Abstract: The present disclosure provides a hot-press formed part comprising a plated steel sheet and an aluminum alloy plated layer formed on the plated steel sheet, wherein the aluminum alloy plated layer comprises: an alloying layer (I) formed on the plated steel sheet and containing, by weight %, 5-30% of Al; an alloying layer (II) formed on the alloying layer (I) and containing, by weight %, 30 to 60% of Al; an alloying layer (III) formed on the alloying layer (II) and containing, by weight %, 20-50% of Al and 5-20% of Si; and an alloying layer (IV) formed continuously or discontinuously on at least a part of the surface of the alloying layer (III), and containing 30-60% of Al, wherein the rate of the alloying layer (III) exposed on the outermost surface of the aluminum alloy plated layer is 10% or more.

Abstract: A cold-rolled and heat-treated steel sheet, having a composition including, by weight percent: 0.10%?C?0.40%, 3.5%?Mn?8.0%, 0.5%?Si?2.5%, 0.003%?Al?3.0%, with Si+Al?0.8%, 0.001%?Mo?0.5%, S?0.010%, P?0.020%, N?0.008%, and optionally one or more elements selected from a group comprising Cr, Ti, Nb, V and B, such that: 0.01%?Cr?2.0%, 0.010%?Ti?0.080%, 0.010%?Nb?0.080%, 0.010%?V?0.30%, 0.0005%?B?0.003%, the remainder of the composition being iron and unavoidable impurities resulting from the smelting. The microstructure includes, in surface fraction, between 10% and 50% of retained austenite, at most 8% of fresh martensite, and tempered martensite. The retained austenite includes Mn-enriched austenite, having a Mn content higher than 1.3*Mn %, Mn % designating the Mn content of the steel sheet, a surface fraction of the Mn-enriched austenite with respect to the whole microstructure is between 2% and 12%, and Mn-poor austenite, having an Mn content between 0.5*Mn % and 1.3*Mn %.

Abstract: A system for cooling rolling mill material is provided that includes a conveyor system that receives rolling mill material and passes the rolling mill material through one or more cooling regions. A cooling structure that operates uniformly across the central and edge regions of the conveyor system. The cooling structure uses a first jet of air for cooling the central portion of the rolling mill material. A nozzle deck is positioned on the edge regions of the conveyor system produces a second of jet of air for cooling the edge portions of the rolling mill. The nozzle deck includes one or more adjustable nozzle structures for controlling the air flow produced by the second jet of air by varying the size of their air passage regions.

Abstract: A method for manufacturing a steel sheet having a yield strength YS of more than 1000 MPa, a tensile strength TS of more than 1150 MPa and a total elongation E of more than 8%, comprising the steps of: —preparing a steel sheet through rolling from a steel containing in percent by weight 0.19% to 0.22% C, 2% to 2.6% Mn, 1.45% to 1.55% Si, 0.15% to 0.4% Cr, less than 0.020% P, less than 0.05% S, less than 0.08% N, 0.015% to 0.070% Al, the reminder being Fe and unavoidable impurities, —soaking the sheet at an annealing temperature TA between 860° C. and 890° C. for a time between 100 s and 210 s, cooling the sheet to a quenching temperature QT between 220° C. and 330° C., from a temperature TC not less than 500° C. at a cooling speed not less than 15° C./s, heating the steel sheet during a time between 115 s and 240 s up to a first overaging temperature TOA1 higher than 380° C., then heating the sheet during a time between 300 s and 610 s up to a second overaging temperature TOA2 between 420° and 450° C.

Abstract: A zinc-coated steel may be produced by performing a pre-alloying heat treatment after galvannealing the steel and prior to the hot stamping the steel. The pre-alloying heat treatment is conducted at a temperature between about 850° F. and about 950° F. in an open coil annealing process. The pre-alloying heat treatment allows for shorter time at the austenitization temperature to form a desired ?-Fe phase in the coating by increasing the concentration of iron. This also decreases the loss of zinc, and a more adherent oxide exists after hot stamping.

Abstract: A high carbon hot rolled steel sheet and a method for manufacturing the same are provided, wherein excellent cold workability and excellent hardenability are obtained stably. The high carbon hot rolled steel sheet has a composition containing C: 0.20% to 0.48%, Si: 0.1% or less, Mn: 0.5% or less, P: 0.03% or less, S: 0.01% or less, sol. Al: more than 0.10% and 1.0% or less, N: 0.005% or less, B: 0.0005% to 0.0050%, and the remainder composed of Fe and incidental impurities, on a percent by mass basis, and a microstructure composed of ferrite and cementite, wherein the average grain size of the above-described ferrite is 10 to 20 ?m and the spheroidization ratio of the above-described cementite is 90% or more.

Abstract: The invention relates to a process for coating a metal strip, in which a layer of an oxidizable metal or an oxidizable metal alloy or a metal oxide is vacuum-deposited on a metal strip precoated with zinc or with a zinc alloy, the coated metal strip is then coiled, and the wound coil undergoes a static diffusion treatment so as to obtain a strip having a coating that comprises, in the upper portion, a layer of an alloy formed by diffusion of the oxidizable metal or the oxidizable metal alloy in all or part of the zinc or zinc alloy layer, and also to equipment for implementing the process.

Abstract: A process for fabricating a steel sheet is provided. The process includes soaking a steel sheet. The steel has a composition including iron, carbon, manganese, silicon, aluminum, sulfur, phosphorus and nitrogen and at least one metallic element X chosen among vanadium, titanium, niobium, molybdenum, and chromium. A quantity Xp of metallic element under the form of carbides, nitrides or carbonitrides is, by weight: 0.030%?Vp?0.40%; 0.030%?Tip?0.50%; 0.040%?Nbp?0.40%; 0.14%?Mop?0.44%; or 0.070%?Crp?0.6%. The soaking step occurs under a pure nitrogen or argon atmosphere with a dew point lower than ?30° C. at a soaking temperature ? between 250 and 900° C. and with a dynamic circulation of a regenerated atmosphere.

Abstract: An apparatus (un-interleaver) for unwinding a roll of material interleaved with another material, and for separating the materials, includes a first platform, a second platform, a tension-sensor, an edge-sensor, and a controller. The controller monitors signals generated by the tension-sensor and the edge-sensor, and in response to the signals: a) causes the speed at which the second platform rotates to change to maintain a predetermined tension in the second material as the second material travels from the first platform toward the second platform, and b) causes the second platform to move relative to the first platform to align the edge of the second material traveling toward the roll of second material with the edge of the second material in the roll.

Abstract: Device (10) and method for winding/unwinding rolled products (20). The device (10) is interposed between a rolling unit located upstream (102) and a rolling unit located downstream (105). The device (10) comprises a heating furnace (11) and a support structure (16) disposed outside the heating furnace (11). On the support structure (16), substantially in a diametrically opposite position, two winding/unwinding drums (18a, 18b) are assembled, positioned inside the furnace (11). The support structure (16) is selectively rotating to alternatively dispose a first of the two drums (18a or 18b) in its winding position or in its unwinding position of a reel (29). A second of the two drums (18b or 18a) consequently assuming the opposite unwinding or winding position.

Abstract: A cold rolled strip (3) of aluminum is continuously transported along a transport path where a ramp of Direct Flame Impingement (DFI) burners (1) are located, for heating the strip. The ramp (1) is located perpendicular, or substantially perpendicular, to the direction of movement of the strip (3), the DFI burners (1) are mutually located such that the whole width of the strip (3) is heated to the same, or substantially the same, temperature. The velocity of the strip (3) passing the ramp and the heating power of the burners (1) are adapted to heat treat the strip (3) such that annealing of the strip is carried out and the heat treated strip is wound to a coil (5).

Abstract: Apparatus and method are provided for making the longitudinal temperature distribution of the bulbous end of a longitudinally oriented workpiece, such as a rail's head, generally uniform when the head has a non-uniform longitudinal temperature distribution. A combination of crown and skirt electric inductors is used to achieve the generally uniform temperature distribution by modulating the magnetic field intensity produced by current flow through one or more of the combination of crown and skirt inductors as required for the non-uniformly heated regions of the rail's head.

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: In a device and a method for recovering energy from at least one metal hot strip bundle (B) which has a temperature of more than 200° C. and is produced in a hot rolling mill (H), the at least one hot strip bundle (B) passes through an energy recovery device (3). In order to recover energy, a gaseous medium (G) flows around the at least one hot strip bundle (B) within the energy recovery device (3) such that said hot strip bundle absorbs energy, particularly heat, dissipated by the at least one hot strip bundle (B), thereby providing a technically simple method and a corresponding device for recovering energy, both of which can be used for any kind of hot strip, independently of the further processing thereof. Furthermore, CO2 and energy can be saved.

Abstract: A high-strength hot-rolled steel sheet has a tensile strength (TS) of 540 to 780 MPa, only small variations in strength, and excellent uniformity in strength using a general-purpose Ti-containing steel sheet, which is inexpensive. The high-strength hot-rolled steel sheet includes, on a mass percent basis, 0.05%-0.12% C, 0.5% or less Si, 0.8%-1.8% Mn, 0.030% or less P, 0.01% or less S, 0.005%-0.1% Al, 0.01% or less N, 0.030%-0.080% Ti, and the balance being Fe and incidental impurities. The microstructure have a bainitic ferrite fraction of 70% or more, and the amount of Ti present in a precipitate having a size of less than 20 nm is 50% or more of the value of Ti* calculated using formula (1): Ti*=[Ti]?48/14×[N] (1) where [Ti] and [N] represent a Ti content (percent by mass) and a N content (percent by mass), respectively, of the steel sheet.

Abstract: A method for operating a continuous annealing or galvanizing line for a metal strip, uses a direct flame heating section with an upstream zone and a downstream zone. The direct flame heating section is followed by a radiant tube heating section. The metal strip is indirectly heated in the direct flame heating section. The heating of the metal strip is achieved in the upstream zone by combustion of a mixture of atmospheric air and fuel such that the temperature of the combustion gas is between 1250° C. and 1500° C., preferably close to 1350° C. and in the downstream zone, the heating of the metal strip is achieved by combustion of a superoxygenated substoichiometric mixture of air and fuel such that the temperature of the combustion gas achieved at the end of the upstream zone is maintained until the end of the downstream zone of the direct flame heating section.

Abstract: A hot rolled steel strip made by the steps including assembling a twin roll caster, forming a casting pool of molten steel of such composition that the cast strip produced comprises by weight, greater than 0.25% and up to 1.1% carbon, between 0.40 and 2.0% manganese, between 0.05 and 0.50% silicon, less than 0.01% aluminum, counter rotating the casting rolls to solidify metal shells and forming a steel strip, hot rolling the steel strip such that mechanical properties at 10% and 35% reduction are within 10% for yield strength, tensile strength and total elongation, and coiling the hot rolled steel strip at a temperature between 550 and 750° C. to provide a majority of the microstructure comprising pearlite, along with bainite and acicular ferrite. The steel may have a free oxygen content between 5 and 50 ppm or between 25 and 45 ppm.

Abstract: A method of manufacturing a hot-rolled thin steel sheet includes: hot-rolling a steel base material having a composition containing, as mass %, C: 0.10 to 0.20%, Si: 0.01 to 1.0%, Mn: 0.5 to 2.0%, P: 0.03% or less, S: 0.01% or less, Al: 0.01 to 0.10%, N: 0.005% or less, Ti: 0.01 to 0.15%, B: 0.0005 to 0.0050%, the balance of Fe, and unavoidable impurities at a finishing temperature of finish rolling of 820 to 880° C. to produce a hot-rolled steel sheet with a thickness of less than 6 mm; cooling the hot-rolled steel sheet to a temperature range on a surface of the hot-rolled steel sheet to 550 to 650° C. at a surface cooling rate of 15 to 50° C. per second; and coiling the hot-rolled steel sheet at the temperature range.

Abstract: A hot-rolled high strength steel sheet in which, without using expensive Mo, and by effectively using Ti, which is an expensive element, the amount of precipitation hardening of which is large, both ductility and stretch-flangeability are improved at a tensile strength of 780 MPa or higher, and desirable tensile fatigue properties are exhibited. The hot-rolled high strength steel sheet has a composition including, in percent by mass, C: 0.06% to 0.15%, Si: 1.2% or less, Mn: 0.5% to 1.6%, P: 0.04% or less, S: 0.005% or less, Al: 0.05% or less, and Ti: 0.03% to 0.20%, the balance being Fe and incidental impurities, wherein the steel sheet has a structure in which the volume fraction of ferrite is 50% to 90%, the balance is substantially bainite, the total volume fraction of ferrite and bainite is 95% or more, precipitates containing Ti are precipitated in the ferrite, and the precipitates have an average diameter of 20 nm or less; and 80% or more of the Ti content in the steel is precipitated.

Abstract: Disclosed is a hot rolled steel sheet which contains C, Si, Mn, Al, Ti, N, and S. The C, Ti, N, and sulfur contents satisfy the following condition (1), and the Si and Mn contents satisfy the following condition (2): [C]?{[Ti]?(48/14)×[N]?(48/32)×[S]}/4?0.01??(1) 0.20?([Si]/[Mn])?0.85??(2) in which the symbol [X] represents the content (percent by mass) of the element X, and the steel sheet has a microstructure having an area percentage of bainitic ferrite of 90% or more, an area percentage of martensite of 5% or less, and an area percentage of bainite of 5% or less, based on the area of an observed field. This steel sheet excels in properties demanded in press working, such as shape freezing ability, hole-expandability, and bendability, even though it has a high tensile strength of 980 MPa or more.

Abstract: A cooling device including an air source, preferably a fan, that provides air flow and a shroud for directing air flow from the air source at an object, particularly a coil of material, preferably a metal or metal alloy having a temperature greater than the ambient room temperature. The cooling device provides cooling efficiency by directing the air from the air source at an increased velocity to a desirable area or areas on an end surface of the object, thereby increasing heat transfer from the object. The cooling device shroud includes an air directing surface that influences the direction of air flow across the object in a desired pattern. Methods for preparing cooling devices and for cooling objects are also described.

Abstract: A method for producing a wide steel strip using thin slab continuous casting and rolling by the following steps a) casting a molten steel into a thin slab having a thickness of between 50 and 90 mm; b) cutting; c) soaking; d) heating by electromagnetic induction; e) descaling; f) rolling; g) cooling with laminar flow; and h) coiling. The method can effectively control the solution and precipitation of carbon, nitrogen, and sulfide in steel with a low cost. The process is easy and flexible, and steel can be produced in a wide range of categories. Further provided is a system for producing a wide steel strip with thin slab continuous casting and rolling.

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

Abstract: A high-tensile strength welded steel tube has excellent formability and torsional fatigue endurance after being formed into cross-sectional shape and then stress-relief annealed. A steel material used has a composition which contains C, Si, Al, 1.01% to 1.99% Mn, 0.041% to 0.150% Ti, 0.017% to 0.150% Nb, P, S, N, and O such that the sum of the content of Ti and that of Nb is 0.08% or more, the content of each of C, Si, and Al being within an appropriate range, the content of each of P, S, N, and O being adjusted to a predetermined value or less.

Abstract: A continuous process for producing a shaped metal member from a feedstock comprising a flat web of metal includes a roll-forming station for shaping the web, a cutting station for cutting the shaped web into individual members, and a processing station for altering a physical characteristic of the metal comprising the members. The processing may include heat treating and/or shaping. The process may also be operable to carry out further operations such as marking, inspection, sorting and the like. Also disclosed is an apparatus for carrying out the process.

Abstract: Disclosed is a hot rolled steel sheet which contains C, Si, Mn, Al, Ti, N, and S. The C, Ti, N, and sulfur contents satisfy the following condition (1), and the Si and Mn contents satisfy the following condition (2): [C]—{[Ti]-(48/14)x[N]-(48/32)x[S]}/4?0.01 ??(1) 0.20?([Si]/[Mn])?0.85 ??(2) in which the symbol [X] represents the content (percent by mass) of the element X, and the steel sheet has a microstructure having an area percentage of bainitic ferrite of 90% or more, an area percentage of martensite of 5% or less, and an area percentage of bainite of 5% or less, based on the area of an observed field. This steel sheet excels in properties demanded in press working, such as shape freezing ability, hole-expandability, and bendability, even though it has a high tensile strength of 980 MPa or more.

Abstract: Coil winding method for steel bars providing, at the outlet of the rolling mill (2), cooling stages by means of WB (4?, 4?, 4??) and equallsation in air so as to perform “soft” hardening on the bar which generates a microstructure consisting, on the surface, of martensite and bainite and, in the center, of ferrite and pearlite, and winding of the bar in the form of a compact coil by means of a coil winder (5). In the position wound on the coil, the bar cools slowly with tempering of the bainite and martensite formed on the surface. This is followed by a straightening stage, jo performed during the coil unwinding phase, and a natural ageing stage, maintaining the bar at ambient temperature.

Abstract: Dual phase steel sheet is made using a time/temperature cycle including a soak at about AC1+45° F. to AC1+135° F. and a hold at 850-940F, where the steel has the composition in weight percent, carbon: 0.02-0.20; aluminum: 0.010-0.150; titanium: 0.01 max; silicon: 0.5 max; phosphorous: 0.060 max; sulfur: 0.030 max; manganese: 0.8-2.40; chromium: 0.03-1.50; molybdenum: 0.03-1.50; with the provisos that the amounts of manganese, chromium and molybdenum have the relationship: (Mn+6Cr+10 Mo)=at least 3.5%. The sheet is preferably in the form of a strip suitable for coating in a continuous galvanizing or galvannealing line, and the product is predominantly ferrite and martensite. The strip may be galvanized or galvannealed at a temperature within thirty degrees F. of the temperature of the bath.

Abstract: Disclosed is a high temperature annealing furnace for hot rolled steel coils. The furnace of the present invention pivotably rotates about a pivot member between an opened and closed position. Prior to the annealing step, the hot rolled steel coils are placed within the housing of the furnace. The hot rolled steel coils are supported on a retaining element secured to a base portion located within the housing of the furnace. The hot rolled steel coils may be positioned on the base portion such that the axial opening of each coil is generally horizontal with the base portion.

Abstract: A method of manufacturing a high strength steel sheet containing, in mass %, C: 0.02 to 0.04%, Si: at most 0.4%, Mn: 0.5-3.0%, P: at most 0.15%, S: at most 0.03%, Al: at most 0.50%, N: at most 0.01%, and Mo: 0.01-1.0%. The method includes performing hot rough rolling either directly or after heating to a temperature of at most 1300° C., commencing hot finish rolling either directly or after reheating or holding, completing finish rolling at a temperature of at least 780° C., performing coiling after cooling to a temperature of 750° C. or below at an average cooling rate of at least 3° C./second, heating to an annealing temperature of at least 700° C. and then cooling to a temperature of 600° C. or below at an average cooling rate of at least 3° C./second, then holding in a temperature range of 450-600° C. for at least 10 seconds, and performing hot dip galvanizing after cooling.

Abstract: The present invention relates to a method for the manufacture of galvannealed metal sheet, wherein a hot strip is produced from an IF steel containing 0.01 to 0.1 wt. % silicon, wherein the hot strip is coiled at a coiler temperature no lower than 700° C. and no higher than 750° C., wherein a cold strip is rolled from the coiled hot strip, wherein the cold strip is recrystallization-annealed in an annealing furnace in an annealing gas atmosphere, wherein the cold strip thus annealed is provided with a zinc coating in a zinc bath, and wherein the coated cold strip is post-annealed at a galvannealing temperature no lower than 500° C. and no higher than 540° C. The invention also relates to a galvannealed metal sheet which possesses improved adhesion of the coating layer to the base material and proposes a method which is suited for the manufacture of metal sheet having such properties.

Abstract: The invention relates to a method for producing hot strip which features good forming ability and increased strength. This is achieved in that a hot strip (W) which is produced in particular from continuous casting in the shape of reheated slabs or slabs obtained directly from the casting heat, from thin slabs or cast strip, based on a steel comprising (in mass %) C: 0.001-1.05%; Si: ?1.5%; Mn: 0.05-3.5%; Al: ?2.

Abstract: The invention concerns a method for making a multiphase hot-rolled steel strip comprising an ultra-fast cooling operations, which consists in carrying out said ultra-fast cooling operation after controlled slow cooling of the strip on a conventional slow cooling table of the rolling mill. The controlled cooling constitutes a first slow cooling, at the output of the finishing mill, from an end-of-roll temperature to an intermediate temperature of about 750° C. to 500° C.; said first cooling determines the fraction of the first phase (ferrite) in the steel. The ultra-fast cooling (>150° C./s), which solidifies the resulting structure, lowers the temperature of the strip down to a coiling temperature, ranging between about 600° C. and room temperature, at which a second slow cooling is performed which results if the formation of the second phase (bainite or martensite).

Abstract: The invention relates to a method of producing coils of sheet metal consisting in coiling the sheet metal (1) following a hot-rolling, cold-rolling or cleaning operation. The inventive method is characterised in that it comprises the following steps, namely: coiling a part of said sheet metal (1) fixing a spacer (2) to one edge of the non-coiled part of the sheet metal (1) and coiling the rest of the sheet metal (1), thereby creating a coil (7) comprising a space (6) between two of the wraps thereof, with the possibility of fixing said spacer (2) either with or without interrupting the coiling; said coil (7) is then disposed in a heat treatment installation; a heat measuring device (8) is inserted in the space (6) created between the wraps of the coil (7) which is fitted with a spacer (2); the coil (7), which is fitted with a heat measuring device (8), is subsequently heat treated. The invention also relates to a spacer that can be used in order to implement said method.

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 minutes; cooling the reheated steel sheet down to room temperature; and coiling the cooled steel sheet.

Abstract: The present invention provides an effective method for mechanically removing iron oxide films formed on the surfaces of a hot rolled steel strip with a high temperature. The method comprises the steps of: maintaining a steel strip coil at a high temperature of 400° C. or more until the phase transformation is completed, after hot rolling; water-cooling the steel strip coil at a speed of at least 50° C./sec to 100° C. or less while uncoiling the coil; correcting the shape of the steel strip using a correction rolling mill; removing oxide films formed on surfaces of the shape-corrected steel strip by injecting water jets to the surface; and drying the steel strip free of oxide films and winding the steel strip. Also, the present invention provides an apparatus for carrying out this method.

Abstract: The present invention relates to a steel sheet that consists essentially of 0.10 to 0.37% C, 1% or less Si, 2.5% or less Mn, 0.1% or less P, 0.03% or less S, 0.01 to 0.1% sol.Al, 0.0005 to 0.0050% N, 0.0003 to 0.0050% B, by mass, and balance of Fe, [14B/(10.8N)] being 0.5 or more, average particle size of precipitate BN being 0.1 &mgr;m or more, and grain size of prior austenite after the hardening treatment being 2 to 25 &mgr;m. The steel sheet according to the present invention allows an inexpensive hardening treatment method to be applied to improve the strength to a level required for the structural components and the functional components of automobiles, while providing excellent toughness after the hardening treatment.

Abstract: The present invention provides a steel wire rod excellent in scale peelability for mechanical descaling, and a manufacturing method thereof.

Abstract: A method of heat treatment of wire including cooling the wire stock immediately after the stock leaves the rolling heat region to a temperature below the starting temperature of martensite formation and, thereafter, forming wire coils.

Abstract: In the thermal treatment of continuous-cast or hot-rolled steel strip, by using particular solutions regarding the choice of the strip rolling temperatures, the transfer times from the coiler to the furnace, as well as specific process steps in annealing, it is possible to treat any type of steel by sending the coils of strip, still at a high temperature, directly to the annealing furnace, at the same time maintaining the mechanical and microstructural characteristics obtainable in traditional cold-strip annealing.

Abstract: A method for making a low carbon and low manganese cold rolled steel strip for deep-drawing whereby a steel strip hot rolled in the austenistic region coiled at the end of the high temperature hot rolling process (680° C.<T<750° C.) is subjected to a cold rolling process with a reduction rate between 65 and 80 %, and finally subjected to an annealing and overageing heat treatment. The method consists in heating the steel strip at a heating rate Vh ranging between 150° C./s and 1000° C. up to the annealing temperature Ta ranging between 650° C. and 750° C., and in maintaining it at said annealing temperature for a time interval between 1 and 20 seconds, then in cooling it at cooling rate Vc between 100° C./s and 500° C./s up to an overageing temperature Toa ranging between 150° C. and 450° C.

Abstract: The present invention relates a train of in-line continuous manufacturing equipment for producing steel wire, considered difficult with a block mill up to now, capable of efficiently carrying out controlled-rolling and slow-cooling by an effective in-line combination of controlled rolling apparatuses and slow cooling apparatuses, having a hot rolling mill for steel wire, a winder to wind the rolled steel wire into rings, bundling apparatuses to pack the wound steel wire into bundled coils and an in-line heat treatment furnace to slow-cool the steel wire bundled into coils, which are sequentially connected, and using, preferably, a block mill with an area reduction rate of 25 to 60% having at most 4 roll stands as a final finish rolling mill of the hot rolling mill.

Abstract: A steel wire of pearlite structure containing 0.8-1.0 mass % of C and 0.8-1.5 mass % of Si is disclosed. In the cross section of the steel wire the average hardness in a region up to 100 &mgr;m from the surface thereof is at least 50 higher that that in a deeper region based on micro-Vickers hardness. The steel wire is manufactured by working a wire rod having the abovementioned chemical composition through shaving, patenting and drawing processes, then strain-relief annealing the resultant wire, and thereafter subjecting the thus annealed wire to a short peening process. The steel wire can be produced through a drawing process without applying a quenching and tempering process, and are superior in heat resistance and fatigue strength.

Abstract: A steel for forming a high strength steel sheet contains, in mass %, C: at most 0.04%, Si: at most 0.4%, Mn: 0.5-3.0%, P: at most 0.15%, S: at most 0.03%, Al: at most 0.50%, N: at most 0.01%, and Mo: 0.01-1.0%. Steel sheet formed from the steel is suitable for use as automotive panels.

Abstract: A process of producing a high toughness iron-based amorphous alloy strip, using a single roll liquid quenching method, the strip having a thickness of more than 55 &mgr;m up to 100 &mgr;m and a width of 20 mm or more and having a fracture strain &egr;f satisfying the relationship &egr;f>0.1 where &egr;f=t/(D-t), t=thickness of the strip, and D=bent diameter upon fracture, &egr;f being determined by bending the strip with a free cooling surface thereof facing outward, the process comprising the steps of: ejecting a molten metal alloy through a nozzle; applying the ejected molten metal alloy to a surface of a rotating roll; allowing the applied molten metal alloy to be quenched by the roll surface to form an amorphous strip of the metal alloy, the strip being quenched at a cooling rate, determined at a free surface thereof, of 103° C./sec or more in a temperature range of from 500° C. to 200° C.; and continuously coiling the quenched strip at a temperature of 200° C.

Abstract: Apparatus to transport and cool rolled products such as bars, round pieces, rods or similar, arrangable downstream of a coil-forming head, comprising a plurality of transport rollers, at least partly motorized and parallel to each other to define a substantially horizontal transport plane on which the rolled products arranged in coils are able to lie, ventilator in correspondence with the transport rollers to blow air towards the rolled products and a conveyor to convey more air towards the lateral edges of the coils than towards the central zone of the coils, the conveyor comprising a plurality of elements, arranged at intervals between the transport rollers. Each of the elements shaped to define transit channels having a first transverse section greater in correspondence with the ends of the transport rollers and a second transverse section less in correspondence with the median zone of the transport rollers.

Abstract: A hot-dip galvanized steel sheet is produced by rough rolling a steel, finish rolling the rough rolled steel at a temperature of Ar3 point or more, coiling the finish rolled steel at a temperature of 700° C. or less, and hot-dip galvanizing the coiled steel at a pre-plating heating temperature of Ac1 to Ac3. A continuous hot-dip galvanizing operation is performed by soaking a pickled strip at a temperature of 750 to 850° C., cooling the soaked strip to a temperature range of 600° C. or less at a cooling rate of 1 to 50° C. per second, hot-dip galvanizing the cooled strip, and cooling the galvanized strip so that the residence time at 400 to 600° C. is within 200 seconds. The steel sheet has a structure consisting essentially of ferrite and martensite.

Abstract: An apparatus and a method for suppressing growth of an oxide film on a coil which is a spirally wound, rolled strip are disclosed. A rolled strip subjected to rolling by hot rolling equipment is wound spirally by a down-coiler to make a coil. Covers are disposed on the opposite sides of the coil such that heat resistant materials intimately contact the opposite sides of the coil. The covers are fixed by L-bolts and nuts to cover the opposite sides of the coil with the covers. In this state, the coil is naturally cooled for a predetermined time to suppress growth of an oxide film and increase productivity.

Abstract: A process and apparatus is provided for forming spring wire into coils. A take-up block with a peripheral surface receives convolutions of wire as it is rotated. At least one pinch roll confines convolutions of the spring wire to the peripheral surface. The shape of the peripheral surface of the block and the circumferential surface of the pinch roll combine to define a gap for urging the convolutions of spring wire to migrate upward. At least one rotatable wire receiving basket is mounted adjacent the take-up block, and further drive means are provided for rotating the at least one wire receiving basket. In a preferred form, stationary guide loops are utilized to keep the spring wire moving in a predetermined trajectory from the take-up block to the rotating wire receiving basket.

Abstract: The invention concerns a method for manufacturing steel wire comprising the following steps: manufacturing a reinforcing wire of sizeable length by rolling or hot wire drawing from steel containing the following elements: 0.18% to 0.45 % C, 0.4% to 1.8% Mn, 1% to 4% Cr, 0.1% to 0.6% Si, 0% to 1.5% Mo, 0% to 1.5% Ni, at most 0.01% S and 0.02% P, the reinforcing wire having, after being rolled or hot drawn, a temperature at least higher than the AC3 temperature, preferably by 50 to 200° C. and in particular by 100 to 150° C.; winding the wire in reels before air cooling the raw manufacturing wire to obtain a HRC hardness not less than 40 and preferably higher than 45. In a variant, the method consists in quenching and tempering so that the wire has a hardness between 20 HRC and 35 HRC. The invention also concerns a reinforcing wire and a flexible tube for carrying effluents.