JP2852313B2 - Method and apparatus for manufacturing large diameter square steel pipe including hot forming - Google Patents

Method and apparatus for manufacturing large diameter square steel pipe including hot forming

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Publication number
JP2852313B2
JP2852313B2 JP30157992A JP30157992A JP2852313B2 JP 2852313 B2 JP2852313 B2 JP 2852313B2 JP 30157992 A JP30157992 A JP 30157992A JP 30157992 A JP30157992 A JP 30157992A JP 2852313 B2 JP2852313 B2 JP 2852313B2
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JP
Japan
Prior art keywords
steel pipe
forming
steel
square
heating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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JP30157992A
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Japanese (ja)
Other versions
JPH06122019A (en
Inventor
拓 中島
Original Assignee
ナカジマ鋼管株式会社
中島 功雄
拓 中島
中島 教雄
中島 伸
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Application filed by ナカジマ鋼管株式会社, 中島 功雄, 拓 中島, 中島 教雄, 中島 伸 filed Critical ナカジマ鋼管株式会社
Priority to JP30157992A priority Critical patent/JP2852313B2/en
Publication of JPH06122019A publication Critical patent/JPH06122019A/en
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Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【産業上の利用分野】本発明は、圧延鋼帯および鋼板を
使用する熱間成形を含む大径角形鋼管の段階的製造方法
および装置にかかり、より詳しくは、鋼帯または鋼板
を、その長手方向に平行して冷間塑性加工により丸形断
面に成形し、その両側縁継目を順次突合わせ溶接して大
径丸鋼管を形成した後、複数段よりなる角形成形ロール
装置に装入して鋼管断面を順次、角形に成形する工程に
おいて、前記角形成形ロール工程を、第1成形工程およ
び第2成形工程に二分し、丸鋼管成形に連続する第1成
形工程において冷間加工により粗角形成形を施した後、
長手方向に単位長に切断し、同単位長鋼管を第1成形工
程と第2成形工程との中間に設備した加熱装置に挿入し
て所定温度に均等に加熱することにより、鋼板材に加え
られた冷間塑性変形により生じた残留応力、加工硬化等
を除去し粗成形鋼管の機械的性質を改善すると共に、加
熱温度が低下しないうちに、同鋼管を仕上げ成形ロール
を含む複数段よりなる第2成形工程に装入して熱間塑性
加工により成形し、少なくとも規格どおりに断面成形し
た角形鋼管を均一に冷却することにより、角形鋼管の機
械的性質、特にコーナーR部付近の材質劣化を改善した
ことを特徴とする熱間成形を含む大径角形鋼管の製造法
および装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for the stepwise production of a large-diameter rectangular steel pipe including hot forming using a rolled steel strip and a steel sheet. In parallel with the direction, it is formed into a round section by cold plastic working, and the both side edge joints are sequentially butt-welded to form a large-diameter round steel pipe, and then charged into a square-shaped roll device consisting of a plurality of stages. In the step of sequentially forming the steel pipe cross section into a square shape, the horn forming roll step is divided into a first forming step and a second forming step, and the rough forming form is formed by cold working in the first forming step following the round steel pipe forming. After applying
It is cut into unit lengths in the longitudinal direction, and the unit length steel pipe is inserted into a heating device provided between the first forming step and the second forming step, and is uniformly heated to a predetermined temperature, whereby the steel pipe is added to the steel sheet material. In addition to removing the residual stress, work hardening, etc. caused by the cold plastic deformation and improving the mechanical properties of the rough-formed steel pipe, the steel pipe is made up of multiple stages including finishing rolls before the heating temperature is reduced. (2) The mechanical properties of the square steel pipe, especially the material deterioration near the corner R, are improved by uniformly cooling the square steel pipe, which is formed by hot plastic working in the forming process and at least the cross section is formed according to the standard. The present invention relates to a method and an apparatus for manufacturing a large-diameter rectangular steel pipe including hot forming characterized by the following.

【0002】[0002]

【従来の技術】建築構造物の柱材用として広く使用され
ている大径角形鋼管の冷間塑性加工による量産方法の一
つとして、従来、略、次のような工法が実施されてい
る。 熱間圧延コイルをレベラーに掛けてフラットな帯鋼板
とし、その両側縁を幅決め加工する。 前記帯鋼板を、ブレークダウン、クラスター、フィン
パススタンド等の加工段に直列に通して、その間に鋼板
を順次、冷間ロール成形し、その直角断面を円形に近い
形状に変形し、
2. Description of the Related Art As one of mass production methods by cold plastic working of a large-diameter rectangular steel pipe, which is widely used as a column material of a building structure, the following construction method has been generally carried out. The hot-rolled coil is hung on a leveler to form a flat steel strip, and the edges on both sides are determined. The strip steel plate is passed in series to a processing stage such as a breakdown, a cluster, and a fin pass stand, during which the steel plate is sequentially cold-rolled, and its right-angle cross section is deformed into a shape close to a circle,

【0003】帯鋼板の両側継目を高周波溶接、アーク
溶接法などを利用して溶接し、ワンシーム丸鋼管を形成
する。 丸鋼管の溶接部を徐冷してから、サイザー、スケアリ
ングスタンド、タークスヘッド等の工程を経て、断面を
順次、角形に成形し大径角形鋼管を製造する。 上述工法においては、平坦な鋼板を円弧状曲面に、また
鋼管コーナーR部形成のために円弧状曲面の肉厚鋼板を
冷間塑性加工によって、略、90゜折り曲げる工程が含
まれている。
[0003] Both side joints of a strip steel plate are welded using high frequency welding, arc welding or the like to form a one-seam round steel pipe. After gradually cooling the welded portion of the round steel pipe, the cross section is sequentially formed into a square shape through processes such as a sizer, a scoring stand, and a turks head to produce a large-diameter square steel pipe. The above-mentioned method includes a step of bending a flat steel plate into an arcuate curved surface, and forming a thick steel plate having an arcuate curved surface by cold plastic working to form a steel pipe corner R portion, approximately 90 °.

【0004】ところで、肉厚鋼帯または鋼板を冷間で、
略、90゜折曲げ加工をした場合には、コーナーにRを
与えて曲げ加工を施すにしても、その鋼板断面における
中立面を境にして、両側に引張り力または圧縮力が働き
ながら弾性限界を越えて塑性変形が進み、変形個所、特
にコーナーR部材質の機械的特性が劣化し、当該部分に
脆性破壊を生じる条件が潜在するようになる。たとえ
ば、冷間での曲げ加工により当該コーナーR部鋼材に生
ずる加工硬化、高い残留応力、靭性の低下などと相俟っ
て、同部鋼板に対し、冬期低温時に施す溶接作業に基づ
く局部材質の割れ、溶融亜鉛メッキ施工の際の割れな
ど、が生ずる場合がある。
By the way, a thick steel strip or a steel sheet is cold
In the case of approximately 90 ° bending, even if the corner is bent by giving a radius, even if a tensile force or a compressive force acts on both sides with respect to the neutral surface in the cross section of the steel plate, the elasticity is increased. Plastic deformation proceeds beyond the limit, and the mechanical properties of the deformed portion, particularly the corner R member material, are degraded, and a condition that causes brittle fracture in the portion becomes latent. For example, due to the work hardening, high residual stress, and reduced toughness that occur in the corner R steel due to cold bending, the local steel based on the welding operation performed at low temperature in winter is applied to the steel at the corner. Cracking and cracking during hot-dip galvanizing may occur.

【0005】この種の大径角形鋼管を柱材として使用す
る鉄骨構造物、建築物等は一般に、長期にわたり地震、
風圧、基礎地盤の変形その他の負荷に対して安全に耐え
ることが要求され、しかも、これらの柱材(コラム)は
原則的に交換・補修が可能でないといった状態で施工さ
れている場合が多い。殊に最近の建築物は、高層建築が
主流を占め、また、各部屋に冷暖房装置を設備すると
か、OA機器、電算機の類を装備するなど、建物に付帯
する設備に基づき増加する重量も無視することができな
いし、また、あらかじめ考慮されるべき設備重量が増加
する傾向にあるため、肉厚大径鋼管をコラムとして多用
する傾向があるので、前記冷間塑性加工に基づく鋼管材
質の劣化の問題は、益々、無視できない状況になりつつ
ある。
[0005] Steel structures, buildings and the like using this kind of large-diameter rectangular steel pipe as a column material are generally subjected to earthquakes,
It is required to safely withstand wind pressure, deformation of the foundation ground and other loads, and moreover, these pillars (columns) are often constructed in such a manner that they cannot be replaced or repaired in principle. Especially in recent buildings, high-rise buildings occupy the mainstream, and the weight that increases due to facilities attached to the buildings, such as installing air conditioning and heating equipment in each room, OA equipment, computers, etc., is also increasing. It cannot be neglected, and the equipment weight to be considered in advance tends to increase, so that there is a tendency to frequently use thick-walled large-diameter steel pipes as columns. Is becoming increasingly non-negligible.

【0006】このような事情に鑑み、角形鋼管成形時に
おける冷間塑性加工に基づく角形鋼管材質の劣化、特に
コーナーR部の材質の劣化が改めて問題視されている。
そこで、近来、残留応力が少なく、充分な靭性を備えコ
ーナーR部を有する高品質の大形角形鋼管を提供するよ
うに、需要者層から要望されている。
In view of such circumstances, deterioration of the material of the rectangular steel pipe due to cold plastic working at the time of forming the rectangular steel pipe, particularly deterioration of the material of the corner R portion, has been regarded as a problem again.
Therefore, in recent years, there has been a demand from a group of consumers to provide a high-quality large rectangular steel pipe having a small residual stress, sufficient toughness, and having a corner R portion.

【0007】冷間塑性加工による大径肉厚角形鋼管が内
包する、この種の材質的問題点を解決するために、従
来、メーカー側では、 既製丸鋼管、シームレスパイプなどを、油、ガス等の
化石燃料または電気エネルギーを熱源とする加熱炉また
は装置により加熱した後、これを複数段の圧延機を通し
て熱間塑性加工により断面角形に成形することが提案さ
れている。上記工法によるときは、製品の品質は良好で
あるが、鋼管の両端部断面が形状不良になり、これを切
り捨てるために製品の歩留まりが悪いとか、鋼管断面に
対するシーム部の位置がセンターから左右に大幅にずれ
不安定になりがちで商品価値が低下する。また、加熱、
冷却時の鋼管に生じる熱応力歪を無視できない、鋼管を
一本宛加工するので生産が低いといった問題点があっ
た。
[0007] In order to solve this kind of material problem in which a large-diameter thick-walled square steel pipe formed by cold plastic working is included, conventionally, manufacturers have used existing pipes such as oil, gas, etc. After heating by a heating furnace or apparatus using a fossil fuel or electric energy as a heat source, it is proposed to form it into a rectangular cross section by hot plastic working through a plurality of rolling mills. When the above method is used, the quality of the product is good, but the cross section at both ends of the steel pipe becomes defective and the yield of the product is poor because it is cut off. The product value tends to be significantly deviated and unstable. Also heating,
There is a problem that the thermal stress strain generated in the steel pipe during cooling cannot be ignored, and the production is low because the steel pipe is processed one by one.

【0008】別に冷間加工により成形済みの大径角形
鋼管を焼鈍炉に挿入し、鋼材中の残留応力を略、除去
し、コーナー部材質の靭性を改善するまで全体的に加熱
した後、これを徐冷する工法も知られている。この場合
にも、上記同様の問題点があり得る。 あるいは、熱間圧延コイルをレベラーに掛け、各種成
形ロールスタンドを通して冷間塑性加工により鋼板断面
を丸形に成形し、高周波溶接法などにより両側縁継目を
順次、突合わせ溶接して丸鋼管を形成した後、同鋼管を
インラインで電気エネルギー、ガスまたは油等の化石燃
料により加熱し、これを複数段の熱間成形ロール装置に
通し、断面角形の鋼管に成形し冷却して製品を得る(た
とえば、本出願人が、さきに出願した特願平2−180
497号参照)ことが考えられている。
Separately, a large-diameter rectangular steel pipe formed by cold working is inserted into an annealing furnace, and the residual stress in the steel material is substantially removed, and the whole is heated until the toughness of the corner member is improved. There is also known a method of gradually cooling the water. In this case as well, there may be similar problems as described above. Alternatively, a hot-rolled coil is hung on a leveler, the cross section of the steel sheet is formed into a round shape by cold plastic working through various forming roll stands, and the both side edge joints are sequentially butt-welded by high frequency welding or the like to form a round steel pipe After that, the steel pipe is heated in-line with fossil fuel such as electric energy, gas or oil, passed through a multi-stage hot forming roll device, formed into a square-shaped steel pipe and cooled to obtain a product (for example, And Japanese Patent Application No. 2-180 filed earlier by the present applicant.
No. 497).

【0009】(a)上述工法は、加熱時の熱的不均一、
特に冷却時における不均一温度分布による鋼管の変形が
問題であり、これを無くするためには冷却ゾーンを充分
長くとり、鋼管を徐冷する必要がある。また、冷却時
に、丸鋼管と異なり気流が鋼管コーナーR部で乱れて、
周壁を均一に冷却することが困難になり、不均一温度分
布が生じ易い。そして一旦、鋼管に変形が生じると、そ
れを矯正することは角形鋼管の場合、非常に困難であ
る。
[0009] (a) The above-described method is not uniform in heat during heating,
In particular, deformation of the steel pipe due to non-uniform temperature distribution during cooling is a problem. To eliminate this problem, it is necessary to provide a sufficiently long cooling zone and gradually cool the steel pipe. In addition, at the time of cooling, unlike the round steel pipe, the air flow is disturbed at the steel pipe corner R,
It becomes difficult to cool the peripheral wall uniformly, and a non-uniform temperature distribution is likely to occur. Once the steel pipe is deformed, it is very difficult to correct it in the case of a square steel pipe.

【0010】(b)ガス、油等の化石燃料を利用する加
熱炉をインラインで設備する場合は、丸鋼管の成形スピ
ードが速い(高周波溶接法を用いて良好な溶接品質を得
るには、ある程度の溶接スピードが要求されるから)た
めに、角形鋼管の内部応力が完全に解消する鋼材のA3
変態点温度まで鋼管を加熱するのに、100 m〜150 mの
長さの加熱炉を設置するスペースが必要になり、製造ラ
インが長大になり過ぎて立地条件の選定が困難になると
か、設備投資額が予想以上に膨らむ恐れがある。加え
て、ガス、油等の化石燃料による丸鋼管の加熱では、熱
源を鋼管の内側に入れることができないため、同鋼管を
均一に加熱することがむずかしく、鋼管加熱の温度管理
の面で問題があり、これが、断面の成形形状、歪みの発
生に関係するので、結局、均等な品質の製品が得られな
いといったこともあり得る。
(B) When a heating furnace utilizing a fossil fuel such as gas or oil is installed in-line, a round steel pipe is formed at a high speed (for obtaining good welding quality by using a high frequency welding method, a certain degree of the welding speed is from is required) for the, steel internal stress of square steel is completely eliminated a 3
In order to heat the steel pipe to the transformation point temperature, a space for installing a heating furnace with a length of 100 m to 150 m is required, and the production line becomes too long, making it difficult to select location conditions, There is a risk that the investment amount will expand more than expected. In addition, when heating round steel pipes with fossil fuels such as gas and oil, it is difficult to heat the steel pipes uniformly because the heat source cannot be inserted inside the steel pipes, and there is a problem in the temperature control of steel pipe heating. Since this is related to the shape of the cross-section and the occurrence of distortion, a product of uniform quality may not be obtained after all.

【0011】(c)さらに、熱間塑性加工に使用される
成形ロールは、ロール周面にスリップ疵が付き易く、耐
用時間が短いので熱間成形ロール段数が多いほどメンテ
ナンスが面倒である。 (d)一方、電気エネルギーを利用した加熱装置は、鋼
管加熱のためのスペースが小さくてすみ、鋼管材の均一
加熱並びに加熱温度の制御が容易にできる利点があるも
のの、電力コストが高く、立地条件によっては必要とす
る大容量の電力の入手が困難な場合がある。 等々の技術的問題点があることが知られている。
(C) Further, since the forming roll used for hot plastic working tends to have a slip flaw on the roll peripheral surface and has a short service life, the maintenance becomes more troublesome as the number of hot forming roll stages increases. (D) On the other hand, a heating device using electric energy has an advantage that a space for heating a steel pipe is small and uniform heating of a steel pipe material and control of a heating temperature can be easily performed. Depending on the conditions, it may be difficult to obtain a large amount of required power. It is known that there are technical problems.

【0012】[0012]

【発明が解決しようとする課題】本発明は、上述したよ
うな事情を背景にして開発されたもので、角形鋼管材質
の残留応力を許容応力以下にすると共に、コーナーR部
の靱性を改善し、鋼管全体の材質の劣化を回避して、均
一、かつ、安定した材質よりなる高品質の大径角形鋼管
を製造する工法、装置を提供することを目的とする。ま
た、本発明の別の目的は、従来、公知の製造装置を改良
し、オフラインで熱処理を施す装置を設備することによ
って設備投資額を節減して、均一な材質の角形鋼管を成
形するようにし、従来製法に内在する上述問題点を可及
的に解決できる新規な手段を開発することにある。
SUMMARY OF THE INVENTION The present invention has been developed in view of the above-mentioned circumstances, and has been made to reduce the residual stress of a rectangular steel pipe material to an allowable stress or less and to improve the toughness of a corner R portion. Another object of the present invention is to provide a method and an apparatus for manufacturing a high-quality large-diameter rectangular steel pipe made of a uniform and stable material while avoiding deterioration of the material of the entire steel pipe. Further, another object of the present invention is to improve a conventionally known manufacturing apparatus, reduce the capital investment by installing an apparatus for performing off-line heat treatment, and form a square steel pipe of uniform material. Another object of the present invention is to develop a new means capable of solving the above-mentioned problems inherent in the conventional manufacturing method as much as possible.

【0013】[0013]

【課題を解決するための手段】上述の目的を達成するた
め、本発明工法は、以下に述べるとおりの各構成要件を
具備する。 (1) 鋼帯または鋼板を長手軸方向に直角断面で丸形
に成形し、その両側縁継目を順次突合わせ溶接し形成し
た丸鋼管を、複数段よりなる角形鋼管成形ロール装置に
搬送し、丸鋼管断面を順次角形断面に成形する工程にお
いて、前記角形鋼管成形ロール工程を、第1成形工程お
よび第2成形工程に二分し、その第1成形工程において
丸鋼管を粗角形成形すると共に、第1成形工程と第2成
形工程との中間に、前記粗成形鋼管を単位長に切断する
工程、前記単位長粗成形鋼管を加熱する加熱装置を配置
し、単位鋼管毎に加熱装置に挿入して所定温度に均等に
加熱した後、前記高温単位長粗成形鋼管を仕上げ成形ロ
ールを含む複数段よりなる第2成形工程に搬入して熱間
塑性加工を施し、少なくとも規格どおりの断面を備えた
角形鋼管を成形し、次に前記規格断面鋼管を均一に冷却
する冷却装置を設置し、同鋼管を徐冷または強制適に冷
却した後、長手軸方向の大曲り、捩じれなどの歪を矯正
することを特徴とする熱間成形を含む大径角形鋼管製造
法。
In order to achieve the above-mentioned object, the method of the present invention has the following components. (1) The steel strip or the steel sheet is formed into a round shape in a cross section perpendicular to the longitudinal axis direction, and the round steel pipe formed by sequentially butting and welding the both-side edge seams is transferred to a square steel pipe forming roll device having a plurality of stages. In the step of sequentially forming the round steel pipe section into a square cross section, the square steel pipe forming roll step is divided into a first forming step and a second forming step, and in the first forming step, the round steel pipe is formed into a rough angle, A step of cutting the coarsely formed steel pipe into a unit length, a heating device for heating the unit length coarsely formed steel pipe, and inserting the heating device for each unit steel pipe into the heating device between the 1 forming step and the second forming step. After being uniformly heated to a predetermined temperature, the high-temperature unit-length roughly formed steel pipe is carried into a second forming step including a plurality of steps including a finish forming roll, subjected to hot plastic working, and is provided with a square having at least a standard cross section. Forming a steel pipe, Next, a cooling device for uniformly cooling the steel pipe having the standard cross section is installed, and after gradually cooling or forcibly cooling the steel pipe, the heat is characterized by correcting distortion such as large bending in the longitudinal axis direction and twisting. A method for manufacturing large-diameter rectangular steel pipes including hot forming

【0014】(2) 鋼帯または鋼板を長手軸方向に直
角な断面で丸形に成形し、その両側縁継目を順次突合わ
せ溶接し形成する丸鋼管成形装置、前記装置に連結され
丸鋼管断面を冷間加工により粗成形する第1角形成形ロ
ール装置、前記第1角形成形ロール装置により成形され
た粗成形断面を有する鋼管を単位長毎に切断する切断装
置、前記単位長粗成形鋼管を所定温度に均等に加熱する
加熱装置、加熱装置から搬出した前記高温単位長粗成形
鋼管を挿入し、熱間塑性加工により前記鋼管断面を規格
どおりの角形形状断面に成形する仕上げ成形ロールを含
む複数段よりなる第2角形成形ロール装置、前記規格断
面鋼管を均一に冷却する冷却装置、長手軸方向の大曲
り、捩じれなどの歪を矯正する装置とよりなる熱間成形
を含む大径角形鋼管製造装置。
(2) A round steel pipe forming apparatus for forming a steel strip or a steel sheet into a round shape with a cross section perpendicular to the longitudinal axis direction and sequentially butt-welding both side edges of the steel strip or the steel sheet. , A cutting device for cutting a steel pipe having a roughly formed cross section formed by the first square forming roll device into unit lengths, and A heating device for heating evenly to a temperature, a plurality of stages including a finish forming roll for inserting the high-temperature unit-length coarsely-formed steel pipe unloaded from the heating device and forming the steel pipe cross-section into a square-shaped cross-section as specified by hot plastic working. A large-diameter rectangular steel pipe including hot forming comprising a second square forming roll device, a cooling device for uniformly cooling the standard-section steel pipe, and a device for correcting distortion such as large bending and twisting in the longitudinal axis direction. Manufacturing equipment.

【0015】[0015]

【作用】市場に流通している大径角形鋼管について問題
視されている材質的欠陥は、鋼管成形工程中の冷間塑性
加工に基づく、鋼管材質の劣化、特にコーナーR部の鋼
板靭性の低下、残留応力の存在、加工硬化等、材質の脆
性化による構造材の弱体化である。 (1)上述のような事情に鑑み、本発明では、 冷間塑性加工により丸鋼管を成形した後、引き続いて
前記鋼管を角形粗成形ロール装置(第1成形ロール工
程)に搬入し、同装置において冷間塑性加工のもとに丸
鋼管の断面に四つのコーナーR部を形成する。
[Function] The material defects that have been regarded as problems with large-diameter rectangular steel pipes on the market are the deterioration of the steel pipe materials due to cold plastic working during the steel pipe forming process, especially the reduction of the toughness of the steel sheet at the corner R. , Weakening of the structural material due to brittleness of the material, such as the presence of residual stress, work hardening and the like. (1) In view of the above circumstances, in the present invention, after forming a round steel pipe by cold plastic working, the steel pipe is subsequently carried into a square rough forming roll device (first forming roll process), and , Four corners R are formed in the cross section of the round steel pipe under cold plastic working.

【0016】その際の加工率を可及的に小さくして鋼管
材質の劣化を回避しながら、丸形断面から外に凸の糸巻
き形断面に鋼管断面を変形させ、これによって、一つに
は、鋼管断面中のコーナーR部およびシーム部の配置を
確定すること、二つには、鋼管断面を規格どおりの角形
にまで熱間変形する加工量を少しでも小さくする。上記
第1成形ロール工程は、前述のように丸鋼管の成形に連
続する冷間塑性加工であるから、同装置に装着した成形
ロールは耐用時間が長く、そのメンテナンスが簡単、容
易である。また、第1成形ロール工程は、丸鋼管成形工
程に連続し、また、冷間塑性加工のために、塑性変形に
よる鋼管材の角形成形性が良い。
At this time, while reducing the working ratio as much as possible to avoid deterioration of the steel pipe material, the cross section of the steel pipe is deformed from a round cross section to a thread winding cross section which protrudes outward. In order to determine the arrangement of the corner R portion and the seam portion in the steel pipe cross section, the second problem is to reduce the amount of hot deformation of the steel pipe cross section to a rectangular shape as specified. Since the first forming roll process is a cold plastic working which is continuous to the forming of the round steel pipe as described above, the forming roll attached to the apparatus has a long service life and its maintenance is simple and easy. In addition, the first forming roll step is continuous with the round steel pipe forming step, and the steel pipe material has good angulation formability by plastic deformation due to cold plastic working.

【0017】連続成形された前記粗成形鋼管を、走間
切断装置などにより、カッタを粗成形鋼管の搬送方向に
同期して間欠的に移動させ、これを単位長ごとに切断す
る。これによって、粗成形鋼管の前後端断面の成形不良
を回避することができる。また、同工程により、それ以
前の第1成形ロール工程と、加熱工程以下の第2成形ロ
ール工程との間を不連続にし、その間に粗成形鋼管収容
スペースを設け、前記単位長粗成形鋼管を保留し、両工
程の間の加工効率の差異を緩衝する。
The cutter is intermittently moved in the continuously formed rough-formed steel pipe in synchronization with the transport direction of the rough-formed steel pipe by a running cutting device or the like, and is cut into unit lengths. As a result, it is possible to avoid poor forming of the front and rear end cross sections of the roughly formed steel pipe. Further, by the same step, the first forming roll step before that and the second forming roll step below the heating step are discontinuous, and a coarsely formed steel pipe accommodation space is provided therebetween, and the unit length coarsely formed steel pipe is removed. Hold and buffer any differences in processing efficiency between the two steps.

【0018】仮りに、インラインで、鋼管全体を鋼板
のA3 変態点まで加熱しようとすれば、化石燃料を用い
た加熱炉のみでは鋼管を所要温度まで加熱するのに前述
のとおり長大な加熱炉の設備が必要になって、生産ライ
ンの立地条件の選択が困難になるおそれがあるが、前記
の方式を採用することによって、生産ラインのスピー
ドを遅くして化石燃料の加熱炉を用いても、その設備長
さを適宜短縮することが可能となる。また、この成形ラ
インであれば、既存の設備を改修して利用する余地が多
分にあり、経済的に設備を更新することができる。
[0018] temporary, in-line, if an attempt heat the entire steel pipe to A 3 transformation point of the steel sheet, long heating furnace as described above to heat the steel pipe only heating furnace using fossil fuels to the required temperature Although the equipment of the above may be required, it may be difficult to select the location conditions of the production line.However, by adopting the above-described method, it is possible to reduce the speed of the production line and use a fossil fuel heating furnace. The length of the equipment can be appropriately reduced. In addition, with this molding line, there is ample room for renovating and using existing equipment, and equipment can be economically updated.

【0019】粗成形鋼管を単位ごとに加熱装置に挿入
し、送りロールにより鋼管を長手方向(または直角方
向)に搬送する間に鋼材のA3 変態点付近まで加熱し
て、冷間塑性加工時に鋼板に生じた加工効果、残留応
力、靭性の低下などに対し材質改善をすると共に、仕上
げ成形ロール段を含む第2成形ロール工程を可及的に鋼
材のA1 変態点以上の温度ですべて熱間加工ができる程
度に同鋼管を加熱する。上述加熱装置(炉)は、立地条
件、設備費、経済性、加熱エネルギーの入手方法、稼働
コストなどを考慮して、ガスまたは石油などの化石燃料
を利用した加熱炉を採用する。しかし、事情が許せば電
力による加熱手段、たとえば電熱加熱方式、高周波加熱
方式などによる加熱手段の採用を除外するものではな
い。
[0019] Insert the crude molded steel pipe to the heating device for each unit, and heated to around A 3 transformation point of the steel material while conveying the steel pipe by feeding a roll in the longitudinal direction (or perpendicular), when cold plastic working processing effects produced on the steel sheet, residual stresses, while the material improvement over such as a decrease in toughness, all heat in the second forming roll step a above the a 1 transformation point of the steel as much as possible a temperature comprised finish forming roll stage The steel pipe is heated to the extent that hot working is possible. The heating device (furnace) employs a heating furnace using a fossil fuel such as gas or petroleum in consideration of location conditions, equipment costs, economics, a method of obtaining heating energy, operating costs, and the like. However, this does not exclude the use of heating means using electric power, for example, an electric heating method or a high-frequency heating method, if circumstances permit.

【0020】前記粗成形鋼管の前記加熱温度が低下し
ないうちに、同鋼管を一本宛、仕上げロール段を含む複
数段よりなる第2成形ロール装置に装入して、熱間塑性
加工のもとに、糸巻き形断面鋼管を規格どおりの断面を
備えた角形鋼管断面形状に成形する。 (a)前記第2成形ロール工程は、前工程において鋼管
断面が一応角形に初期(粗)成形されているため、挿入
される鋼管断面が成形ロールの型になじみ、熱間加工に
よるコーナーR部の変形位置およびシーム部の相対的位
置が断面に対し、安定して形成される。 (b)第2成形ロール工程は、粗成形断面を規格角形断
面に成形するための各段ごとの加工量を小さくすると共
に、断面全周を隙間なく絞るように成形加工(たとえ
ば、本出願人が、さきに出願した特願平4−14200
5号参照)し、規格どおりの断面を正確に成形する。こ
のため、成形鋼管前後端の成形不良部分が極めて少な
く、歩留りがよい。
Before the heating temperature of the crudely formed steel pipe is lowered, the steel pipe is loaded one by one into a second forming roll device comprising a plurality of stages including a finishing roll stage to perform hot plastic forming. At the same time, the thread-wound cross-section steel pipe is formed into a square steel pipe cross-section having a cross section as specified. (A) In the second forming roll step, since the cross section of the steel pipe is initially (roughly) formed into a square shape in the previous step, the cross section of the inserted steel pipe fits into the mold of the forming roll, and the corner R portion is formed by hot working. Are formed stably with respect to the cross section. (B) In the second forming roll step, the forming amount is reduced in each step for forming the rough forming section into the standard square section, and the forming process is performed so that the entire circumference of the section is narrowed without a gap (for example, the applicant of the present invention). Applied for Japanese Patent Application No. 4-1200
No. 5) and accurately form a cross section as specified. For this reason, there are very few molding defects at the front and rear ends of the formed steel pipe, and the yield is good.

【0021】(c)常温程度に冷却された規格断面鋼管
は、次に、矯正ロール機(または矯正プレス機)に装入
され、ここで長手軸方向に生じた大曲り、捩じれなどの
歪矯正のための若干の加工を施す。 (d)第2成形ロール工程は、あらかじめ冷間塑性加工
により鋼管断面を角形に粗成形しているため、規格角形
断面を得るまでの加工量が少なくて済む。 (e)また、熱間塑性変形であるため、材質に再度、残
留応力が増加することなく、靭性の低下に配慮すること
なくコーナーR部の曲率半径を規格値よりも小さく形成
することができる。
(C) The standard-section steel pipe cooled to about room temperature is then loaded into a straightening roll machine (or straightening press machine), where straightening such as large bending and twisting occurring in the longitudinal axis direction is straightened. Apply some processing for (D) In the second forming roll step, the steel pipe section is roughly formed into a rectangular shape by cold plastic working in advance, so that a small amount of processing is required until a standard rectangular cross section is obtained. (E) Further, because of hot plastic deformation, the radius of curvature of the corner R can be formed smaller than the standard value without increasing residual stress in the material again and without considering the decrease in toughness. .

【0022】要するに、圧延鋼帯から冷間成形加工に
て丸鋼管に、その丸鋼管を角形鋼管に成形する段階での
全加工量は、実質的に熱処理され、または熱間塑性加工
のもとに施されているので、鋼板の変形による鋼材の機
械的性質の劣化は全くない。 (a)しかも、同成形工程中、角形成形ロール装置の全
工程が熱間塑性加工に当てられているものに比べ、熱間
塑性の加工量が少ないから、成形ロールのメンテナンス
に余分な労力を費やすことを要さない。 (b)比較的にロール周面が傷みやすい第2成形ロール
装置は、セットにして一括置換、装着が可能なように設
けることによって保守・整備の能率を高めることができ
る。 (c)熱間塑性加工が行われる第2成形ロール装置の駆
動動力は、比較的に小容量のものであって良い。
In short, the total amount of processing at the stage of forming a rolled steel strip into a round steel pipe by cold forming and then forming the round steel pipe into a square steel pipe is substantially heat-treated or subjected to hot plastic working. Therefore, there is no deterioration of the mechanical properties of the steel material due to the deformation of the steel sheet. (A) In addition, in the same forming step, the amount of hot plastic working is smaller than that in which all steps of the square forming roll device are applied to hot plastic working, so that extra labor is required for forming roll maintenance. No need to spend. (B) The efficiency of maintenance / maintenance can be enhanced by providing the second forming roll device in which the roll peripheral surface is relatively easily damaged so as to be able to be replaced and mounted collectively as a set. (C) The driving power of the second forming roll device for performing the hot plastic working may have a relatively small capacity.

【0023】規格断面鋼管は、熱間塑性加工後、その
加熱温度が下がらないうちに成形ロール装置から離れ
て、直ちに冷却装置に搬入され、ここで可及的に均等に
常温付近まで冷却される。冷却装置は、一般的に自然放
冷によるが、たとえば、搬送鋼管の周りから冷却空気を
吹き付けるとか、霧を噴射する機構を設備するとかし、
また、200 ℃以下の角形鋼管には必要に応じて冷却水を
噴射するなどの、角形鋼管の強制冷却手段を装備するこ
ともできる。前述の熱間加工、熱処理などに基づく熱応
力によって冷却後の鋼管に生じる歪みの総和は、無視す
ることができる程度を超えない。また、その程度の歪み
が生じることを許容する冷却スピードに制御・調整する
ようにして、装置のスペースの節減を図る。
After the hot plastic working, the standard-section steel pipe is separated from the forming roll device and immediately carried into the cooling device before the heating temperature is lowered, where it is cooled as much as possible to around room temperature as uniformly as possible. . The cooling device is generally naturally cooled, for example, by blowing cooling air from around the transport steel pipe, or by installing a mechanism to spray mist,
The rectangular steel pipe having a temperature of 200 ° C. or less may be provided with a forced cooling means for the rectangular steel pipe, such as spraying cooling water as necessary. The sum of the strains generated in the steel pipe after cooling by the thermal stress based on the above-mentioned hot working, heat treatment and the like does not exceed a negligible level. In addition, the cooling speed is controlled and adjusted to allow such distortion, thereby saving the space of the apparatus.

【0024】充分に冷却した規格断面鋼管の前後端断
面不良箇所を切り落し、規格長どおりの形状を備えた製
品に成形する。もっとも、歪み矯正機などの工程を経
て、鋼管溶接部の探傷装置による検査を行ってから、製
品を市場に出荷することは当然である。これによって、
鋼管材質の劣化を生ぜず、また、鋼材の靭性を損なうこ
となくコーナーR部をシャープに形成でき、使い勝手が
良く、見映えが良好な商品を作成し、また、同一材料を
用いて断面係数が大きな鋼管を得る。
A sufficiently cooled section of the steel pipe having a cross section at the front and rear ends is cut off to form a product having a shape conforming to the standard length. However, it is natural that the product is shipped to the market after the inspection of the welded portion of the steel pipe by a flaw detector through a process such as a straightening machine. by this,
The corner R part can be formed sharply without deteriorating the steel pipe material and without deteriorating the toughness of the steel material, and it is easy to use and creates a good-looking product. Obtain a large steel pipe.

【0025】本発明工法および装置は、圧延鋼帯から
成形した丸鋼管を連続して粗角形断面に冷間塑性加工に
より成形する第1成形ロール工程の後に、同粗成形鋼管
を単位長に切断して、同鋼管を全体的に鋼材のA3 変態
点近くまで加熱し熱処理を施すことにより、前工程の塑
性加工および突合わせ溶接などにより生じた鋼管の残留
応力を除去し、コーナーR部鋼材の靭性を改善する一
方、第2成形ロール工程において、実質的に熱間塑性加
工により可及的に鋼板のA1 変態点を下らない高温で鋼
管を規格どおりの断面形状に成形するようにして、鋼管
の四隅コーナーR部を略、90゜に曲げることにより生
じる鋼管材質の靭性低下、鋼板の加工硬化、残留応力な
どの材質劣化を改善した、均一で高品質な大径角形鋼管
の成形工法を提供すると共に、経済的にも優秀な装置を
開発したものである。
The method and apparatus according to the present invention are characterized in that after the first forming roll step of continuously forming a round steel pipe formed from a rolled steel strip into a rough rectangular section by cold plastic working, the rough formed steel pipe is cut into unit lengths. to, by performing a heating and heat treated to near a 3 transformation point of overall steel of the same steel, to remove residual stress of the resulting steel pipe due plastic working and butt welding of the previous step, the corner R part steel On the other hand, in the second forming roll step, the steel pipe is formed into a standard cross-sectional shape at a high temperature that does not fall below the A 1 transformation point of the steel sheet as much as possible by substantially hot plastic working, A uniform, high-quality, large-diameter rectangular steel pipe forming method that improves the toughness of the steel pipe material caused by bending the four corners R of the steel pipe to approximately 90 °, work hardening of the steel pipe, and material deterioration such as residual stress. When you provide Both have developed equipment that is economically excellent.

【0026】したがって、本発明工法、装置によれば、
昨今問題視されている大径角形鋼管の隅角部塑性変形に
基づく鋼管コーナーR部の材質劣化の欠陥を実用上差支
えない範囲内に改善することができる。 しかも、従来工法にみられるようなオフラインにおい
て、化石燃料を熱源とする焼鈍炉を設備するものに比べ
て、本発明工法の場合は生産性が高く、実質的に鋼管鋼
材を熱処理している割には、コストに影響するところが
少ない。 また、インラインに設置した従来工法における加熱炉
に比べ設備スペースが小さくて済み、また、既存の設備
を改良する余地もある上に、鋼材の加熱温度の管理およ
び均一加熱の点で優れており、さらに成形加工を高精度
で施すことができるから、結局、本発明工法および装置
によれば、高品質かつ、均一な大径角形鋼管を製造する
ことができる。
Therefore, according to the method and apparatus of the present invention,
It is possible to improve the defect of material deterioration at the corner R of the steel pipe due to plastic deformation at the corner of the large-diameter rectangular steel pipe, which has been regarded as a problem in recent years, within a range that does not hinder practical use. In addition, the method according to the present invention has a higher productivity and is substantially heat-treated for steel pipe steel, compared with the case where an annealing furnace using a fossil fuel as a heat source is installed in an off-line as in the conventional method. Has little effect on cost. In addition, the equipment space is smaller than the heating furnace in the conventional method installed in-line, and there is room for improvement of existing equipment, and it is excellent in terms of controlling the heating temperature of steel materials and uniform heating, Further, since the forming process can be performed with high accuracy, the method and apparatus of the present invention can eventually produce a high-quality and uniform large-diameter rectangular steel pipe.

【0027】[0027]

【実施例】以下に、本発明工法および同工法を実施する
ための大径角形鋼管の製造ラインの一実施例を図面に沿
って説明するが、右ラインを構成する各工程における設
備の具体的構造は、本出願当時の当業界における公知技
術の範囲内で、当業者による任意の部分的変形が可能で
あるから、格別の理由を示すことなしに本実施例記載の
具体的構造のみに基づいて、本発明工法および装置の要
旨を限定的に解釈することは許されない。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention and a production line of a large-diameter rectangular steel pipe for carrying out the same will be described below with reference to the drawings. The structure can be arbitrarily modified by those skilled in the art without departing from the scope of the technology known in the art at the time of the filing of the present application. Therefore, it is not permissible to interpret the gist of the method and apparatus of the present invention in a limited manner.

【0028】図1は、本発明工法および同工法を実施す
る大径角形鋼管の成形装置の一実施例ラインを示す概略
ブロック図で、図2は、前記装置の各工程に対応する肉
厚鋼帯の成形、加工状態を示すものである。図中、材料
の搬送方向に沿って直線的に、1は、アンコイラーで、
コイル状肉厚鋼帯11を巻き戻して、これをレベリングに
掛け、連続的に巻取り歪みを矯正し平面帯鋼板12を成形
する。2は、鋼板幅決め装置で、前記平面帯鋼板12の両
側をトリミングカッターによって切断し、所定幅に形成
する。
FIG. 1 is a schematic block diagram showing an embodiment of the method of the present invention and an apparatus for forming a large-diameter rectangular steel pipe for implementing the method of the present invention. FIG. 2 is a thick steel sheet corresponding to each step of the apparatus. This shows the state of forming and processing the belt. In the figure, 1 is an uncoiler linearly along the material conveyance direction,
The coil-shaped thick steel strip 11 is unwound, applied to leveling, and continuously corrected for winding distortion to form the flat strip steel sheet 12. Reference numeral 2 denotes a steel sheet width determining device which cuts both sides of the flat strip steel sheet 12 with a trimming cutter to form a predetermined width.

【0029】3は、丸鋼管成形ロール装置で、プリフォ
ーム、ブレークダウンロール、クラスター、フィンパス
ロール、高周波溶接装置4、スクイズロール等より成
り、前記帯鋼板12は、同装置を通過する間に、冷間塑性
加工により丸断面の電縫鋼管13に成形される。上記丸鋼
管13は、直径が637 mmであって、板厚は、16mmであつ
た。5は、外面ビード切削機、プルアウトロールなどを
備え、溶接による鋼管の加熱を冷却して、鋼管を均一な
定温まで戻すための冷却ゾーン、6は、第1角形成形ロ
ール装置で、通常、一段より構成され、ここに丸鋼管を
連続して装入し、鋼管断面を冷間塑性加工により、順次
丸断面から粗成形された角形近似断面に変形させる。
Reference numeral 3 denotes a round steel pipe forming roll device, which comprises a preform, a breakdown roll, a cluster, a fin pass roll, a high-frequency welding device 4, a squeeze roll, and the like. Then, it is formed into an electric resistance welded steel pipe 13 having a round cross section by cold plastic working. The round steel pipe 13 had a diameter of 637 mm and a plate thickness of 16 mm. 5 is a cooling zone for cooling the heating of the steel pipe by welding and returning the steel pipe to a uniform constant temperature, which is provided with an external bead cutting machine, a pull-out roll, and the like. A round steel pipe is continuously charged therein, and the cross section of the steel pipe is sequentially deformed from a round cross section to a roughly approximated square cross section by cold plastic working.

【0030】これによって第1角形成形ロール工程を経
て形成された粗成形鋼管14断面は、略、コーナーR部が
成形された外に凸の糸巻き形状であって、その断面周上
での上述コーナーR部および鋼材の突合わせ溶接継手
(シームライン)の相対位置は確定している。要する
に、前記冷間塑性加工によって、角形成形加工の一部を
負担すると共に、最終角形製品の鋼管断面形状の基礎成
形を終了する。7は、走間切断装置であって、連続して
成形した粗成形鋼管14を所定の単位長毎に切断する。8
は、デポジットスペースであって、ここに相当な面積を
割り当て、切断された単位長鋼管14を受け入れて集積
し、かつ、搬送して、それぞれ、単位長鋼管毎、次工程
の加熱装置まで搬送する。
The cross section of the roughly formed steel pipe 14 formed through the first square forming roll process has a substantially thread-shaped outwardly convex shape with a corner R formed therein. The relative positions of the R part and the butt weld joint (seam line) of the steel material are determined. In short, by the cold plastic working, a part of the square forming process is borne, and the basic forming of the sectional shape of the steel pipe of the final square product is completed. Reference numeral 7 denotes a running cutting device, which cuts the continuously formed rough-formed steel pipe 14 at predetermined unit lengths. 8
Is a deposit space, which allocates a considerable area here, receives and accumulates the cut unit length steel pipes 14, and conveys them, respectively, and conveys each unit length steel pipe to the heating device in the next process. .

【0031】20は、加熱装置(炉)であって、本実施例
ではガスまたは液体燃料よりなる化石燃料を熱源とする
加熱炉より成り、単位長粗成形鋼管15を、順次、挿入
し、回転させながら同装置を通過するまでには鋼管の長
手軸方向および直角断面内では、鋼材内外面で、略、均
等温度に加熱され、加熱装置の最終段階での当該加熱温
度は、前記角管粗成形時の残留応力が残らず、コーナー
R部付近の鋼材の靭性を改善できる程度の温度、角形鋼
管の材質、外径および板厚などにもよるが略、900 ℃〜
1050℃程度に加熱されている。
Numeral 20 denotes a heating device (furnace), which in this embodiment is constituted by a heating furnace using a fossil fuel made of gas or liquid fuel as a heat source. Before passing through the same device, the steel pipe is heated to a substantially uniform temperature on the inner and outer surfaces of the steel material in the longitudinal axis direction and in the cross section perpendicular to the longitudinal direction of the steel pipe. Although it depends on the temperature at which there is no residual stress during molding and the toughness of the steel near the corner R can be improved, the material of the square steel pipe, the outer diameter and the plate thickness, it is approximately 900 ° C.
Heated to about 1050 ° C.

【0032】鋼管の板厚および搬送スピードに対する加
熱装置(炉)の容量の大小にもよるが、より高温加熱の
方が冷間塑性加工時における鋼材の加工硬化および残留
応力の除去、靭性の改善について実効があるが、鋼材表
面に対する肌あれ(ミルスケール)の程度は、より低温
加熱のほうが、良好に保持できることは当然である。ま
た、熱処理コストも節減できる。
Depending on the thickness of the steel pipe and the capacity of the heating device (furnace) with respect to the conveying speed, heating at a higher temperature is more effective for work hardening of the steel material during cold plastic working, removal of residual stress, and improvement of toughness. However, the degree of skin roughness (mil scale) with respect to the steel material surface can be maintained better by heating at a lower temperature. Also, heat treatment costs can be reduced.

【0033】21は、第2角形成形ロール装置で仕上げ成
形ロール工程を含み、熱間塑性加工であって、その構成
段は、実質的に三〜六段より構成され、同成形工程の鋼
管断面に対する加工量(度)は、前記角形全加工量の
略、70〜95%を占め、ピンチロール、第2角形成形ロー
ル工程を通過し、規格どおりの角形断面となる。
Reference numeral 21 denotes a second square forming roll device, which includes a finish forming roll step and is hot plastic working, and the constituent steps thereof are substantially composed of three to six steps. (Degree) accounts for approximately 70 to 95% of the total processing amount of the square, passes through the pinch roll and the second square forming roll process, and has a square cross section as specified.

【0034】粗成形単位長鋼管15は、第2成形ロール工
程に掛かる前に加熱されており、高温のままで第2成形
ロール装置21に搬入されるから、そこでは実質上、熱間
塑性変形が行われ、当該角形成形に基づく材質の劣化は
生じない。この工程に使用される成形ロールには、加熱
鋼管15からの熱エネルギーが絶えず伝導・輻射するの
で、ロール、その他に対する冷却手段を設備しなければ
ならない。また、当該工程のロール部材は、ロール疵な
どが生じ易く耐用時間が比較的に短いから、ロール交換
作業、調整作業等の管理が容易である構造、たとえば第
2成形ロール装置は、クレーンを使用して一度に交換可
能なような設備にする。
The rough forming unit long steel pipe 15 is heated before being subjected to the second forming roll process, and is carried into the second forming roll device 21 at a high temperature. Is performed, and the material is not deteriorated based on the corner forming shape. Since the heat energy from the heated steel pipe 15 is constantly transmitted and radiated to the forming roll used in this step, a cooling means for the roll and the like must be provided. In addition, since the roll member in the process is liable to cause roll flaws and the like and the service life thereof is relatively short, a structure in which the roll exchange operation, the adjustment operation, and the like can be easily managed, for example, a second forming roll device uses a crane Equipment that can be replaced at one time.

【0035】22は、規格成形断面鋼管15の冷却装置で、
この冷却ゾーンでは搬入された前記鋼管15を、同一断面
内では、対象的に略、均等に、長手軸方向には略、均一
に冷却することが求められている。同冷却ゾーンにおい
て、熱間成形および冷却装置の熱制御から外れた不均一
な温度分布によって、鋼管の軸方向の曲がり、断面形状
の歪み、板厚方向に対する凹み、ゆがみ等が生じるとし
ても、その大きさは微々たるものと見てよい。また、冷
却装置22における単位長鋼管15の冷却スピードは、略、
上述程度の鋼材の変形を許容することを前提とし、結
局、その鋼管温度を略、室温近くまで冷やす。この段階
において、鋼管材は全体として、母材に近い靭性を維持
し、残留応力は殆どない状態を保持している。
Reference numeral 22 denotes a cooling device for the standard-shaped section steel pipe 15,
In the cooling zone, it is required that the steel pipe 15 carried in is cooled substantially and uniformly in the same cross section and substantially uniformly in the longitudinal axis direction. In the same cooling zone, even if the non-uniform temperature distribution deviates from the heat control of the hot forming and cooling device, bending of the steel pipe in the axial direction, distortion of the cross-sectional shape, dent in the sheet thickness direction, distortion, etc. will occur. The size may be considered insignificant. The cooling speed of the unit length steel pipe 15 in the cooling device 22 is substantially
On the premise that the above-described deformation of the steel material is allowed, the temperature of the steel pipe is eventually cooled to approximately the room temperature. At this stage, the steel pipe material maintains the toughness close to that of the base material as a whole, and keeps almost no residual stress.

【0036】この第2成形ロール加工によって、鋼管断
面形状を規格どおりの断面形状に成形し、コーナー材質
の劣化を招くことなく、当該部分を均一に、かつ、シャ
ープに、たとえば、略、R=(2〜2.5)×tに成形
する。ただし、R=外側曲率半径、t=鋼管素材の板厚
By this second forming roll processing, the cross-sectional shape of the steel pipe is formed into a standard cross-sectional shape, and the portion is uniformly and sharply formed without deteriorating the corner material. (2 to 2.5) × t. Where R = outer radius of curvature, t = thickness of steel pipe material

【0037】23は、規格長角形鋼管16の長手軸方向の大
曲り、捩じれ等の歪の矯正機および溶接継手、その他の
部分の超音波などによる探傷検査器。24は、両端切断機
であって、単位長規格断面鋼管15の両端の、第2成形ロ
ール加工によって生じた不良断面部分を切断し、規格長
角形鋼管(製品)16とする。25は、製品搬出テーブルで
あって、前記規格長鋼管16を収容、保管する。
Reference numeral 23 denotes a machine for correcting a distortion such as a large bend or torsion of the standard rectangular steel pipe 16 in the longitudinal axis direction, a welded joint, and a flaw detector for ultrasonic inspection of other parts. Numeral 24 denotes a both-end cutting machine, which cuts the defective cross-section portions at both ends of the unit-length standard cross-section steel pipe 15 caused by the second forming roll processing to obtain a standard rectangular steel pipe (product) 16. Reference numeral 25 denotes a product carry-out table, which accommodates and stores the standard-length steel pipe 16.

【0038】図2中、11は、熱間圧延鋼帯、12は、平面
を構成する肉厚帯鋼板、13は、丸鋼管、14は、第1角形
成形ロールにより冷間加工された粗成形鋼管、15は、第
2成形ロール装置により熱間塑性成形された規格断面鋼
管で、その大きさは、たとえば、500 mm角である。16
は、同型の規格長製品を示している。本実施例工法およ
び装置により加工し得る鋼板の板厚は、差し当たり、9
〜28mm、角形鋼管外径は、略、200 mm〜600 mmを、予定
している。以上のとおりであって、本実施例における、
その他の作用、効果の詳細は、さきに述べた(作用)の
項に詳説したとおりであるから、省略する。
In FIG. 2, reference numeral 11 denotes a hot-rolled steel strip, 12 denotes a thick steel strip constituting a plane, 13 denotes a round steel pipe, and 14 denotes a rough forming cold-worked by a first square forming roll. The steel pipe 15 is a standard-section steel pipe hot-plastically formed by the second forming roll device, and its size is, for example, 500 mm square. 16
Indicates a standard-length product of the same type. The thickness of the steel sheet that can be processed by the method and apparatus of the present embodiment is 9
The outer diameter of the square steel pipe is about 200 mm to 600 mm, which is about 28 mm. As described above, in the present embodiment,
The details of the other functions and effects are the same as those described in the section of (function) described above, and thus will not be described.

【0039】[0039]

【発明の効果】本発明工法および装置は、以上述べたと
おりであるので、 (1)冷間塑性加工により成形されている従来の大径角
形鋼管において問題視されている肉厚鋼管材質の加工硬
化、コーナーR部の靭性の劣化を改善し、また、鋼材に
生じた残留応力を除去して許容量以下にすると共に、全
体的に高品質の大径角形鋼管を形成できる。 (2)材質の劣化を伴なうことなくコーナーR部を可及
的にシャープに、かつ、それぞれ均一にした角形鋼管を
成形して、使い勝手を良好にし、商品の見映えを良くす
る一方、同一鋼材を用いて、より丈夫で商品価値の高
い、かつ、品質の良い鋼管を提供する。
The method and apparatus of the present invention are as described above. (1) Processing of a thick steel pipe material which is regarded as a problem in a conventional large-diameter rectangular steel pipe formed by cold plastic working. Hardening and deterioration of toughness of the corner R portion can be improved, and residual stress generated in the steel material can be reduced to an allowable value or less, and a high-quality large-diameter rectangular steel pipe can be formed as a whole. (2) The corner R portion is formed as sharply as possible without deteriorating the material, and a square steel tube is formed, each of which is uniform, to improve the usability and improve the appearance of the product. Using the same steel material, we will provide more durable, high commercial value, and high quality steel pipes.

【0040】(3)丸鋼管を冷間加工により初期(予
備)成形して角形鋼管断面上でのコーナーR部およびシ
ームラインの位置を確定したので、角形断面を熱間成形
しているにもかかわらず、製品上でのシームラインの位
置を常に一定(一辺の平坦面の中央部近傍)に保持する
ことができる。 (4)角形ロール成形に当たり、鋼管両端の断面不良部
の長さが著しく少なく、歩留まりが向上する。 (5)その他、前述(作用)の項において述べた各効果
を奏する。 等々、従来公知の工法および装置には期待することがで
きない、格別の作用、効果を奏するものとなる。
(3) Since the round steel pipe is initially (preliminarily) formed by cold working to determine the positions of the corner R and the seam line on the cross section of the square steel pipe, the round cross section is hot formed. Regardless, the position of the seam line on the product can always be kept constant (near the center of a flat surface on one side). (4) In forming the square roll, the length of the defective section at both ends of the steel pipe is extremely small, and the yield is improved. (5) In addition, each of the effects described in the above section (action) is exhibited. For example, special functions and effects that cannot be expected from conventionally known methods and apparatuses are exhibited.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明工法を実施する大径角形鋼管成形装置の
一実施例ラインのブロック図。
FIG. 1 is a block diagram of an embodiment line of a large-diameter rectangular steel pipe forming apparatus for implementing the method of the present invention.

【図2】前記装置中の各工程に対応する鋼管、鋼材の断
面形状図。
FIG. 2 is a sectional view of a steel pipe and a steel material corresponding to each step in the apparatus.

【符号の説明】[Explanation of symbols]

1 アンコイラー 2 鋼帯幅決め装置 3 丸鋼管成形ロール(冷間) 4 高周波溶接装置 5 冷却ゾーン 6 第1角形成形ロール装置(冷間) 7 走間切断装置 8 デポジットスペース 11 熱間圧延鋼帯 12 肉厚帯鋼板 13 電縫丸鋼管 14 粗成形角形鋼管 15 単位長角形鋼管 16 製品 20 加熱装置 21 第2角形成形ロール装置(熱間) 22 冷却装置 23 歪矯正機、探傷検査器 24 両端切断機 25 製品搬出テーブル。 REFERENCE SIGNS LIST 1 uncoiler 2 steel strip width determining device 3 round steel tube forming roll (cold) 4 high frequency welding device 5 cooling zone 6 first square forming roll device (cold) 7 running cutting device 8 deposit space 11 hot rolled steel strip 12 Thick strip steel plate 13 ERW round steel pipe 14 Rough-formed rectangular steel pipe 15 Unit rectangular steel pipe 16 Product 20 Heating device 21 Second square forming roll device (hot) 22 Cooling device 23 Strain straightening machine, flaw detector 24 Both ends cutting machine 25 Product delivery table.

───────────────────────────────────────────────────── フロントページの続き (73)特許権者 598134835 中島 伸 東京都武蔵野市吉祥寺本町4丁目26番27 号 (72)発明者 中島 拓 兵庫県伊丹市緑ケ丘3−70 (56)参考文献 特開 昭61−115614(JP,A) 特開 平1−266913(JP,A) 特開 平3−97810(JP,A) 特開 平3−151117(JP,A) (58)調査した分野(Int.Cl.6,DB名) B21C 37/15──────────────────────────────────────────────────続 き Continued on the front page (73) Patent holder 598134835 Shin Nakajima 4-26-27 Kichijoji Honmachi, Musashino City, Tokyo (72) Inventor Taku Nakajima 3-70 Midorigaoka, Itami City, Hyogo Prefecture (56) References JP JP-A-61-115614 (JP, A) JP-A-1-266913 (JP, A) JP-A-3-97810 (JP, A) JP-A-3-151117 (JP, A) (58) Fields investigated (Int .Cl. 6 , DB name) B21C 37/15

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 鋼帯または鋼板を長手軸方向に直角断面
で丸形に成形し、その両側縁継目を順次突合わせ溶接し
形成した丸鋼管を、複数段よりなる角形鋼管成形ロール
装置に搬送し、丸鋼管断面を順次角形断面に成形する工
程において、前記角形鋼管成形ロール工程を、第1成形
工程および第2成形工程に二分し、その第1成形工程に
おいて丸鋼管を粗角形成形すると共に、第1成形工程と
第2成形工程との中間に、前記粗成形鋼管を単位長に切
断する工程、前記単位長粗成形鋼管を加熱する加熱装置
を配置し、単位鋼管毎に加熱装置に挿入して所定温度に
均等に加熱した後、前記高温単位長粗成形鋼管を仕上げ
成形ロールを含む複数段よりなる第2成形工程に搬入し
て熱間塑性加工を施し、少なくとも規格どおりの断面を
備えた角形鋼管を成形し、次に前記規格断面鋼管を均一
に冷却する冷却装置を設置し、同鋼管を徐冷または強制
適に冷却した後、長手軸方向の大曲り、捩じれなどの歪
を矯正することを特徴とする熱間成形を含む大径角形鋼
管製造法。
1. A round steel pipe formed by forming a steel strip or a steel sheet into a round shape with a cross section perpendicular to the longitudinal axis direction, and butt-welding both side edge joints thereof sequentially to a square steel pipe forming roll device comprising a plurality of stages. Then, in the step of sequentially forming the round steel pipe cross-section into a square cross section, the square steel pipe forming roll step is divided into a first forming step and a second forming step, and in the first forming step, the round steel pipe is formed into a coarse angle. A step of cutting the coarsely formed steel pipe into a unit length, a heating device for heating the unit length coarsely formed steel pipe disposed between the first forming step and the second forming step, and inserting the united steel pipe into the heating apparatus. After uniformly heating to a predetermined temperature, the high-temperature unit-length coarsely formed steel pipe is carried into a second forming step including a plurality of steps including a finish forming roll and subjected to hot plastic working, and has at least a cross section as specified. Formed square steel pipe Forming and then installing a cooling device for uniformly cooling the steel pipe with the specified cross section, gradually cooling or forcibly cooling the steel pipe, and then correcting a distortion such as a large bending in the longitudinal axis direction and a twist. Large diameter square steel pipe production method including hot forming.
【請求項2】 鋼帯または鋼板を長手軸方向に直角な断
面で丸形に成形し、その両側縁継目を順次突合わせ溶接
し形成する丸鋼管成形装置、前記装置に連結され丸鋼管
断面を冷間加工により粗成形する第1角形成形ロール装
置、前記第1角形成形ロール装置により成形された粗成
形断面を有する鋼管を単位長毎に切断する切断装置、前
記単位長粗成形鋼管を所定温度に均等に加熱する加熱装
置、加熱装置から搬出した前記高温単位長粗成形鋼管を
挿入し、熱間塑性加工により前記鋼管断面を規格どおり
の角形形状断面に成形する仕上げ成形ロールを含む複数
段よりなる第2角形成形ロール装置、前記規格断面鋼管
を均一に冷却する冷却装置、長手軸方向の大曲り、捩じ
れなどの歪を矯正する装置とよりなる熱間成形を含む大
径角形鋼管製造装置。
2. A round steel pipe forming apparatus for forming a steel strip or a steel sheet into a round shape with a cross section perpendicular to the longitudinal axis direction, and butt-welding both side edge joints thereof sequentially. A first square forming roll device for roughly forming by cold working, a cutting device for cutting a steel pipe having a rough forming cross section formed by the first square forming roll device for each unit length, and a predetermined temperature for the unit length roughly formed steel tube. A plurality of stages including a heating device for evenly heating the steel tube inserted from the heating device, a finish forming roll for forming the steel tube cross-section into a rectangular cross-section according to a standard by inserting the high-temperature unit-length roughly-formed steel pipe, and performing hot plastic working. A large-diameter rectangular steel pipe manufacturing apparatus including hot forming comprising a second square forming roll device, a cooling device for uniformly cooling the steel pipe having the specified cross section, and a device for correcting distortion such as large bending and twisting in the longitudinal axis direction. .
JP30157992A 1992-10-15 1992-10-15 Method and apparatus for manufacturing large diameter square steel pipe including hot forming Expired - Lifetime JP2852313B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP30157992A JP2852313B2 (en) 1992-10-15 1992-10-15 Method and apparatus for manufacturing large diameter square steel pipe including hot forming

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30157992A JP2852313B2 (en) 1992-10-15 1992-10-15 Method and apparatus for manufacturing large diameter square steel pipe including hot forming

Publications (2)

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JPH06122019A JPH06122019A (en) 1994-05-06
JP2852313B2 true JP2852313B2 (en) 1999-02-03

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011121112A (en) * 2009-12-11 2011-06-23 Sango Co Ltd Method of manufacturing special-shaped tube
CN105268772A (en) * 2014-07-22 2016-01-27 广东冠邦科技有限公司 High-precision straightening machine for externally-square and internally-circular tubes

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JPH06122019A (en) 1994-05-06

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