JP6973146B2 - Manufacturing method of H-section steel - Google Patents

Manufacturing method of H-section steel Download PDF

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JP6973146B2
JP6973146B2 JP2018022086A JP2018022086A JP6973146B2 JP 6973146 B2 JP6973146 B2 JP 6973146B2 JP 2018022086 A JP2018022086 A JP 2018022086A JP 2018022086 A JP2018022086 A JP 2018022086A JP 6973146 B2 JP6973146 B2 JP 6973146B2
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浩 山下
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本発明は、例えば矩形断面であるスラブ等を素材としてＨ形鋼を製造する製造方法に関する。 The present invention relates to a manufacturing method for manufacturing H-shaped steel using, for example, a slab having a rectangular cross section as a material.

Ｈ形鋼を製造する場合には、加熱炉から抽出されたスラブやブルーム等の素材を粗圧延機（ＢＤ）によって粗形材（所謂ドッグボーン形状の被圧延材）に造形し、中間ユニバーサル圧延機によって上記粗形材のウェブやフランジの厚さを圧下し、併せて前記中間ユニバーサル圧延機に近接したエッジャー圧延機によって被圧延材のフランジに対し幅圧下や端面の鍛錬と整形が施される。そして、仕上ユニバーサル圧延機によってＨ形鋼製品が造形される。 In the case of manufacturing H-section steel, materials such as slabs and blooms extracted from the heating furnace are formed into rough-shaped materials (so-called dogbone-shaped rolled materials) by a rough rolling mill (BD), and intermediate universal rolling is performed. The machine reduces the thickness of the web and flange of the rough-shaped material, and the edger rolling mill close to the intermediate universal rolling mill performs width rolling and forging and shaping of the end face of the flange of the material to be rolled. .. Then, the H-shaped steel product is molded by the finishing universal rolling mill.

このようなＨ形鋼の製造方法において、矩形断面であるスラブ素材から所謂ドッグボーン形状の粗形材を造形する際には、粗圧延工程の第１の孔型においてスラブ端面に割り込みを入れた後、第２以降の孔型において当該割り込みを割広げる、又は、割り込み深さを深くさせ、それ以降の孔型にてスラブ端面の割り込みを消去する技術が知られている（例えば特許文献１参照）。 In such a method for manufacturing H-section steel, when a so-called dogbone-shaped rough shape material is formed from a slab material having a rectangular cross section, an interrupt is inserted in the slab end face in the first hole mold of the rough rolling process. Later, a technique is known in which the interrupt is expanded or the interrupt depth is increased in the second and subsequent hole types, and the interrupt on the slab end face is eliminated in the subsequent hole types (see, for example, Patent Document 1). ).

また、Ｈ形鋼の製造においては、スラブ等の素材の端面（スラブ端面）をエッジングするいわゆるエッジング圧延の後に、被圧延材を９０°又は２７０°回転させ、ウェブ相当部の圧下を行う平造形圧延を行うことが知られている。この平造形圧延では、ウェブ相当部の圧下と共にフランジ相当部の圧下及び整形が行われるが、近年、大型のＨ形鋼製品が求められていることに鑑み、大型の素材を被圧延材とした場合に、一般的な平造形圧延では、ウェブ高さ方向の伸びやフランジ相当部の変形等、種々の問題が生じることがあり、形状の修正が求められる場合があった。具体的には、ウェブ相当部の圧下に伴い、ウェブ相当部が長手方向に延伸し、当該延伸に引っ張られてフランジ相当部も長手方向に延伸し、フランジ相当部の厚みが薄くなってしまうといった現象が懸念されていた。 Further, in the production of H-section steel, after so-called edging rolling in which the end face (slab end face) of a material such as a slab is edging, the material to be rolled is rotated by 90 ° or 270 ° to perform flat rolling in which a part corresponding to the web is rolled. It is known to perform rolling. In this flat rolling, the part corresponding to the web is reduced and the part corresponding to the flange is reduced and shaped. However, in view of the recent demand for large H-shaped steel products, a large material is used as the material to be rolled. In some cases, in general flat-shaped rolling, various problems such as elongation in the height direction of the web and deformation of the flange corresponding portion may occur, and it may be required to correct the shape. Specifically, as the web equivalent portion is compressed, the web equivalent portion is stretched in the longitudinal direction, and the flange equivalent portion is also stretched in the longitudinal direction by being pulled by the stretching, and the thickness of the flange equivalent portion is reduced. The phenomenon was a concern.

このような平造形圧延に関し、例えば特許文献２には、ウェブ相当部への圧下を選択的に行う技術が開示されており、ウェブ相当部の中央に未圧下部を設け、その後形成された凸部（本発明の***部に相当）を消去し、ウェブ相当部の拡幅を行うことで、大型のＨ形鋼の製造を効率的に行うこととしている。また、例えば特許文献３には、ウェブ相当部の未圧下部（非圧下部分）の範囲を好適に規定する技術が開示され、被圧延材の全断面積に対する非圧下部分の断面積が０．６以上とする旨が記載されている。 Regarding such flat-shaped rolling, for example, Patent Document 2 discloses a technique for selectively performing rolling on a web-corresponding portion, in which an uncompressed lower portion is provided in the center of the web-corresponding portion, and then a convex shape is formed. By erasing 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-shaped steel. Further, for example, Patent Document 3 discloses a technique for preferably defining the range of the uncompressed lower portion (non-compressed portion) of the web corresponding portion, and the cross-sectional area of the non-compressed portion with respect to the total cross-sectional area of the material to be rolled is 0. It is stated that the number is 6 or more.

特開平７−８８５０１号公報Japanese Unexamined Patent Publication No. 7-88501 特開昭５７−１４６４０５号公報Japanese Unexamined Patent Publication No. 57-146405 特開昭５７−１７１５０１号公報Japanese Unexamined Patent Publication No. 57-171501

上述したように、近年、構造物等の大型化に伴い大型のＨ形鋼製品の製造が望まれている。特にＨ形鋼の強度・剛性に大きく寄与するフランジを従来に比べて広幅化した製品が望まれている。フランジが広幅化されたＨ形鋼製品を製造するためには、粗圧延工程における造形から従来に比べフランジ幅の大きな被圧延材を造形する必要がある。 As described above, in recent years, with the increase in size of structures and the like, it has been desired to manufacture large H-shaped steel products. In particular, a product having a wider flange than the conventional one, which greatly contributes to the strength and rigidity of the H-section steel, is desired. In order to manufacture an H-shaped steel product with a wide flange, it is necessary to form a material to be rolled with a larger flange width than before from the modeling in the rough rolling process.

しかしながら、例えば上記特許文献１に開示されている技術では、スラブ等の素材の端面（スラブ端面）に割り込みを入れ、当該端面をエッジングし、その幅拡がりを利用して粗圧延を行う方法において、フランジの広幅化に限界がある。即ち、従来の粗圧延方法においてフランジの広幅化を図るためにはウェッジ設計（割り込み角度の設計）、圧下調整、潤滑調整といった技術により幅拡がりの向上が図られるが、いずれの方法もフランジ幅に大幅に寄与するものではないため、エッジング量に対するフランジ幅の拡がり量の比率を示す幅拡がり率は、エッジングの初期段階の効率が最も高い条件でも０．８程度であり、同一孔型でエッジングを繰り返す条件では、フランジ幅の拡がり量が大きくなるにつれて低下し、最終的には０．５程度になることが知られている。また、スラブ等の素材自体を大型化し、エッジング量を大きくすることも考えられるが、粗圧延機の設備規模や圧下量等には装置限界があるため十分な製品フランジの広幅化が実現されないといった事情がある。 However, for example, in the technique disclosed in Patent Document 1, in a method of inserting an interrupt into an end face (slab end face) of a material such as a slab, edging the end face, and performing rough rolling by utilizing the width expansion thereof. There is a limit to the widening of the flange. That is, in the conventional rough rolling method, in order to widen the flange, the width can be improved by wedge design (interruption angle design), reduction adjustment, lubrication adjustment, etc., but all methods have the flange width. Since it does not contribute significantly, the width expansion ratio, which indicates the ratio of the flange width expansion to the edging amount, is about 0.8 even under the condition where the efficiency at the initial stage of edging is the highest, and edging is performed with the same hole type. Under repeated conditions, it is known that the flange width decreases as the amount of expansion increases, and finally reaches about 0.5. It is also possible to increase the size of the material itself such as slabs and increase the amount of edging, but it is said that the product flange cannot be widened sufficiently due to the equipment limit of the equipment scale and rolling amount of the rough rolling mill. There are circumstances.

また、大型のＨ形鋼製品を製造する際に、粗圧延工程において大型の粗形材を圧延造形する場合がある。大型の粗形材を従来とは異なる方法で圧延造形し、粗形材の形状をよりＨ形鋼に近い形状に造形した場合には、上記特許文献２、３に記載された技術によって平造形圧延を行うと、ウェブ高さ方向の伸びやフランジ相当部の変形等の問題が生じることが分かってきている。 Further, when manufacturing a large-sized H-shaped steel product, a large-sized rough-shaped material may be rolled and shaped in the rough-rolling process. When a large rough-shaped material is rolled and shaped by a method different from the conventional method and the shape of the rough-shaped material is formed into a shape closer to that of H-shaped steel, flat molding is performed by the techniques described in Patent Documents 2 and 3 above. It has been found that rolling causes problems such as elongation in the height direction of the web and deformation of the flange corresponding portion.

例えば、特許文献３では、ウェブ相当部に未圧下部（非圧下部分）を設けた際の孔型圧延そのものでの圧延効果にのみ着眼しており、当該孔型での変形において、フランジ減肉が生じない条件を開示している。しかしながら、実際の操業では、選択的に圧下した部分以外の未圧下部については、後段のプロセスにて消去（圧下）を行う必要があり、フランジ減肉は、その後段のプロセスを経た後の最終的な断面形状にて評価する必要があると考えられる。 For example, in Patent Document 3, only the rolling effect of the hole-shaped rolling itself when the uncompressed lower portion (non-compressed portion) is provided in the web corresponding portion is focused on, and in the deformation in the hole-shaped portion, the flange thickness is reduced. Discloses the conditions under which However, in the actual operation, it is necessary to erase (reduce) the uncompressed lower part other than the selectively compressed part in the subsequent process, and the flange thinning is the final after passing through the subsequent process. It is considered necessary to evaluate with a specific cross-sectional shape.

本発明者らは、このような点に鑑み、後段のプロセスでの未圧下部の消去を含む総合的なプロセス全体において評価を行っている。具体的には、後述する本発明の実施の形態で説明するように、例えば３００厚スラブを素材とした場合に被圧延材のウェブ部内法の２５％以上５０％以下の幅に未圧下部の幅を設定し、その後、所定の設計条件を満たすような拡幅孔型（未圧下部の消去孔型）を用いて未圧下部の消去を行うことでフランジの生成効率を高めることを見出し、本発明に至っている。 In view of these points, the present inventors evaluate the entire comprehensive process including the elimination of the unpressurized lower portion in the subsequent process. Specifically, as will be described later in the embodiment of the present invention, for example, when a 300-thick slab is used as a material, the uncompressed lower portion has a width of 25% or more and 50% or less of the method inside the web portion of the material to be rolled. We found that the flange generation efficiency can be improved by setting the width and then erasing the uncompressed lower part using a widened hole type (erasing hole type of the unrolled lower part) that satisfies the predetermined design conditions. It has led to the invention.

上記事情に鑑み、本発明の目的は、エッジング圧延後に実施される平造形圧延において、ウェブ高さ方向の伸びやフランジ相当部の変形といった問題を生じさせることなくフランジの生成効率を向上させ、大型の粗形材の平造形圧延を行い、大型Ｈ形鋼製品を効率的且つ安定的に製造する技術を提供することにある。 In view of the above circumstances, an object of the present invention is to improve the flange generation efficiency without causing problems such as elongation in the height direction of the web and deformation of the flange corresponding portion in the flat section rolling performed after edging rolling, and to make the large size. It is an object of the present invention to provide a technique for efficiently and stably producing a large H-shaped steel product by performing flat rolling of a rough-shaped material.

また、Ｈ形鋼を製造する際の孔型を用いた粗圧延工程において、スラブ等の矩形断面素材の端面に鋭角の先端形状をした突起部で深く割り込みを入れ、それによって形成されたフランジ部を順次折り曲げることによって、被圧延材における形状不良の発生を抑制させ、従来に比べフランジ幅の大きなＨ形鋼製品を効率的且つ安定的に製造することが可能なＨ形鋼の製造技術を提供することを目的とする。 Further, in the rough rolling process using a hole mold when manufacturing H-section steel, a flange portion formed by deeply interrupting the end face of a rectangular cross-sectional material such as a slab with a protrusion having a sharp tip shape. Providing a manufacturing technology for H-shaped steel that can suppress the occurrence of shape defects in the material to be rolled and efficiently and stably manufacture H-shaped steel products with a larger flange width than before. The purpose is to do.

前記の目的を達成するため、本発明によれば、粗圧延工程、中間圧延工程、仕上圧延工程を備えたＨ形鋼の製造方法であって、前記粗圧延工程は、被圧延材を所定の略ドッグボーン形状に圧延造形するエッジング圧延工程と、エッジング圧延工程完了後の被圧延材を９０°あるいは２７０°回転させてウェブ部の圧延を行う平圧延工程を有し、前記平圧延工程を行う孔型には、少なくとも、被圧延材のウェブ部中央に***部を形成させる窪み部が設けられた***部形成孔型と、前記***部が形成された被圧延材に対し、当該***部を圧下する***部消去孔型が刻設され、前記平圧延工程において形成される***部の幅は被圧延材のウェブ部内法の２５％以上５０％以下に設定され、前記***部消去孔型における前記***部に対する圧下率を２．１以下とし、前記***部消去孔型の内法寸法は、前記***部形成孔型の内法寸法未満に設計され、且つ、前記***部消去孔型には、被圧延材の外法寸法を所定値以下に抑える孔型側壁が設けられることを特徴とする、Ｈ形鋼の製造方法が提供される。
In order to achieve the above object, according to the present invention, it is a method for manufacturing an H-shaped steel including a rough rolling step, an intermediate rolling step, and a finish rolling step. It has an edging rolling step of rolling into a substantially dogbone shape and a plan rolling step of rolling the web portion by rotating the material to be rolled by 90 ° or 270 ° after the completion of the edging rolling step, and the plan rolling step is performed. The hole type includes at least a raised portion forming hole type in which a recess for forming a raised portion is provided in the center of the web portion of the material to be rolled, and the raised portion for the rolled material in which the raised portion is formed. A raised portion erasing hole type to be rolled down is engraved, and the width of the raised portion formed in the plan rolling step is set to 25% or more and 50% or less of the method inside the web portion of the material to be rolled. The rolling reduction ratio with respect to the raised portion is set to 2.1 or less, and the internal dimension of the raised portion erasing hole type is designed to be smaller than the internal dimension of the raised portion forming hole type, and the raised portion erasing hole type is used. Provided a method for producing H-shaped steel, characterized in that a hole-shaped side wall that suppresses the outer dimension of the material to be rolled to a predetermined value or less is provided.

前記孔型側壁間の間隔は、前記***部消去孔型における被圧延材非定常部の幅拡がり量に基づき設計されても良い。 The spacing between the hole-shaped side walls may be designed based on the amount of width expansion of the unrolled material unsteady portion in the raised portion erasing hole type.

前記平圧延工程を行う孔型には、前記***部消去孔型で圧延造形された後の被圧延材に対し、ウェブ部を略平坦に圧延造形し、且つ、拡幅圧延を行う１又は複数の拡幅用孔型が更に含まれても良い。 In the hole mold for which the plan rolling step is performed, one or a plurality of the web portions are rolled and shaped substantially flat with respect to the material to be rolled after being rolled and shaped by the raised portion erasing hole mold, and widening rolling is performed. A widening hole type may be further included.

前記拡幅用孔型で圧延造形された被圧延材のウェブ部厚みは、前記***部形成孔型で圧延造形された被圧延材のウェブ部厚みに比べ薄く設定され、前記***部消去孔型では、前記***部の圧下と併せて被圧延材のウェブ部の圧下が行われても良い。 The thickness of the web portion of the material to be rolled formed by rolling in the widening hole type is set to be thinner than the thickness of the web portion of the material to be rolled formed by rolling in the raised portion forming hole type. In addition to the reduction of the raised portion, the reduction of the web portion of the material to be rolled may be performed.

前記粗圧延工程を行う圧延機には、被圧延材を圧延造形する６以上の複数の孔型が刻設され、当該複数の孔型では被圧延材の１又は複数パス造形が行われ、前記複数の孔型のうち、第１孔型及び第２孔型には、被圧延材の幅方向に対し鉛直に割り込みを入れて被圧延材端部に分割部位を形成させる突起部が形成され、前記複数の孔型のうち、後段に位置する前記平圧延工程を行う孔型を除く第３孔型以降の孔型には、前記割り込みに当接し、形成された分割部位を順次折り曲げる突起部が形成されても良い。 In the rolling mill performing the rough rolling step, six or more hole molds for rolling and shaping the material to be rolled are engraved, and one or more pass molding of the material to be rolled is performed in the plurality of hole molds. Of the plurality of hole types, the first hole type and the second hole type are formed with protrusions that vertically interrupt the width direction of the material to be rolled to form a split portion at the end of the material to be rolled. Of the plurality of hole types, the hole types of the third and subsequent hole types, excluding the hole type that performs the flat rolling step, which are located in the subsequent stage, have protrusions that abut on the interrupt and sequentially bend the formed divided portions. It may be formed.

厚み２９０ｍｍ以上３１０ｍｍ以下の矩形断面スラブを素材として用い、ウェブ高さ１０００ｍｍ以上、且つ、フランジ幅４００ｍｍ以上のＨ形鋼製品を製造しても良い。 An H-shaped steel product having a web height of 1000 mm or more and a flange width of 400 mm or more may be manufactured by using a rectangular cross-section slab having a thickness of 290 mm or more and 310 mm or less as a material.

本発明によれば、エッジング圧延後に実施される平造形圧延において、ウェブ高さ方向の伸びやフランジ相当部の変形といった問題を生じさせることなくフランジの生成効率を向上させ、大型の粗形材の平造形圧延を行い、大型Ｈ形鋼製品を効率的且つ安定的に製造することが可能となる。 According to the present invention, in flat shaping rolling performed after edging rolling, the efficiency of flange formation is improved without causing problems such as elongation in the height direction of the web and deformation of the flange corresponding portion, and a large rough shaped material can be used. Flat forming rolling can be performed to efficiently and stably manufacture large H-shaped steel products.

Ｈ形鋼の製造ラインについての概略説明図である。It is a schematic explanatory drawing about the production line of H-shaped steel. 第１孔型の概略説明図である。It is a schematic explanatory drawing of the 1st hole type. 第２孔型の概略説明図である。It is a schematic explanatory drawing of the 2nd hole type. 第３孔型の概略説明図である。It is a schematic explanatory drawing of the 3rd hole type. 第４孔型の概略説明図である。It is a schematic explanatory drawing of the 4th hole type. 第５孔型の概略説明図である。It is a schematic explanatory drawing of the 5th hole type. 第６孔型の概略説明図である。It is a schematic explanatory drawing of the 6th hole type. 逃がし率とＨ形粗形材造形後のフランジ幅増減率との関係を示すグラフである。It is a graph which shows the relationship between the relief rate and the flange width increase / decrease rate after H-shaped rough shape material molding. 被圧延材の反りに関する説明図である。It is explanatory drawing about the warp of the material to be rolled. 反りとウェブ厚みとの関係を示したグラフである。It is a graph which showed the relationship between the warp and the web thickness. 圧下部分の圧下後厚みと、***部の高さとの関係において、反りが発生して通材不良となる場合と、反りが発生せずに通材良好となる場合と、を比較検討した結果を示すグラフである。Regarding the relationship between the thickness of the reduced portion after reduction and the height of the raised portion, the results of a comparative study of the case where warpage occurs and the material is poorly passed and the case where warpage does not occur and the material is good through are compared. It is a graph which shows. 第６孔型での圧延前と圧延後の被圧延材ウェブ高さの変化を示すグラフである。It is a graph which shows the change of the web height of the material to be rolled before and after rolling in the 6th hole type. 第５孔型の内法と第６孔型の内法を等しくした場合と、第６孔型の内法を第５孔型の内法未満とした場合の、圧延造形後のフランジ部形状を示す解析図である。The shape of the flange after rolling molding when the inner method of the 5th hole type and the inner method of the 6th hole type are equalized and when the inner method of the 6th hole type is less than the inner method of the 5th hole type. It is an analysis figure which shows. 従来孔型と本発明孔型との両方において圧延造形を行い、その後、拡幅圧延を行った場合のフランジ部形状を示す解析図である。It is an analysis figure which shows the shape of the flange part in the case where rolling molding was performed in both the conventional hole type and the hole type of the present invention, and then widening rolling was performed. フランジ肉量の増量化に関する概略説明図である。It is a schematic explanatory drawing about increasing the amount of a flange wall.

以下、本発明の実施の形態について図面を参照して説明する。なお、本明細書および図面において、実質的に同一の機能構成を有する構成要素については、同一の符号を付することにより重複説明を省略する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

図１は、本実施の形態にかかる圧延設備１を含むＨ形鋼の製造ラインＴについての説明図である。図１に示すように、製造ラインＴには上流側から順に、加熱炉２、サイジングミル３、粗圧延機４、中間ユニバーサル圧延機５、仕上ユニバーサル圧延機８が配置されている。また、中間ユニバーサル圧延機５に近接してエッジャー圧延機９が設けられている。なお、以下では、説明のために製造ラインＴにおける鋼材を、総称して「被圧延材Ａ」と記載し、各図において適宜その形状を破線・斜線等を用いて図示する場合がある。 FIG. 1 is an explanatory diagram of an H-section steel production line T including a rolling equipment 1 according to the present embodiment. As shown in FIG. 1, 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 order from the upstream side on the production line T. Further, an edger rolling mill 9 is provided in the vicinity of the intermediate universal rolling mill 5. In the following, for the sake of explanation, the steel materials in the production line T are collectively referred to as “rolled material A”, and the shape may be appropriately illustrated by using broken lines, diagonal lines, or the like in each drawing.

図１に示すように、製造ラインＴでは、加熱炉２から抽出された例えばスラブ１１である矩形断面素材（後の被圧延材Ａ）がサイジングミル３ならびに粗圧延機４において粗圧延される。次いで、中間ユニバーサル圧延機５において中間圧延される。この中間圧延時には、必要に応じてエッジャー圧延機９によって被圧延材のフランジ先端部（フランジ対応部１２）に対して圧下が施される。通常の場合、サイジングミル３及び粗圧延機４のロールには、エッジング孔型及びウェブ部分を減厚し、フランジ部分の形状を成形するいわゆる平造形孔型が刻設されており、これらを経由して複数パスのリバース圧延でＨ形粗形材１３が造形され、該Ｈ形粗形材１３を前記中間ユニバーサル圧延機５−エッジャー圧延機９の２つの圧延機からなる圧延機列を用いて、複数パスの圧下が加えられ、中間材１４が造形される。そして中間材１４は、仕上ユニバーサル圧延機８において製品形状に仕上圧延され、Ｈ形鋼製品１６が製造される。 As shown in FIG. 1, in the production line T, a rectangular cross-section material (later to be rolled material A), for example, a slab 11 extracted from the heating furnace 2, is roughly rolled in the sizing mill 3 and the rough rolling mill 4. Then, the intermediate rolling is performed in the intermediate universal rolling mill 5. At the time of this intermediate rolling, rolling is applied to the flange tip portion (flange corresponding portion 12) of the material to be rolled by the edger rolling mill 9 as needed. Normally, the rolls of the sizing mill 3 and the rough rolling mill 4 are engraved with a so-called flat hole type in which the edging hole type and the web portion are reduced in thickness and the shape of the flange portion is formed. Then, the H-shaped rough profile 13 is formed by reverse rolling in a plurality of passes, and the H-shaped rough profile 13 is rolled by using a rolling mill consisting of two rolling mills of the intermediate universal rolling mill 5-edger rolling mill 9. , Rolling of a plurality of passes is applied, and the intermediate material 14 is formed. Then, the intermediate material 14 is finished and rolled into a product shape in the finishing universal rolling mill 8, and the H-shaped steel product 16 is manufactured.

ここで、加熱炉２から抽出されるスラブ１１のスラブ厚は、例えば、２９０ｍｍ以上３１０ｍｍ以下の範囲内である。これは、大型のＨ形鋼製品を製造する際に用いられるいわゆる３００厚スラブと呼ばれるスラブ素材の寸法である。 Here, the slab thickness of the slab 11 extracted from the heating furnace 2 is, for example, in the range of 290 mm or more and 310 mm or less. This is the dimension of a slab material called a so-called 300-thick slab used when manufacturing a large H-shaped steel product.

次に、以下では図１に示したサイジングミル３及び粗圧延機４に刻設される孔型構成や孔型形状について図面を参照して説明する。図２〜図７は粗圧延工程を行うサイジングミル３及び粗圧延機４に刻設される孔型についての概略説明図である。ここで、説明する第１孔型〜第６孔型は、例えばサイジングミル３に全て刻設されても良く、サイジングミル３及び粗圧延機４に第１孔型〜第６孔型の６つの孔型が分けて刻設されても良い。即ち、第１孔型〜第６孔型はサイジングミル３及び粗圧延機４の両方に亘って刻設されても良く、どちらか一方の圧延機に刻設されても良い。通常のＨ形鋼の製造における粗圧延工程では、これら各孔型において１又は複数パスでの造形が行われる。 Next, the hole-shaped configuration and the hole-shaped 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. 2 to 7 are schematic explanatory views of the hole molds engraved in the sizing mill 3 and the rough rolling mill 4 that perform the rough rolling process. Here, the first hole type to the sixth hole type described here may be all engraved in, for example, the sizing mill 3, and the sizing mill 3 and the rough rolling mill 4 have six types, the first hole type to the sixth hole type. The hole type may be separately engraved. That is, the first hole type to the sixth hole type may be carved over both the sizing mill 3 and the rough rolling mill 4, or may be carved in either rolling mill. In the rough rolling process in the production of ordinary H-section steel, molding with one or more passes is performed in each of these hole molds.

また、本実施の形態では刻設される孔型が６つの場合を例示して説明するが、その孔型数についても、必ずしも６孔型である必要はなく、６以上の複数の孔型数であっても良い。例えば、後述する第６孔型Ｋ６の後段に一般的な拡幅圧延孔型を設けるような構成としても良い。即ち、Ｈ形粗形材１３を造形するために好適な孔型構成であれば良い。なお、図２〜図７では、各孔型における造形時の被圧延材Ａの概略最終パス形状を破線にて図示している。 Further, in the present embodiment, the case where the number of hole types to be engraved is 6 will be described as an example, but the number of hole types does not necessarily have to be 6 holes, and the number of holes is 6 or more. It may be. For example, a general widening rolled hole mold may be provided after the sixth hole mold K6 described later. That is, any hole-shaped structure suitable for modeling the H-shaped rough shape member 13 may be used. In FIGS. 2 to 7, the approximate final path shape of the material A to be rolled at the time of molding in each hole type is shown by a broken line.

図２は第１孔型Ｋ１の概略説明図である。第１孔型Ｋ１は、一対の水平ロールである上孔型ロール２０と下孔型ロール２１に刻設され、これら上孔型ロール２０と下孔型ロール２１のロール隙において被圧延材Ａが圧下・造形される。また、上孔型ロール２０の周面（即ち、第１孔型Ｋ１の上面）には、孔型内部に向かって突出する突起部２５が形成されている。更に、下孔型ロール２１の周面（即ち、第１孔型Ｋ１の底面）には、孔型内部に向かって突出する突起部２６が形成されている。これら突起部２５、２６はテーパー形状を有しており、その突出長さ等の寸法は、突起部２５と突起部２６とでそれぞれ等しく構成されている。突起部２５、２６の高さ（突出長さ）をｈ１とし、先端部角度をθ１ａとする。 FIG. 2 is a schematic explanatory view of the first hole type K1. The first hole type K1 is engraved on the upper hole type roll 20 and the prepared hole type roll 21 which are a pair of horizontal rolls, and the material A to be rolled is formed in the roll gap between the upper hole type roll 20 and the prepared hole type roll 21. Rolled 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), a protrusion 25 protruding toward the inside of the hole type is formed. Further, a protrusion 26 projecting toward the inside of the hole type is formed on the peripheral surface of the prepared hole type roll 21 (that is, the bottom surface of the first hole type K1). These protrusions 25 and 26 have a tapered shape, and the dimensions such as the protrusion length thereof are the same for the protrusion 25 and the protrusion 26, respectively. The height (projection length) of the protrusions 25 and 26 is h1, and the tip angle is θ1a.

この第１孔型Ｋ１においては、突起部２５、２６が被圧延材Ａの上下端部（スラブ端面）に押し当てられ、割り込み２８、２９が形成される。ここで、突起部２５、２６の先端部角度（ウェッジ角度とも呼称される）θ１ａは例えば２５°以上４０°以下であることが望ましい。 In the first hole type K1, the protrusions 25 and 26 are pressed against the upper and lower ends (slab end faces) of the material A to be rolled, and interrupts 28 and 29 are formed. Here, it is desirable that the tip angle (also referred to as a wedge angle) θ1a of the protrusions 25 and 26 is, for example, 25 ° or more and 40 ° or less.

ここで、第１孔型Ｋ１の孔型幅は、被圧延材Ａの厚み（即ち、スラブ厚）とほぼ等しいことが好ましい。具体的には、第１孔型Ｋ１に形成された突起部２５、２６の先端部における孔型の幅と、スラブ厚を同一にすることで、被圧延材Ａの左右センタリング性が好適に確保される。また、このような孔型寸法の構成とすることで、図２に示すように、第１孔型Ｋ１での造形時において、被圧延材Ａの上下端部（スラブ端面）においては、上記突起部２５、２６及び孔型側面（側壁）の一部が被圧延材Ａと接していて、割り込み２８、２９により４つの要素（部位）に分割されたスラブ上下端部に対して、第１孔型Ｋ１の上面及び底面にて積極的な圧下が行われない方が好ましい。孔型の上面及び底面による圧下は、被圧延材Ａの長手方向への伸びを生じさせてしまい、フランジ（後述するフランジ部８０）の生成効率を低下させてしまうからである。即ち、第１孔型Ｋ１においては、突起部２５、２６が被圧延材Ａの上下端部（スラブ端面）に押し当てられ、割り込み２８、２９が形成される際の突起部２５、２６における圧下量（ウェッジ先端圧下量）は、スラブ上下端部における圧下量（スラブ端面圧下量）よりも十分に大きなものとされ、これにより割り込み２８、２９が形成される。 Here, it is preferable that the hole type width of the first hole type K1 is substantially equal to the thickness of the material A to be rolled (that is, the slab thickness). Specifically, by making the width of the hole type at the tips of the protrusions 25 and 26 formed in the first hole type K1 the same as the slab thickness, the left-right centering property of the material A to be rolled is suitably ensured. Will be done. Further, by adopting such a hole-shaped size configuration, as shown in FIG. 2, the protrusions are formed on the upper and lower end portions (slab end faces) of the material A to be rolled during molding with the first hole-shaped K1. The first hole is provided with respect to the upper and lower end portions of the slab, which are in contact with the material A to be rolled and are divided into four elements (parts) by interrupts 28 and 29. It is preferable that active rolling is not performed on the upper surface and the bottom surface of the mold K1. This is because the rolling reduction by the upper surface and the bottom surface of the hole type causes the material A to be rolled to stretch in the longitudinal direction, which lowers 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 ends (slab end faces) of the material A to be rolled, and the protrusions 25 and 26 are pressed down when the interrupts 28 and 29 are formed. The amount (wedge tip rolling down amount) is set to be sufficiently larger than the rolling down amount (slab end face rolling down amount) at the upper and lower ends of the slab, whereby interrupts 28 and 29 are formed.

図３は第２孔型Ｋ２の概略説明図である。第２孔型Ｋ２は、一対の水平ロールである上孔型ロール３０と下孔型ロール３１に刻設される。上孔型ロール３０の周面（即ち、第２孔型Ｋ２の上面）には、孔型内部に向かって突出する突起部３５が形成されている。更に、下孔型ロール３１の周面（即ち、第２孔型Ｋ２の底面）には、孔型内部に向かって突出する突起部３６が形成されている。これら突起部３５、３６はテーパー形状を有しており、その突出長さ等の寸法は、突起部３５と突起部３６とでそれぞれ等しく構成されている。これら突起部３５、３６の先端部角度は２５°以上４０°以下のウェッジ角度θ１ｂであることが望ましい。 FIG. 3 is a schematic explanatory view of the second hole type K2. The second hole type K2 is engraved on the upper hole type roll 30 and the lower hole type roll 31, which are a pair of horizontal rolls. A protrusion 35 projecting toward the inside of the hole type is formed on the peripheral surface of the upper hole type roll 30 (that is, the upper surface of the second hole type K2). Further, a protrusion 36 protruding toward the inside of the hole type is formed on the peripheral surface of the prepared hole type roll 31 (that is, the bottom surface of the second hole type K2). These protrusions 35 and 36 have a tapered shape, and the protrusion length and other dimensions are the same for the protrusion 35 and the protrusion 36, respectively. It is desirable that the tip angle of these protrusions 35 and 36 is a wedge angle θ1b of 25 ° or more and 40 ° or less.

なお、上記第１孔型Ｋ１のウェッジ角度θ１ａは、フランジ相当部の先端部厚みを確保し、誘導性を高め、圧延の安定性を担保するために、後段の第２孔型Ｋ２のウェッジ角度θ１ｂと同じ角度であることが好ましい。 The wedge angle θ1a of the first hole type K1 is the wedge angle of the second hole type K2 in the subsequent stage in order to secure the thickness of the tip corresponding to the flange, enhance the inductivity, and ensure the stability of rolling. It is preferable that the angle is the same as θ1b.

突起部３５、３６の高さ（突出長さ）ｈ２は、上記第１孔型Ｋ１の突起部２５、２６の高さｈ１より高く構成されており、ｈ２＞ｈ１となっている。また、突起部３５、３６の先端部角度は上記第１孔型Ｋ１の突起部２５、２６の先端部角度と同じであることが圧延寸法精度上、好ましい。これら上孔型ロール３０と下孔型ロール３１のロール隙において、上記第１孔型Ｋ１通材後の被圧延材Ａが更に造形される。 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. Further, it is preferable that the tip angle of the protrusions 35 and 36 is the same as the tip angle of the protrusions 25 and 26 of the first hole type K1 in terms of rolling dimensional accuracy. 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 through the first hole type K1 is further formed.

ここで、第１孔型Ｋ１に形成される突起部２５、２６の高さｈ１より、第２孔型Ｋ２に形成される突起部３５、３６の高さｈ２の方が高く、被圧延材Ａの上下端部（スラブ端面）への侵入長さも同様に第２孔型Ｋ２の方が長くなる。第２孔型Ｋ２での突起部３５、３６の被圧延材Ａへの侵入深さは、突起部３５、３６の高さｈ２と同じである。即ち、第１孔型Ｋ１での突起部２５、２６の被圧延材Ａへの侵入深さｈ１’と、第２孔型Ｋ２での突起部３５、３６の被圧延材Ａへの侵入深さｈ２はｈ１’＜ｈ２との関係になっている。
また、被圧延材Ａの上下端部（スラブ端面）に対向する孔型上面３０ａ、３０ｂ及び孔型底面３１ａ、３１ｂと、突起部３５、３６の傾斜面とのなす角度θｆは、図３に示す４箇所ともに約９０°（略直角）に構成されている。 Here, the height h2 of the protrusions 35 and 36 formed in the second hole type K2 is higher than the height h1 of the protrusions 25 and 26 formed in the first hole type K1, and the material A to be rolled is higher. Similarly, the second hole type K2 has a longer penetration depth into the upper and lower end portions (slab end faces). 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 in the first hole type K1 into the rolled material A and the penetration depth of the protrusions 35 and 36 in the second hole type K2 into the rolled material A. h2 has a relationship with h1'<h2.
Further, the angle θf formed by the hole-shaped upper surfaces 30a and 30b and the hole-shaped bottom surfaces 31a and 31b facing the upper and lower ends (slab end faces) of the material A to be rolled and the inclined surfaces of the protrusions 35 and 36 is shown in FIG. All four locations shown are configured at approximately 90 ° (approximately right angles).

図３に示すように、被圧延材Ａの上下端部（スラブ端面）へ押し当てられた時の突起部の侵入長さが長いことから、第２孔型Ｋ２においては、第１孔型Ｋ１において形成された割り込み２８、２９が更に深くなるように造形が行われ、割り込み３８、３９が形成される。なお、ここで形成される割り込み３８、３９の寸法に基づき粗圧延工程でのフランジ造形工程終了時のフランジ片幅が決定される。 As shown in FIG. 3, since the penetration length of the protrusion when pressed against the upper and lower ends (slab end faces) of the material A to be rolled is long, in the second hole type K2, the first hole type K1 The interrupts 28 and 29 formed in the above are shaped so as to be deeper, and the interrupts 38 and 39 are formed. The width of the flange piece at the end of the flange molding process in the rough rolling process is determined based on the dimensions of the interrupts 38 and 39 formed here.

図４は第３孔型Ｋ３の概略説明図である。第３孔型Ｋ３は、一対の水平ロールである上孔型ロール４０と下孔型ロール４１に刻設される。上孔型ロール４０の周面（即ち、第３孔型Ｋ３の上面）には、孔型内部に向かって突出する突起部４５が形成されている。更に、下孔型ロール４１の周面（即ち、第３孔型Ｋ３の底面）には、孔型内部に向かって突出する突起部４６が形成されている。これら突起部４５、４６はテーパー形状を有しており、その突出長さ等の寸法は、突起部４５と突起部４６とでそれぞれ等しく構成されている。 FIG. 4 is a schematic explanatory view of the third hole type K3. The third hole type K3 is engraved on a pair of horizontal rolls, an upper hole type roll 40 and a lower hole type roll 41. A protrusion 45 projecting toward the inside of the hole type is formed on the peripheral surface of the upper hole type roll 40 (that is, the upper surface of the third hole type K3). Further, a protrusion 46 protruding toward the inside of the hole type is formed on the peripheral surface of the prepared hole type roll 41 (that is, the bottom surface of the third hole type K3). These protrusions 45 and 46 have a tapered shape, and the protrusion length and other dimensions are the same for the protrusion 45 and the protrusion 46, respectively.

上記突起部４５、４６の先端部角度θ２は、上記角度θ１ｂに比べ広角に構成され、突起部４５、４６の被圧延材Ａへの侵入深さｈ３は、上記突起部３５、３６の侵入深さｈ２よりも短くなっている（即ち、ｈ３＜ｈ２）。この角度θ２は例えば７０°以上１１０°以下が好ましい。
また、被圧延材Ａの上下端部（スラブ端面）に対向する孔型上面４０ａ、４０ｂ及び孔型底面４１ａ、４１ｂと、突起部４５、４６の傾斜面とのなす角度θｆは、図４に示す４箇所ともに約９０°（略直角）に構成されている。 The tip angle θ2 of the protrusions 45 and 46 is configured to be wider than the angle θ1b, and the penetration depth h3 of the protrusions 45 and 46 into the material to be rolled is the penetration depth of the protrusions 35 and 36. It is shorter than h2 (that is, h3 <h2). The angle θ2 is preferably 70 ° or more and 110 ° or less, for example.
Further, the angle θf formed by the hole-shaped upper surfaces 40a and 40b and the hole-shaped bottom surfaces 41a and 41b facing the upper and lower ends (slab end faces) of the material A to be rolled and the inclined surfaces of the protrusions 45 and 46 is shown in FIG. All four locations shown are configured at approximately 90 ° (approximately right angles).

図４に示すように、第３孔型Ｋ３では、第２孔型Ｋ２通材後の被圧延材Ａに対し、被圧延材Ａの上下端部（スラブ端面）において第２孔型Ｋ２において形成された割り込み３８、３９が、突起部４５、４６が押し当てられることにより、割り込み４８、４９となる。即ち、第３孔型Ｋ３での造形における最終パスでは、割り込み４８、４９の最深部角度（以下、割り込み角度とも呼称する）がθ２となる。換言すると、第２孔型Ｋ２において割り込み３８、３９の形成と共に造形された分割部位（後述するフランジ部８０に対応する部位）が外側に折り曲げられるような造形が行われる。 As shown in FIG. 4, in the third hole type K3, the material to be rolled after the second hole type K2 is passed is formed in the second hole type K2 at the upper and lower ends (slab end faces) of the material A to be rolled. The interrupts 38 and 39 that have been generated become interrupts 48 and 49 when the protrusions 45 and 46 are pressed against the interrupts 38 and 39. That is, in the final path in the modeling with the third hole type K3, the deepest angle of the interrupts 48 and 49 (hereinafter, also referred to as an interrupt angle) is θ2. In other words, in the second hole type K2, the divided portion (the portion corresponding to the flange portion 80 described later) formed together with the formation of the interrupts 38 and 39 is bent outward.

図５は第４孔型Ｋ４の概略説明図である。第４孔型Ｋ４は、一対の水平ロールである上孔型ロール５０と下孔型ロール５１に刻設される。上孔型ロール５０の周面（即ち、第４孔型Ｋ４の上面）には、孔型内部に向かって突出する突起部５５が形成されている。更に、下孔型ロール５１の周面（即ち、第４孔型Ｋ４の底面）には、孔型内部に向かって突出する突起部５６が形成されている。これら突起部５５、５６はテーパー形状を有しており、その突出長さ等の寸法は、突起部５５と突起部５６とでそれぞれ等しく構成されている。 FIG. 5 is a schematic explanatory view of the fourth hole type K4. The fourth hole type K4 is engraved on a pair of horizontal rolls, an upper hole type roll 50 and a lower hole type roll 51. A protrusion 55 projecting toward the inside of the hole type is formed on the peripheral surface of the upper hole type roll 50 (that is, the upper surface of the fourth hole type K4). Further, a protrusion 56 protruding toward the inside of the hole type is formed on the peripheral surface of the prepared hole type roll 51 (that is, the bottom surface of the fourth hole type K4). These protrusions 55 and 56 have a tapered shape, and the protrusion length and other dimensions are the same for the protrusion 55 and the protrusion 56, respectively.

上記突起部５５、５６の先端部角度θ３は、上記角度θ２に比べ広角に構成され、突起部５５、５６の被圧延材Ａへの侵入深さｈ４は、上記突起部４５、４６の侵入深さｈ３よりも短くなっている（即ち、ｈ４＜ｈ３）。この角度θ３は例えば１３０°以上１７０°以下が好ましい。
また、被圧延材Ａの上下端部（スラブ端面）に対向する孔型上面５０ａ、５０ｂ及び孔型底面５１ａ、５１ｂと、突起部５５、５６の傾斜面とのなす角度θｆは、上記第３孔型Ｋ３と同様に、図５に示す４箇所ともに約９０°（略直角）に構成されている。 The tip angle θ3 of the protrusions 55 and 56 is wider than the angle θ2, and the penetration depth h4 of the protrusions 55 and 56 into the material A to be rolled is the penetration depth of the protrusions 45 and 46. It is shorter than h3 (that is, h4 <h3). The angle θ3 is preferably 130 ° or more and 170 ° or less, for example.
Further, the angle θf formed by the hole-shaped upper surfaces 50a and 50b and the hole-shaped bottom surfaces 51a and 51b facing the upper and lower ends (slab end faces) of the material A to be rolled and the inclined surfaces of the protrusions 55 and 56 is the third. Similar to the hole type K3, all four locations shown in FIG. 5 are configured at about 90 ° (substantially right angles).

第４孔型Ｋ４では、第３孔型Ｋ３通材後の被圧延材Ａに対し、被圧延材Ａの上下端部（スラブ端面）において第３孔型Ｋ３において形成された割り込み４８、４９が、突起部５５、５６が押し当てられることにより押し広げられ、割り込み５８、５９となる。即ち、第４孔型Ｋ４での造形における最終パスでは、割り込み５８、５９の最深部角度（以下、割り込み角度とも呼称する）がθ３となる。換言すると、第３孔型Ｋ３において割り込み４８、４９の形成と共に造形された分割部位（後述するフランジ部８０に対応する部位）が更に外側に折り曲げられるような造形が行われる。このようにして造形された被圧延材Ａの上下端部の部位は、後のＨ形鋼製品のフランジに相当する部位であり、ここではフランジ部８０と呼称する。 In the fourth hole type K4, interrupts 48 and 49 formed in the third hole type K3 at the upper and lower ends (slab end faces) of the material to be rolled A with respect to the material A to be rolled after passing through the third hole type K3. , The protrusions 55 and 56 are pressed against each other to be expanded and become interrupts 58 and 59. That is, in the final path in the modeling with the fourth hole type K4, the deepest angle of the interrupts 58 and 59 (hereinafter, also referred to as an interrupt angle) is θ3. In other words, in the third hole type K3, the divided portion (the portion corresponding to the flange portion 80 described later) formed together with the formation of the interrupts 48 and 49 is further bent outward. The portion of the upper and lower ends of the material A to be rolled formed in this way is a portion corresponding to the flange of the later H-shaped steel product, and is referred to here as the flange portion 80.

以上の第１孔型Ｋ１〜第４孔型Ｋ４を用いた圧延造形は、被圧延材Ａを所定の略ドッグボーン形状となるように造形するエッジング圧延工程とも呼称され、矩形断面の素材スラブを立てた状態で実施される。 The rolling molding using the first hole type K1 to the fourth hole type K4 is also referred to as an edging rolling process for forming the material A to be rolled into a predetermined substantially dogbone shape, and a material slab having a rectangular cross section is formed. It is carried out in an upright position.

図６は第５孔型Ｋ５の概略説明図である。第５孔型Ｋ５は、一対の水平ロールである上孔型ロール８５と下孔型ロール８６から構成される。図６に示すように、第５孔型Ｋ５では、第４孔型Ｋ４までに造形された被圧延材Ａが９０°あるいは２７０°回転させられ、第４孔型Ｋ４までは被圧延材Ａの上下端に位置していたフランジ部８０が、圧延ピッチライン上に来るような配置となる。そして、第５孔型Ｋ５では、２か所のフランジ部８０を繋ぐ接続部であるウェブ部８２の圧下が行われる。 FIG. 6 is a schematic explanatory view of the fifth hole type K5. The fifth hole type K5 is composed of a pair of horizontal rolls, an upper hole type roll 85 and a lower hole type roll 86. As shown in FIG. 6, in the 5th hole type K5, the material A to be rolled formed up to the 4th hole type K4 is rotated by 90 ° or 270 °, and up to the 4th hole type K4, the material A to be rolled is rotated. The flange portions 80 located at the upper and lower ends are arranged so as to be on the rolling pitch line. Then, in the fifth hole type K5, the web portion 82, which is a connecting portion connecting the two flange portions 80, is reduced.

ここで、第５孔型Ｋ５の上下孔型ロール８５、８６は、そのロール胴長中央部において所定長さＬ１の窪み部８５ａ、８６ａが形成された形状となっている。このような図６に示す孔型構成により、ウェブ部８２の圧下は部分的に行われることになり、圧下後のウェブ部８２には、ウェブ高さ方向両端の圧下部分８２ａと、その中央部に未圧下部分としての***部８２ｂが形成されることになる。このようにして、いわゆるドッグボーン形状の被圧延材においてウェブ部８２に***部８２ｂを形成する圧延造形が行われる。 Here, the upper and lower hole type rolls 85 and 86 of the fifth hole type K5 have a shape in which recessed portions 85a and 86a having a predetermined length L1 are formed at the central portion of the roll body length. Due to the hole-shaped configuration shown in FIG. 6, the web portion 82 is partially reduced, and the reduced web portion 82 has the reduced portions 82a at both ends in the web height direction and the central portion thereof. A raised portion 82b is formed as an uncompressed portion. In this way, in the so-called dogbone-shaped material to be rolled, rolling molding is performed in which the raised portion 82b is formed on the web portion 82.

なお、この第５孔型Ｋ５では、ウェブ部８２を部分的に圧下し、***部８２ｂを形成されるような圧延造形が実施されることから、当該孔型は「ウェブ部分圧延孔型」あるいは「***部形成孔型」とも呼称される。また、形成後の***部８２ｂの幅長さと同じ長さは上記窪み部８５ａ、８６ａの幅長さＬ１と同じ長さ（後述する逃がし量Ｌ１）となる。ここで、図６の拡大図に示すように、本明細書における窪み部８５ａ、８６ａの幅長さＬ１は、当該窪み部８５ａ、８６ａの深さｈｍの１／２の深さでの幅長さとして規定する。 In the fifth hole type K5, the web portion 82 is partially pressed down to form a raised portion 82b, so that the hole type is a "web partially rolled hole type" or. It is also called "raised portion forming hole type". Further, the same length as the width length of the raised portion 82b after formation is the same length as the width length L1 of the recessed portions 85a and 86a (the relief amount L1 described later). Here, as shown in the enlarged view of FIG. 6, the width length L1 of the recessed portions 85a and 86a in the present specification is a width length at a depth of 1/2 of the depth hm of the recessed portions 85a and 86a. It is specified as a measure.

なお、第５孔型Ｋ５における圧延造形に関し、その圧延造形条件、即ち、逃がし量Ｌ１の具体的な範囲や、窪み部８５ａ、８６ａの深さｈｍに関する好適な数値範囲、第５孔型Ｋ５において圧下部分８２ａをどの程度の厚みまで圧下することが好適であるか、といった種々の条件については、本発明者らが得られた知見等に基づき、本実施の形態での説明においてより詳しく後述する。 Regarding the rolling molding in the 5th hole type K5, the rolling molding conditions, that is, the specific range of the relief amount L1, the suitable numerical range regarding the depth hm of the recesses 85a and 86a, and the 5th hole type K5. Various conditions such as to what thickness it is preferable to roll the rolling portion 82a will be described in more detail in the description of the present embodiment based on the findings obtained by the present inventors. ..

図７は第６孔型Ｋ６の概略説明図である。第６孔型Ｋ６は、一対の水平ロールである上孔型ロール９５と下孔型ロール９６から構成される。第６孔型Ｋ６では、第５孔型Ｋ５において圧延造形された被圧延材Ａに対し、ウェブ部８２に形成された***部８２ｂを消去するように圧下が行われ、また、圧下部分８２ａに対する更なる圧下も行われ、且つ、ウェブ部８２の内法を拡幅するような圧延造形が複数パス圧延により行われる。 FIG. 7 is a schematic explanatory view of the sixth hole type K6. The sixth hole type K6 is composed of a pair of horizontal rolls, an upper hole type roll 95 and a lower hole type roll 96. In the sixth hole type K6, the material A to be rolled formed in the fifth hole type K5 is reduced so as to eliminate the raised portion 82b formed on the web portion 82, and the rolling portion 82a is reduced. Further rolling is performed, and rolling modeling is performed by multiple-pass rolling so as to widen the inner method of the web portion 82.

この第６孔型Ｋ６においては、ウェブ部８２に形成された***部８２ｂに上下孔型ロール９５、９６を当接させて当該***部８２ｂを圧下（消去）する圧延が行われる。また、併せて圧下部分８２ａに対する更なる圧下も行われる。この第６孔型Ｋ６による圧延造形により、***部８２ｂの圧下に伴うウェブ高さ方向への拡がり及びフランジ部８０へのメタルフローを促進させ、フランジ減面をなるべく生じさせずに圧延造形を実施することが可能となる。また、フランジ減面をなるべく生じさせないといった観点から、この第６孔型Ｋ６の孔型構成は、圧延ピッチライン上に位置するフランジ部８０の外側面を拘束するような形状であることが好ましい。即ち、上下孔型ロール９５、９６には、フランジ部８０の外側面に当接するような側壁が設けられていることが好ましい。
この第６孔型Ｋ６は、ウェブ部８２に形成された***部８２ｂを消去することから、「***部消去孔型」とも呼称される。 In the sixth hole type K6, rolling is performed in which the upper and lower hole type rolls 95 and 96 are brought into contact with the raised portion 82b formed on the web portion 82 to reduce (erase) the raised portion 82b. At the same time, further reduction with respect to the reduction portion 82a is performed. By rolling molding with the sixth hole type K6, the expansion in the web height direction and the metal flow to the flange portion 80 due to the reduction of the raised portion 82b are promoted, and the rolling molding is carried out without causing the flange reduction surface as much as possible. It becomes possible to do. Further, from the viewpoint of preventing the flange reduction as much as possible, the hole type configuration of the sixth hole type K6 is preferably shaped so as to restrain the outer surface of the flange portion 80 located on the rolling pitch line. That is, it is preferable that the upper and lower hole type rolls 95 and 96 are provided with a side wall that abuts on the outer surface of the flange portion 80.
This sixth hole type K6 is also referred to as a "raised portion erasing hole type" because it erases the raised portion 82b formed on the web portion 82.

また、上述してきた第１孔型Ｋ１〜第６孔型Ｋ６を経た被圧延材Ａに対しては、必要に応じて更なるウェブ部８２の厚み圧下や拡幅圧延を行っても良い。この場合には、第６孔型Ｋ６での圧延造形の後段において、１又は複数の拡幅用孔型を用いた拡幅圧延を行えば良い。なお、その場合の厚み圧下や拡幅圧延のための孔型は、従来より既知の孔型であるため、本明細書での拡幅圧延用の孔型の説明は省略する。 Further, the material A to be rolled that has passed through the first-hole type K1 to the sixth-hole type K6 described above may be further reduced in thickness of the web portion 82 or widened and rolled, if necessary. In this case, widening rolling may be performed using one or a plurality of widening hole molds in the subsequent stage of rolling molding with the sixth hole mold K6. Since the hole type for thickness reduction and widening rolling in that case is a conventionally known hole type, the description of the hole type for widening rolling is omitted in the present specification.

以上の第５孔型Ｋ５、第６孔型Ｋ６（及び必要に応じた拡幅用孔型）を用いた圧延造形は、エッジング圧延工程で造形された被圧延材Ａを９０°あるいは２７０°回転させた略Ｈ形姿勢で実施されることから、平圧延造形あるいは平圧延工程とも呼称される。 In the rolling molding using the above-mentioned 5th hole type K5 and 6th hole type K6 (and the hole type for widening if necessary), the material A to be rolled formed in the edging rolling process is rotated by 90 ° or 270 °. Since it is carried out in a substantially H-shaped posture, it is also called a plan rolling molding or a plan rolling process.

上述してきた第１孔型Ｋ１〜第６孔型Ｋ６や必要に応じた拡幅圧延用孔型を用いて、図１に示すＨ形粗形材１３が造形される。このように造形されたＨ形粗形材１３に対し、既知の圧延機である中間ユニバーサル圧延機５−エッジャー圧延機９の２つの圧延機からなる圧延機列を用いて、複数パスのリバース圧延が加えられ、中間材１４が造形される。そして中間材１４は、仕上ユニバーサル圧延機８において製品形状に仕上圧延され、Ｈ形鋼製品１６が製造される（図１参照）。 The H-shaped rough shape member 13 shown in FIG. 1 is formed by using the first hole type K1 to the sixth hole type K6 and the hole type for widening rolling as needed. Reverse rolling of a plurality of passes is performed on the H-shaped rough profile 13 thus formed by using a rolling mill row consisting of two rolling mills, an intermediate universal rolling mill 5-edger rolling mill 9, which is a known rolling mill. Is added, and the intermediate material 14 is formed. Then, the intermediate material 14 is finished and rolled into a product shape in the finishing universal rolling mill 8, and an H-shaped steel product 16 is manufactured (see FIG. 1).

上述したように、本実施の形態にかかるＨ形鋼の製造方法では、第１孔型Ｋ１〜第４孔型Ｋ４を用いて被圧延材Ａの上下端部（スラブ端面）に割り込みを入れ、それら割り込みによって左右に分かれた各部分を左右に折り曲げる加工を行い、フランジ部８０を形成するといった造形をすることで、被圧延材Ａ（スラブ）の上下端面をほぼ上下方向に圧下することなくＨ形粗形材１３の造形を行うことができる。即ち、従来行われていたスラブ端面を常に圧下する粗圧延方法に比べ、フランジ幅を広幅化させてＨ形粗形材１３を造形することが可能となり、その結果、フランジ幅の大きな最終製品（Ｈ形鋼）を製造することができる。 As described above, in the method for producing H-shaped steel according to the present embodiment, the first-hole type K1 to the fourth-hole type K4 are used to interrupt the upper and lower ends (slab end faces) of the material A to be rolled. By bending each part divided into left and right by these interruptions to form a flange portion 80, the upper and lower end surfaces of the material A (slab) to be rolled are not pressed down in the vertical direction. The rough shape member 13 can be shaped. That is, it is possible to form the H-shaped rough profile 13 by widening the flange width as compared with the conventional rough rolling method in which the end face of the slab is always pressed, and as a result, the final product having a large flange width ( H-shaped steel) can be manufactured.

ここで本発明者らは、本実施の形態に係る第５孔型Ｋ５及び第６孔型Ｋ６による圧延造形に関し、更なる検討を行ったところ、第５孔型Ｋ５での圧延造形によって形成された***部８２ｂを消去する第６孔型Ｋ６による圧延造形時には、通材不良が発生する場合があり、その通材不良により被圧延材Ａの形状が崩れてしまう場合があることが知見された。また、***部８２ｂを消去する場合には部分的な圧延となることから、第６孔型Ｋ６による圧延造形時には被圧延材Ａの非定常部において長手方向への延伸が生じやすく、クロップの成長に繋がり、フランジ断面積の減少が懸念されて長手方向での寸法変動が生じることも知見された。 Here, the present inventors further examined the rolling molding by the 5th hole type K5 and the 6th hole type K6 according to the present embodiment, and found that they were formed by the rolling molding by the 5th hole type K5. It has been found that during rolling molding by the sixth hole type K6 that eliminates the raised portion 82b, a material passing defect may occur, and the shape of the material to be rolled A may be deformed due to the material passing defect. .. Further, since the raised portion 82b is partially rolled, stretching in the longitudinal direction is likely to occur in the unsteady portion of the material A to be rolled during rolling molding by the sixth hole type K6, and the crop grows. It was also found that dimensional fluctuations occur in the longitudinal direction due to concerns about a decrease in the cross-sectional area of the flange.

上記のような知見に鑑み、本発明者らは、第６孔型Ｋ６による***部８２ｂを消去する圧延造形において、通材不良が発生せず、また、被圧延材Ａの長手方向における寸法変動を抑制させ、定常部のみならず非定常部においてもフランジ断面積の減少を抑制させてフランジ幅及びフランジ厚みの大きなＨ形粗形材を安定的に圧延造形することが可能となるような条件についてより詳細な検討を行った。以下、本検討について図面やグラフ等を参照して説明する。 In view of the above findings, the present inventors did not cause a material passing defect in the rolling molding in which the raised portion 82b by the sixth hole type K6 was eliminated, and the dimensional variation in the longitudinal direction of the material A to be rolled. Conditions that enable stable rolling and shaping of H-shaped rough shaped materials with large flange width and flange thickness by suppressing the decrease in flange cross-sectional area not only in the stationary portion but also in the unsteady portion. Was examined in more detail. Hereinafter, this study will be described with reference to drawings, graphs, and the like.

（ウェブ内法における逃がし量（***部形成幅）の比率）
上述した通り、本実施の形態に係る第５孔型Ｋ５（図６参照）では、被圧延材Ａのウェブ部８２の中央に***部８２ｂが形成され、形成された***部８２ｂは、後段の第６孔型Ｋ６において消去される。そして、***部消去後に必要に応じてウェブ内法の拡幅圧延が行われ、Ｈ形粗形材が造形されるが、従来に比べフランジ幅の大きな大型Ｈ形鋼製品を製造するためには、Ｈ形粗形材のフランジ幅もできるだけ大きくすることが望まれる。
本発明者らは、第５孔型Ｋ５において形成する***部８２ｂの幅長さＬ１（即ち、第５孔型Ｋ５での圧延造形におけるウェブ内法の逃がし量）を変えることで、最終的に得られるＨ形粗形材のフランジ幅に違いが出ることを見出した。これは、***部８２ｂの幅長さを大きくする程フランジ肉量が確保しやすい反面、後の***部消去時（第６孔型Ｋ６での圧延造形）において被圧延材Ａの長手方向延伸作用によってフランジ幅が減少することに起因する。 (Ratio of relief amount (raised portion formation width) in the in-web method)
As described above, in the fifth hole type K5 (see FIG. 6) according to the present embodiment, the raised portion 82b is formed in the center of the web portion 82 of the material A to be rolled, and the formed raised portion 82b is in the subsequent stage. It is erased in the sixth hole type K6. Then, after erasing the raised portion, widening rolling is performed by the in-web method as necessary to form an H-shaped rough shaped material. However, in order to manufacture a large H-shaped steel product having a larger flange width than before, It is desirable to increase the flange width of the H-shaped rough material as much as possible.
The present inventors finally change the width and length L1 of the raised portion 82b formed in the fifth hole type K5 (that is, the amount of relief of the method in the web in the rolling molding in the fifth hole type K5). It was found that there is a difference in the flange width of the obtained H-shaped rough material. The larger the width and length of the raised portion 82b, the easier it is to secure the amount of flange wall thickness. This is due to the decrease in flange width.

そこで、本発明者らは、第５孔型Ｋ５での圧延造形におけるウェブ内法の逃がし量（以下、単に「逃がし量Ｌ１」とも記載）の好適な範囲を定めるべく、逃がし率とＨ形粗形材造形後のフランジ幅の増減との関係に着目し、逃がし率の好適な数値範囲を導き出した。なお、逃がし率とは以下の式（１）で定義される値である。
逃がし率［％］＝（逃がし量Ｌ１／ウェブ内法Ｌ２）×１００ ・・・（１） Therefore, the present inventors have determined the relief rate and the coarseness of the H-shape in order to determine a suitable range of the relief amount (hereinafter, also simply referred to as “relief amount L1”) of the in-web method in rolling molding with the fifth hole type K5. Focusing on the relationship with the increase / decrease in the flange width after molding the shape material, a suitable numerical range of the relief rate was derived. The relief rate is a value defined by the following equation (1).
Relief rate [%] = (Relief amount L1 / Web method L2) × 100 ・ ・ ・ (1)

図８は、逃がし率とＨ形粗形材造形後のフランジ幅増減率との関係を示すグラフである。なお、図８におけるフランジ幅増減率とは、逃がし率が０％である場合のフランジ幅を基準（１．０００）として、逃がし率が各値（１２％〜５６％）である場合のフランジ幅を示した値である。 FIG. 8 is a graph showing the relationship between the relief rate and the flange width increase / decrease rate after molding the H-shaped rough shape material. The flange width increase / decrease rate in FIG. 8 is the flange width when the relief rate is each value (12% to 56%) with the flange width as a reference (1.000) when the relief rate is 0%. It is a value indicating.

図８に示すように、逃がし率が大きくなるとＨ形粗形材のフランジ幅を増大する傾向にあるが、逃がし率が約２５％以上となった領域ではフランジ幅増減はほぼ一定値（グラフ中の破線部参照）となっている。
図８に示す結果から、従来に比べフランジ幅の大きな大型Ｈ形鋼製品を製造する場合には、Ｈ形粗形材のフランジ幅も大きくなるような圧延造形が所望されることに鑑み、逃がし率の数値範囲は２５％〜５０％とすることが望ましいことが分かる。 As shown in FIG. 8, when the relief rate increases, the flange width of the H-shaped rough profile material tends to increase, but in the region where the relief rate is about 25% or more, the increase / decrease in the flange width is almost a constant value (in the graph). (Refer to the broken line part of).
From the results shown in FIG. 8, when manufacturing a large H-shaped steel product having a larger flange width than the conventional one, it is desired to perform rolling molding so that the flange width of the H-shaped rough profile member is also large. It can be seen that the numerical range of the rate is preferably 25% to 50%.

（***部消去時の通材性）
上述したように、***部８２ｂを形成する際の逃がし率の数値範囲は２５％〜５０％とすることが望ましいことが図８の結果から分かっているが、一方で、このような数値範囲の逃がし率で***部８２ｂを形成する際のウェブの圧下部分８２ａの厚みの値については更なる検討を行う必要がある。これは、***部８２ｂを形成した後に、当該***部８２ｂを消去するための圧延造形を第６孔型Ｋ６で実施する際に、圧下部分８２ａが薄すぎ、***部８２ｂのメタル移動が断面内で行われず、被圧延材Ａの長手方向へのメタル移動が生じてしまった結果であると推定される。 (Material permeability when erasing the raised part)
As described above, it is known from the results of FIG. 8 that the numerical range of the relief rate when forming the raised portion 82b is preferably 25% to 50%, but on the other hand, such a numerical range It is necessary to further study the value of the thickness of the reduced portion 82a of the web when the raised portion 82b is formed by the relief rate. This is because, after forming the raised portion 82b, when rolling molding for erasing the raised portion 82b is performed with the sixth hole type K6, the rolling down portion 82a is too thin and the metal movement of the raised portion 82b is within the cross section. It is presumed that this is a result of metal movement in the longitudinal direction of the material A to be rolled, which was not performed in the above.

そこで本発明者らは、素材として２０００×３００ｍｍの矩形断面スラブを用いて、製品フランジ幅４００ｍｍ以上のＨ形鋼を製造する場合に、本実施の形態に係る第１孔型Ｋ１〜第６孔型Ｋ６により圧延造形を行うに際し、第５孔型Ｋ５での圧延造形時のウェブ圧下量を変えた条件で造形性（圧延安定性）の評価を行った。具体的な条件としては、圧下部分８２ａの圧下後厚みを２００ｍｍ、１６０ｍｍ、１４０ｍｍ、１２０ｍｍ、１００ｍｍとした場合をそれぞれ水準１〜５とした。なお、比較水準として***部８２ｂを形成せずにウェブ厚み圧下を実施する場合を水準６とした。 Therefore, the present inventors use the first hole type K1 to the sixth hole according to the present embodiment when manufacturing an H-shaped steel having a product flange width of 400 mm or more by using a rectangular cross-section slab having a size of 2000 × 300 mm as a material. When rolling and molding with the mold K6, the formability (rolling stability) was evaluated under the condition that the amount of web reduction during rolling and molding with the fifth hole mold K5 was changed. As specific conditions, the cases where the thickness after the reduction of the reduction portion 82a was 200 mm, 160 mm, 140 mm, 120 mm, and 100 mm were set to levels 1 to 5, respectively. As a comparative level, the case where the web thickness reduction was performed without forming the raised portion 82b was set as level 6.

以下に示す表１は、上記水準１〜水準６のパススケジュールを示すものであり、表中の各孔型Ｇ１、Ｇ２−２、Ｇ３−１、Ｇ３−２、Ｇ４−１、Ｇ４−２は、本実施の形態で説明した第１孔型Ｋ１〜第６孔型Ｋ６に相当する。また、造形性の評価については、表１の最下段に記載し、通材不良・形状不良が発生した場合を「不良」、通材不良・形状不良が発生しなかった場合を「良好」としている。 Table 1 shown below shows the path schedules of the above levels 1 to 6, and the hole types G1, G2-2, G3-1, G3-2, G4-1, and G4-2 in the table are shown. , Corresponds to the first hole type K1 to the sixth hole type K6 described in the present embodiment. In addition, the evaluation of formability is described in the bottom of Table 1, and the case where the material passing defect / shape defect occurs is regarded as "defective", and the case where the material passing defect / shape defect does not occur is regarded as "good". There is.

Figure 0006973146
Figure 0006973146

表１に示すように、圧下部分８２ａの圧下後厚みを２００ｍｍ、１６０ｍｍ、１４０ｍｍとした場合（水準１〜３）には、***部８２ｂの消去時において通材不良・形状不良は発生していない。一方で、圧下部分８２ａの圧下後厚みを１２０ｍｍ、１００ｍｍとした場合（水準４、５）には、***部８２ｂの消去時において通材不良・形状不良が発生している。また、***部８２ｂを形成させずにウェブ厚み圧下を１００ｍｍまで実施した場合（水準６）も、同様の通材不良・形状不良が発生している。 As shown in Table 1, when the reduced thickness of the reduced portion 82a is 200 mm, 160 mm, and 140 mm (levels 1 to 3), no material passing defect or shape defect occurs when the raised portion 82b is erased. .. On the other hand, when the thickness after the reduction of the reduction portion 82a is 120 mm and 100 mm (levels 4 and 5), poor material passage and poor shape occur when the raised portion 82b is erased. Further, even when the web thickness reduction is carried out up to 100 mm (level 6) without forming the raised portion 82b, the same material passing defect and shape defect occur.

ここで、造形性（圧延安定性）の評価基準について説明する。造形性の評価は、***部８２ｂを消去する圧延造形を実施した際に、被圧延材Ａの長手方向に生じる反りに基づき行われる。
図９は、被圧延材Ａの反りに関する説明図であり、被圧延材Ａの長手方向端部において反りが生じた際の概略側面図である。図９に示すように、被圧延材Ａの長手方向端部において反りが生じた際の端部と定常部との差異が「反り量」として規定される。そして、被圧延材Ａにおいて反りが発生した長手方向長さに対し発生した反り量の比率が以下の式（２）で定義される「反り（％）」とされる。
反り［％］＝反り量／反りの発生した被圧延材長さ ・・・（２） Here, the evaluation criteria for formability (rolling stability) will be described. The evaluation of the formability is performed based on the warp generated in the longitudinal direction of the material A to be rolled when the rolling molding for erasing the raised portion 82b is performed.
FIG. 9 is an explanatory view regarding the warp of the material A to be rolled, and is a schematic side view when the warp occurs at the longitudinal end portion of the material A to be rolled. As shown in FIG. 9, the difference between the end portion and the stationary portion when warpage occurs at the longitudinal end portion of the material A to be rolled is defined as the “warp amount”. Then, the ratio of the amount of warpage generated to the length in the longitudinal direction in which the warp occurs in the material A to be rolled is defined as "warp (%)" defined by the following formula (2).
Warp [%] = Warp amount / Length of material to be rolled with warp ... (2)

上述した式（２）で定義される「反り（％）」と、圧下部分８２ａの圧下後厚みとの関係について検証した。図１０は、反りとウェブ厚み（圧下部分８２ａの圧下後厚み）との関係を示したグラフである。なお、図１０に示すグラフは、逃がし率を約３３％とした条件でのデータである。 The relationship between the "warp (%)" defined by the above-mentioned equation (2) and the post-compression thickness of the reduction portion 82a was verified. FIG. 10 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. 10 is data under the condition that the relief rate is about 33%.

図１０に示すように、圧下部分８２ａの圧下後厚みが薄くなる程、反りが大きくなる傾向が有る。特に、圧下部分８２ａの圧下後厚みが１４０ｍｍ以下である場合には反りが約３％以下と小さく、圧下部分８２ａの圧下後厚みが１４０ｍｍ超となると反りが約１０％以上と大きくなり形状の悪化が著しいことが分かっている。
操業上、被圧延材Ａで生じた反りが１０％以上となると、次パス以降での寸法形状悪化が著しく圧延続行が困難である。即ち、図１０に示す結果から、ウェブ厚み（圧下部分８２ａの圧下後厚み）を１４０ｍｍ以上となるように第５孔型Ｋ５での圧延造形を行うことで、良好な造形性が担保されることが分かる。これは、表１に示す水準１〜３の条件で造形性が良好であることと一致する。 As shown in FIG. 10, the thinner the reduced thickness of the reduced portion 82a after reduction, the larger the warp tends to be. In particular, when the reduced thickness of the reduced portion 82a is 140 mm or less, the warp is as small as about 3% or less, and when the reduced thickness of the reduced portion 82a exceeds 140 mm, the warp becomes large as about 10% or more and the shape deteriorates. Is known to be remarkable.
In terms of operation, if the warp generated in the material A to be rolled is 10% or more, the dimensional shape deteriorates significantly after the next pass, and it is difficult to continue rolling. That is, from the results shown in FIG. 10, good formability is ensured by performing rolling molding with the fifth hole type K5 so that the web thickness (thickness after rolling of the reduced portion 82a) is 140 mm or more. I understand. This is consistent with the good formability under the conditions of levels 1 to 3 shown in Table 1.

ここで、反りに係る閾値を１０％としているのは、被圧延材の端部数ｍに対し、１０％の割合で数百ｍｍ程度の最大反り量が発生した場合に、上下肉量差異が発生することが当業者には容易に確認されることであり、操業上、圧延続行が困難となることが明らかな値が１０％であるからである。
なお、同条件下において反りが数％（１０％未満）である場合には、数十ｍｍ程度の反りが通常操業にて観察されるが、操業上問題無い程度であることは当業者であれば容易に推察することが可能である。 Here, the threshold value for warpage is set to 10% because a difference in the amount of upper and lower meat is generated when a maximum warp amount of about several hundred mm is generated at a rate of 10% with respect to the number of ends m of the material to be rolled. This is because it is easily confirmed by those skilled in the art, and the value at which it is clear that it is difficult to continue rolling in terms of operation is 10%.
If the warp is several percent (less than 10%) under the same conditions, a warp of about several tens of mm is observed in normal operation, but it should be a matter of skill in the art that there is no problem in operation. It can be easily inferred.

図１０から分かる通り、第６孔型Ｋ６での圧延造形において、圧下部分８２ａに反りが発生しないような最小の圧下後厚みは１４０ｍｍであるため、この時の***部８２ｂの延伸λは２．１４（＝３００／１４０）である。
なお、第５孔型Ｋ５においてウェブ厚み（圧下部分８２ａの圧下後厚み）を所定の値（例えば１４０ｍｍ）以上となるようにした場合、後段の第６孔型Ｋ６においてウェブ厚みが更に薄くなるようなウェブの減厚圧下を行っても良い。 As can be seen from FIG. 10, in the rolling molding with the sixth hole type K6, the minimum thickness after rolling so that the rolling portion 82a does not warp is 140 mm, so that the stretching λ of the raised portion 82b at this time is 2. 14 (= 300/140).
When the web thickness (thickness after reduction of the reduction portion 82a) is set to a predetermined value (for example, 140 mm) or more in the fifth hole type K5, the web thickness is further reduced in the sixth hole type K6 in the subsequent stage. You may perform thickening and reducing of the web.

また、図１１は、第５孔型Ｋ５における圧下部分８２ａの圧下後厚み（圧下後の仕上りウェブ厚）と、***部８２ｂの圧下を行う前の高さとの関係を示すグラフである。図８を参照して上述した「逃がし率」を好適な条件に設定（例えば２５％〜５０％）した場合、***部８２ｂの長手方向への延伸作用は小さく、孔型によって***部高さに制約を加えない限り、***部高さは素材のスラブ厚のままである。
例えば、スラブ厚が３００ｍｍ、***部８２ｂの高さを十分な高さに孔型を取った場合、***部高さは３００ｍｍのままである。その状態から、***部消去孔型（図７の第６孔型Ｋ６）において***部８２ｂの消去をしたところ、第５孔型Ｋ５での圧下後仕上りウェブ厚が１４０ｍｍのケースでは通材性に問題はなかったが、１３０ｍｍのケースでは通材不良が発生した。これらのケースでは***部８２ｂの厚みはいずれも３００ｍｍとなっており、***部８２ｂの延伸は１４０ｍｍの場合、３００ｍｍから１４０ｍｍまで圧下されるので２．１４であり、１３０ｍｍの場合、３００ｍｍから１３０ｍｍまで圧下されるので２．３１である。同様に種々のケースについてプロットすると、図１１に示すように、通材不良の閾値を示す限界延伸はいずれも２．１程度となっている。 Further, FIG. 11 is a graph showing the relationship between the thickness of the reduced portion 82a after reduction (the thickness of the finished web after reduction) and the height of the raised portion 82b before reduction in the fifth hole type K5. When the above-mentioned "relief rate" is set to a suitable condition (for example, 25% to 50%) with reference to FIG. 8, the stretching action of the raised portion 82b in the longitudinal direction is small, and the height of the raised portion is increased by the hole type. Unless constrained, the height of the ridge remains the slab thickness of the material.
For example, when the slab thickness is 300 mm and the height of the raised portion 82b is formed into a hole shape to a sufficient height, the height of the raised portion remains at 300 mm. From that state, when the raised portion 82b was erased in the raised portion erasing hole type (6th hole type K6 in FIG. 7), the material permeability was improved in the case where the finished web thickness after reduction in the 5th hole type K5 was 140 mm. There was no problem, but in the case of 130 mm, poor material flow occurred. In 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 from 300 mm to 130 mm in the case of 130 mm. It is 2.31 because it is overwhelmed. Similarly, when plotting for various cases, as shown in FIG. 11, the limit stretch indicating the threshold value of poor material passage is about 2.1.

即ち、図１１に示すように、第６孔型Ｋ６での***部消去の際の圧下率（延伸）が２．１超となる場合、通材不良（図１１中の×）が生じることが実験的に明らかとなっている。第６孔型Ｋ６での***部消去の際の圧下率が２．１以下となるような条件で孔型設計を行うことで、通材不良を生じさせることなく、第５孔型Ｋ５及び第６孔型Ｋ６による圧延造形を実施することが可能であることが分かる。なお、第６孔型Ｋ６での***部消去圧延を行った後、更にウェブの厚み圧下が必要な場合には、第６孔型Ｋ６での圧延造形の後段において、１又は複数の拡幅用孔型を用いた拡幅圧延を行えば良い。 That is, as shown in FIG. 11, when the reduction rate (stretching) at the time of erasing the raised portion in the sixth hole type K6 exceeds 2.1, poor material passage (x in FIG. 11) may occur. It has been clarified experimentally. By designing the hole type under the condition that the rolling reduction rate at the time of eliminating the raised portion in the sixth hole type K6 is 2.1 or less, the fifth hole type K5 and the fifth hole type K5 and the first It can be seen that it is possible to carry out rolling modeling with the 6-hole type K6. If it is necessary to further reduce the thickness of the web after performing erasing rolling of the raised portion in the 6-hole type K6, one or a plurality of widening holes may be formed in the latter stage of the rolling molding in the 6-hole type K6. Widening rolling using a mold may be performed.

（***部消去時の長手方向寸法変動への対策）
また、本発明者らは、上述した第５孔型Ｋ５及び第６孔型Ｋ６を用いた圧延造形技術では、被圧延材Ａの定常部と非定常部とで長手方向への拘束力が異なっていることから、断面内のメタルフローが定常部と非定常部で変化し、長手方向で圧延造形後のウェブ高さが大きく変化することを見出した。即ち、第６孔型Ｋ６における圧延造形では、被圧延材Ａの非定常部では端部の拘束がないために、***部８２ｂの圧下が長手方向へのメタルフローを生じさせやすく、ウェブ内法（ウェブ高さ）が定常部とは異なってしまう。このような被圧延材Ａの非定常部と定常部の断面形状の差異（長手方向での寸法変動）は、次工程以降の孔型との孔型形状マッチングが不十分となることから好ましくない。図１２は、上述した第５孔型Ｋ５及び第６孔型Ｋ６を用いた圧延造形技術の一例として、２０００×３００ｍｍの矩形断面スラブ素材を用いて、以下の表２に示すロール諸元でもって製品フランジ幅４００ｍｍ以上のＨ形鋼を製造する場合において、第６孔型Ｋ６での圧延前と圧延後の被圧延材ウェブ高さの変化を示すグラフである。 (Countermeasures against longitudinal dimensional fluctuations when erasing raised parts)
Further, in the rolling molding technique using the 5th hole type K5 and the 6th hole type K6 described above, the present inventors have different binding forces in the longitudinal direction between the stationary portion and the unsteady portion of the material A to be rolled. Therefore, it was found that the metal flow in the cross section changes between the stationary part and the unsteady part, and the web height after rolling and molding changes greatly in the longitudinal direction. That is, in the rolling molding in the sixth hole type K6, since there is no restraint of the end portion in the non-steady portion of the material A to be rolled, the rolling down of the raised portion 82b tends to cause a metal flow in the longitudinal direction, which is the method in the web. (Web height) is different from the stationary part. Such a difference in cross-sectional shape (dimensional variation in the longitudinal direction) between the non-stationary portion and the stationary portion of the material A to be rolled is not preferable because the hole shape matching with the hole shape in the next and subsequent steps is insufficient. .. FIG. 12 shows, as an example of the rolling molding technique using the above-mentioned 5th hole type K5 and 6th hole type K6, using a 2000 × 300 mm rectangular cross-section slab material with the roll specifications shown in Table 2 below. It is a graph which shows the change of the web height of the material to be rolled before and after rolling in the 6th hole type K6 in the case of manufacturing H-section steel with a product flange width of 400 mm or more.

Figure 0006973146
なお、表中の各孔型Ｇ１、Ｇ２−２、Ｇ３−１、Ｇ３−２、Ｇ４−１、Ｇ４−２は、本実施の形態で説明した第１孔型Ｋ１〜第６孔型Ｋ６に相当する。
Figure 0006973146
 The hole types G1, G2-2, G3-1, G3-2, G4-1, and G4-2 in the table are the same as the first hole type K1 to the sixth hole type K6 described in the present embodiment. Equivalent to.

図１２に示すように、被圧延材Ａの長手方向において、圧延後のウェブ高さは定常部と非定常部（トップ端及びボトム端）で大きく異なっている。即ち、外法寸法の違いは内法寸法の違いに繋がり、後段の拡幅圧延の安定性等に悪影響を及ぼす恐れがある。また、寸法精度の悪化によりクロップの増大が懸念され生産性が低下する恐れがある。 As shown in FIG. 12, in the longitudinal direction of the material A to be rolled, the height of the web after rolling is significantly different between the stationary portion and the unsteady portion (top end and bottom end). That is, the difference in the outer dimension may lead to the difference in the inner dimension, which may adversely affect the stability of the widening rolling in the subsequent stage. In addition, there is a concern that crops will increase due to deterioration of dimensional accuracy, and productivity may decrease.

このような知見に基づき、本発明者らは第６孔型Ｋ６の孔型設計において、圧延造形時にフランジ部８０の外側面同士の間隔（外法寸法）を所定の値以下の一定寸法に抑えるための孔型側壁１００（１００ａ、１００ｂ）を設けることとしている（図７参照）。ここで、左右の孔型側壁１００ａ、１００ｂ間の間隔は、当該孔型側壁を設けない場合の圧延後のウェブ高さ（幅拡がり量）の最小値よりも小さい間隔に設計することが好ましい。これにより、ウェブ外法の大きい定常部の断面に対して孔型を積極的に接触させることで被圧延材の長手方向の寸法変動を抑えることができる。具体的には、第６孔型Ｋ６における左右の側壁１００ａ、１００ｂ間の距離Ｌ３（図７参照）を、被圧延材Ａの非定常部のウェブ外法以下に設定することで、被圧延材Ａの外法が全長に亘って孔型に接触することになる。これにより、第６孔型Ｋ６での圧延造形後のウェブ高さを、長手方向において所定の一定の値に揃えることが可能となり、寸法精度の向上やクロップ抑制を図ることができる。なお、左右の側壁１００ａ、１００ｂ間の距離Ｌ３は、被圧延材Ａの外法の最大箇所に対向する左右の孔型側壁部間の距離で規定される。 Based on such knowledge, the present inventors suppress the distance (external dimension) between the outer surfaces of the flange portions 80 to a constant dimension of a predetermined value or less at the time of rolling molding in the hole type design of the sixth hole type K6. Hole-shaped side walls 100 (100a, 100b) for this purpose are provided (see FIG. 7). Here, it is preferable to design the distance between the left and right hole-shaped side walls 100a and 100b to be smaller than the minimum value of the web height (width expansion amount) after rolling when the hole-shaped side wall is not provided. As a result, it is possible to suppress dimensional fluctuations in the longitudinal direction of the material to be rolled by positively contacting the hole mold with respect to the cross section of the large stationary portion of the web outer method. Specifically, by setting the distance L3 (see FIG. 7) between the left and right side walls 100a and 100b in the sixth hole type K6 to be equal to or less than the web outer method of the non-stationary portion of the material A to be rolled, the material to be rolled The outer method of A comes into contact with the hole shape over the entire length. As a result, the height of the web after rolling and molding in the sixth hole type K6 can be made uniform to a predetermined constant value in the longitudinal direction, and dimensional accuracy can be improved and cropping can be suppressed. The distance L3 between the left and right side walls 100a and 100b is defined by the distance between the left and right hole-shaped side walls facing the maximum portion of the outer method of the material A to be rolled.

（***部形成孔型の内法と***部消去孔型の内法との関係）
上述したように、第６孔型Ｋ６での圧延造形では、当該孔型に側壁を設けて圧延造形後の被圧延材Ａのウェブ高さ（即ち、被圧延材外法）を所定の値に揃えることが好ましいが、その場合、フランジ肉量（平均フランジ幅×平均フランジ厚）をできるだけ多く確保するとの観点からは、第５孔型Ｋ５の内法と第６孔型Ｋ６の内法との関係を好適なものとすることが望ましい。 (Relationship between the internal method of the raised portion forming hole type and the internal method of the raised portion erasing hole type)
As described above, in the rolling molding with the sixth hole mold K6, the web height of the material A to be rolled (that is, the method outside the material to be rolled) is set to a predetermined value by providing a side wall in the hole mold. It is preferable to align them, but in that case, from the viewpoint of securing as much flange thickness (average flange width x average flange thickness) as possible, the inner method of the 5th hole type K5 and the inner method of the 6th hole type K6 are used. It is desirable that the relationship be suitable.

本発明者らは、以下に説明する検証結果に基き、第６孔型Ｋ６（***部消去孔型）の内法を第５孔型Ｋ５（***部形成孔型）の内法未満とすることで、最終的に残存するフランジ肉量の増量化が図られるとの知見を見出した。以下、本知見について説明する。 Based on the verification results described below, the present inventors shall make the internal method of the 6th hole type K6 (raised portion erasing hole type) less than the internal method of the 5th hole type K5 (raised portion forming hole type). Therefore, we found that the amount of flange meat that remains in the end can be increased. Hereinafter, this finding will be described.

図１３は、第５孔型Ｋ５の内法と第６孔型Ｋ６の内法を等しくした場合（従来孔型）と、第６孔型Ｋ６の内法を第５孔型Ｋ５の内法未満とした場合（本発明孔型）の、圧延造形後のフランジ部形状を示す解析図である。図１３には、第６孔型Ｋ６での圧延造形前形状（即ち、第５孔型Ｋ５での圧延造形後形状）を元形状として図示し、従来孔型による圧延造形後形状を実線、本発明孔型による圧延造形後形状をメッシュで図示している。なお、本発明孔型では第６孔型Ｋ６の内法を第５孔型Ｋ５の内法に比べ５０ｍｍ減じた設計を採っている。 FIG. 13 shows a case where the internal method of the 5th hole type K5 and the internal method of the 6th hole type K6 are equalized (conventional hole type), and the internal method of the 6th hole type K6 is less than the internal method of the 5th hole type K5. It is an analysis figure which shows the shape of the flange part after rolling molding in the case of (the hole type of this invention). FIG. 13 shows the shape before rolling molding with the 6-hole mold K6 (that is, the shape after rolling molding with the 5th hole mold K5) as the original shape, and the shape after rolling molding with the conventional hole mold is shown as a solid line. The shape after rolling and molding by the invention hole type is shown by a mesh. The hole type of the present invention is designed so that the internal method of the 6-hole type K6 is reduced by 50 mm as compared with the internal method of the 5th hole type K5.

図１３に示すように、従来孔型では、第５孔型Ｋ５での圧延造形後の被圧延材形状に対してウェブ圧下面積が大きいために、ウェブ高さ方向への拡がり量が大きく、フランジ幅及びフランジ厚が大きく減じていることが分かる。それに比べ、本発明孔型では、フランジ幅及びフランジ厚が大きく残っている。 As shown in FIG. 13, in the conventional hole type, since the web reduction area is large with respect to the shape of the material to be rolled after rolling in the fifth hole type K5, the amount of expansion in the web height direction is large, and the flange. It can be seen that the width and flange thickness are greatly reduced. In comparison, in the hole type of the present invention, the flange width and the flange thickness remain large.

また、図１４は、従来孔型と本発明孔型との両方において圧延造形を行い、その後、拡幅圧延を行った場合（拡幅済形状）のフランジ部形状を示す解析図である。図１４に示すように、第６孔型Ｋ６の内法を第５孔型Ｋ５の内法未満とした場合（本発明孔型）には、第６孔型Ｋ６を経て、更に拡幅圧延を行った後においてもフランジ肉量の増量化が実現されていることが分かり、また、フランジ部形状についても後段の中間圧延工程のロール形状に合致し、大きな形状変化等を引き起こすことなく安定的な圧延造形が実施できることが分かる。また、フランジ部内面の平坦化も実現されている。 Further, FIG. 14 is an analysis diagram showing the shape of the flange portion when rolling molding is performed in both the conventional hole type and the hole type of the present invention and then widening rolling is performed (widened shape). As shown in FIG. 14, when the internal method of the 6-hole type K6 is smaller than the internal method of the 5th hole type K5 (hole type of the present invention), widening rolling is further performed through the 6-hole type K6. It was found that the amount of flange wall was increased even after the rolling process, and the shape of the flange part matched the roll shape of the intermediate rolling process in the subsequent stage, and stable rolling was performed without causing a large change in shape. It can be seen that modeling can be carried out. In addition, the inner surface of the flange portion is flattened.

図１５は、フランジ肉量の増量化に関する概略説明図である。第５孔型Ｋ５で圧延造形された***部８２ｂを有する形状の被圧延材Ａにおいて、フランジ部８０への直接的なメタルフローを決定する部分は、主に、フランジ部８０とウェブ部８２との接続部であるコーナー部１１０（図１５中の破線部）である。例えば、当該コーナー部１１０をフラットな円筒ロールで上下方向から狭圧した場合に最も長手方向への延伸が生じやすく、その結果、フランジ部８０の減肉を誘発する。このような観点から、コーナー部１１０に対する圧下は、当該コーナー部１１０に接触する箇所にＲ（曲率）を設けた形状の孔型でもってフランジ部８０へのメタルフローを引き起こすような形状とし、且つ、できるだけ後段の孔型においてコーナー部１１０の圧下を行うことでフランジ部８０の減肉を抑制させることができると考えられる。 FIG. 15 is a schematic explanatory view regarding an increase in the amount of flange meat. In the material A to be rolled having a raised portion 82b rolled and shaped by the fifth hole type K5, the portions that determine the direct metal flow to the flange portion 80 are mainly the flange portion 80 and the web portion 82. It is a corner portion 110 (broken line portion in FIG. 15) which is a connecting portion of the above. For example, when the corner portion 110 is narrowly pressed from the vertical direction with a flat cylindrical roll, stretching in the longitudinal direction is most likely to occur, and as a result, thinning of the flange portion 80 is induced. From this point of view, the reduction with respect to the corner portion 110 has a hole shape having an R (curvature) at the portion in contact with the corner portion 110, and has a shape that causes metal flow to the flange portion 80. It is considered that the wall thinning of the flange portion 80 can be suppressed by reducing the corner portion 110 in the hole type in the latter stage as much as possible.

以上、図１３〜図１５を参照して説明したように、第５孔型Ｋ５の内法と第６孔型Ｋ６の内法を等しくした場合（従来孔型）と、第６孔型Ｋ６の内法を第５孔型Ｋ５の内法未満とした場合（本発明孔型）と、を比較すると、第６孔型Ｋ６（***部消去孔型）の内法を第５孔型Ｋ５（***部形成孔型）の内法未満とすることでフランジ肉量の増量化が図られ、フランジの生成効率を向上させ、大型の粗形材、大型Ｈ形鋼製品を効率的且つ安定的に製造することが可能となる。 As described above with reference to FIGS. 13 to 15, when the internal method of the 5th hole type K5 and the internal method of the 6th hole type K6 are equalized (conventional hole type), the 6th hole type K6 Comparing the case where the internal method is less than the internal method of the 5th hole type K5 (hole type of the present invention), the internal method of the 6th hole type K6 (raised portion erasing hole type) is the 5th hole type K5 (raised). By using less than the internal method of the part-forming hole type), the amount of flange wall thickness can be increased, the flange generation efficiency can be improved, and large-sized rough-shaped materials and large-sized H-shaped steel products can be manufactured efficiently and stably. It becomes possible to do.

以上説明した、本実施の形態に係るＨ形鋼の製造方法によれば、いわゆるエッジング圧延工程後に実施される平造形圧延を、***部８２ｂを形成させる第５孔型Ｋ５と、***部８２ｂを消去し、且つ、ウェブ部８２の内法を拡幅する第６孔型Ｋ６と、を備えた孔型構成で実施することとしている。そして、このような工程で実施される平造形圧延において、「ウェブ部分圧延孔型」あるいは「***部形成孔型」と呼ばれる第５孔型Ｋ５での逃がし率を２５％〜５０％とし、第６孔型Ｋ６での***部消去の際の圧下率が２．１以下となるような条件で第５孔型Ｋ５の孔型設計が行われる。これにより、「***部消去孔型」と呼ばれる第６孔型Ｋ６での通材不良や形状不良の発生を抑制させ、且つ、フランジ生成効率の向上を実現させることが可能となる。 According to the method for producing H-shaped steel according to the present embodiment described above, the flat forming rolling carried out after the so-called edging rolling step is performed by forming the fifth hole type K5 and the raised portion 82b to form the raised portion 82b. It is decided to carry out with a hole type configuration including a sixth hole type K6 that is erased and widens the inner method of the web portion 82. Then, in the flat forming rolling carried out in such a process, the relief rate in the fifth hole type K5 called "web partial rolling hole type" or "raised portion forming hole type" is set to 25% to 50%, and the first The hole type design of the fifth hole type K5 is performed under the condition that the rolling reduction rate at the time of erasing the raised portion in the six-hole type K6 is 2.1 or less. This makes it possible to suppress the occurrence of material passing defects and shape defects in the sixth hole type K6 called the "raised portion erasing hole type", and to improve the flange generation efficiency.

また、第６孔型Ｋ６の孔型設計において、圧延造形時にフランジ部８０の外側面同士の間隔（外法寸法）を所定の値以下の一定寸法に抑えるための孔型側壁１００を設けることで、第６孔型Ｋ６での圧延造形後のウェブ高さを、長手方向において所定の一定の値に揃えることが可能となり、寸法精度の向上やクロップ抑制を図ることができる。 Further, in the hole type design of the sixth hole type K6, by providing the hole type side wall 100 for suppressing the distance (external dimension) between the outer surfaces of the flange portions 80 to a constant size of a predetermined value or less at the time of rolling molding. , The height of the web after rolling and molding in the 6-hole type K6 can be made uniform to a predetermined constant value in the longitudinal direction, and dimensional accuracy can be improved and cropping can be suppressed.

以上、本発明の実施の形態の一例を説明したが、本発明は図示の形態に限定されない。当業者であれば、特許請求の範囲に記載された思想の範疇内において、各種の変更例または修正例に想到し得ることは明らかであり、それらについても当然に本発明の技術的範囲に属するものと了解される。 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 clear that a person skilled in the art can come up with various modifications or modifications within the scope of the ideas described in the claims, and these also naturally belong to the technical scope of the present invention. It is understood that it is a thing.

例えば、上記実施の形態において、第１孔型Ｋ１〜第４孔型Ｋ４の４つの孔型を用いて被圧延材Ａの造形を行い、その後、第５孔型Ｋ５、第６孔型Ｋ６（及び必要に応じた拡幅圧延孔型）を用いてＨ形粗形材の圧延造形を行う技術を説明したが、粗圧延工程を実施する孔型数はこれに限られるものではなく、第１孔型Ｋ１〜第４孔型Ｋ４に示す圧延造形工程を更に多くの孔型を用いて実施しても良い。即ち、上記実施の形態に示した孔型構成は一例であり、サイジングミル３や粗圧延機４に刻設される孔型の数は任意に変更可能であり、好適に粗圧延工程を実施することができる程度に適宜変更される。 For example, in the above embodiment, the material A to be rolled is formed using the four hole types of the first hole type K1 to the fourth hole type K4, and then the fifth hole type K5 and the sixth hole type K6 ( And the technique of rolling and forming an H-shaped rough shape material using widening rolled hole molds as needed), but the number of hole molds for carrying out the rough rolling process is not limited to this, and the first hole is not limited to this. The rolling molding step shown in the molds K1 to the fourth hole mold K4 may be carried out using more hole molds. That is, the hole type configuration shown in the above embodiment is an example, and the number of hole types engraved in the sizing mill 3 and the rough rolling machine 4 can be arbitrarily changed, and the rough rolling step is preferably carried out. It will be changed as appropriate to the extent that it can be done.

また、一般的なＨ形鋼製造過程における平造形圧延工程では、平造形圧延後の被圧延材形状において、フランジ部外面に疵が発生する場合があることが知られており、その際には、エッジング孔型（例えば上記実施の形態の第４孔型Ｋ４）に被圧延材Ａを戻し入れ、再度エッジング圧延を行うことで疵を消去するいわゆる「耳取り圧延」が実施される場合がある。このような「耳取り圧延」について、上記実施の形態では特に説明していないが、上記実施の形態に係る孔型構成やそれに伴う製造方法では平造形圧延でのウェブ高さ方向へのメタルの拡がり量が小さいため、「耳取り圧延」を行う必要はない。即ち、上記実施の形態で説明した第４孔型Ｋ４と、第５孔型Ｋ５あるいは第６孔型Ｋ６と、を同一スタンド（同一孔型ロール）に刻設する必要が無い。そのため、孔型ロールへの孔型刻設設計の効率化といった生産性の向上が図られる。 Further, it is known that in the flat forming rolling process in a general H-shaped steel manufacturing process, a defect may occur on the outer surface of the flange portion in the shape of the material to be rolled after the flat forming rolling. In some cases, so-called "ear-cutting rolling" is performed in which the material A to be rolled is put back into the edging hole type (for example, the fourth hole type K4 of the above embodiment) and the edging rolling is performed again to eliminate the flaws. .. Such "ear-picking rolling" is not particularly described in the above-described embodiment, but in the hole-shaped configuration and the manufacturing method associated therewith according to the above-described embodiment, the metal in the web height direction in the flat rolling is used. Since the amount of spread is small, there is no need to perform "ear-picking rolling". That is, it is not necessary to engrave the fourth hole type K4 and the fifth hole type K5 or the sixth hole type K6 described in the above embodiment on the same stand (same hole type roll). Therefore, productivity can be improved by improving the efficiency of the hole-shaped engraving design on the hole-shaped roll.

また、上記実施の形態では、第５孔型Ｋ５において***部８２ｂを形成させ、その後、第６孔型Ｋ６において***部８２ｂを消去するといった平造形圧延工程を説明しているが、これら第５孔型Ｋ５による***部形成と第６孔型による***部消去は繰り返し実施されても良い。即ち、***部消去後のウェブ厚みが所望の厚みとなるまで、第５孔型Ｋ５及び第６孔型Ｋ６による平造形圧延を繰り返し行っても良い。 Further, in the above embodiment, the flat forming rolling process in which the raised portion 82b is formed in the fifth hole type K5 and then the raised portion 82b is erased in the sixth hole type K6 is described. The formation of the raised portion by the hole type K5 and the elimination of the raised portion by the sixth hole type may be repeatedly performed. That is, flat rolling may be repeated by the fifth hole type K5 and the sixth hole type K6 until the web thickness after erasing the raised portion becomes a desired thickness.

また、上記実施の形態では、第１孔型Ｋ１〜第４孔型Ｋ４において、被圧延材Ａの上下端部（スラブ端面）に割り込みを入れ、それら割り込みによって左右に分かれた各部分を左右に折り曲げる加工を行い、フランジ部８０を形成するといった造形方法を説明している。しかしながら、本発明に係る第５孔型Ｋ５及び第６孔型Ｋ６を用いた圧延造形技術は、このような技術によって造形された被圧延材Ａに対してのみ適用されるものではなく、例えば特許文献１に代表されるような従来のＨ形粗形材（いわゆるドッグボーン材）に対しても適用することが可能である。 Further, in the above embodiment, in the first hole type K1 to the fourth hole type K4, an interrupt is inserted in the upper and lower end portions (slab end faces) of the material A to be rolled, and each portion divided into left and right by the interruption is left and right. A modeling method such as forming a flange portion 80 by performing a bending process is described. However, the rolling molding technique using the fifth hole type K5 and the sixth hole type K6 according to the present invention is not applied only to the material A to be rolled formed by such a technique, for example, a patent. It can also be applied to a conventional H-shaped rough material (so-called dogbone material) represented by Document 1.

本発明は、例えば矩形断面であるスラブ等を素材としてＨ形鋼を製造する製造方法に適用できる。 The present invention can be applied to a manufacturing method for manufacturing H-shaped steel using, for example, a slab having a rectangular cross section as a material.

１…圧延設備
２…加熱炉
３…サイジングミル
４…粗圧延機
５…中間ユニバーサル圧延機
８…仕上ユニバーサル圧延機
９…エッジャー圧延機
１１…スラブ
１３…Ｈ形粗形材
１４…中間材
１６…Ｈ形鋼製品
２０…上孔型ロール（第１孔型）
２１…下孔型ロール（第１孔型）
２５、２６…突起部（第１孔型）
２８、２９…割り込み（第１孔型）
３０…上孔型ロール（第２孔型）
３１…下孔型ロール（第２孔型）
３５、３６…突起部（第２孔型）
３８、３９…割り込み（第２孔型）
４０…上孔型ロール（第３孔型）
４１…下孔型ロール（第３孔型）
４５、４６…突起部（第３孔型）
４８、４９…割り込み（第３孔型）
５０…上孔型ロール（第４孔型）
５１…下孔型ロール（第４孔型）
５５、５６…突起部（第４孔型）
５８、５９…割り込み（第４孔型）
８０…フランジ部
８２…ウェブ部
８２ａ…圧下部分
８２ｂ…***部（未圧下部分）
８５…上孔型ロール（第５孔型）
８５ａ…窪み部
８６…下孔型ロール（第５孔型）
８６ａ…窪み部
９５…上孔型ロール（第６孔型）
９６…下孔型ロール（第６孔型）
１００…孔型側壁
１１０…コーナー部
Ｋ１…第１孔型
Ｋ２…第２孔型
Ｋ３…第３孔型
Ｋ４…第４孔型
Ｋ５…第５孔型（***部形成孔型）
Ｋ６…第６孔型（***部消去孔型）
Ｔ…製造ライン
Ａ…被圧延材 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 profile 14 ... Intermediate material 16 ... H-shaped steel product 20 ... Top hole type roll (first hole type)
21 ... Prepared hole type roll (first hole type)
25, 26 ... Protrusion (first hole type)
28, 29 ... Interrupt (1st hole type)
30 ... Top hole type roll (second hole type)
31 ... Prepared hole type roll (second hole type)
35, 36 ... Protrusion (second hole type)
38, 39 ... Interrupt (second hole type)
40 ... Top hole type roll (third hole type)
41 ... Prepared hole type roll (third hole type)
45, 46 ... Protrusion (third hole type)
48, 49 ... Interrupt (3rd hole type)
50 ... Top hole type roll (4th hole type)
51 ... Prepared hole type roll (4th hole type)
55, 56 ... Protrusion (4th hole type)
58, 59 ... Interrupt (4th hole type)
80 ... Flange part 82 ... Web part 82a ... Reduced part 82b ... Raised part (Uncompressed part)
85 ... Top hole type roll (fifth hole type)
85a ... Recessed portion 86 ... Prepared hole type roll (fifth hole type)
86a ... Recessed portion 95 ... Top hole type roll (6th hole type)
96 ... Pilot hole type roll (6th hole type)
100 ... Hole type side wall 110 ... Corner part K1 ... 1st hole type K2 ... 2nd hole type K3 ... 3rd hole type K4 ... 4th hole type K5 ... 5th hole type (raised part forming hole type)
K6 ... 6th hole type (raised part erasing hole type)
T ... Production line A ... Material to be rolled

Claims (6)

粗圧延工程、中間圧延工程、仕上圧延工程を備えたＨ形鋼の製造方法であって、
前記粗圧延工程は、被圧延材を所定の略ドッグボーン形状に圧延造形するエッジング圧延工程と、エッジング圧延工程完了後の被圧延材を９０°あるいは２７０°回転させてウェブ部の圧延を行う平圧延工程を有し、
前記平圧延工程を行う孔型には、少なくとも、被圧延材のウェブ部中央に***部を形成させる窪み部が設けられた***部形成孔型と、前記***部が形成された被圧延材に対し、当該***部を圧下する***部消去孔型が刻設され、
前記平圧延工程において形成される***部の幅は被圧延材のウェブ部内法の２５％以上５０％以下に設定され、
前記***部消去孔型における前記***部に対する圧下率を２．１以下とし、
前記***部消去孔型の内法寸法は、前記***部形成孔型の内法寸法未満に設計され、
且つ、前記***部消去孔型には、被圧延材の外法寸法を所定値以下に抑える孔型側壁が設けられることを特徴とする、Ｈ形鋼の製造方法。 It is a manufacturing method of H-shaped steel including a rough rolling process, an intermediate rolling process, and a finish rolling process.
The rough rolling process includes an edging rolling process in which the material to be rolled is rolled into a predetermined substantially dogbone shape, and a flat portion in which the material to be rolled after the completion of the edging rolling process is rotated by 90 ° or 270 ° to roll the web portion. Has a rolling process,
The hole type for performing the plan rolling step includes at least a raised portion forming hole type in which a recess for forming a raised portion is provided in the center of the web portion of the material to be rolled and a material to be rolled in which the raised portion is formed. On the other hand, a raised portion erasing hole type that rolls down the raised portion is engraved.
The width of the raised portion formed in the plan rolling step is set to 25% or more and 50% or less of the method inside the web portion of the material to be rolled.
The reduction rate for the raised portion in the raised portion erasing hole type is set to 2.1 or less .
The internal dimension of the raised portion erasing hole type is designed to be smaller than the internal dimension of the raised portion forming hole type.
Further, a method for manufacturing an H-shaped steel, characterized in that the raised portion erasing hole type is provided with a hole type side wall that suppresses the outer dimension of the material to be rolled to a predetermined value or less. 前記孔型側壁間の間隔は、前記***部消去孔型における被圧延材非定常部の幅拡がり量に基づき設計されることを特徴とする、請求項１に記載のＨ形鋼の製造方法。The method for producing an H-section steel according to claim 1, wherein the distance between the hole-shaped side walls is designed based on the amount of width expansion of the unsteady portion of the material to be rolled in the raised portion erasing hole type. 前記平圧延工程を行う孔型には、前記***部消去孔型で圧延造形された後の被圧延材に対し、ウェブ部を略平坦に圧延造形し、且つ、拡幅圧延を行う１又は複数の拡幅用孔型が更に含まれることを特徴とする、請求項１又は２に記載のＨ形鋼の製造方法。In the hole mold for which the plan rolling step is performed, one or a plurality of the web portions are rolled and shaped substantially flat with respect to the material to be rolled after being rolled and shaped by the raised portion erasing hole mold, and widening rolling is performed. The method for producing an H-section steel according to claim 1 or 2, further comprising a hole type for widening. 前記拡幅用孔型で圧延造形された被圧延材のウェブ部厚みは、前記***部形成孔型で圧延造形された被圧延材のウェブ部厚みに比べ薄く設定され、The thickness of the web portion of the material to be rolled formed by rolling in the widening hole mold is set to be thinner than the thickness of the web portion of the material to be rolled formed by rolling in the raised portion forming hole mold.
前記***部消去孔型では、前記***部の圧下と併せて被圧延材のウェブ部の圧下が行われることを特徴とする、請求項３に記載のＨ形鋼の製造方法。The method for producing an H-section steel according to claim 3, wherein in the raised portion erasing hole type, the web portion of the material to be rolled is reduced in addition to the reduction of the raised portion. 前記粗圧延工程を行う圧延機には、被圧延材を圧延造形する６以上の複数の孔型が刻設され、In the rolling mill that performs the rough rolling step, a plurality of hole molds of 6 or more for rolling and shaping the material to be rolled are engraved.
当該複数の孔型では被圧延材の１又は複数パス造形が行われ、In the plurality of hole molds, one or more paths of the material to be rolled are formed.
前記複数の孔型のうち、第１孔型及び第２孔型には、被圧延材の幅方向に対し鉛直に割り込みを入れて被圧延材端部に分割部位を形成させる突起部が形成され、Of the plurality of hole types, the first hole type and the second hole type are formed with protrusions that vertically interrupt the width direction of the material to be rolled to form a split portion at the end of the material to be rolled. ,
前記複数の孔型のうち、後段に位置する前記平圧延工程を行う孔型を除く第３孔型以降の孔型には、前記割り込みに当接し、形成された分割部位を順次折り曲げる突起部が形成されることを特徴とする、請求項１〜４のいずれか一項に記載のＨ形鋼の製造方法。Of the plurality of hole types, the hole types of the third and subsequent hole types excluding the hole type that performs the flat rolling step, which are located in the subsequent stage, have protrusions that abut on the interrupt and sequentially bend the formed divided portions. The method for producing an H-shaped steel according to any one of claims 1 to 4, wherein the H-shaped steel is formed. 厚み２９０ｍｍ以上３１０ｍｍ以下の矩形断面スラブを素材として用い、ウェブ高さ１０００ｍｍ以上、且つ、フランジ幅４００ｍｍ以上のＨ形鋼製品を製造することを特徴とする、請求項５に記載のＨ形鋼の製造方法。The H-section steel according to claim 5, wherein a rectangular cross-section slab having a thickness of 290 mm or more and a thickness of 310 mm or less is used as a material to manufacture an H-section steel product having a web height of 1000 mm or more and a flange width of 400 mm or more. Production method.
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