JP2852311B2 - Forming method and equipment for large diameter square steel pipe - Google Patents

Forming method and equipment for large diameter square steel pipe

Info

Publication number
JP2852311B2
JP2852311B2 JP27631591A JP27631591A JP2852311B2 JP 2852311 B2 JP2852311 B2 JP 2852311B2 JP 27631591 A JP27631591 A JP 27631591A JP 27631591 A JP27631591 A JP 27631591A JP 2852311 B2 JP2852311 B2 JP 2852311B2
Authority
JP
Japan
Prior art keywords
steel pipe
forming
steel
section
square
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.)
Expired - Lifetime
Application number
JP27631591A
Other languages
Japanese (ja)
Other versions
JPH0592214A (en
Inventor
功雄 中島
拓 中島
教雄 中島
伸 中島
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NAKAJIMA KOKAN KK
Original Assignee
NAKAJIMA KOKAN KK
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Application filed by NAKAJIMA KOKAN KK filed Critical NAKAJIMA KOKAN KK
Priority to JP27631591A priority Critical patent/JP2852311B2/en
Publication of JPH0592214A publication Critical patent/JPH0592214A/en
Application granted granted Critical
Publication of JP2852311B2 publication Critical patent/JP2852311B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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、大径角形鋼管のコーナ
ーR部材質の残留応力を除去すると共に、材質の劣化を
回復し、特に、当該鋼材について伸びの著しい低下と降
伏点比の上昇を改善した厚肉大径角形鋼管の熱処理工程
を含む成形工法および、その装置にかかり、より詳しく
は、厚肉の一枚鋼板を冷間プレス加工により、その長手
方向に平行して複数回曲げ、縁部を突合わせ溶接して、
その断面を五角形近似または六角形近似の鋼管を形成し
た後、加熱装置に装入して前記鋼管を所定温度に均一に
加熱することにより、少なくとも、それ以前に鋼板に加
えられた冷間塑性変形、その他に基づき生じる鋼材の加
工硬化、歪み、材質の劣化などを改善・調質するととも
に、同鋼管を徐冷した後、冷間塑性加工により鋼管断面
を規格どおりの角形形状に成形すると共に、熱処理に基
づき生じた鋼管の歪み、捩じれ、曲がり等を矯正し、あ
わせて材質の強化を図ることを特徴とする大径角形鋼
管、特に、そのコーナーR部材質の残留応力の除去と靭
性を改善するようにした肉厚大径角形鋼管の成形工法お
よび装置に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention eliminates the residual stress in the material of the corner R of a large-diameter rectangular steel pipe and recovers the deterioration of the material. In particular, the steel material has a remarkable decrease in elongation and an increase in the yield point ratio. The forming method including the heat treatment process for thick-walled large-diameter rectangular steel pipe with improved thickness, and its equipment. More specifically, a thick single-walled steel plate is bent multiple times in parallel with its longitudinal direction by cold pressing. Butt-weld the edges,
After forming a pentagonal or hexagonal approximation of the cross-section of the steel pipe, it is inserted into a heating device to uniformly heat the steel pipe to a predetermined temperature, so that at least the cold plastic deformation previously applied to the steel sheet In addition to improving and refining the work hardening, distortion, material deterioration, etc. of the steel material generated based on others, after gradually cooling the steel pipe, the cross section of the steel pipe is formed into a square shape as specified by cold plastic working, A large-diameter rectangular steel pipe characterized by correcting the distortion, torsion, bending, etc. of the steel pipe caused by the heat treatment, and at the same time, strengthening the material. TECHNICAL FIELD The present invention relates to a method and an apparatus for forming a large-diameter rectangular steel pipe having a large wall thickness.

【0002】[0002]

【従来の技術】鉄骨構造物のコラムとして需要が伸びて
いる厚肉大径角形鋼管のプレス加工を利用する量産方法
には、従来、略、次のような工法が知られている。 一枚鋼板を、その長手軸方向に並行して複数回、冷間
プレス加工により、それぞれの個所を、略、90°近くに
曲げ、 前記鋼板の長手軸方向直角断面を、略、一部開口した
五角形近似形状に成形する。または、同断面を、略、コ
字形断面形状に成形する。
2. Description of the Related Art As a mass production method utilizing press working of a thick-walled large-diameter rectangular steel pipe, which is growing in demand as a column of a steel structure, the following construction methods are generally known. A single steel sheet is bent a plurality of times in parallel with its longitudinal axis direction by cold pressing, and each portion is bent to approximately 90 °, and a cross section perpendicular to the longitudinal axis direction of the steel plate is substantially partially opened. Into an approximated pentagonal shape. Alternatively, the cross section is formed into a substantially U-shaped cross section.

【0003】前記五角形近似鋼材の長手軸方向前後両
端を溶接をしてつなぎ、長手軸方向に連続した前記鋼材
を形成した後、これを複数段よりなる角形鋼管成形ロー
ルに装入して、冷間加工により、その断面を角形に成形
しつつ、高周波または電弧溶接法によって長手軸方向継
目を突合せ溶接し、規格どおりの断面角形の厚肉鋼管を
成形し、次に、矯正ロールに掛け、 または、前記コ字形断面鋼材を一対向き合わせて六角
形近似鋼管を形成し、相互の脚端を突合せ溶接して六角
形近似鋼管としてから、その長手軸方向前後端を互いに
溶接してつなぎ、軸方向に連続した前記鋼管を形成し
て、これを複数段の角形鋼管成形ロールに装入し、冷間
塑性加工により、その断面を規格どおりの角形形状に成
形する。 その後、鋼管の前記直角溶接部を切断して、規格長の
大径角形鋼管を形成する。
[0003] The pentagonal approximation steel material is welded and connected at both ends in the longitudinal axis direction to form the steel material continuous in the longitudinal axis direction. The steel material is charged into a rectangular steel tube forming roll composed of a plurality of stages and cooled. While forming the cross section into a square shape by hot working, butt welding of the longitudinal axis seam by high frequency or electric arc welding method to form a thick steel pipe with a square cross section according to the standard, and then hang it on a straightening roll, or A pair of the U-shaped cross-section steel members face each other to form a hexagonal approximation steel pipe, and butt-weld the legs of each other to form a hexagonal approximation steel pipe. The steel pipe is formed into a plurality of stages of a square steel pipe forming roll, and the cross section thereof is formed into a square shape as specified by cold plastic working. Thereafter, the right-angle welded portion of the steel pipe is cut to form a large-diameter rectangular steel pipe having a standard length.

【0004】上述角形鋼管の成形工法においては、いず
れの場合にも鋼管コーナーR部成形のために平坦な厚肉
鋼板を折り曲げプレス型および/または成形ロールなど
の冷間塑性加工によって略、90゜曲げる工程が含まれて
いる。ところで、厚肉鋼板を冷間で、略、90゜曲げ加工
をした場合には、前記コーナーR部の鋼板断面における
中立面を境にして、引張り力または圧縮力が働きながら
変形が行われるため、当該素材の塑性変形が著しく進
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、同部分に脆性破壊が生じる条件が備わる。たとえ
ば、冷間曲げ加工によって形成した鋼管コーナーR部に
は、当該材質の歪み硬化、靭性低下、高い残留応力等が
相俟って、冬期低温時に施す溶接加工に基づく溶接割
れ、溶融亜鉛メッキ施工の際の割れなどが発生する場合
がある。また、これらの割れの存在、その他母材の微小
欠陥により、低温で使用し大負荷が加わったときに、脆
性破壊が発生するおそれがある。
[0004] In the above-described method of forming a square steel pipe, in each case, a flat thick steel plate is bent at about 90 ° by cold plastic working such as a press die and / or a forming roll to form a steel pipe corner R portion. A bending step is included. By the way, when a thick steel plate is coldly bent by approximately 90 °, deformation is performed while a tensile force or a compressive force acts on the neutral surface in the steel plate cross section at the corner R. For this reason, the plastic deformation of the material is remarkably progressed, and the mechanical properties of the deformed portion, particularly the corner R member material, are deteriorated, and a condition for causing brittle fracture in the same portion is provided. For example, in the corner R of a steel pipe formed by cold bending, due to the combination of strain hardening, reduced toughness, and high residual stress of the material, welding cracking based on welding performed at low temperature in winter, hot-dip galvanizing In some cases, cracking may occur. In addition, due to the presence of these cracks and other small defects in the base material, brittle fracture may occur when used at a low temperature and a large load is applied.

【0005】この種の大径角形鋼管をコラムとして使用
する鉄骨構造物、建築物等は一般に、長期にわたり構造
物に対して所定の荷重にも安全に耐えることが要求さ
れ、しかも、一度施工した後は、これらのコラムは原則
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、各階毎に冷暖房装置を設備する、OA機
器、電算機の類が配置されるなど、建物に付帯する設備
重量が増加する傾向にあるため、対策として厚肉大径角
形鋼管を柱材として採用するケースが増加する傾向があ
るので、冷間プレス加工の厚肉角形鋼管に内在する上述
のような鋼管材質の劣化の問題は、ますます無視できな
い状況になっている。
[0005] Generally, steel structures, buildings, and the like using such a large-diameter rectangular steel pipe as a column are required to safely withstand a predetermined load on the structure for a long period of time. Later, these columns are often constructed in such a way that they cannot be replaced or repaired in principle. Particularly in recent buildings, high-rise buildings occupy the mainstream, and the weight of equipment attached to the building tends to increase, such as installation of air conditioning and heating equipment for each floor, OA equipment and computers, etc. Therefore, as a countermeasure, there is a tendency to increase the case of adopting a thick-walled large-diameter rectangular steel pipe as a column material, so the problem of deterioration of the steel pipe material as described above inherent in the cold-pressed thick-walled rectangular steel pipe is as follows. It is increasingly difficult to ignore.

【0006】このような事情に鑑み、厚肉鋼管成形時に
おけるコーナーR部の冷間プレス加工に基づく材質の劣
化が、改めて問題視されている。そこで、近来、充分な
靭性を備え、残留応力の少ないコーナーR部材質を備え
た高品質の角形鋼管の提供が需要者層から要望されてい
る。
[0006] In view of such circumstances, the deterioration of the material due to the cold pressing of the corner R at the time of forming a thick-walled steel pipe is regarded as a problem again. Therefore, recently, there has been a demand from customers for providing a high-quality rectangular steel pipe having sufficient toughness and a corner R member quality with little residual stress.

【0007】冷間成形による厚肉大径角形鋼管が内包す
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た加熱装置によ
って加熱し、複数段の圧延機を通して熱間塑性加工によ
り、断面角形にすることを提案した。上記工法によると
きは、製品の品質は良好であるが、鋼管の両端部が形状
不良になり材料の歩留まりが悪いとか、加熱、冷却時に
生じる歪みを無視できないとか、鋼管を一本宛加工する
ので生産が低いとかいった問題点がある。
[0007] In order to solve this kind of material problem in which a thick-walled large-diameter rectangular steel pipe formed by cold forming is included, a manufacturer has conventionally used an existing round steel pipe, a seamless pipe, or the like to remove oil, gas or the like. It has been proposed that fossil fuel or electric energy is heated by a heating device using a heat source, and that the cross section is made square by hot plastic working through a multi-stage rolling mill. When the above method is used, the quality of the product is good, but the shape of both ends of the steel pipe is poor and the yield of the material is poor, the distortion generated during heating and cooling cannot be ignored, or the steel pipe is processed one by one. There is a problem such as low production.

【0008】別に成形済みの大径角形鋼管を焼鈍炉に
装入して、材質中の残留応力が、略、除去される温度ま
で全体的に加熱し、コーナーR部材質の靭性を改善した
後、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
形ロールスタンドおよび電弧溶接、高周波溶接装置など
を通し冷間塑性加工により丸鋼管に成形した後、同鋼管
を電気エネルギー、ガスまたは油等の化石燃料を利用し
た加熱装置に装入して加熱し、かつ、複数段の成形ロー
ル装置を通し、断面角形鋼管に熱間塑性成形した後、徐
冷し、製品にする(たとえば、本出願人が、さきに出願
した、特願平2−180497号参照のこと)ことも提案され
ている。
[0008] A separately formed large-diameter rectangular steel pipe is charged into an annealing furnace, and the residual stress in the material is generally heated to a temperature at which the residual stress is substantially removed to improve the toughness of the corner R member material. Also, a slow cooling method is known. In this case as well, there may be similar problems as described above. Alternatively, a hot-rolled coil is hung on a leveler and formed into a round steel pipe by cold plastic working through various forming roll stands, electric arc welding, high-frequency welding equipment, etc., and the steel pipe is then subjected to fossil fuel such as electric energy, gas or oil. And heated through a multi-stage forming roll device, hot-plastically formed into a square-section steel pipe, and then gradually cooled to produce a product (for example, Japanese Patent Application No. 2-180497, filed earlier, has also been proposed.

【0009】(a)上述工法は、加熱時におけるの熱的
不均一、特に冷却時の不均一温度分布による鋼管の変形
が問題であり、それを均一温度分布にするため冷却ライ
ンを充分長く取り、徐冷する必要がある。また、均一徐
冷しても丸鋼管と異なり、角形鋼管では冷却時の熱気流
の流れがコーナーR部周辺で乱れるから、均一冷却温度
を維持することが難しい。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、極め
て困難である。 (b)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
いのでロール段数が多いほどメンテナンスが面倒であ
る。
(A) The above-mentioned method has a problem of thermal non-uniformity at the time of heating, particularly deformation of the steel pipe due to non-uniform temperature distribution at the time of cooling, and a sufficiently long cooling line is required to make the temperature distribution uniform. It is necessary to cool slowly. In addition, unlike a round steel pipe, even in the case of uniform slow cooling, it is difficult to maintain a uniform cooling temperature in a square steel pipe because the flow of hot air flow during cooling is disturbed around the corner R. Then, once the steel pipe is deformed, it is extremely difficult to correct it in the case of a square steel pipe. (B) Further, the forming roll used for hot plastic working tends to have slip flaws on the peripheral surface of the roll and has a short service life. Therefore, the maintenance is troublesome as the number of roll stages increases.

【0010】(c)製造ライン中に、ガス、油等の化石
燃料を利用する加熱炉を設備する場合は、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
形成するためには、ある程度の溶接スピードが要求され
る)ために、角形鋼管の内部応力が、略、完全に解消す
るA3 変態点温度まで鋼材を加熱するのに、ラインの中
途に、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
らむおそれがある。加えて、ガス、油等の化石燃料を丸
鋼管の加熱に利用すると、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、鋼管断面の成形形状、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場合もあり得る。
(C) When a heating furnace utilizing fossil fuels such as gas and oil is installed in the production line, the forming speed of the steel pipe is high (in order to form good welding quality by using a high frequency welding method). in it is required a certain degree of welding speed) to the internal stress of the square tube is substantially, to heat the steel up to a 3 transformation point temperature to completely eliminate, the middle of the line, 100 M~150 A space for installing a heating furnace having a length of m is required, and the production line becomes too long, which makes it difficult to select location conditions, or the amount of capital investment may increase more than expected. In addition, if fossil fuels such as gas and oil are used for heating the round steel pipe, it is difficult to heat the steel pipe uniformly because the heat source cannot be put inside the steel pipe, and it is difficult to control the temperature of the steel pipe heating. There is a problem, because this is related to the shape of the cross section of the steel pipe, the occurrence of distortion,
As a result, products of equal quality may not be obtained.

【0011】(d)一方、電気エネルギーを利用した加
熱装置は、加熱のためのスペースが小さくて済み、鋼材
の均一加熱ならびに加熱温度の管理を徹底することがで
きる利点があるものの、電力コストが高くかかり、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で
ある場合がある。等々の技術的問題点があることが知ら
れている。
(D) On the other hand, a heating device using electric energy requires a small space for heating, and has the advantage that the steel material can be uniformly heated and the heating temperature can be thoroughly controlled, but the power cost is low. It may be expensive, and it may be difficult to obtain the required large capacity power depending on the location conditions. 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、角形鋼管の靱
性を改善すると共に、残留応力を許容限度以下にし、均
一、かつ、安定化した高品質の大径角形鋼管を製造する
工法および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、知られているオフラインまた
はインライン熱処理装置による均一な材質よりなる角形
鋼管の成形工法、装置に内在する上述問題点を可及的に
解消する新規な熱処理工程を含む大径角形鋼管成形工法
および装置を開発することにある。
SUMMARY OF THE INVENTION The present invention has been developed in view of the circumstances described above, and has been developed to improve the toughness of a rectangular steel pipe, reduce residual stress to below an allowable limit, and achieve uniform and stable operation. It is an object of the present invention to provide a method and an apparatus for manufacturing a high-quality large-diameter rectangular steel pipe. Another object of the present invention is to provide a method for forming a square steel pipe made of a uniform material using a conventionally known off-line or in-line heat treatment apparatus, and a novel heat treatment that minimizes the above-described problems inherent in the apparatus. An object of the present invention is to develop a method and an apparatus for forming a large-diameter rectangular steel pipe including processes.

【0013】[0013]

【課題を解決するための手段】本発明は、上述の目的を
達成するために、以下に述べるとおりの各構成要件を具
備する。 (1) 一枚厚肉鋼板を、プレス加工により長手軸方向
に沿い複数回曲げ、各コーナーR部を形成し、その断面
を一部開口した五角形またはコ字形に成形した後、長手
軸方向継目を溶接して断面五角形近似または六角形近似
の半成形鋼管を形成し、前記鋼管を所定温度に均一加熱
して熱処理した後、鋼管全体を常温付近の温度まで冷却
し、角形成形ロール工程に装入して、前記半成形鋼管を
冷間塑性加工により、規格に沿った角形断面鋼管に形成
することを特徴とする大径角形鋼管の成形工法。
SUMMARY OF THE INVENTION The present invention has the following components in order to achieve the above object. (1) A single thick steel plate is bent a plurality of times along the longitudinal axis direction by press working to form each corner R portion, and the cross section thereof is formed into a partially opened pentagon or U-shape, and then joined in the longitudinal axis direction. To form a semi-formed steel pipe having a pentagonal or hexagonal cross-section and uniformly heating the steel pipe to a predetermined temperature and then heat-treating the entire steel pipe to a temperature near room temperature, and then mounting the pipe in a square forming roll process. And forming the semi-formed steel pipe into a square-section steel pipe conforming to the standard by cold plastic working.

【0014】(2) 一枚厚肉鋼板を、長手軸方向に沿
い複数回折り曲げ各コーナーR部を形成し、その断面を
一部開口した五角形またはコ字形に成形するプレス装
置、前記開口部を閉じ、その継目を長手軸方向に溶接し
て断面五角形近似鋼管を形成するか、コ字形材を一対向
き合わせて相対する脚部を突合せ溶接し、六角形近似形
状の半成形鋼管を形成する溶接装置、前記鋼管を所定温
度に均一加熱する加熱装置、冷却装置、前記角形半成形
鋼管断面を冷間塑性加工により規格に沿った角形断面に
整形する、複数段よりなる角形成形ロール装置とより成
ることを特徴とする大径角形鋼管の成形装置。
(2) A single thick-walled steel plate is bent a plurality of times along the longitudinal axis direction to form each corner R portion, and a cross section thereof is formed into a pentagon or U-shape with a partially open cross section. Close and weld the seam in the longitudinal axis direction to form a pentagonal approximate steel pipe, or butt-weld a pair of U-shaped members facing each other to form a semi-formed steel pipe with a hexagonal approximate shape An apparatus, a heating apparatus for uniformly heating the steel pipe to a predetermined temperature, a cooling apparatus, and a square forming roll apparatus comprising a plurality of stages for shaping the cross section of the square semi-formed steel pipe into a square cross section conforming to a standard by cold plastic working. An apparatus for forming a large-diameter rectangular steel pipe.

【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プレ
ス加工に基づく厚肉鋼管材質の靭性の低下、残留応力の
増加等、材質の劣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、 冷間プレス加工によりワンシームまたはツーシームの
角形近似鋼管を成形した後、同鋼管を角形成形ロール工
程に送り込む前に、鋼管全体を加熱装置に通し、鋼材を
1 変態点またはA3 変態点近くまで均一に加熱するこ
とにより、それ以前に施された冷間プレス加工等に基づ
き生じた鋼材の残留応力を解消、局部鋼材の靭性の改
善、溶接歪みの除去を図る。
[Function] The material defects that have been regarded as problems with large-diameter rectangular steel pipes on the market include the reduction of toughness and the increase in residual stress of thick steel pipe materials based on cold pressing during the steel pipe forming process. This is the weakening of the structural material due to the deterioration of the material. (1) In view of the circumstances described above, in the present invention, after forming a one-seam or two-seam square approximate steel pipe by cold pressing, the entire steel pipe is supplied to a heating device before the steel pipe is sent to a square forming roll process. through, by uniformly heating the steel up to the a 1 transformation point or a 3 transformation point close earlier on the basis of the decorated with cold pressing or the like resulting eliminate residual stress of the steel, improving the toughness of the local steel , To eliminate welding distortion.

【0016】加熱した前記角形近似鋼管は、その後工
程で冷却装置に装入され、可及的に均一に、かつ、常温
になるまで放冷する。あるいは、強制冷却によって温度
を下げる。これにより、熱処理・調質のため軟化した鋼
材の機械的強度が改善される可能性がある。同装置にお
いて、熱処理・冷却に基づき前記角形近似鋼管に生じる
歪み量は、前記半成形鋼管断面から角形規格断面形状に
成形する全加工量の数%程度をでない。また、その程度
の歪み量が生じることを許容して冷却工程を制御し、冷
却装置に要するスペースを節減する。 前記常温鋼管を角形成形ロール工程に搬入して、鋼管
断面の残りの加工量を冷間塑性変形によつて成形し、規
格どおりの断面形状の角形鋼管を形成すると共に、 前記加工により、熱処理・冷却などに基づき半成形鋼
管に生じた前記歪み、捩じり、曲がりなどを矯正する一
方、 同冷間塑性変形により角形近似鋼管材質に加工硬化を
生じさせ、前工程において施した熱処理により軟化した
鋼材の機械的強度、特に降伏点強さを向上させることが
できる。
The heated square approximate steel pipe is charged into a cooling device in a subsequent step, and is allowed to cool as uniformly as possible and to room temperature. Alternatively, the temperature is lowered by forced cooling. Thereby, the mechanical strength of the steel material softened due to heat treatment and tempering may be improved. In the apparatus, the amount of strain generated in the approximate square steel pipe due to heat treatment and cooling is not about several percent of the total processing amount for forming the square shaped cross section from the semi-formed steel pipe cross section. In addition, the cooling process is controlled while allowing the amount of distortion to occur to such an extent, and the space required for the cooling device is reduced. The cold steel pipe is carried into a square forming roll process, and the remaining processing amount of the steel pipe cross-section is formed by cold plastic deformation to form a square steel pipe having a cross-sectional shape as specified. While correcting the distortion, torsion, bending, etc., which occurred in the semi-formed steel pipe due to cooling, etc., the same cold plastic deformation caused work hardening to occur in the square approximate steel pipe material, and it was softened by the heat treatment performed in the previous process It is possible to improve the mechanical strength of the steel material, particularly the yield point strength.

【0017】(2)これによって、 一枚鋼板断面を角形近似断面の形状に形成するまでの
比較的に加工度の大きな冷間プレス加工および溶接加工
に基づく前記一枚厚肉鋼板の残留応力の増加、局部材質
の靭性の低下、溶接加工歪みなどによる鋼材の劣化は、
熱処理によって、すべて調質され、その後、残りの加工
量を冷間塑性加工により成形するにもかかわらず、鋼管
コーナーR部を含めて鋼材の残留応力が殆ど増加しない
とか、鋼材の機械的性質を改善する等々、それ以前の工
程で冷間加工により鋼板に加えられた機械的変形などが
成形鋼管に悪影響を及ぼすことが殆どない。
(2) Accordingly, the residual stress of the single thick steel plate based on the cold pressing and the welding, which have a relatively large workability, until the cross section of the single steel plate is formed into a rectangular approximate cross-sectional shape. Deterioration of steel material due to increase, toughness of local material quality, welding distortion, etc.
After heat treatment, all are tempered, and then, despite the remaining working amount being formed by cold plastic working, the residual stress of the steel including the steel pipe corner R hardly increases, or the mechanical properties of the steel are reduced. For example, the mechanical deformation applied to the steel sheet by the cold working in the previous process hardly adversely affects the formed steel pipe.

【0018】熱処理および強制冷却工程を経て生じた
角形近似鋼管の歪み、曲がり、捩じれなどの総和は、
略、角形近似断面を角形規格断面に成形する全加工量の
数%程度を出ないから、前記歪み量は、同鋼管に対する
角形ロール成形と共に自然に矯正され、最終製品には、
残らないか、残ったとしても極めて小量である。 角形近似鋼管を冷間塑性加工により角形成形をするこ
とによって、鋼管材に対し加工硬化を生じさせ、鋼板の
機械的強度を改善する。なお、鋼板材の調質は、半成形
鋼管冷却装置における鋼材の冷却処理によりコントロー
ルをすることが可能である。
The sum of the distortion, bending, twist, etc. of the square approximation steel pipe generated through the heat treatment and the forced cooling step is as follows:
Since approximately a few percent of the total processing amount for forming the approximate square section into the square standard section does not come out, the distortion amount is naturally corrected together with the square roll forming for the steel pipe, and the final product has
It does not remain or, if it does, is extremely small. By forming a square-shaped steel pipe into a square shape by cold plastic working, work hardening occurs in the steel pipe material, and the mechanical strength of the steel sheet is improved. The tempering of the steel sheet can be controlled by cooling the steel in a semi-formed steel pipe cooling device.

【0019】同角形ロール成形により鋼管断面コーナ
ーR部を材質劣化を伴なうことなくシャープに形成する
ことができるから、鋼管の使い勝手を良好にし、見映え
を良好にして商品価値を高め、同一鋼材を用いた場合
に、より断面係数を大にする。 角形成形ロール工程が、冷間塑性加工により施される
ために、成形ロールの耐用時間が長くでき、同ロールの
メンテナンスが容易である。 冷却装置の後に角形成形ロール工程がつながっている
ので、同工程における成形ロールの交換、調整等の整備
作業が、容易、かつ、安全にできる。
Since the corner R of the cross section of the steel pipe can be formed sharply without deterioration of the material by the same square roll forming, the usability of the steel pipe is improved, the appearance is improved, and the commercial value is enhanced. When steel is used, the section modulus is further increased. Since the square forming roll process is performed by cold plastic working, the service life of the forming roll can be lengthened, and maintenance of the roll is easy. Since the horn forming roll process is connected after the cooling device, maintenance work such as replacement and adjustment of the forming roll in the process can be performed easily and safely.

【0020】本発明においては、材料に一枚鋼板を使
用するけれども、規格長鋼管の長手軸方向端面を連続し
て溶接することにより、長手軸方向に長い鋼管を成形し
て、その後の処理・加工を、連続丸鋼管の場合と同等に
施すことができ、必要な加工・成形後は、前記直角継手
部分を切断して単位の角形鋼管とするから、材料の歩留
まりが良好である。 いずれにしても、本発明工法・装置では、それ以前に
冷間で加えられた機械的加工などに基づく鋼管コーナー
R部の残留応力を除去し、鋼材の靭性を改善した後、最
終工程において残りの冷間塑性加工を施し角形鋼管を成
形することにより、前述熱処理により鋼管に生じた歪み
を矯正し、均一で高品質な大径角形鋼管を得ることがで
きる。
In the present invention, although a single steel plate is used as the material, a steel pipe having a long length in the longitudinal axis direction is formed by continuously welding the end faces in the longitudinal direction of the standard length steel pipe. The processing can be performed in the same manner as in the case of a continuous round steel pipe, and after the necessary processing and forming, the right-angle joint is cut into a rectangular steel pipe as a unit, so that the material yield is good. In any case, in the method and apparatus of the present invention, after removing the residual stress in the corner R of the steel pipe based on the mechanical processing or the like previously applied in a cold state and improving the toughness of the steel material, the remaining in the final step By performing the cold plastic working described above to form a rectangular steel pipe, the distortion generated in the steel pipe by the heat treatment can be corrected, and a uniform, high-quality, large-diameter rectangular steel pipe can be obtained.

【0021】(3)本発明工法・装置では、角形近似鋼
管全体をA3 変態点まで加熱するのに化石燃料を利用し
た加熱手段のみでは鋼管を一定時間、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
あるため、 設備費および稼動コストが若干高く付くことには目を
つむって、省スペースで、鋼管周壁のすべてを均一に、
効率良く、かつ、正確に加熱・制御することができる高
周波加熱装置をインラインで設備する。
[0021] (3) In the present invention method and devices, the entire square approximation steel A 3 a certain period of time only with the steel pipe heating means utilizing fossil fuels to heat up transformation point, described above to heat to the required temperature As described above, large heating furnace equipment is required, which may make it difficult to select the location conditions of the production line. All of the steel pipe surrounding wall,
A high-frequency heating device capable of heating and controlling efficiently and accurately is installed in-line.

【0022】ただし、鋼管の加熱手段として、大量に
入手することが容易で比較的にコストの低い化石燃料を
利用する加熱装置を、高周波加熱装置と併用した複合加
熱手段を採用することは妨げない。しかし、その場合
も、少なくとも鋼管周壁全体および内外共、均一温度に
加熱することができことを要する。本発明工法におい
て、電力を利用した加熱装置と化石燃料を用いた加熱炉
との複合加熱手段を設備すれば、比較的に熱処理コスト
を低減することができると共に、それによって加熱設備
の長大化を防止できるから、立地条件の選択が比較的に
容易になる等々のメリットが得られる。 なお、丸鋼管周壁の加熱のために、化石燃料を利用す
ることを妨げない。これによって、加工能率が若干、低
下することを免れないとしても、全体的に鋼管の加熱、
焼鈍コストを大幅に低下させることができる。
However, as the heating means for the steel pipe, it is not impeded to employ a combined heating means using a fossil fuel, which is easily available in large quantities and is relatively inexpensive, in combination with a high-frequency heating apparatus. . However, also in this case, it is necessary that at least the entire peripheral wall of the steel pipe and the inside and outside can be heated to a uniform temperature. In the method of the present invention, if a combined heating means of a heating device using electric power and a heating furnace using fossil fuel is provided, it is possible to relatively reduce the heat treatment cost and thereby increase the length of the heating equipment. Since this can be prevented, there are advantages such as relatively easy selection of location conditions. In addition, it does not prevent using a fossil fuel for heating the round steel pipe peripheral wall. As a result, even if the processing efficiency is inevitably reduced, the heating of the steel pipe as a whole,
Annealing costs can be significantly reduced.

【0023】(4)角形近似鋼管の冷却装置には、自然
放冷と強制冷却とを併用するとか、搬送鋼管周壁に対し
て直角方向周辺から均等に水を噴霧する設備などを施し
て、可及的に均一に鋼管壁を冷却し、かつ、歪の発生を
防ぐと共に、冷却装置のスペースを短くする必要があ
る。 冷却装置における加熱鋼管の冷却には、鋼材に対する
若干の硬化を期待してもよい。 冷却装置における鋼管の温度は、必ずしも正しく常温
まで低下させることを要しない。また、鋼管を、ある程
度以下の温度まで冷却した後は、冷水により冷しても歪
みが発生する心配がない。
(4) The cooling device for the square-shaped steel pipe may be a combination of natural cooling and forced cooling, or a facility for spraying water evenly from the periphery at right angles to the peripheral wall of the conveyed steel pipe. It is necessary to cool the steel pipe wall as uniformly as possible, to prevent the occurrence of distortion, and to shorten the space of the cooling device. For the cooling of the heated steel pipe in the cooling device, some hardening of the steel material may be expected. The temperature of the steel pipe in the cooling device does not always need to be correctly lowered to room temperature. Further, after the steel pipe is cooled to a certain temperature or less, there is no fear that distortion occurs even if the steel pipe is cooled with cold water.

【0024】(5)要するに角形近似鋼管断面を形成す
るプレス成形工程、溶接工程までに、冷間により鋼材に
加えられた大部分の機械的変形、溶接歪みなどに基づく
鋼材の劣化を熱処理によって解消するようにしたので、
鋼板を、略、90゜に曲げることにより生じる鋼管コーナ
ーR部の加工硬化、残留応力などの材質劣化が実用上差
支えない程度に改善、除去され、製品鋼管内に残留応力
が存在しない。または、コーナーR部の材質の劣化は殆
んどないに等しい。したがって、本発明工法および装置
によれば、昨今問題視されている大径角形鋼管の隅角部
冷間プレス変形に基づく鋼管コーナーR部の材質劣化の
欠陥を、実用上差支えない程度に除去することができ
る。
(5) In short, by the heat treatment, most of the deterioration of the steel material due to the mechanical deformation, welding distortion, etc. applied to the steel material by cold is eliminated by the heat forming process up to the press forming process and the welding process for forming the square approximate steel pipe cross section. I decided to
Material deterioration such as work hardening and residual stress at the corners of the steel pipes caused by bending the steel sheet to approximately 90 ° is improved and removed to the extent that practically acceptable, and no residual stress exists in the product steel pipes. Alternatively, the deterioration of the material of the corner R portion is almost negligible. Therefore, according to the method and the apparatus of the present invention, the defect of the material deterioration of the corner R of the steel pipe due to the cold press deformation at the corner of the large-diameter rectangular steel pipe, which has been regarded as a problem in recent years, is removed to the extent that it is practically acceptable. be able to.

【0025】[0025]

【実施例】以下に、本発明工法および前記工法を実施す
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、同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
技術の範囲内で任意に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、本発明工法の構成要件を限定的に解釈
することは許されない。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method of the present invention and a production line of a large-diameter rectangular steel pipe for carrying out the method will be described below with reference to the drawings. Since the structure can be arbitrarily partially modified within the range of known technology in the art at the time of the filing of the present application, the present invention can be implemented based on only the specific structure described in the present embodiment without any special reason. It is not permissible to restrictively interpret the constituent elements of the invention method.

【0026】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のレイアウトを示
す概略ブロック図で、図2は、前記装置の各工程に対応
する厚肉鋼板の成形状態を示すものである。本実施例
は、一枚厚肉鋼板を長手軸方向に沿って、四回折り曲
げ、一部に開口を有する五角形近似断面鋼板を形成する
工法にかかるものである。他の実施例として、一枚厚肉
鋼板を長手軸方向に沿って、二回折り曲げて断面コ字状
鋼材とし、同鋼材を一対向き合わせて両脚縁相互を突合
せ溶接する工法があるが、その外の工程・装置は略、以
下と同一なので、説明は省略する。図中、材料の搬送方
向に沿って直線的に、1は、アンコイラーで熱間圧延コ
イル(厚肉鋼板)11を巻き戻し、これをレベリングに掛
けて連続的にコイル歪みを矯正し、帯鋼板12を成形す
る。2は、幅決め・開先装置で、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、所要幅に成形
すると共に、開先加工を施す。3は、鋼板切断装置で、
前記帯鋼板12を規格長に切断し、一枚鋼板13を形成す
る。前記一枚鋼板の板厚は、22mm、板幅は、略、1800mm
であった。4は、折曲げ成形プレス装置であって、曲げ
型によって前記鋼板を、その長手軸方向に並行して、本
実施例では四回、それぞれの個所を、略、92°〜115 °
の範囲で曲げ、鋼板断面を一部に開口を備えた、略、五
角形状に形成する。なお、鋼管の前記開口部から、プレ
スの曲げ型を抜き出し可能とする。
FIG. 1 is a schematic block diagram showing a layout of an embodiment of a method for forming a large-diameter rectangular steel pipe according to the present invention and the method of the present invention, and FIG. 2 shows a thick wall corresponding to each step of the apparatus. It shows the forming state of the steel sheet. The present embodiment relates to a method of bending a single thick steel plate four times along the longitudinal axis direction to form a pentagonal approximate sectional steel plate having an opening in a part. As another embodiment, there is a construction method in which one thick steel plate is bent twice to form a U-shaped steel material along the longitudinal axis direction, and the steel materials are opposed to each other in a pair to butt-weld the edges of both legs. The other steps / apparatuses are substantially the same as those described below, and a description thereof will be omitted. In the figure, linearly along the direction of material transport, 1 unwinds a hot-rolled coil (thick steel plate) 11 with an uncoiler, applies it to leveling, continuously corrects coil distortion, Mold 12 Reference numeral 2 denotes a width determining / beveling device which cuts both sides of the flat strip steel plate 12 with a trimming cutter, forms the required width, and performs beveling. 3 is a steel plate cutting device,
The strip steel plate 12 is cut into a standard length to form a single steel plate 13. The thickness of the single steel plate is 22 mm, the plate width is approximately 1800 mm
Met. Reference numeral 4 denotes a bending press machine, and the steel plate is bent by a bending die in parallel with the longitudinal axis direction of the steel plate four times in this embodiment.
To form a substantially pentagonal shape with an opening in a part of the steel plate cross section. In addition, the bending mold of the press can be extracted from the opening of the steel pipe.

【0027】5は、溶接装置で、ここでは前記折曲げ鋼
材14の開口部に外力を加えて閉鎖し、長手方向に突合せ
溶接を施して、ここに溶接継手を形成し、各辺が外に膨
らんだ五角形近似断面のワンシーム半成形鋼管15を成形
する。6は、加熱装置であって高周波誘導加熱装置より
成り、前記半成形鋼管15の長手軸方向前、後端を相互に
溶接して同方向に長い鋼管を形成し、これを連続的に前
記高周波誘導加熱装置に装入して鋼管全周を均一温度に
加熱・調質する。当該加熱温度は、鋼材の材質、たとえ
ば、SS400 、SM490 A、SM520 B、非調質高張力鋼60Kg
など材質の相違にもよるが、同鋼管が加熱装置から搬出
されるとき、略、450 ℃〜700 ℃の範囲を可とする。加
熱時間の長短にもよるが、より高温加熱の方が冷間プレ
ス変形による鋼材の加工硬化、残留応力の除去および靭
性の改善ならび溶接加工歪みの除去には有効であるが、
鋼材表面に対する肌あれは、より低温加熱の方が、良好
であることは当然である。
Reference numeral 5 denotes a welding device, in which an external force is applied to the opening of the bent steel material 14 to close the opening, and butt welding is performed in the longitudinal direction to form a welded joint. A one-seam semi-formed steel pipe 15 having an expanded pentagonal approximate cross section is formed. Numeral 6 is a heating device comprising a high-frequency induction heating device. The front and rear ends of the semi-formed steel tube 15 in the longitudinal direction are welded to each other to form a long steel tube in the same direction. Heating and tempering the entire circumference of the steel pipe to a uniform temperature by charging it into an induction heating device. The heating temperature is the material of the steel, for example, SS400, SM490A, SM520B, non-heat treated high tensile steel 60Kg
Although it depends on the material, etc., when the steel pipe is unloaded from the heating device, the range of approximately 450 ° C. to 700 ° C. is acceptable. Depending on the length of heating time, higher temperature heating is more effective for work hardening of steel by cold press deformation, removal of residual stress and improvement of toughness and removal of welding distortion,
Naturally, the surface roughness of the steel surface is better when the temperature is lower.

【0028】7は、前記鋼管の冷却装置で、ここでは、
加熱された半成形鋼管15を可及的に均等に、かつ、全体
的に素早く冷却することが求められている。前記冷却ゾ
ーンにおける当該冷却温度は、略、室温に近いものとす
る。なお、加熱半成形鋼管を強制的に冷却すれば、鋼材
に軽く硬化させることもできる。ここでは、熱処理およ
び冷却装置における温度管理から外れた不均一な温度分
布によって生じる半成形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、ゆがみ等の総和は、
その後に、同鋼管に施される残りの角形成形加工量に比
べて、僅少である。そして、この段階においては鋼管素
材は全体として、母材に近い靭性を維持し、残留応力が
低い状態を保持している。8は、鋼管の角形成形ロール
装置を示し、同装置は、冷間塑性加工工程より構成され
ている。
Reference numeral 7 denotes a cooling device for the steel pipe.
It is required to cool the heated semi-formed steel pipe 15 as uniformly as possible and as a whole quickly. The cooling temperature in the cooling zone is substantially close to room temperature. If the heated semi-formed steel pipe is forcibly cooled, it can be lightly hardened into a steel material. Here, the sum of the bending in the axial direction of the semi-formed steel pipe, the distortion of the cross-sectional shape, the dent in the sheet thickness direction, the distortion, etc., caused by the non-uniform temperature distribution deviating from the temperature control in the heat treatment and cooling device,
After that, it is small compared to the remaining square forming amount to be applied to the steel pipe. At this stage, the steel pipe material as a whole maintains the toughness close to that of the base material, and keeps the state where the residual stress is low. Numeral 8 denotes a steel pipe horn forming roll device, which is constituted by a cold plastic working process.

【0029】この加工によって、材質の劣化を招くこと
なく鋼管断面形状を規格どおり、コーナーR部分をシャ
ープに、たとえば略、r=(2〜2.5)×tに成形す
る。ただし、r=コーナー部外側曲率半径、t=鋼管素
材の板厚同時に、冷却後に生じた半成形鋼管の捩じれ、
断面変形、曲がりを矯正する。同工程における残りの加
工量は僅少であり、、熱処理歪の矯正量を超えるもので
あっても、その成形により、改めて鋼管材質の劣化を招
くことはなく、鋼材に対し僅かに加工硬化を与える程度
である。さらに、鋼材の冷却と相俟って、熱処理によっ
て軟化した鋼材の機械的強度、特にコーナーR部鋼材の
靭性を改善する。角形成形工程を経て成形された、規格
断面の成形鋼管18の外径は、たとえば、450 mm角であ
る。
By this working, the corner R portion is formed sharply, for example, substantially to r = (2 to 2.5) × t without deteriorating the material and conforming to the standard in the cross-sectional shape of the steel pipe. However, r = radius of curvature outside the corner portion, t = thickness of the steel pipe material, and torsion of the semi-formed steel pipe generated after cooling,
Corrects cross-sectional deformation and bending. The remaining processing amount in the same process is very small, and even if it exceeds the correction amount of the heat treatment distortion, the forming does not cause the deterioration of the steel pipe material again and gives a slight work hardening to the steel material. It is about. Further, in combination with the cooling of the steel material, the mechanical strength of the steel material softened by the heat treatment, in particular, the toughness of the corner R portion steel material is improved. The outer diameter of the formed steel pipe 18 having a standard cross section formed through the angulation forming step is, for example, 450 mm square.

【0030】9は、切断装置であって、走間切断機構を
設備し、そこでは連続成形された厚肉大径角形鋼管の搬
送スピードに沿ってミーリングを移動させながら、前記
成形鋼管18を長手軸方向規格長毎に切断して、単位製品
20を形成する。10は、製品搬出テーブルであって、前記
規格長鋼管を収容し、積重ね、保管する。上記製品搬出
テーブル上の製品は、要すれば、鋼管の溶接継手、その
他の部分の探傷検査、歪み矯正を行った後、市場に出荷
する。
Reference numeral 9 denotes a cutting device, which is equipped with a running cutting mechanism, in which the formed steel pipe 18 is longitudinally moved while moving the milling along the conveying speed of the continuously formed thick large-diameter rectangular steel pipe. Unit products cut by the standard length in the axial direction
Form 20. Numeral 10 denotes a product carry-out table for accommodating, stacking and storing the standard length steel pipes. The product on the product delivery table is shipped to the market after being subjected to flaw detection inspection and distortion correction of the welded joint of the steel pipe and other parts, if necessary.

【0031】図2は、図1の生産ラインに含まれる各工
程に対応する鋼材の形状を示すもので、11は、熱間圧延
コイル、12は、平面状に成形した厚肉帯鋼板で、幅決
め、開先加工が施されている。13は、規格長の一枚鋼
板、14は、折り曲げプレスにより、一部に開口を備えた
断面五角形近似形状の半成形鋼材、15は、継目を溶接し
形成した半成形鋼管、18は、冷間加工により規格断面に
成形された角形鋼管、20は、同鋼管の最終製品、を示し
ている。以上のとおりであって、本実施例に関する、そ
の他の作用、効果の詳細は、さきに述べた(作用)の項
に記載したとおりであるから、参照されたい。
FIG. 2 shows the shape of a steel material corresponding to each process included in the production line of FIG. 1, 11 is a hot-rolled coil, 12 is a thick strip steel plate formed into a flat shape, The width is determined and beveling is applied. 13 is a single-piece steel plate of a standard length, 14 is a semi-formed steel material having an approximate shape of a pentagonal cross section partially provided with an opening by a bending press, 15 is a semi-formed steel pipe formed by welding seams, and 18 is a cold-formed steel pipe. A square steel pipe 20 formed into a standard cross section by cold working indicates a final product of the steel pipe. As described above, the details of the other operations and effects relating to the present embodiment are as described in the section of (operation) described above, and therefore, reference is made thereto.

【0032】[0032]

【発明の効果】本発明工法および装置は、以上述べたと
おり、 (1)従来公知の大径角形鋼管の冷間成形において問題
視されている鋼材の残留応力を除去し、これを許容量以
下にすると共に、鋼管材質の加工硬化、靭性の低下を改
善して、殊にコーナーR部材質の劣化を改善し、全体的
に高品質の大径角形鋼管を得る。 (2)冷間塑性加工により残りの加工量を成形して、材
質劣化を伴なうことなく鋼管コーナーR部を可及的にシ
ャープに成形した角形鋼管を成形し、使い勝手および見
映えを良好にする一方、同一鋼材を用いて、より断面係
数が大きい品質の良い鋼管を提供する。
As described above, the method and the apparatus of the present invention are as follows: (1) To remove the residual stress of a steel material which is regarded as a problem in the cold forming of a conventionally known large-diameter rectangular steel pipe, and to reduce the residual stress to an allowable amount or less. At the same time, the work hardening of the steel pipe material and the decrease in toughness are improved, especially the deterioration of the corner R member quality is improved, and a large-diameter rectangular steel pipe of high quality as a whole is obtained. (2) Forming the remaining processing amount by cold plastic working to form a square steel pipe in which the steel pipe corner R is formed as sharply as possible without deteriorating the material, improving the usability and appearance. On the other hand, using the same steel material, a high-quality steel pipe having a larger section modulus is provided.

【0033】(3)残りの冷間塑性加工によって、熱処
理などに基づく鋼材の歪み、曲がり、捩じれなど、それ
以前に鋼管に生じた変形を同時に矯正すると共に、鋼材
の機械的性質を向上させる。 (4)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、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) The remaining cold plastic working simultaneously corrects the deformation of the steel pipe, such as distortion, bending, twisting, etc., caused by heat treatment or the like, and simultaneously improves the mechanical properties of the steel material. (4) In addition, the respective effects described in the above section (action) are exhibited. For example, special functions and effects that cannot be expected from 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素材の断面
形状図。
FIG. 2 is a sectional view of a steel pipe material corresponding to each step in the apparatus.

【符号の説明】[Explanation of symbols]

1 アンコイラー 2 鋼板幅決め・開先装置 3 鋼板切断装置 4 折曲げ成形プレス装置 5 仮成形、溶接装置 6 加熱装置 7 冷却装置 8 角形成形ロール装置 9 切断装置 10 製品搬出テーブル 11 熱間圧延コイル 12 帯鋼板 13 一枚鋼板 14 折曲げ成形鋼材 15 半成形鋼管 18 角形成形鋼管 20 最終製品。 DESCRIPTION OF SYMBOLS 1 Uncoiler 2 Steel plate width determination and beveling device 3 Steel plate cutting device 4 Bending press device 5 Temporary forming and welding device 6 Heating device 7 Cooling device 8 Square forming roll device 9 Cutting device 10 Product unloading table 11 Hot rolling coil 12 Strip steel plate 13 Single steel plate 14 Bent formed steel 15 Semi-formed steel pipe 18 Square formed steel pipe 20 Final product.

───────────────────────────────────────────────────── 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 功雄 大阪府豊中市東豊中町1−11−5 (72)発明者 中島 拓 兵庫県伊丹市緑ケ丘3−70 (72)発明者 中島 教雄 静岡県袋井市小川町12−26 (72)発明者 中島 伸 東京都武蔵野市吉祥寺本町4−26−27 (58)調査した分野(Int.Cl.6,DB名) B21C 37/15──────────────────────────────────────────────────続 き Continuing from the front page (73) Patent holder 598134835 Shin Nakajima 4-26-27 Kichijoji Honmachi, Musashino City, Tokyo (72) Inventor Isao Nakajima 1-1-11-5 Higashi Toyonakacho, Toyonaka City, Osaka (72) Invention Taku Nakajima 3-70 Midorigaoka, Itami-shi, Hyogo (72) Inventor Norio Nakajima 12-26, Ogawa-cho, Fukuroi-shi, Shizuoka (72) Inventor Shin Shin Nakajima 4-26-27, Kichijoji-honmachi, Musashino-shi, Tokyo (58) Field (Int.Cl. 6 , DB name) B21C 37/15

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 一枚厚肉鋼板を、プレス加工により長手
軸方向に沿い複数回曲げ、各コーナーR部を形成し、そ
の断面を一部開口した五角形またはコ字形に成形した
後、長手軸方向継目を溶接して断面五角形近似または六
角形近似の半成形鋼管を形成し、前記鋼管を所定温度に
均一加熱して熱処理した後、鋼管全体を常温付近の温度
まで冷却し、角形成形ロール工程に装入して、前記半成
形鋼管を冷間塑性加工により、規格に沿った角形断面鋼
管に成形することを特徴とする大径角形鋼管の成形工
法。
1. A single thick steel plate is bent a plurality of times along a longitudinal axis direction by press working to form each corner R portion, and a cross section thereof is formed into a partially opened pentagon or U-shape. After forming the semi-formed steel pipe having a pentagonal or hexagonal cross-section by welding the direction joints, uniformly heating the steel pipe to a predetermined temperature and heat-treating the steel pipe, cooling the entire steel pipe to a temperature near room temperature, and forming a horn-formed roll. And forming the semi-formed steel pipe into a square-section steel pipe conforming to a standard by cold plastic working.
【請求項2】 一枚厚肉鋼板を、長手軸方向に沿い複数
回折り曲げ各コーナーR部を形成し、その断面を一部開
口した五角形またはコ字形に成形するプレス装置、前記
開口部を閉じ、その継目を長手軸方向に溶接して断面五
角形近似鋼管を形成するか、コ字形材を一対向き合わせ
て相対する脚部を突合せ溶接し、六角形近似形状の半成
形鋼管を形成する溶接装置、前記鋼管を所定温度に均一
加熱する加熱装置、冷却装置、前記角形半成形鋼管断面
を冷間塑性加工により規格に沿った角形断面に整形す
る、複数段よりなる角形成形ロール装置とより成ること
を特徴とする大径角形鋼管の成形装置。
2. A press machine for bending a single thick steel plate a plurality of times along the longitudinal axis direction to form each corner R and forming a pentagon or U-shape with a partially open cross section, and closing the opening. A welding device for forming a semi-formed steel pipe having a hexagonal approximation by welding the joint in the longitudinal axis direction to form a pentagonal approximation steel pipe, or by butt-welding a pair of U-shaped members facing each other and opposing legs. A heating device that uniformly heats the steel pipe to a predetermined temperature, a cooling device, and a horn forming roll device having a plurality of stages for shaping the cross section of the square semi-formed steel pipe into a square cross section conforming to a standard by cold plastic working. A large diameter square steel pipe forming apparatus characterized by the following.
JP27631591A 1991-09-30 1991-09-30 Forming method and equipment for large diameter square steel pipe Expired - Lifetime JP2852311B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP27631591A JP2852311B2 (en) 1991-09-30 1991-09-30 Forming method and equipment for large diameter square steel pipe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP27631591A JP2852311B2 (en) 1991-09-30 1991-09-30 Forming method and equipment for large diameter square steel pipe

Publications (2)

Publication Number Publication Date
JPH0592214A JPH0592214A (en) 1993-04-16
JP2852311B2 true JP2852311B2 (en) 1999-02-03

Family

ID=17567745

Family Applications (1)

Application Number Title Priority Date Filing Date
JP27631591A Expired - Lifetime JP2852311B2 (en) 1991-09-30 1991-09-30 Forming method and equipment for large diameter square steel pipe

Country Status (1)

Country Link
JP (1) JP2852311B2 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002034198A (en) * 2000-07-18 2002-01-31 Minebea Co Ltd Spindle motor
JP5439041B2 (en) 2009-06-02 2014-03-12 三菱重工業株式会社 Combustor component manufacturing method, combustor component, gas turbine combustor, and gas turbine
KR20130112902A (en) * 2010-11-03 2013-10-14 존슨 컨트롤스 게엠베하 Method for the roll-forming of profiles and a structural part produced thereby

Also Published As

Publication number Publication date
JPH0592214A (en) 1993-04-16

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