Abstract: A cold rolled and heat treated steel sheet having a composition with the following elements, expressed in percentage by weight 0.10%?Carbon?0.5%, 1%?Manganese?3.4%, 0.5%?Silicon?2.5%, 0.03%?Aluminum?1.5%, Sulfur?0.003%, 0.002%?Phosphorus?0.02%, Nitrogen?0.01% and can contain one or more of the following optional elements 0.05%?Chromium?1%, 0.001%?Molybdenum?0.5%, 0.001%?Niobium?0.1%, 0.001%?Titanium?0.1%, 0.01%?Copper?2%, 0.01%?Nickel?3%, 0.0001%?Calcium?0.005%, Vanadium?0.1%, Boron?0.003%, Ceriums?0.1%, Magnesiums?0.010%, Zirconiums?0.010% the remainder composition being composed of iron and the unavoidable impurities caused by processing, and a microstructure of the said rolled steel sheet having by area fraction, 10 to 30% Residual Austenite, 5 to 50% Annealed Bainite, 10 to 40% of Bainite, 1% to 20% Quenched Martensite, and less than 30% Tempered Martensite where the combined presence of Bainite and Residual Austenite shall be 30% or more.

Abstract: A method and device for producing a press-quenched part having a rim hole with a collar formed at the periphery of the rim hole includes inserting a temperature-controlled die into the rim hole of the part. The temperature of the temperature-controlled die is controlled such that the temperature of the part in a region of the collar is held above the martensite start temperature of the material from which the part is made. While the temperature of the collar is being held above the martensite start temperature, the remainder of the part is press quenched.

Abstract: A method for hot forming, in particular for press hardening, a component is disclosed, wherein in a local region of the component a reduced martensitic hardness is produced by locally reducing a forming pressure which is exerted on a surface of the component.

Abstract: A metal piece having at least two areas of lower mechanical strength than the body of the piece, said pieces being respectively arranged on one side and the other of a longitudinal central section (PM) of said piece and alternatively located in two locations separated longitudinally along the piece, the areas of lower mechanical strength than the body of the piece being formed by local control of the stamping temperature during a stamping process of the piece, notably a process comprising steps including heating the piece to a temperature range suitable for obtaining an austenitic stage, then stamping this piece in a stamping tool suitable for defining different temperatures in the different areas of the stamped piece, for example by virtue of the voids formed in the stamping tool or by local reheating of the stamping tool.

Abstract: A method for bending a sheet metal comprises: a hardness adjustment process wherein a blank (10), including a high-hardness region (11) and a low-hardness region (12) having a lower hardness than the high hardness region (11), is formed by changing the hardness of at least a part of a sheet metal; and a bending process wherein a product (20) is formed by bending low-hardness region (12) of blank (10).

Abstract: The present invention relates to a method for producing a hot-formed and press-hardened metal component for an automobile having at least two regions of different hardness. A hardenable sheet-metal blank is heated to at least an austenizing temperature and a first region of the sheet-metal blank is intermediately cooled at a cooling speed greater than the lower critical cooling speed of the material of the sheet-metal blank. The sheet-metal blank is then hot-formed and press-hardened in a press-hardening tool by quenching the first region from a bainitic structure transformation stage, thereby adjusting a mixed structure of martensite and bainite in the first region.

Abstract: The invention relates to a method for producing a shaped and at least regionally hardened sheet metal component, particularly a sheet steel component (15), with at least one perforation (16) produced in it, in which method a preform (13) is heated to forming temperature, subsequently shaped and then at least regionally hardened by corresponding cooling, wherein the at least one perforation (16) in the preform (13) is produced during the course of a punching process before the preform (13) is hardened. According to the invention, the metal piece (14) separated from the preform (13) by punching is fed back to its original position or a corresponding position in the perforation (16), remains there for the duration of the quenching process and is only pressed out during or after removal of the sheet steel component (13) from the die (1), in which it is held during quenching.

Abstract: A steel sheet for hot pressing use according to the present invention has a specified chemical component composition, wherein some of Ti-containing precipitates contained in the steel sheet, each of which having an equivalent circle diameter of 30 nm or less, have an average equivalent circle diameter of 6 nm or less, the precipitated Ti amount and the total Ti amount in the steel fulfill the relationship represented by formula (1) shown below, and the sum total of the fraction of bainite and the fraction of martensite in the metal microstructure is 80 area % or more. Precipitated Ti amount (mass %)?3.4[N]?0.5×[(total Ti amount (mass %))?3.4[N]]??(1) (In the formula (1), [N] represents the content (mass %) of N in the steel.

Abstract: In a press-hardening plant, a contact-cooling press (12) is provided between the furnace (11) and the press-hardening press (13). Preselected parts of the blank (18) are contact-cooled such that corresponding parts of the finished product are softer and display a lower yield point.

Abstract: A hot press-forming method includes a forming step that clamps a steel sheet heated to a temperature not less than an austenite transformation temperature and press-forms the steel sheet into a desired shape by causing a forming concave of a die and a convex of a punch to be close to each other. A formed portion has side and top portions that merge. The side portion rises up from an inner circumferential edge of a flange portion having been clamped by the die and the blank holder. A cooling step cools a region of the steel sheet after the heating step has been completed and before the forming step is completed. The particular region is along an inter-edge area formed between an opening circumferential edge of the forming concave and a top circumferential edge of the forming convex before the forming step is completed.

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

Abstract: The invention relates to a method for producing partially hardened steel components in which a blank is subjected to a temperature increase that is sufficient for a quench-hardening and after reaching a desired temperature, the blank is transferred to a forming tool in which the blank is quench-hardened or the blank is cold-formed and the component obtained by the cold-forming is then subjected to a temperature increase. During the heating of the blank or component, absorption masses rest against and/or are spaced with a small gap apart from regions that are intended to have a lower hardness and/or higher ductility; with regard to its expansion and thickness, its thermal conductivity, and its thermal capacity and/or with regard to its emissivity, the absorption mass is dimensioned so that the thermal energy acting on the component in the region to remain ductile flows through the component into the absorption mass.

Abstract: A method of manufacturing a lift transmitting component (2), particularly for a gas exchange valve train or a fuel pump drive of an internal combustion engine (1), is provided, The lift transmitting component includes a housing (6), a bearing pin (7) fixed in a reception bore (9) of the housing (6) and a roller (8) mounted through a sliding or a rolling bearing on the bearing pin (7). The bearing pin is core-hardened over an entire axial length to a core hardness of at least 650 HV, and pin ends (10) of the core-hardened bearing pin are radially widened relative to the reception bore for enabling a connection of the bearing pin to the housing (6) through positive engagement. The hardness of the bearing pin is at the most 780 HV, the radial widening of one of the pin ends being realized with a shaping die (11) which travels axially parallel to the bearing pin (7) and applies a force to the pin end in a transition region between a periphery and a front end surface of the bearing pin.

Abstract: A multi physical properties part used in automotive components required to be lightweight and provide collision safety, and a method of manufacturing a multi physical properties part, in which the multi physical properties part may be more economically and simply manufactured by using two or more separated die sets without using an additional heating device or treating a die surface. A method of manufacturing a multi physical properties part, which includes positioning a single heated formed article in two or more die sets, and then manufacturing a multi physical properties part including two or more regions having different physical properties by differing cooling conditions in the respective die set.

Abstract: A shaped part with different microstructures is made by continuously conveying a succession of hardenable steel blanks having first and second regions through a furnace such that the blanks reach an outlet of the furnace each with both of the respective first and second regions heated to an austenitization temperature. Then the blanks are positioned with the second regions thereof in a chamber of a holding unit and the first regions outside the chamber, and, while holding the second regions in the chamber and the first regions outside the chamber the second regions are heated and maintained at the austenitization temperature and the first regions are cooled with air to a temperature at which their microstructures become ferritic-pearlitic. Thereafter the blanks are transferred from the holding unit to a press where they are hardened and finish shaped.

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

Abstract: A structural motor-vehicle element is made by hot-shaping and press-hardening a steel workpiece into the element and thereafter heating the hot-shaped and press-hardened workpiece to between 320° C. and 400° C. The steel workpiece constitutes in weight percent, Carbon (C) 0.18% to 0.3% Silicon (Si) 0.1% to 0.7% Manganese (Mn) 1.0% to 2.5% Phosphorus (P) max. 0.025% Chromium (Cr) up to 0.8% Molybdenum (Mo) up to 0.5% Sulfur (S) max. 0.01% Titanium (Ti) 0.02% to 0.05% Boron (B) 0.002% to 0.005% Aluminum (Al) 0.01% to 0.06% the rest iron including impurities caused by the smelting process.

Abstract: The invention relates to a method for producing hardened structural parts from sheet steel. The method includes shaping at least one shaped part made of sheet steel provided with a cathodic corrosion protection coating, performing any required final trim of the shaped part and possibly any required punching, or the creation of a perforation pattern, subsequently heating the shaped part, at least over partial areas, under the admission of atmospheric oxygen to a temperature which permits austenizing of the steel material, and thereafter transferring the structural part to a mold-hardening tool and performing mold-hardening in the mold-hardening tool, wherein the structural part is cooled by the contact with and pressing by the mold-hardening tool and is hardened thereby.

Abstract: An automobile column and to a method for producing an automobile column are disclosed. The automobile column has a region of a first type and a region of a second type which have mutually different strengths. A transition region having a width of less than 50 mm is formed between the two regions. The automobile column has in the region of the first type a bainitic structure and in the region of the second type a martensitic structure.

Abstract: The present invention relates to a method for producing a hot-formed and press-hardened metal component for an automobile having at least two regions of different hardness. A hardenable sheet-metal blank is heated to at least an austenizing temperature and a first region of the sheet-metal blank is intermediately cooled at a cooling speed greater than the lower critical cooling speed of the material of the sheet-metal blank. The sheet-metal blank is then hot-formed and press-hardened in a press-hardening tool by quenching the first region from a bainitic structure transformation stage, thereby adjusting a mixed structure of martensite and bainite in the first region.

Abstract: A method for producing a metallic component (B) allows adjoining zones (Z1, Z2, Z3) having differing material properties to be produced in a manner which is simple in terms of production. This is achieved in that a sheet metal element (E) heated to a forming temperature is shaped in a forming tool (1) into an end-shaped component (B), wherein the forming tool (1) has a temperature adjustment means for adjusting the temperature of at least one of the portions (5, 7, 16) thereof that comes into contact with the sheet metal element (E) during the forming process, and in that the forming speed is controlled in consideration of the time for which the portion (5, 7, 16) of the forming tool (1) that is regulated with regard to the temperature thereof is in contact with the respective region (E1, E2, E3) of the sheet metal element (E) that rests against said portion.

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

Abstract: A hot forged product including hardened areas introduced by partial cooling after hot forging, and unhardened areas, wherein Vickers hardness V1 of the hardened areas on the surface and Vickers hardness V2 of the unhardened areas satisfy the following formula (1): (V1?V2)/V2: 0.1 to 0.8.

Abstract: The invention relates to a method for forming a steel container having a curled open end, comprising the steps of i) providing a steel cup; ii) deep drawing the steel cup into a drawn container preform; iii) thin drawing the body of the drawn container preform; and iv) curling an open end of the drawn container preform by forming a precurl and by curling the precurl into an elongated curl, to an apparatus for forming a steel container, and to such steel container and its preform.

Abstract: A shaped part having at least two structural regions of different ductility is made from one unitary blank of a hardenable steel alloy by first heating the entire blank to an elevated temperature below an AC3 point of the alloy. Then only first regions of the blank are heated by a plurality of infrared lamps to above the AC3 point of the alloy while maintaining the rest of the blank below the AC3 point of the alloy. Finally the first regions are hardened in a thermoshaping and hardening tool.

Abstract: A method of working metal in which the microstructure of metal body is rendered fine to thereby enhance the strength, ductility or homogeneity thereof; a metal body obtained by the metal working method; and a metal-containing ceramic body obtained by the metal working method. In this metal working method, the deformation resistance of metal body or metal-containing ceramic body (hereinafter referred to simply as “metal body”) is lowered locally to thereby form low deformation resistance regions in the metal body, and shear deformation of the low deformation resistance regions is effected so as to fine the microstructure of metal body. In particular, the metal body is formed in unidirectionally drawn configuration so as to produce low deformation resistance regions crossing the metal body.

Abstract: A method of manufacturing forks for lift trucks comprises the steps of: providing a straight metal bar designed to make the fork, heating the bar at a segment thereof where the fork knee is to be formed, bending the bar at the heated segment in order to form the knee by carrying out bending in a closed-die press provided with containment walls that, when bending has been completed, enclose the knee so as to define the surface contours of the latter.

Abstract: A common-rail injection system is provided for a diesel engine and has excellent internal pressure fatigue resisting characteristics, vibrational fatigue resisting characteristics and cavitation resisting property and sheet face flawing resisting property, and can be made thin and light in weight. A main pipe rail is manufactured by transformation induced plastic type strength steel. After the main pipe rail is processed, residual austenite is generated by heat treatment, and the reduction processing of stress concentration of a branch hole and a main pipe rail side flow passage crossing portion is performed. Further, it is preferable that an induced plastic transformation is generated on the inner surface of the main pipe rail by autofrettage processing, and compression residual stress is left.

Abstract: A method for producing a metallic component (B) allows adjoining zones (Z1, Z2, Z3) having differing material properties to be produced in a manner which is simple in terms of production. This is achieved in that a sheet metal element (E) heated to a forming temperature is shaped in a forming tool (1) into an end-shaped component (B), wherein the forming tool (1) has a temperature adjustment means for adjusting the temperature of at least one of the portions (5, 7, 16) thereof that comes into contact with the sheet metal element (E) during the forming process, and in that the forming speed is controlled in consideration of the time for which the portion (5, 7, 16) of the forming tool (1) that is regulated with regard to the temperature thereof is in contact with the respective region (E1, E2, E3) of the sheet metal element (E) that rests against said portion.

Abstract: A method of making a shaped and hardened steel part has the steps of sequentially heating a steel plate entirely above the AC3 temperature, cooling specific regions of the heated plate without hardening the specific regions, and then engaging the heated plate with the cooled regions in a cool deforming tool with the specific regions out of contact with the deforming tool. This cools the plate where it contacts the tool and deforms the plate with the tool at the specific regions and both cooling and hardening the plate by contact with the tool.

Abstract: In a process for the production of a screw comprising a low-alloy carbon steel, having a head, an adjoining holding portion and a functional tip which, in the outer region of limited radial depth, is of a greater hardness than the holding portion, in which the screw body is shaped by pressing and rolling and then the functional tip is subjected to a hardening operation, hardening is effected by momentary heating with a high level of energy transfer and subsequent quenching and is limited to portions of the periphery of the functional tip.

Abstract: In a method for the treatment of metallic materials especially for the consolidation of the texture of the materials, a blank of the metallic material is heated to a transformation temperature and the blank is then subjected to twisting preferably while, at the same time, being compressed. In this way, the texture can be refined to a large degree in a simple and inexpensive manner.

Abstract: A method of forming a vehicle component, particularly an elongated impact beam, having an open section structure, in a manner to provide predetermined strategically strengthened portions, comprising the steps of cold forming unhardened steel into a workpiece having mounting surfaces, selectively fixturing the mounting surfaces, static induction heating the workpiece with lengthwise surface eddy currents on selected portions, followed by quenching of the fixtured heated workpiece to form strengthened portions, and unfixturing the resulting component. Also disclosed is apparatus to accomplish this, and the resulting novel vehicle component.

Abstract: A method for producing a stainless steel with improved corrosion resistance includes homogenizing at least a portion of an article of a stainless steel including chromium, nickel, and molybdenum and having a PREN of at least 50, as calculated by the equation: PREN=Cr+(3.3×Mo)+(30×N), where Cr is weight percent chromium, Mo is weight percent molybdenum, and N is weight percent nitrogen in the steel. In one form of the method, at least a portion of the article is remelted to homogenize the portion. In another form of the method, the article is annealed under conditions sufficient to homogenize at least a surface region of the article. The method of the invention enhances corrosion resistance of the stainless steel as reflected by the steel's critical crevice corrosion temperature.

Abstract: A vehicle structural beam, such as a door intrusion beam, which possesses an elongate tubular beam part which at opposite ends is provided with mounting flanges for securement to a vehicle frame. The elongate tubular beam part and the flanges provided at opposite ends are defined by an integral, one-piece, monolithic steel structure which has been initially roll-formed from an elongate flat metal sheet to define the closed tubular structure of the tubular beam part, and which has been subjected to heating and quenching so that the elongate tubular beam part is of relatively high strength steel throughout its entire length, whereas the integrally and monolithically joined end flanges remain as lower strength steel which has been significantly unaffected by the heat treatment and quenching so as to permit appropriate shaping thereof and ease of welding to the vehicle frame.

Abstract: The invention relates to a method for manufacturing components from critical cold forming of light metal strip, preferably naturally hard Al alloys of the AlMg or AlMg—Mn types, in which the desired component is manufactured from the strip by at least one cold forming step and the plasticity is improved before the cold forming by means of a soft annealing. According to the invention, it is proposed that the region of the longitudinal edges of the cold-slit strips is heated in a depth in the strip width of at least 1 mm to a maximum of 10 mm in such a way that a temperature of over 150° C. is reached over a time span of more than 0.1 seconds to a maximum of 10 seconds.

Abstract: At least both ends of a sheet bar in the length direction, which is obtained by roughly rolling a steel slab including 0.1 wt % or less of C, 0.5 wt % or less of Si, 1.0 wt % or less of Mn, 0.1 wt % or less of P, 0.05 wt % or less of S, 0.20 wt % or less of Al, and 0.015 wt % or less of N, are heated so that the temperature at both ends of the sheet bar in the length direction is 15° C. or more higher than the temperature of the remainder of the sheet bar. The rolling finish temperature is Ar3+20° C. to Ar3+100° C. in both end portions of the sheet bar in the length direction, and Ar3+10° C. to Ar3+60° C. in the remainder, and the rolling finish temperature in the both end portions in the length direction is 10° C. or more higher than that of the remainder, so that a steel strip after cold rolling and annealing has r values within ±0.3 of the average r value, and &Dgr;r within ±0.

Abstract: A steel slab is rough-rolled into a sheet bar and butt-joined onto a preceding sheet bar and a widthwise end portion of the sheet bar is heated by means of an edge heater and then subjected to a continuous finish rolling through pair-cross rolls rolling on at least 3 stands to provide a hot rolled steel strip having a width of not less than 950 mm, a thickness of 0.5-2 mm and a crown within .+-.40 .mu.m, and the hot rolled steel strip is subjected to cold rolling, continuous annealing, temper rolling and, if necessary, plating treatment on the surface of the cold rolled steel strip, whereby there is obtained a steel sheet having an average thickness of not more than 0.20 mm and a width of not less than 950 mm, a thickness variation quantity in a widthwise direction is within .+-.4% of the average thickness in a region corresponding to not less than 95% of the width of the steel sheet as cold rolled and a hardness (HR30T) variation in the widthwise direction is within .+-.3 of an average hardness.

Abstract: The invention is directed to a process for the manufacture of a metallic molded structural part (1) for motor vehicle components such as door impact girders or bumpers with areas (2) with a higher ductility in relation to the rest of the structural component part. For this purpose, partial areas (2) of a plate (5) are initially heated to a temperature of 900.degree. C. within a period of less than 30 seconds. Subsequently, the thermal-treated plate (5') is shaped in a pressing tool (7) to form the molded structural part (1) and is heat-treated in the pressing tool (7).

Abstract: A product of sheet steel is formed in a pair of cooled tools when hot and is then hardened to a martensitic structure while still in the tools. In this manner, the tools function as a fixture while the steel is hardening. The steel is kept mild in the areas in which it is to be machined, for example punched. Inserts in the tools are used to prevent rapid cooling of the steel sheet and thereby a martensitic structure in the areas adjacent the inserts. The same effect can be obtained by recesses in the tools so that there will be a gap between the sheet steel and the tools.

Abstract: A method for drawing a portion of metallic material having a known hardness. The method includes the step of applying a localized heat treatment to predetermined portions of the metallic material. Additionally, the method comprises forming the localized heat treated regions into a desired drawn or stamped configuration, wherein the configuration is substantially devoid of cracks.

Abstract: A base plate for a suspension assembly in a hard disk drive wherein the base plate has a hardened flange and soft hub. The base plate is stamped in a progressive die in a sequence of forging and coining operations. The base plate is subsequently fully annealed to allow the material to yield at a low stress level so that the hub will create a press fit against the inner wall of an actuator arm boss hole. The base plate is passed through a secondary coining operation following the annealing step to work-harden the flange portion only. The result is a base plate with a flange portion that is hardened and a hub portion that is softer than the flange portion. The advantage is that the hardened flange is more resistant to deformation of a load beam welded thereto and the hub is more disposed to plastically deform and harden during swaging which is desirable for maintaining a press fit.

Abstract: A method for producing a steel section by a rolling process including a rough rolling step, an intermediate rolling step and a finishing rolling step. The intermediate rolling step comprises water-cooling the flange portion of the rough-rolled steel section between rolling passes in the intermediate rolling step to cool the surface layer of the flange to a temperature not higher than 750.degree. C., and rolling the flange portion during recuperation of the surface layer of the flange at least one time between the rolling passes with a total draft not less than 20% and at an average rolling temperature not higher than 950.degree. C. and, after the finishing rolling step the outer surface of the flange is cooled at a cooling rate ranging from 0.5.degree. to 10.degree. C./sec depending on the thickness of the flange. Also the carbon equivalent of the steel is controlled. The advantage is that steel sections of various contours and dimensions can be produced from minimized varieties of steel compositions.

Abstract: The present invention relates to a process for producing a superplastic aluminum alloy capable of being used for plastic working such as extrusion, forging and rolling. An object of the present invention is to provide an ingot-made high speed superplastic aluminum alloy in which superplasticity is developed at a strain rate higher than that of conventional static recrystallization type superplastic aluminum alloys, and a process for producing the same. The superplastic aluminum alloy of the invention has structure which is obtained by adding to a basic alloy containing from at least 4.0 to 15% by weight of Mg and from 0.1 to 1.0% by weight of one or more elements selected from the group consisting of Mm, Zr, V, W, Ti, Ni, Nb, Ca, Co, Mo and Ta, and further selective elements of Sc, Cu, Li, Sn, In and Cd, which contains from 0.1 to 4.0% by volume fraction of spheroidal precipitates of intermetallic compounds having a particle size from 10 to 200 nm, and which has a mean grain size from 0.1 to 10 .mu.m.

Abstract: The invention relates to a process for the production of very hard armour plates from steel slabs, wherein the slabs are hot rolled to a final thickness above 50 mm and then hardened and possibly tempered. The characterizing feature of the invention is that a continuously cast slab is produced from a steel having0.25 to 0.32% C0.05 to 0 75% Si0.10 to 1.50% Mn0.90 to 2.00% Cr0.10 to 0.70% Mo1 20 to 4 50% Ni0.01 to 0.08% Almax 0.015% Pmax 0.005% Smax 0.012% Nresidue Fe, including usual impurities,the slab then being heated to a temperature of 1150.degree. C. or higher and heated through, whereafter following cooling in air and by the spraying of its two wide sides with pressurized water, the slab is hot rolled with a surface temperature in the range of 1050.degree. to 900.degree. C. in shaping passes having an individual deformation of .epsilon..sub.h >0.1 and with a shape factor SF>0.40 to the final thickness.

Abstract: A thin-webbed H-beam steel having a web thinner that flanges is produced by forcibly water cooling the outer surface of the flanges during an intermediate hot rolling prior to a final hot rolling by cooling to less than 700.degree. C., interrupting the cooling to return the temperature to greater than 700.degree. C., and repeating the cooling and interrupting in order to refine the microstructure of the surface of the flanges to a predetermined depth from the surface; final-hot rolling the intermediate-hot rolled H-beam steel; and forcibly water cooling the flanges of the final-hot rolled H-beam steel in a manner such that the web does not wave during this forcible water cooling, and such that upon completion of the forcible water cooling, thermal stress, generated in the web during air cooling to room temperature, does not exceed the buckling strength of the web.