provided. The process includes soaking a steel slab with a desired chemical composition within a temperature range of 1200-1350° C., followed by hot rolling of the slab into hot strip. The cold rolled sheet is continuously annealed within a temperature range of 730-850° C. and temper rolled between 1.0-2.0%. The temper rolled sheet has a yield strength greater than 280 megapascals (MPa), a tensile strength greater than 400 MPa, an elongation to fracture greater than 30%, an n-value greater than 0.15, and a bakehard index between 15-35 MPa. | 09-18-2014 |
| 20140326369 | STEEL FOR MECHANICAL STRUCTURE FOR COLD WORKING, AND METHOD FOR MANUFACTURING SAME - Provided are a steel for a mechanical structure for cold working, and a method for manufacturing the same, whereby softening and variations in hardness can be reduced even when a conventional spheroidizing annealing process is performed. A steel having a predetermined chemical composition, the total area ratio of pearlite and pro-eutectoid ferrite being at least 90 area % with respect to the total metallographic structure of the steel, the area ratio (A) of pro-eutectoid ferrite satisfying the relationship A>Ae with an Ae value expressed by a predetermined relational expression, the average equivalent circular diameter of bcc-Fe crystal grains being 15-35 μm, and the average of the maximum grain diameter and the second largest grain diameter of the bcc-Fe crystal grains being 50 μm or less in terms of equivalent circular diameter. | 11-06-2014 |
| 20140332123 | HIGH-STRENGTH STEEL SHEET AND METHOD FOR PRODUCING THE SAME - Provided are a high-strength steel sheet and a method for producing the same. A high-strength steel sheet has a composition containing 0.10% to 0.18% C, more than 0.5% to 1.5% Si, 0.5% to 1.5% Mn, 0.05% or less P, 0.005% or less S, and 0.05% or less Al on a mass basis, the remainder being Fe and inevitable impurities and also has a microstructure containing ferrite and pearlite. The volume fraction of the ferrite is 70% to 97%. The volume fraction of the pearlite is 3% or more. The volume fraction of cementite present at grain boundaries of the ferrite is 2% or less. The sum of the volume fractions of phases other than the ferrite, the pearlite, and the cementite is less than 3%. The average grain size of the ferrite is 7 μm or less. | 11-13-2014 |
| 20150007914 | METHOD AND APPARATUS FOR MICRO-TREATING IRON-BASED ALLOY, AND THE MATERIAL RESULTING THEREFROM - The invention discloses a process and apparatus for micro-treating an iron-based alloy including heating and immediately quenching to room temperature to produce high tensile iron-based alloy with varying thicknesses. The process may or may not be practiced with or without tension, under various controllable tensions in order to create desirable effects. The micro-treated iron-based alloy contains desirable bainite to increase its formability and tensile strength. The varying thickness of the iron-based alloys is desirable for different applications, such as forming automobile panels. | 01-08-2015 |
| 20150034219 | HIGH-STRENGTH COLD-ROLLED STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME - A steel sheet has a microstructure including ferrite phase: 40% to 60%, bainite phase: 10% to 30%, tempered martensite phase: 20% to 40%, and retained austenite phase: 5% to 20% by volume fraction, and satisfying a condition that a ratio of tempered martensite phase having major axis length ≦5 μm to a total volume fraction of the tempered martensite phase is 80% to 100%. | 02-05-2015 |
| 20150041029 | STEEL FOR MECHANICAL STRUCTURE FOR COLD WORKING, AND METHOD FOR MANUFACTURING SAME - The present invention is a steel for a mechanical structure for cold working, the steel characterized in containing C, Si, Mn, P, S, Al, N, and Cr, the remainder being iron and inevitable impurities; the metal composition having pearlite and pro-eutectoid ferrite; the combined area of the pearlite and pro-eutectoid ferrite being 90% or more of the total composition; the area percentage A of the pro-eutectoid ferrite having the relationship A>Ae, where Ae=(0.8−Ceq)×96.75 (Ceq=[C]+0.1×[Si]+0.06×[Mn]−0.11×[Cr], and “(element names)” indicates the element content (percent in mass); and the mean grain size of the pro-eutectoid ferrite and the ferrite in the pearlite being 15 to 25 μm. | 02-12-2015 |
| 20150047757 | STEEL SHEET FOR ROTOR CORE FOR IPM MOTOR, AND METHOD FOR MANUFACTURING SAME - The present invention provides a steel sheet for a rotor core for an IPM motor, wherein the steel sheet has a magnetic flux density B | 02-19-2015 |
| 20150075682 | HIGH TENSILE STRENGTH STEEL PLATE HAVING EXCELLENT WELD HEAT-AFFECTED ZONE LOW-TEMPERATURE TOUGHNESS AND METHOD FOR PRODUCING SAME - The present invention provides a high tensile strength steel plate having a chemical composition containing, in percent by mass, 0.03% to 0.12% of C, 0.01% to 0.30% of Si, 0.5% to 1.95% of Mn, 0.008% or less of P, 0.005% or less of S, 0.015% to 0.06% of Al, 0.011% to 0.05% of Nb, 0.005% to 0.02% of Ti, 0.001% to 0.006% of N, 0.0005% to 0.003% of Ca, optionally, one or two or more of Cr, Mo, V, Cu, and Ni, in which Ceq is 0.44 or less, Ti/N is 1.5 to 3.5, and parameter formulas composed of specific elements for controlling the sulfide morphology and the degree of center segregation in the steel are satisfied, and the balance being Fe and incidental impurities, in which the hardness of the center segregation area of the steel sheet is further specified. | 03-19-2015 |
| 20150129094 | BEARING STEEL EXCELLENT IN COLD WORKABILITY AND MANUFACTURING METHOD THEREOF - This bearing steel material satisfies a predetermined elemental composition, and is characterized by having, in the region (boundary region) from the boundary surface of spheroidal cementite to a position at 20 nm away in a base material, no greater than 0.6% (excluding 0%) of Si (boundary Si), no greater than 0.10% (excluding 0%) of Ni (boundary Ni), no greater than 0.10% (excluding 0%) of Cu (boundary Cu), no greater than 0.03% (including 0%) of Mo (boundary Mo), no greater than 0.10% (excluding 0%) of Mn (boundary Mn), and no greater than 0.9% (excluding 0%) of Cr (boundary Cr), and the circularity coefficient of the spheroidized cementite being at least 0.80. The bearing steel material exhibits favorable cold-workability during the production of a bearing component by means of cold working. | 05-14-2015 |
| 20150144233 | HYBRID MOLD STEEL AND MANUFACTURING METHOD THEREOF - Provided is a mold steel for plastic injection that is excellent in fatigue strength and tensile strength and available for long term use, where the mold steel includes: 0.15 to 0.40 wt. % of carbon (C), 0.15 to 0.50 wt. % of silicon (Si), 0.70 to 1.50 wt. % of manganese (Mn), 0.50 to 1.20 wt. % of nickel (Ni), 1.50 to 2.50 wt. % of chrome (Cr), 0.25 to 0.70 wt. % of molybdenum (Mo), 0.20 wt. % or less of vanadium (V), 0.010 wt. % or less of boron (B), and a trace of iron (Fe) and a plurality of impurities. | 05-28-2015 |
| 20150315682 | HIGH STRENGTH STEEL SHEET HAVING EXCELLENT CRYOGENIC TEMPERATURE TOUGHNESS AND LOW YIELD RATIO PROPERTIES, AND METHOD FOR MANUFACTURING SAME - A high strength steel sheet comprises 0.02 to 0.12 wt % of carbon (C), 0.5 to 2.0 wt % of manganese (Mn), 0.05 to 0.5 wt % of silicon (Si), 0.05 to 1.0 wt % of nickel (Ni), 0.005 to 0.1 wt % of titanium (Ti), 0.005 to 0.5 wt % of aluminum (Al), 0.015 wt % or less of phosphorus (P), 0.015 wt % or less of sulfur (S), and the balance of Fe and other inevitable impurities. The microstructure thereof includes 70% to 90% of ultrafine ferrite and 10% to 30% of MA (martensite/austenite) structure by area fraction, and the yield ratio (YS/TS) thereof is 0.8 or less. | 11-05-2015 |
| 20160010193 | THICK STEEL PLATE AND PRODUCTION METHOD FOR THICK STEEL PLATE | 01-14-2016 |
| 20160017466 | HOT-ROLLED STEEL SHEET AND METHOD FOR PRODUCING THE SAME (AS AMENDED) - A hot-rolled steel sheet is provided having high strength and excellent toughness and ductility includes a composition that contains, on a mass percent basis, 0.04% or more and 0.15% or less of C, 0.01% or more and 0.55% or less of Si, 1.0% or more and 3.0% or less of Mn, 0.03% or less P, 0.01% or less S, 0.003% or more and 0.1% or less of Al, 0.006% or less N, 0.035% or more and 0.1% or less Nb, 0.001% or more and 0.1% or less of V, 0.001% or more and 0.1% or less Ti, and the balance being Fe and incidental impurities, in which the hot-rolled steel sheet includes a microstructure in which the proportion of precipitated Nb to the total amount of Nb is 35% or more and 80% or less, the volume fraction of tempered martensite and/or tempered bainite having a lath interval of 0.2 μm or more and 1.6 μm or less is 95% or more at a position 1.0 mm from a surface of the sheet in the thickness direction, and the volume fraction of ferrite having a lath interval of 0.2 μm or more and 1.6 μm or less at the center position of the sheet in the thickness direction is 95% or more. | 01-21-2016 |
| 20160040274 | THICK STEEL SHEET HAVING EXCELLENT CTOD PROPERTIES IN MULTILAYER WELDED JOINTS, AND MANUFACTURING METHOD FOR THICK STEEL SHEET - Provided are a thick steel plate with which a welded joint having good CTOD property is formed by low-to-medium heat input multipass welding and a method for producing the thick steel plate. | 02-11-2016 |
| 20160130677 | Systems and Methods for Tailoring Coefficients of Thermal Expansion Between Extreme Positive and Extreme Negative Values - Systems and methods disclosed herein relate to the manufacture of metallic material with a thermal expansion coefficient in a predetermined range, comprising: deforming, a metallic material comprising a first phase and a first thermal expansion coefficient. In response to the deformation, at least some of the first phase is transformed into a second phase, wherein the second phase comprises martensite, and orienting the metallic material in at least one predetermined orientation, wherein the metallic material, subsequent to deformation, comprises a second thermal expansion coefficient, wherein the second thermal expansion coefficient is within a predetermined range, and wherein the thermal expansion is in at least one predetermined direction. In some embodiments, the metallic material comprises the second phase and is thermo-mechanically deformed to orient the grains in at least one direction. | 05-12-2016 |
