Title of invention: Method for manufacturing H-section steel Technical field [0001] (Cross Reference of Related Applications) The 　present application claims priority based on Japanese Patent Application No. 2018-022105 filed in Japan on Feb. 9, 2018, and the content thereof is incorporated herein. [0002] 　The present invention relates to a manufacturing method for manufacturing an H-section steel by using, for example, a slab having a rectangular cross section as a raw material. Background technology [0003] 　When manufacturing H-section steel, raw materials such as slabs and blooms extracted from a heating furnace are shaped into a rough shape material (so-called dogbone-shaped material to be rolled) by a rough rolling mill (BD), and intermediate universal rolling is performed. Machine is used to reduce the thickness of the web and flange of the crude material, and at the same time, the edger rolling machine adjacent to the intermediate universal rolling machine performs width reduction and edge face forging and shaping on the flange of the material to be rolled. .. Then, the H-shaped steel product is formed by the finish universal rolling machine. [0004] 　In the method for producing the H-section steel described above, when a so-called dogbone-shaped rough material is formed from a slab material having a rectangular cross section, an interruption is made in the slab end face in the first hole die of the rough rolling step. After that, in the second and subsequent hole types, there is known a technique in which the interrupt is spread or the interrupt depth is deepened, and then the hole type interrupt holes in the subsequent hole types are erased (see, for example, Patent Document 1). ). [0005] 　Further, in the production of H-section steel, a flat-molding in which the material to be rolled is rotated by 90° or 270° after the so-called edging rolling for edging the end surface (slab end surface) of a material such as a slab to reduce the web-equivalent portion. It is known to perform rolling. In this flat forming rolling, the corresponding portion of the web is reduced and the corresponding portion of the flange is reduced and shaped, but in view of the demand for a large H-shaped steel product in recent years, a large material is used as the material to be rolled. In this case, in general flat forming rolling, various problems such as elongation in the height direction of the web and deformation of the flange-corresponding part may occur, and there are cases where correction of the shape is required. Specifically, as the web-corresponding portion is rolled down, the web-corresponding portion is stretched in the longitudinal direction, and the flange-corresponding portion is also stretched in the longitudinal direction by being stretched by the stretching, and the flange-corresponding portion becomes thin. There was concern about the phenomenon. [0006] 　Regarding such flat shaping rolling, for example, Patent Document 2 discloses a technique of selectively performing reduction to a portion corresponding to the web. An unpressed lower portion is provided at the center of the portion corresponding to the web, and a convex formed thereafter is disclosed. By deleting the portion (corresponding to the raised portion of the present invention) and widening the portion corresponding to the web, it is possible to efficiently manufacture a large H-section steel. Prior art documents Patent literature [0007] Patent Document 1: JP-A-7-88501 Patent Document 2: JP-A-57-146405 Summary of the invention Problems to be Solved by the Invention [0008] 　As described above, in recent years, with the increase in the size of structures and the like, it is desired to manufacture large H-section steel products. In particular, there is a demand for a product in which the flange, which greatly contributes to the strength and rigidity of H-section steel, is made wider than in the past. In order to manufacture an H-shaped steel product with a widened flange, it is necessary to form a material to be rolled having a wider flange width than that in the past from the shaping in the rough rolling process. [0009] 　However, for example, in the technique disclosed in Patent Document 1 described above, an interrupt is made in the end face (slab end face) of a material such as a slab, the end face is edged, and the widening is used to perform rough rolling, There is a limit to the widening of the flange. That is, in order to widen the flange in the conventional rough rolling method, the width expansion can be improved by techniques such as wedge design (interruption angle design), reduction adjustment, and lubrication adjustment. Since it does not contribute significantly, the width expansion ratio, which indicates the ratio of the expansion amount of the flange width to the edging amount, is about 0.8 even when the efficiency at the initial stage of edging is the highest. It is known that under repeated conditions, the flange width decreases as the expansion amount increases, and finally becomes about 0.5. It is also possible to increase the edging amount by enlarging the material itself such as slab, but there is a limit to the equipment scale and reduction amount of the rough rolling mill, etc. There are circumstances. [0010] 　Further, when a large H-shaped steel product is manufactured, a large-sized rough shaped material may be roll-molded in the rough rolling step. When a large-sized rough shaped material is rolled and shaped by a method different from the conventional method and the shape of the rough shaped material is shaped closer to the H-section steel, flat shaping rolling is performed by the technique described in Patent Document 2 above. It has been found that when this is done, problems such as elongation in the web height direction and deformation of the flange equivalent portion occur. [0011] 　Regarding the thickening property of the flange, the present inventors have found that in addition to the process of the first stage having a recess for producing an unpressed part (raised part described later) in the web, the process of erasing the unpressed part in the process of the latter stage Evaluation is carried out in an integrated process including. Specifically, as described in an embodiment of the present invention to be described later, for example, when a 300-thick slab is used as a material, the unpressurized lower part is made to have a width of 25% or more and 50% or less of a web internal method of a material to be rolled. The present invention has been found to improve the efficiency of flange formation by setting the width, and has reached the present invention. [0012] 　In view of the above circumstances, the present invention provides a large-sized rough material without causing problems such as elongation in the web height direction and deformation of the flange-corresponding portion in a rough rolling process using a hole die when manufacturing an H-shaped steel. It is an object of the present invention to provide a technique for efficiently and stably manufacturing an H-shaped steel product having a wider flange width than that of the conventional product by performing the flat shaping rolling. Means for solving the problems [0013] 　In order to achieve the above-mentioned object, according to the present invention, there is provided a method for manufacturing an H-section steel including a rough rolling step, an intermediate rolling step, and a finish rolling step, wherein the rough rolling step is performed on a material to be rolled in a predetermined manner. It has an edging rolling step of rolling and shaping into a substantially dogbone shape, and a flat rolling step of rolling the web part by rotating the material to be rolled by 90° or 270° after completion of the edging rolling step, and performing the flat rolling step. Among the hole type, at least one hole type upper and lower hole type roll is provided with a recessed portion for forming a raised portion in the center of the web portion of the material to be rolled, at the central part of the roll body length of the upper and lower hole type roll, As a hole type for performing a rolling step, there is a raised portion erasing hole type for pressing down the raised portion with respect to the rolled material on which the raised portion is formed, and for performing an internal widening of the web portion of the rolled material. Further included, the rolling shaping with the raised portion erasing hole type is performed on the material to be rolled after the raised portion is formed in the hole type having a recess portion that forms the raised portion, and the raised portion is formed. There is provided a method for producing an H-section steel, characterized in that the rolling shaping for forming is not performed after the reduction of the raised portion. [0014] 　Rolling shaping in the raised portion erasing hole type is performed in multiple passes, and in at least one pass of the multiple passes, rolling shaping is performed in a state where the flange inner surface of the material to be rolled and the hole type roll are in contact with each other. May be. [0015] 　Rolling shaping with the raised portion erasing hole type is performed in multiple passes, and in the first pass of the multiple passes, rolling shaping is performed in a state where the flange inner surface of the material to be rolled and the hole type roll are in contact with each other. Is also good. [0016] 　In the rolling molding with the raised portion erasing hole type, the bulging portion may be partially erased, and the remaining raised portion may be erased by rolling shaping with an arbitrary hole type in the subsequent stage. [0017] 　The width of the raised portion formed in the flat rolling step may be set to 25% or more and 50% or less of the method in the web portion of the material to be rolled. [0018] 　The reduction rate of the raised portion erasing hole type with respect to the raised portion may be 2.1 or less. [0019] 　The edging step is performed by a plurality of four or more hole dies, and in the plurality of hole dies, one or more pass shaping of the material to be rolled is performed. The die is provided with a protrusion that inserts a vertical interruption in the width direction of the material to be rolled to form a divided portion at the end of the material to be rolled. The mold may be formed with a protrusion that abuts the interrupt and sequentially bends the formed divided portions. Effect of the invention [0020] 　ADVANTAGE OF THE INVENTION According to this invention, in the rough rolling process which used the hole die at the time of manufacturing H-section steel, the flat forming of the large-sized rough shape material does not generate|occur|produce, such as the elongation of a web height direction, and the deformation of a flange equivalent part. By rolling, it is possible to efficiently and stably manufacture an H-shaped steel product having a flange width larger than that of a conventional product. Brief description of the drawings [0021] FIG. 1 is a schematic explanatory view of an H-section steel production line. FIG. 2 is a schematic explanatory view of a first hole type. FIG. 3 is a schematic explanatory view of a second hole type. FIG. 4 is a schematic explanatory view of a third hole type. FIG. 5 is a schematic explanatory view of a fourth hole type. FIG. 6 is a schematic explanatory view of a fifth hole type. FIG. 7 is a schematic explanatory view of a sixth hole type. [Fig. 8] Fig. 8 is a schematic explanatory diagram of a case where rolling shaping is performed in a state where the inner surface of the flange portion and the roll are in contact with each other, in the rolling shaping with the sixth hole type. FIG. 9 is a schematic explanatory view of a desirable sixth hole type configuration. FIG. 10 is a schematic diagram based on a simulation showing the shape of the material to be rolled after the ridges are erased in the pass schedules of Tables 3 and 4. FIG. 11 is a graph showing the relationship between the relief rate and the flange width increase/decrease rate after H-shaped rough material modeling. FIG. 12 is an explanatory diagram regarding warpage of a material to be rolled. FIG. 13 is a graph showing the relationship between warpage and web thickness. [Fig. 14] In the relationship between the thickness after reduction of the reduction portion and the height of the raised portion, comparison is made between the case where warping occurs and the passing is poor, and the case where passing does not occur and the passing is good. It is a graph which shows the result of examination. MODE FOR CARRYING OUT THE INVENTION [0022] 　Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, constituent elements having substantially the same functional configuration are designated by the same reference numerals, and a duplicate description will be omitted. [0023] 　FIG. 1 is an explanatory diagram of an H-section steel production line T including a rolling facility 1 according to the present embodiment. As shown in FIG. 1, in the production line T, a heating furnace 2, a sizing mill 3, a rough rolling mill 4, an intermediate universal rolling mill 5, and a finishing universal rolling mill 8 are arranged in this order from the upstream side. Further, an edger rolling mill 9 is provided near the intermediate universal rolling mill 5. In the following, for the sake of explanation, the steel material in the production line T may be generically referred to as "rolled material A", and the shape thereof may be illustrated using broken lines, oblique lines, etc. in each drawing as appropriate. [0024] 　As shown in FIG. 1, in the production line T, a rectangular cross-section material (later rolled material A), for example, a slab 11 extracted from the heating furnace 2 is roughly rolled in a sizing mill 3 and a rough rolling mill 4. Then, it is subjected to intermediate rolling in the intermediate universal rolling mill 5. During the intermediate rolling, the edger rolling machine 9 performs reduction as necessary on the flange tip portion (flange corresponding portion 12) of the material to be rolled. Usually, the sizing mill 3 and the roll of the rough rolling mill 4 are engraved with a so-called flat-shaped hole die for forming the shape of the flange portion by reducing the thickness of the edging hole die and the web portion. Then, the H-shaped rough material 13 is formed by the reverse rolling of a plurality of passes, and the H-shaped rough material 13 is formed by using the rolling mill train including the two rolling mills of the intermediate universal rolling mill 5 to the edger rolling mill 9. , A plurality of passes of reduction are applied to form the intermediate material 14. Then, the intermediate material 14 is finish-rolled by the finish universal rolling machine 8 into a product shape, and the H-section steel product 16 is manufactured. [0025] 　Here, the slab thickness T of the slab 11 extracted from the heating furnace 2 is in the range of 290 mm or more and 310 mm or less, for example. This is the size of a so-called 300-thick slab material used when manufacturing a large H-section steel product. [0026] 　Next, the hole configuration and the hole shape engraved in the sizing mill 3 and the rough rolling mill 4 shown in FIG. 1 will be described below with reference to the drawings. FIG. 2 to FIG. 7 are schematic explanatory views of a hole die formed in the sizing mill 3 and the rough rolling machine 4 for performing the rough rolling process. Here, the first hole type to the sixth hole type described below may be all engraved on the sizing mill 3, and the sizing mill 3 and the rough rolling mill 4 may have six holes of the first hole type to the sixth hole type. The holes may be engraved separately. That is, the first hole type to the sixth hole type may be engraved on both the sizing mill 3 and the rough rolling mill 4, or may be engraved on either one of the rolling mills. In the rough rolling process in the production of ordinary H-section steel, modeling is performed in one or a plurality of passes in each of these hole dies. [0027] 　Further, in the present embodiment, description will be made by exemplifying a case where the number of hole types to be engraved is six, but the number of hole types does not necessarily have to be six, and a plurality of hole types of six or more can be used. May be For example, a general widening rolling hole die may be provided in the subsequent stage of the sixth hole die K6 described later. That is, any hole-type structure suitable for forming the H-shaped rough material 13 may be used. 2 to 7, the outline final pass shape of the material A to be rolled at the time of shaping in each hole is shown by a broken line. [0028] 　FIG. 2 is a schematic explanatory view of the first hole type K1. The first hole type K1 is engraved on an upper hole type roll 20 and a lower hole type roll 21 which are a pair of horizontal rolls, and the material to be rolled A is rolled in the roll gap between the upper hole type roll 20 and the lower hole type roll 21. It is rolled down and shaped. Further, on the peripheral surface of the upper hole type roll 20 (that is, the upper surface of the first hole type K1), there is formed a protrusion 25 projecting toward the inside of the hole type. Further, on the peripheral surface of the lower hole type roll 21 (that is, the bottom surface of the first hole type K1), there is formed a protrusion 26 protruding toward the inside of the hole type. These protrusions 25 and 26 have a tapered shape, and the protrusion length 25 and the protrusion 26 have the same dimensions such as the protrusion length. The height (projection length) of the protrusions 25 and 26 is h1, and the tip angle is θ1a. [0029] 　In the first hole type K1, the protrusions 25 and 26 are pressed against the upper and lower end portions (slab end faces) of the material A to be rolled, and interrupts 28 and 29 are formed. Here, the tip end angle (also referred to as a wedge angle) θ1a of the protrusions 25 and 26 is preferably, for example, 25° or more and 40° or less. [0030] 　Here, it is preferable that the groove width of the first groove K1 is substantially equal to the thickness of the material A to be rolled (that is, the slab thickness). Specifically, the left and right centering properties of the material A to be rolled are preferably ensured by making the width of the hole die at the tip of the protrusions 25 and 26 formed in the first hole die K1 the same as the slab thickness. To be done. Further, with such a configuration of the hole type dimension, as shown in FIG. 2, at the time of modeling with the first hole type K1, the above-mentioned projections are formed in the upper and lower end portions (slab end surface) of the material A to be rolled. Part 25, 26 and part of the hole type side surface (side wall) are in contact with the material A to be rolled, and the first hole is formed on the upper and lower ends of the slab divided into four elements (parts) by interruptions 28, 29. It is preferable that no positive reduction is performed on the top surface and the bottom surface of the mold K1. This is because the reduction by the top and bottom surfaces of the hole type causes elongation of the material A to be rolled in the longitudinal direction and reduces the production efficiency of the flange (flange portion 80 described later). That is, in the first hole type K1, the protrusions 25 and 26 are pressed against the upper and lower end portions (slab end faces) of the material A to be rolled, and the reduction in the protrusions 25 and 26 when the interruptions 28 and 29 are formed. The amount (wedge tip reduction amount) is made sufficiently larger than the reduction amount (slab end face reduction amount) at the upper and lower ends of the slab, whereby the interruptions 28 and 29 are formed. [0031] 　FIG. 3 is a schematic explanatory view of the second hole type K2. The second hole type K2 is engraved on an upper hole type roll 30 and a lower hole type roll 31 which are a pair of horizontal rolls. On the peripheral surface of the upper hole type roll 30 (that is, the upper surface of the second hole type K2), a projection portion 35 protruding toward the inside of the hole type is formed. Further, on the peripheral surface of the lower hole type roll 31 (that is, the bottom surface of the second hole type K2), a protrusion 36 protruding toward the inside of the hole type is formed. The protrusions 35 and 36 have a tapered shape, and the protrusion length and other dimensions of the protrusions 35 and 36 are equal. It is desirable that the angle of the tip of each of the protrusions 35 and 36 is a wedge angle θ1b of 25° or more and 40° or less. [0032] 　In addition, the wedge angle θ1a of the first hole die K1 is the wedge angle of the second hole die K2 in the latter stage in order to secure the thickness of the tip end portion of the flange, enhance the inductivity, and ensure the stability of rolling. It is preferable that the angle is the same as θ1b. [0033] 　The height (projection length) h2 of the protrusions 35 and 36 is higher than the height h1 of the protrusions 25 and 26 of the first hole type K1, and h2>h1. In addition, in terms of rolling dimensional accuracy, it is preferable that the tip angles of the projections 35 and 36 be the same as the tip angles of the projections 25 and 26 of the first hole mold K1. In the roll gap between the upper hole type roll 30 and the lower hole type roll 31, the material A to be rolled after passing the first hole type K1 is further shaped. [0034] 　Here, the height h2 of the protrusions 35, 36 formed on the second hole mold K2 is higher than the height h1 of the protrusions 25, 26 formed on the first hole mold K1. Similarly, the penetration length into the upper and lower ends (end face of the slab) of the second hole type K2 is longer. The penetration depth of the protrusions 35 and 36 into the material A to be rolled in the second hole type K2 is the same as the height h2 of the protrusions 35 and 36. That is, the penetration depth h1′ of the protrusions 25 and 26 into the rolled material A in the first hole K1 and the penetration depth h1 of the protrusions 35 and 36 into the rolled material A in the second hole K2. h2 has a relationship of h1′L2 in the figure), and it is considered that the rolling is likely to be stable even if the material A to be rolled is asymmetrically deformed. The adjustment of the conditions relating to the configuration of the sixth hole type K6 can be controlled by, for example, the value of the inner diameter of the hole type or the inclination angle of the flange facing portion of the hole type. [0061] 　Table 1 below shows roll hole specifications showing the conventional hole shape design, and the conditions for performing widening of the in-web method by flat rolling shaping and widening rolling without forming a raised portion in flat rolling shaping. FIG. 　In addition, Table 2 below is a roll hole type specification showing the hole type design according to the present invention. It shows the conditions including K6) in the table. The rolls K1 to K6 shown in Table 2 correspond to the first hole type K1 to the sixth hole type K6 according to the present embodiment, and K7 to K9 are general widening hole types. Further, K2-1 and K2-2 indicate interrupt hole types having different projection heights, but both are hole types having a function corresponding to the second hole type K2 according to the present embodiment. [0062] [Table 1] [Table 2] [0063] 　As can be seen by comparing Table 1 and Table 2, in the technique according to the present embodiment, when the ridge elimination and widening rolling are simultaneously performed with the sixth hole type K6, and in the conventional technique, after flat rolling shaping The number of hole types used in the above is the same, and the hole type arrangement and the like have not been changed. That is, by making the hole design of the sixth hole type K6 suitable, and by performing the erasing of the raised portion 82b and the in-web widening of the width at the same time with the sixth hole type K6, the roll body length and the like are reduced. It is possible to roll-form the H-shaped crude material 13 having a large flange width under the conventional conditions, and as a result, it is possible to manufacture an H-shaped steel product having a larger flange width than the conventional one. [0064] 　Further, by using the roll hole type specifications such that the inner surface of the flange portion 80 is brought into contact with the roll when the raised portion 82b is erased, the lateral deformation of the flange portion 80 is equalized, and the rolling stability is maintained. [0065] 　In addition, as one of the conditions for performing the rolling shaping in a state where the inner surface 80a of the flange portion 80 is in contact with the upper hole rolling roll 95, the pass schedule of the rolling shaping in the sixth hole die K6 is preferably designed. It can be mentioned. Specifically, by appropriately adjusting the reduction amount of the hole type (here, sixth hole type K6) for erasing the raised portion and suppressing the reduction amount of the raised portion 82b, the web accompanying the erasing of the raised portion 82b is suppressed. It is possible to suppress the expansion of the inner method of the portion 82 and maintain the rolling stability. [0066] 　First, as described above with reference to FIG. 9, as a preferable hole shape, the roll gap including the variation in the longitudinal direction of the raised portion 82b is evaluated in the first pass rolling shaping, and the minimum value thereof is evaluated. Is designed such that the inner side surface 80a of the flange portion 80 and the inner surface of the roll contact each other when the roll gap (i.e., the roll gap corresponding to the height of the raised portion 82b) is set. By using such a hole type and setting the first pass to the roll gap that actually matches the roll gap of the web portion with the height of the raised portion 82b, it is possible to reliably form the inner side surface 80a of the flange portion 80. Therefore, the rolling stability can be maintained. [0067] 　Further, as a preferable pass schedule, in the hole die for performing the erasure of the raised portion, it is possible to control the contact state of the inner surface of the flange by setting the pass schedule so as to partially erase the raised portion. .. For example, when the ridge erasure rolling molding is performed in a plurality of passes, if the amount of reduction per pass is excessively large, the ridge portion 82b is erased (rolled down) to expand the in-web method. It becomes difficult for the inner side surface 80a to come into contact with the rolls, and the rolling stability is likely to be impaired. Therefore, in the rolling shaping of the first pass, by restricting the amount of reduction of the raised portion 82b, the inner side surface 80a of the flange portion 80 can be reliably molded, and the rolling stability can be maintained. 　In addition, when the ridges are partially erased, it is preferable that the remaining ridges are erased in an arbitrary hole type in the subsequent stage. For example, rolling down or erasing of the ridge remaining after universal rolling in the intermediate universal rolling mill 5 (see FIG. 1) that performs the intermediate rolling process may be performed. [0068] 　Tables 3 and 4 shown below are examples of pass schedules when the raised portion 82b is formed and erased using the fifth hole type K5 and the sixth hole type K6 described above, and Table 3 shows a conventional path schedule. Table 4 is a pass schedule according to the present invention. Each of the hole types K5 and K6 shown in Tables 3 and 4 corresponds to the fifth hole type K5 and the sixth hole type K6 according to the present embodiment. [0069] [Table 3] [Table 4] [0070] 　As can be seen by comparing Table 3 and Table 4, in the conventional pass schedule, the ridge 82b is completely erased in the first pass (the 14th pass) in the sixth hole type K6, and the web edge thickness and the web are reduced. While the protrusions (protrusions) have the same thickness (100.0 mm), in the pass schedule according to the present invention, the protrusions 82b are not completely erased and the protrusions 82b remain (150.0 mm). ). By adopting such a pass schedule, it is possible to suppress the inward expansion of the web portion 82 accompanying the erasing of the raised portion 82b, and it is possible to maintain the rolling stability. [0071] 　FIG. 10 is a schematic diagram based on a simulation showing the shape of the material to be rolled after the ridges are erased in the pass schedules of Tables 3 and 4, and (a) is a schematic diagram of the conventional pass schedule, b) is a schematic diagram of a pass schedule according to the present invention. 　As shown in FIG. 10( a ), in the rolling shaping in which the ridges are erased, when the ridges are completely erased, the flanges of the hole-shaped roll and the material to be rolled are widened as the inside of the web is widened to eliminate the ridges. A gap is created between the inner surface and the inner surface (see the broken line in the figure). On the other hand, as shown in FIG. 10B, when the erasure of the raised portion is limited to a part, the rolling shaping can be completed in a state where the hole-shaped roll and the flange inner surface of the material to be rolled are in contact with each other. 　Thereby, the lateral deformation of the flange portion 80 is equalized, and the rolling stability is maintained. [0072] 　(Ratio of Relief Amount (Rise Forming Width) in Inner Web Method) 　As described above, in the fifth hole type K5 (see FIG. 6) according to the present embodiment, the protrusion is formed in the center of the web portion 82 of the material A to be rolled. The portion 82b is formed, and the formed raised portion 82b is erased in the sixth hole mold K6 in the subsequent stage. Then, after the ridges have been erased, widening rolling by an in-web method is performed as necessary to form an H-shaped rough material, but in order to manufacture a large H-shaped steel product having a larger flange width than in the conventional case, It is desirable to make the flange width of the H-shaped rough material as large as possible. 　The present inventors finally change the width length W1 of the raised portion 82b formed in the fifth hole die K5 (that is, the escape amount of the in-web method in the rolling shaping in the fifth hole die K5). It was found that there is a difference in the flange width of the obtained H-shaped rough material. This is because the larger the width of the raised portion 82b, the easier it is to secure the flange thickness, but the flange width decreases due to the longitudinal stretching action of the material A to be rolled when the raised portion is erased later. [0073] 　Therefore, the inventors of the present invention set a relief ratio and an H-shaped roughening amount in order to determine a suitable range of the relief amount of the in-web method (hereinafter, also simply referred to as “relief amount W1”) in the rolling shaping with the fifth hole type K5. Focusing on the relationship with the increase/decrease in flange width after shaping, a suitable numerical range for the relief rate was derived. The escape rate is a value defined by the following equation (1). Escape rate [%]=(Escape amount W1/Web internal method W2)×100 (1) [0074] 　FIG. 11 is a graph showing the relationship between the relief rate and the flange width increase/decrease rate after the H-shaped rough shaped material is formed. Note that the flange width increase/decrease rate in FIG. 11 refers to the flange width when the clearance rate is 0% (1.000), and the flange width when the clearance rate is each value (12% to 56%). Is a value indicating. [0075] 　As shown in FIG. 11, when the clearance rate increases, the flange width of the H-shaped rough material tends to increase, but in the area where the clearance rate is about 25% or more, the increase or decrease in the flange width is almost constant (in the graph, (See the broken line). 　From the results shown in FIG. 11, in the case of manufacturing a large H-shaped steel product having a larger flange width than in the conventional case, in consideration of the fact that rolling shaping in which the flange width of the H-shaped rough material is also increased is desired, it is possible to release it. It can be seen that the numerical range of the rate is preferably 25% to 50%. [0076] 　(Passability at the time of erasing the raised portion) 　As described above, it is known from the result of FIG. 11 that the numerical range of the relief rate when forming the raised portion 82b is preferably 25% to 50%. On the other hand, it is necessary to further study the value of the thickness of the rolled-down portion 82a of the web when the raised portion 82b is formed with the relief rate in such a numerical range. This is because when the rolling shaping for erasing the raised portion 82b is performed by the sixth hole mold K6 after forming the raised portion 82b, the rolled-down portion 82a is too thin and the metal movement of the raised portion 82b is within the cross section. It is presumed that the result is that the metal movement in the longitudinal direction of the material A to be rolled has occurred. [0077] 　Therefore, when the present inventors manufacture a H-section steel with a product flange width of 400 mm or more using a rectangular cross-section slab of 2000×300 mm as a material, the first hole die K1 to the sixth hole die according to the present embodiment. When performing roll forming with the mold K6, the formability (rolling stability) was evaluated under the condition that the web reduction amount during the roll forming with the fifth hole mold K5 was changed. As specific conditions, the levels 1 to 5 were set when the thickness after reduction of the reduction portion 82a was 200 mm, 160 mm, 140 mm, 120 mm, and 100 mm, respectively. In addition, as a comparative level, the case where the web thickness reduction is performed without forming the raised portion 82b is set to level 6. [0078] 　Table 5 below shows the pass schedules of Levels 1 to 6, and the hole types G1, G2-2, G3-1, G3-2, G4-1 and G4-2 in the table are Correspond to the first hole type K1 to the sixth hole type K6 described in the present embodiment. In addition, the evaluation of the formability is described in the lowermost row of Table 5, and the case where the threading failure/shape failure occurs is “poor”, and the case where the threading failure/shape failure does not occur is “good”. There is. [0079] [Table 5] [0080] 　As shown in Table 5, when the thickness after reduction of the reduction portion 82a is set to 200 mm, 160 mm, and 140 mm (levels 1 to 3), there is no threading defect or shape defect at the time of erasing the raised portion 82b. .. On the other hand, when the post-rolling thickness of the rolled portion 82a is 120 mm and 100 mm (levels 4 and 5), defective passage and defective shape occur when the raised portion 82b is erased. Also, when the web thickness reduction is performed up to 100 mm without forming the raised portion 82b (level 6), the similar passing failure and shape failure are generated. [0081] 　Here, the evaluation criteria of the formability (rolling stability) will be described. The evaluation of the formability is performed based on the warp that occurs in the longitudinal direction of the material A to be rolled when the roll forming is performed to erase the raised portion 82b. 　12: is explanatory drawing regarding the curvature of the to-be-rolled material A, and is a schematic side view when a warp arises in the longitudinal direction edge part of the to-be-rolled material A. FIG. As shown in FIG. 12, the difference between the end portion of the material A to be rolled when warpage occurs in the longitudinal direction and the steady portion is defined as the “warpage amount”. Then, the ratio of the amount of warpage to the length in the longitudinal direction of the material A to be warped is defined as “warpage (%)” defined by the following equation (2). Warp [%] = amount of warp / length of rolled material with warp ... (2) [0082] 　The relationship between the “warpage (%)” defined by the above-described formula (2) and the post-rolling thickness of the rolled portion 82a was verified. FIG. 13 is a graph showing the relationship between the warp and the web thickness (thickness after reduction of the reduction portion 82a). The graph shown in FIG. 13 is data under the condition that the escape rate is about 33%. [0083] 　As shown in FIG. 13, as the post-rolling thickness of the rolled-down portion 82a becomes thinner, the warp tends to increase. In particular, when the thickness after reduction of the reduction portion 82a is 140 mm or less, the warpage is small at about 3% or less, and when the thickness after reduction of the reduction portion 82a exceeds 140 mm, the warpage becomes about 10% or more and the shape deteriorates. Is known to be significant. 　In operation, when the warpage of the material A to be rolled is 10% or more, the dimensional and shape deterioration is remarkable after the next pass, and it is difficult to continue rolling. That is, from the results shown in FIG. 13, good shaping property is ensured by performing the rolling shaping by the fifth hole die K5 so that the web thickness (thickness after reduction of the reduction portion 82a) becomes 140 mm or more. I understand. This is consistent with the good moldability under the conditions of levels 1 to 3 shown in Table 1. [0084] 　Here, the threshold value related to warpage is set to 10% when the maximum warpage amount of about several hundred mm occurs at a rate of 10% with respect to the number m of end portions of the material to be rolled, a difference in vertical wall thickness occurs. This is because it is easily confirmed by those skilled in the art that the value that makes it difficult to continue rolling during operation is 10%. 　Under the same conditions, when the warpage is several% (less than 10%), a warpage of about several tens of mm is observed in normal operation, but it is a person skilled in the art that there is no problem in operation. It is possible to guess easily. [0085] 　As can be seen from FIG. 13, in the rolling shaping with the sixth hole type K6, the minimum post-rolling thickness that does not warp the rolling portion 82a is 140 mm, so the extension λ of the raised portion 82b at this time is 2. 14 (=300/140). 　In addition, when the web thickness (thickness after reduction of the reduction portion 82a) in the fifth hole type K5 is set to a predetermined value (for example, 140 mm) or more, the web thickness becomes further thinner in the sixth hole type K6 in the subsequent stage. It is also possible to reduce the thickness of the web. [0086] 　FIG. 14 is a graph showing the relationship between the thickness after reduction of the reduction portion 82a in the fifth hole type K5 (thickness of finished web after reduction) and the height of the protrusion 82b before reduction. When the “release rate” described above with reference to FIG. 11 is set to a suitable condition (for example, 25% to 50%), the extending action of the raised portion 82b in the longitudinal direction is small, and the height of the raised portion depends on the hole shape. The ridge height remains the slab thickness of the material, unless constrained. 　For example, when the slab has a thickness of 300 mm and the height of the raised portion 82b is a sufficient height, the height of the raised portion remains 300 mm. From that state, when the ridges 82b of the ridge elimination hole type (sixth hole type K6 in FIG. 7) were erased, it was confirmed that the finished web thickness in the case of the fifth hole type K5 after rolling was 140 mm. Although there was no problem, in the case of 130 mm, passing material failure occurred. In each of these cases, the thickness of the raised portion 82b is 300 mm, and the extension of the raised portion 82b is 2.14 because it is reduced from 300 mm to 140 mm in the case of 140 mm and 300 mm to 130 mm in the case of 130 mm. It is 2.31 as it is rolled down. Similarly, when plotted in various cases, as shown in FIG. 14, the critical stretching indicating the threshold value of passing material is about 2.1 in all cases. [0087] 　That is, as shown in FIG. 14, when the rolling reduction (stretching) at the time of erasing the raised portion in the sixth hole type K6 is more than 2.1, a defective threading (x in FIG. 14) may occur. It has been experimentally clarified. By performing the hole type design under the condition that the rolling reduction at the time of erasing the raised portion in the sixth hole type K6 is 2.1 or less, the fifth hole type K5 and It is understood that it is possible to carry out rolling shaping by the 6-hole type K6. If it is necessary to further reduce the thickness of the web after the ridge elimination rolling with the sixth hole type K6, one or a plurality of widening holes are provided in the subsequent stage of the rolling shaping with the sixth hole type K6. Widening rolling using a die may be performed. [0088] 　Although an example of the embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the idea described in the claims, and naturally, they also belong to the technical scope of the present invention. Understood. [0089] 　For example, in the above-described embodiment, the material to be rolled A is shaped using the four hole dies K1 to K4, and then the fifth hole K5 and the sixth hole K6 ( And the technique of performing the rolling shaping of the H-shaped rough material by using the widening rolling hole die as necessary), the number of the hole die for carrying out the rough rolling step is not limited to this, and the first hole The roll forming process shown in the mold K1 to the fourth hole mold K4 may be carried out by using more hole molds. That is, the hole configuration shown in the above embodiment is an example, and the number of the hole dies engraved in the sizing mill 3 and the rough rolling machine 4 can be arbitrarily changed, and the rough rolling step is preferably performed. It can be changed as appropriate. [0090] 　Further, in the above-described embodiment, in the first hole die K1 to the fourth hole die K4, interruptions are made in the upper and lower end portions (slab end surfaces) of the material A to be rolled, and the left and right parts are divided into left and right portions by the interruptions. The modeling method of performing the bending process and forming the flange portion 80 is described. However, the rolling shaping technique with the sixth hole type K6 according to the present invention is not applied only to the material A to be rolled shaped by such a technique, and is represented by Patent Document 1, for example. It can also be applied to a conventional H-shaped rough material (so-called dog bone material). Industrial availability [0091] 　INDUSTRIAL APPLICABILITY The present invention can be applied to a manufacturing method for manufacturing an H-section steel using, for example, a slab having a rectangular cross section as a raw material. Explanation of symbols [0092] 　　DESCRIPTION OF SYMBOLS 　　1... Rolling equipment 　　2... Heating furnace 　　3... Sizing mill 　　4... Rough rolling mill 　　5... Intermediate universal rolling mill 　　8... Finishing universal rolling mill 9... Edger rolling mill 　　11... Slab 　　13... H-shaped rough material 　　14... Intermediate material 　　16... H-shaped steel product 　　20... Upper hole type roll (first hole type) 　　21... Lower hole type roll (first hole type) 　　25, 26... Protrusion (first hole type) 　　28, 29... Interruption ( first hole type) ) 　　30... Upper hole type roll (second hole type) 　　31... Lower hole type roll (second hole type) 　　35, 36... Projection part (second hole type) 　　38, 39... Interruption (second hole type) 　　40... Upper hole type roll (third hole type) 　　41... Lower hole type roll (third hole type) 　　45, 46... Protrusion (third hole type) 　　48, 49... Interruption (third hole type) 　　50... Upper hole type Roll (4th hole type) 　　51... Lower hole type roll (4th hole type) 　　55, 56... Protruding portion (fourth hole type) 　　58, 59... Interruption (fourth hole type) 　　80... Flange portion 　　80a... (Flange portion) inner side surface 　　82... Web portion 　　82a... Rolling down portion 　　82b... 　　Rolling part) 85... Upper hole type roll (fifth hole type) 　　85a... Indented portion 　　86... Lower hole type roll (fifth hole type) 　　86a... Indented portion 　　95... Upper hole type roll (sixth hole type) 　　96... Lower Hole type roll (sixth hole type) 　　K1... First hole type 　　K2... Second hole type 　　K3... Third hole type 　　K4... Fourth hole type 　　K5... Fifth hole type (web partially rolled hole type) 　　K6... Sixth hole Hole type (protuberance erasing hole type) 　　T... Manufacturing line 　　A... Rolled material claims [Claim 1] A method for manufacturing an H-section steel comprising a rough rolling step, an intermediate rolling step, and a finish rolling step, the rough rolling step comprising an edging rolling step of rolling and shaping a material to be rolled into a predetermined substantially dogbone shape, and an edging step. After the rolling process, the material to be rolled is rotated by 90° or 270° to perform a flat rolling process for rolling the web portion , and at least one hole type upper and lower roll among the hole types for performing the flat rolling process. Is provided with a recessed portion for forming a raised portion in the center of the web portion of the material to be rolled in the central portion of the roll cylinder length of the vertical hole type roll , and the raised portion is formed in the hole die for performing the flat rolling step. The rolled material to be rolled further includes a raised portion erasing hole die for pressing down the raised portion and for internally widening the web portion of the rolled material, and the rolling shaping with the raised portion erasing hole die Is performed on the material to be rolled after the ridge is formed in a hole type having a recess for forming the ridge, and the rolling shaping for forming the ridge is performed after the reduction of the ridge. A method for producing an H-section steel, which is characterized in that it is not performed. [Claim 2] Rolling shaping with the raised portion erasing hole type is performed in a plurality of passes, and in at least one pass of the plurality of passes, the rolling shaping is performed in a state where the flange inner surface of the material to be rolled and the hole type roll are in contact with each other. The method for producing an H-section steel according to claim 1, wherein [Claim 3] Rolling shaping with the raised portion erasing hole type is performed in multiple passes, and in the first pass of the multiple passes, rolling shaping is performed in a state where the flange inner surface of the material to be rolled and the hole type roll are in contact with each other. The method for producing an H-section steel according to claim 1, wherein: [Claim 4] In the rolling modeling with the raised portion erasing hole type, erasing of the raised portion is partially performed, and the remaining raised portion is erased by rolling shaping with an arbitrary hole type in the subsequent stage. Item 4. A method for manufacturing an H-section steel according to any one of items 1 to 3. [Claim 5] 5. The width of the raised portion formed in the flat rolling step is set to 25% or more and 50% or less of the in-web portion method of the material to be rolled, according to any one of claims 1 to 4. Manufacturing method of H-section steel. [Claim 6] The method for producing an H-section steel according to claim 1, wherein a rolling reduction of the raised portion erasing hole type with respect to the raised portion is 2.1 or less. [Claim 7] The edging step is performed by a plurality of four or more hole dies, and in the plurality of hole dies, one or more pass shaping of a material to be rolled is performed, and among the plurality of hole dies, a first hole die and a second hole die are formed. A protrusion is formed on the die to insert a vertical interruption in the width direction of the material to be rolled to form a divided portion at the end of the material to be rolled. The method for manufacturing an H-section steel according to any one of claims 1 to 6, wherein the mold is formed with a protrusion that abuts the interrupt and sequentially bends the formed divided portions.