JP4916940B2 - Heat treatment method and heat treatment apparatus for welded steel pipe - Google Patents
Heat treatment method and heat treatment apparatus for welded steel pipe Download PDFInfo
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Description
本発明は、溶接鋼管の熱処理方法及び熱処理装置に関するものであり、特に、製造された溶接鋼管の形状に対応させて、溶接鋼管の溶接部のみを、その全領域にわたって、精度よく均一に、且つ効率的に熱処理する方法及び装置を提供する。 The present invention relates to a heat treatment method and a heat treatment apparatus for a welded steel pipe, and in particular, only the welded portion of the welded steel pipe is accurately and uniformly distributed over the entire region in accordance with the shape of the manufactured welded steel pipe. Provided are a method and an apparatus for efficiently performing a heat treatment.
従来、溶接鋼管の製造法としては、例えば、ＵＯＥ方式による方法、つまり、鋼板を筒状に曲げ成形し、該筒状に成形した鋼板（以下、「Ｏキャン」という）の相対向する鋼板端部を突き合わせ、該突き合せ箇所を溶接することにより溶接鋼管を製造する方法が良く知られている。 Conventionally, as a method for manufacturing a welded steel pipe, for example, a method using a UOE method, that is, a steel plate end formed by bending a steel plate into a cylindrical shape and then forming the cylindrical steel plate (hereinafter referred to as “O can”) A method of manufacturing a welded steel pipe by butting portions and welding the butted portions is well known.
そして、溶接鋼管の溶接部は、溶接時のガス吸収、内部残留応力等により、そのままでは材料特性が劣ることから、溶接部の特性改善に加え、溶接鋼管の母材特性のさらなる改善を図るために、溶接鋼管全体に熱処理（例えば、焼入れ−焼き戻し）を施すことも知られている。
しかし、溶接鋼管の母材と溶接部とでは、適正熱処理条件が異なるために、溶接鋼管全体を同時に熱処理する方法では、母材と溶接部の双方がともにすぐれた特性を有するような溶接鋼管を得ることは非常に困難であった。
And since the welded part of the welded steel pipe is inferior in material properties as it is due to gas absorption, internal residual stress, etc. during welding, in order to further improve the base metal properties of the welded steel pipe in addition to improving the welded part properties In addition, it is also known to perform heat treatment (for example, quenching-tempering) on the entire welded steel pipe.
However, since the appropriate heat treatment conditions differ between the base material of the welded steel pipe and the welded portion, the method of heat treating the entire welded steel pipe simultaneously requires a welded steel pipe that has excellent characteristics in both the base metal and the welded portion. It was very difficult to get.
このような問題を解決するため、例えば、特開昭５５−７３８２２号公報に示されるように、溶接鋼管の母材と溶接部を、それぞれ異なる温度領域に加熱（例えば、母材はＡｃ３点〜１，０００℃の温度範囲に加熱、一方、溶接部はＡｃ１〜Ａｃ３点の温度範囲に加熱）し、母材と溶接部のそれぞれを適正条件で熱処理することにより、母材と溶接部の全体にわたって、すぐれた材料特性（例えば、靭性、耐硫化水素割れ性）を有する溶接鋼管を得ることが知られている。
しかし、上記従来の熱処理においては、母材と溶接部の熱処理温度条件を異なったものにするために母材−溶接部間には温度勾配、熱処理歪が発生し、そのため、溶接鋼管全体として熱処理変形を生じ、例えば、溶接鋼管を連続的に搬送しながら熱処理を施す連続熱処理を行ったような場合には、鋼管の熱処理変形のため溶接部を所定温度条件で加熱することができなくなり、その結果、溶接部の特性が目標値に達しないという事態が生じたり、あるいは、溶接鋼管搬送時の蛇行、溶接鋼管と搬送ロール・熱処理用機器との衝突などの搬送工程でのトラブルが生じることによって、熱処理ラインを一旦停止せざるを得なくなる等、種々の問題が生じていた。
However, in the conventional heat treatment, a temperature gradient and a heat treatment strain are generated between the base metal and the welded portion in order to make the heat treatment temperature conditions of the base metal and the welded portion different. For example, when a continuous heat treatment is performed in which heat treatment is performed while continuously conveying the welded steel pipe, the weld cannot be heated at a predetermined temperature condition due to heat treatment deformation of the steel pipe. As a result, the situation where the characteristics of the welded part do not reach the target value occurs, or troubles in the transport process such as meandering during transport of the welded steel pipe and collision between the welded steel pipe and the transport roll / heat treatment equipment occur. Various problems have arisen, such as the necessity to temporarily stop the heat treatment line.
原油、天然ガスの輸送用ラインパイプ等としては、従来から、溶接鋼管が多用されているが、高圧化による輸送効率向上等の観点から、強度・靭性・耐食性等について、より一層すぐれた材料特性を備えた溶接鋼管が求められている。
そして、要求される材料特性レベルに応えていくためには、溶接鋼管の母材特性の向上に加え、特に、ＨＡＺ靭性など溶接部の特性改善を図っていくことが重要となる。
そこで、本発明は、溶接鋼管を熱処理することによりその特性改善を図るにあたり、製造された溶接鋼管の形状に対応させて、その溶接部のみを、その全領域にわたって、精度よく均一に、かつ、効率的に熱処理する方法及び装置を提供することを目的としている。
Conventionally, welded steel pipes have been widely used as crude oil and natural gas transportation line pipes, etc., but from the viewpoint of improving transportation efficiency by increasing the pressure, etc., further superior material properties in terms of strength, toughness, corrosion resistance, etc. There is a need for welded steel pipes with
In order to meet the required material property level, in addition to improving the base material properties of the welded steel pipe, it is particularly important to improve the properties of the welded portion such as HAZ toughness.
Therefore, in the present invention, in order to improve the characteristics by heat treating the welded steel pipe, the welded steel pipe is made to correspond to the shape of the manufactured welded steel pipe, and only the welded portion thereof is accurately and uniformly over the entire area. It aims at providing the method and apparatus which heat-process efficiently.
本発明の要旨とするところは、次のとおりである。
（１）筒状に成形した鋼板の相対向する鋼板端部を突合せて溶接し、溶接部を有する溶接鋼管を成形した後、該溶接鋼管を熱処理する熱処理方法において、
前記筒状に成形した鋼板の相対向する鋼板端部を突合せて溶接した直後に、前記溶接鋼管の溶接部の全領域のみを、同時に、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱することを特徴とする溶接鋼管の熱処理方法。
（２）筒状に成形した鋼板の相対向する鋼板端部を突合せて溶接した溶接部を有する溶接鋼管の熱処理装置において、
前記溶接鋼管の溶接部の全領域のみを、同時に、溶接部の全領域に亘って、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱する溶接部加熱手段を備え、該溶接部加熱手段は、
前記溶接鋼管の溶接部の全領域を覆う加熱装置を有し、前記加熱装置は、前記溶接鋼管の長手方向に複数に分割された加熱エレメントを含み、さらに、前記加熱エレメントは、前記溶接鋼管と前記加熱エレメントとの間隔を一定に保つための間隔保持脚を有することを特徴とする溶接鋼管の熱処理装置。
（３）前記（２）記載の複数に分割された加熱エレメントの加熱対象域のそれぞれに温度検知器を設け、
該温度検知器で加熱対象域のそれぞれに存在する溶接部の温度を測定し、
その測定温度実績値を前記加熱エレメントにフィードバックするようにしたことを特徴とする前記（２）記載の溶接鋼管の熱処理装置。
（４）前記（３）記載の温度検知器が、溶接鋼管の溶接方向に対して垂直方向にセンサーを振りながら溶接部の温度を測定することを特徴とする前記（３）記載の溶接鋼管の熱処理装置。
（５）前記複数に分割された加熱エレメントと前記温度検知器が、溶接鋼管の溶接部を挟んで溶接鋼管の内側と外側とに対向して配置されていることを特徴とする前記（３）、（４）のいずれかに記載の溶接鋼管の熱処理装置。
（６）前記複数に分割された加熱エレメントが溶接鋼管の外側に、また、前記温度検知器が溶接鋼管の内側に配置されていることを特徴とする前記（５）記載の溶接鋼管の熱処理装置。
The gist of the present invention is as follows.
(1) After the cylindrical steel plate end which faces the shaped steel plates and butt welded to and forming a welded steel pipe having a weld, the heat treatment method of heat-treating the welded steel pipe,
Immediately after butt-welding opposite steel plate ends of the steel plate formed into a cylindrical shape, only the entire area of the welded portion of the welded steel pipe is simultaneously at a temperature within a temperature range of 100 to 500 ° C, and A method for heat treatment of a welded steel pipe, characterized by heating so that a difference between a maximum value and a minimum value of the heating temperature is within 100 ° C.
(2) In a heat treatment apparatus for a welded steel pipe having a welded portion where the opposite ends of a steel plate formed into a cylindrical shape are welded together,
Only the entire region of the welded portion of the welded steel pipe is simultaneously subjected to a temperature within a temperature range of 100 to 500 ° C over the entire region of the welded portion, and the difference between the maximum value and the minimum value of the heating temperature is 100 ° C. A welding part heating means for heating to be within , the welding part heating means,
A heating device that covers the entire area of the welded portion of the welded steel pipe, and the heating device includes a heating element that is divided into a plurality of lengths in the longitudinal direction of the welded steel pipe; An apparatus for heat treatment of a welded steel pipe, comprising a distance maintaining leg for maintaining a constant distance from the heating element .
(3) A temperature detector is provided in each of the heating target areas of the heating element divided into a plurality of (2) ,
The temperature detector measures the temperature of the weld that exists in each of the heating target areas,
The measured temperature actual value is fed back to the heating element. The heat treatment apparatus for a welded steel pipe according to (2), wherein
(4) the (3) the temperature detector described, the welded steel pipe according to (3), wherein the measuring the temperature of the weld waving sensor in a direction perpendicular to the welding direction of the welded steel pipe Heat treatment equipment.
(5) the said temperature detector and the plurality of divided heating elements, characterized in that it is arranged to face the inside and the outside of the welded steel pipe across the weld of the welded steel pipe (3) (4) The heat processing apparatus of the welded steel pipe in any one of.
(6) The heat treatment apparatus for a welded steel pipe according to (5 ), wherein the plurality of heating elements are arranged outside the welded steel pipe, and the temperature detector is arranged inside the welded steel pipe. .
以下に、本発明について、詳細に説明する。
従来から、例えば、ＵＯＥ方式のＯプレスにより、鋼板を筒状に成形し、この筒状に成形した鋼板（Ｏキャン）の相対向する鋼板端部を突合せて溶接することによって、溶接部を有する溶接鋼管を成形することは良く知られている。
The present invention is described in detail below.
Conventionally, for example, a steel plate is formed into a cylindrical shape by an OOE type O press, and the opposite ends of the steel plates formed in this cylindrical shape (O can) are butt-welded to have a welded portion. It is well known to form welded steel pipes.
（１）本発明の熱処理方法；
本発明の熱処理方法は、従来から知られている上記の如き方法で成形された溶接部を有する溶接鋼管に対し、例えば、溶接部に対向して配置した加熱装置の加熱エレメントで加熱を行い、溶接鋼管の溶接部の全領域のみを、同時に、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱することからなるものである。
そして、本発明のこの熱処理方法によれば、Ｏキャンの相対向する鋼板端部を突合せて溶接を行った後、１００〜５００℃の温度範囲内の温度に加熱することによって、溶接部に混入した水素等の有害ガス成分を溶接部から拡散除去することができるので、溶接鋼管の低温割れ発生を防止し、高強度、高靭性等の特性を溶接部に付与することができ、溶接部の機械的特性の向上を図ることができるとともに、溶接部の各部における加熱温度の差、即ち、加熱温度の最高値と最低値の差、が１００℃以内となるように加熱することによって、熱処理による溶接鋼管の曲がり発生を確実に防止することができる。
さらに、本発明の熱処理方法によれば、熱処理に際して溶接鋼管に熱処理変形が生じたとしても、常にその溶接鋼管の形状に対応させて、その溶接部の全領域のみを、精度よく均一に、かつ、効率的に熱処理することも可能である。
本発明の熱処理方法の特徴についてさらに説明する。
まず、本発明では、「溶接部の全領域のみを、同時に、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱する」と規定しているが、それは次のような理由による。
既に述べたように、溶接鋼管の母材と溶接部とは、特性を改善するための適正熱処理条件（その一つとしては、加熱温度）が異なるから、溶接鋼管全体を、例えば、１００〜５００℃という同じ温度に加熱した場合には、溶接鋼管の母材は適正な熱処理が行われていないことになるため、特性の向上が期待できないばかりか、むしろ特性が劣化する恐れがあるため、本発明では、溶接鋼管の母材特性に悪影響を与えないという観点から、「溶接部の全領域のみ」に加熱を行うこととした。
また、本発明では、溶接部の全領域のみを、「同時に、」加熱するとしているが、それは次のような理由による。
例えば、溶接鋼管を連続的に搬送しつつ、溶接部を順次に熱処理する（即ち、溶接部の全領域のみを、「同時に、」熱処理するのではなく、「順次に、」熱処理する）従来技術においては、溶接部は、「室温から熱処理温度への急速加熱による大きな昇温勾配の発生」、「熱処理温度での短時間加熱保持」、「熱処理温度から室温への冷却による大きな降温勾配の発生」と、溶接部の長手方向の温度は短時間の間に急激な変化を受けるため、また、溶接部−母材間にも、短時間の間に急激な温度差が生まれるため、溶接鋼管には大きな熱処理歪（残留応力）が発生し、これらが原因となって熱処理変形が生じるが、従来の熱処理方法では、この熱処理変形への対応が不十分であるため熱処理温度が不正確になり、溶接部に所望特性を付与できなかったり、また、場合によっては、最終製品である溶接鋼管に溶接部割れが発生することもあった。更に、鋼管の曲がりが大きいときには、搬送に支障を来たすこともある。
そして、本発明では、溶接部の「全領域のみを、同時に、」加熱する（具体的には、例えば、請求項２に記載したような間隔保持脚を使用した、溶接鋼管と加熱エレメントとの間隔を一定に保った加熱、あるいは、加熱対象域の測定温度を加熱エレメントへフィードバックする加熱調整によって、溶接部の「全領域のみを、同時に、」加熱することが可能となる）ため、溶接部の長手方向には急激な温度変化、大きな温度勾配を生じることはなく、また、熱処理時に溶接鋼管に熱処理変形が生じたとしても、溶接部と加熱エレメントの間隔が間隔保持脚で一定に保持されているため、また、測定温度値が加熱エレメントにフィードバックされるため、溶接部の加熱温度を常に所定値に維持することができ、溶接鋼管、特に溶接部、には、不均一な熱処理歪を発生することもなく、精度よく目的とする熱処理を行うことができるので、溶接鋼管の溶接部割れ、低温割れ等が生ずる恐れはない。
(1) Heat treatment method of the present invention;
The heat treatment method of the present invention heats a welded steel pipe having a weld formed by the above-described method as described above, for example, with a heating element of a heating device arranged facing the weld, Only the entire region of the welded portion of the welded steel pipe is simultaneously heated to a temperature within the temperature range of 100 to 500 ° C, and the difference between the maximum value and the minimum value of the heating temperature is within 100 ° C. Is.
And according to this heat treatment method of the present invention, the ends of the steel plates facing each other of O-can are butted and welded, and then heated to a temperature within a temperature range of 100 to 500 ° C., thereby being mixed into the welded portion. Since harmful gas components such as hydrogen can be diffused and removed from the welded portion, it is possible to prevent the occurrence of cold cracking in the welded steel pipe and to impart properties such as high strength and high toughness to the welded portion. It is possible to improve the mechanical characteristics, and by heating so that the difference in heating temperature at each part of the welded portion, that is, the difference between the maximum value and the minimum value of the heating temperature is within 100 ° C. Bending of the welded steel pipe can be reliably prevented.
Furthermore, according to the heat treatment method of the present invention, even if heat treatment deformation occurs in the welded steel pipe during the heat treatment, only the entire region of the welded portion is always accurately and uniformly matched to the shape of the welded steel pipe, and It is also possible to perform heat treatment efficiently.
The characteristics of the heat treatment method of the present invention will be further described.
First, in the present invention, “only the entire area of the welded portion is heated at the same time to a temperature within a temperature range of 100 to 500 ° C., and the difference between the maximum value and the minimum value of the heating temperature is within 100 ° C. This is for the following reason.
As described above, since the appropriate heat treatment conditions (for example, heating temperature) for improving the characteristics of the base material and the welded portion of the welded steel pipe are different, the entire welded steel pipe is, for example, 100 to 500. When heated to the same temperature of ℃, the base material of the welded steel pipe is not subjected to proper heat treatment, so not only improvement in characteristics can be expected, but rather the characteristics may deteriorate. In the invention, from the viewpoint of not adversely affecting the base material characteristics of the welded steel pipe, heating is performed only on “all areas of the weld zone”.
In the present invention, only the entire area of the weld is heated at the same time, for the following reason.
For example, a conventional technique in which a welded steel pipe is continuously conveyed and a welded portion is heat treated sequentially (that is, only the entire area of the welded portion is heat treated “sequentially” instead of “simultaneously”). In welded parts, the generation of a large temperature gradient by rapid heating from room temperature to the heat treatment temperature, the generation of a large temperature gradient by cooling from the heat treatment temperature to room temperature, ”Because the temperature in the longitudinal direction of the weld is subject to abrupt changes in a short time, and a rapid temperature difference is created between the weld and the base metal in a short time. Causes large heat treatment distortion (residual stress), which causes heat treatment deformation. However, in the conventional heat treatment method, the heat treatment temperature becomes inaccurate because the heat treatment deformation is insufficient. Can give desired properties to welds Or bought, In some cases, the weld cracking welded steel pipe as a final product had also occurred. Furthermore, when the bending of the steel pipe is large, the conveyance may be hindered.
In the present invention, “only the entire region is heated at the same time” of the welded portion (specifically, for example, between the welded steel pipe and the heating element using a spacing leg as described in claim 2) . (It is possible to heat only the entire area at the same time by heating with a constant interval or by adjusting the heating temperature by feeding back the measured temperature in the heating target area to the heating element.) There is no sudden temperature change or large temperature gradient in the longitudinal direction, and even if heat treatment deformation occurs in the welded steel pipe during heat treatment, the distance between the welded part and the heating element is held constant by the spacing legs. In addition, since the measured temperature value is fed back to the heating element, the heating temperature of the welded portion can always be maintained at a predetermined value, and the welded steel pipe, particularly the welded portion, is uneven. It without which it generates Do heat treatment distortion, because the heat treatment can be performed to accurately purposes, weld cracking welded pipe, there is no risk of cold cracking and the like may occur.
（２）本発明の熱処理装置；
以下、図面とともに本発明の熱処理装置とその動作について説明する。
図１に、本発明の熱処理装置の一つの具体例を、また、図２には、本発明の熱処理装置の他の具体例を示した。
図１に示されるように、例えば、ＵＯＥ方式により、Ｏキャンの相対向する鋼板端部を突合せて溶接された溶接鋼管は、熱処理を施される溶接部が下方になるように、かつ、溶接鋼管の周面が、加熱エレメントに装着された間隔保持脚との接触を常に保つように位置決めされることによって、加熱エレメントの間隔保持脚で保持された状態で、しかも、加熱エレメントとの間に所定間隔を保持した状態で、加熱装置上方に配置される。そして、溶接鋼管の溶接部が位置するさらに下方位置には、溶接部に対向するように、また、溶接部の全領域を覆うように、溶接部を加熱する加熱装置が設けられている。加熱装置は、溶接鋼管の長手方向に、複数に分割された複数の加熱エレメントで構成され、また、それぞれの加熱エレメントには、シリンダ、間隔保持脚が装着されている。そして、加熱エレメントのそれぞれは、その端部側の連接点（図１中、黒丸で示す）で、該連接点を中心として相互に回動自在に接続されており、加熱エレメントに装着されたシリンダの伸縮動作によって、連接点を中心として加熱エレメントは回動することが可能である。
そして、このような装置構成のもと、溶接部加熱手段によって、溶接鋼管の溶接部の全領域のみを、同時に、溶接部の全領域に亘って、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように均一加熱することによって、溶接部に混入した有害ガス成分を拡散除去して溶接割れ発生を防止するとともに、高強度、高靭性化を図り、さらに、熱処理による溶接鋼管の曲がり発生を抑えることができる。
そして、熱処理前の溶接鋼管に既に変形があった場合であっても、溶接鋼管を加熱装置上方に配置する際に、加熱エレメントに装着されたシリンダを伸縮させて、必要個所の加熱エレメントを必要量だけ回動させることによって、加熱エレメントに装着された間隔保持脚が溶接鋼管の周面に接触するように調節することができるので、溶接鋼管の形状に対応させて、溶接部と加熱エレメントの間隔を、常に一定の距離に保つことが可能となる。
さらに、熱処理を行っている最中に溶接鋼管がその長手方向に亘る熱処理変形をおこした場合にも、その溶接鋼管周面箇所と間隔保持脚が常に接触状態を保つように、シリンダの伸縮、加熱エレメントの回動を調節することにより、溶接部と加熱エレメントの間隔は常に一定に保たれるので、溶接部の長手方向全領域に亘って、同時に同一温度に均一に（即ち、加熱温度の最高値と最低値の差が１００℃以内となるように）加熱する所期の熱処理を行うことが可能である。
上記のごとき装置構成において、加熱エレメントに装着された間隔保持脚は、溶接鋼管と加熱エレメントの間隔を常に一定に保つためのスペーサとしての役割を果たすが、間隔保持脚で、溶接鋼管を支持することも可能であり、このような場合には、間隔保持脚は、溶接鋼管支持部材としての機能も果たすことになる。
(2) Heat treatment apparatus of the present invention;
Hereinafter, the heat treatment apparatus of the present invention and its operation will be described with reference to the drawings.
FIG. 1 shows one specific example of the heat treatment apparatus of the present invention, and FIG. 2 shows another specific example of the heat treatment apparatus of the present invention.
As shown in FIG. 1, for example, a welded steel pipe welded by abutting the opposite steel plate end portions of O-can by the UOE method so that the welded portion to be heat-treated is positioned downward and welded. The circumferential surface of the steel pipe is positioned so as to always maintain contact with the spacing legs attached to the heating element, so that the steel pipe is held by the spacing legs of the heating element and between the heating elements. It arrange | positions above a heating apparatus in the state holding the predetermined space | interval. And the heating apparatus which heats a welding part is provided in the further lower position where the welding part of a welded steel pipe is located so that a welding part may be opposed, and the whole area | region of a welding part may be covered. The heating device is composed of a plurality of heating elements divided into a plurality in the longitudinal direction of the welded steel pipe, and each heating element is provided with a cylinder and a spacing leg. Each of the heating elements is connected to the end of the connecting contact (indicated by a black circle in FIG. 1) so as to be rotatable around the connecting contact, and a cylinder attached to the heating element. Thus, the heating element can be rotated around the contact point.
And under such an apparatus configuration, only the entire region of the welded portion of the welded steel pipe is simultaneously brought to a temperature within the temperature range of 100 to 500 ° C. over the entire region of the welded portion by the welded portion heating means. And, by heating uniformly so that the difference between the maximum and minimum heating temperatures is within 100 ° C, the harmful gas components mixed in the weld zone are diffused and removed, preventing the occurrence of weld cracks and high strength. Further, it is possible to increase the toughness and further suppress the occurrence of bending of the welded steel pipe due to heat treatment.
And even when the welded steel pipe before heat treatment has already been deformed, when placing the welded steel pipe above the heating device, the cylinder attached to the heating element is expanded and contracted, and the required heating element is required. Since the distance maintaining leg attached to the heating element can be adjusted so as to come into contact with the peripheral surface of the welded steel pipe by rotating it by an amount, the welded portion and the heating element can be adjusted according to the shape of the welded steel pipe. It is possible to always keep the distance at a constant distance.
In addition, when the welded steel pipe undergoes heat treatment deformation in the longitudinal direction during the heat treatment, the cylinder expansion and contraction is performed so that the peripheral surface portion of the welded steel pipe and the distance maintaining leg are always kept in contact with each other. By adjusting the rotation of the heating element, the distance between the welded part and the heating element is always kept constant, so that the entire temperature in the longitudinal direction of the welded part can be uniformly and uniformly at the same time (that is, the heating temperature is adjusted). It is possible to perform the intended heat treatment to heat (so that the difference between the maximum value and the minimum value is within 100 ° C.).
In the apparatus configuration as described above, the distance maintaining leg attached to the heating element serves as a spacer for keeping the distance between the welded steel pipe and the heating element constant, but the distance maintaining leg supports the welded steel pipe. In such a case, the distance maintaining leg also functions as a welded steel pipe support member.
図２は、溶接鋼管と加熱装置の位置関係が、図１からみて丁度上下逆になった場合の装置構成を示すが、図２の場合も、各装置部材の、溶接鋼管の溶接部に対する作用は、図１の場合と基本的にはかわりはない。
なお、図１、図２に示してはいないが、本発明の熱処理装置は、加熱エレメントで加熱した溶接部の温度を検知し、その値を実績値として加熱エレメントへフィードバックするための温度検知器を、加熱エレメントの加熱対象域のそれぞれに設けることにより、溶接部の加熱温度を、より高い精度でコントロールすることができる。
そして、該温度検知器としては、溶接鋼管の溶接方向に対して垂直方向にセンサーを振りながら溶接部の温度を測定する温度検知器を用いることができる。
また、温度検知器と加熱エレメントは、溶接鋼管の内側、あるいは、外側のいずれ側に配設しても良いが、配設の容易さと正確な温度コントロールという点からは、加熱エレメントと温度検知器を、溶接鋼管の溶接部を挟んで溶接鋼管の内側と外側とに対向して配置すること、または、加熱エレメントを溶接鋼管の外側に、また、温度検知器を溶接鋼管の内側に配置することが望ましい。
FIG. 2 shows the device configuration when the positional relationship between the welded steel pipe and the heating device is just upside down as seen from FIG. 1, but also in FIG. 2, the action of each device member on the welded portion of the welded steel pipe Is basically the same as the case of FIG.
Although not shown in FIGS. 1 and 2, the heat treatment apparatus of the present invention detects the temperature of the welded portion heated by the heating element and feeds back the value to the heating element as an actual value. Is provided in each of the heating target areas of the heating element, so that the heating temperature of the welded portion can be controlled with higher accuracy.
And as this temperature detector, the temperature detector which measures the temperature of a welding part can be used, shaking a sensor perpendicularly | vertically with respect to the welding direction of a welded steel pipe.
In addition, the temperature detector and the heating element may be arranged inside or outside the welded steel pipe, but from the viewpoint of easy arrangement and accurate temperature control, the heating element and the temperature detector. Is placed opposite the inside and outside of the welded steel pipe across the welded part of the welded steel pipe, or the heating element is placed outside the welded steel pipe and the temperature detector is placed inside the welded steel pipe Is desirable.
本発明の溶接鋼管の熱処理方法および熱処理装置によれば、所謂、ＵＯＥ方式等により製造された溶接鋼管の溶接部のみを、溶接鋼管の形状（変形）に追従対応させて、精度よく均一に、かつ、効率的に熱処理することができるとともに、溶接部に含有される有害ガス成分を上記熱処理で拡散除去することにより、溶接欠陥の発生、パイプ曲がりの発生がなく、溶接部の強度、靭性等すぐれた材料特性を備えた溶接鋼管を提供することができる。 According to the heat treatment method and heat treatment apparatus for welded steel pipe of the present invention, only the welded portion of the welded steel pipe manufactured by the so-called UOE method or the like is made to follow the shape (deformation) of the welded steel pipe, and accurately and uniformly. In addition, the heat treatment can be efficiently performed, and the harmful gas components contained in the welded portion are diffused and removed by the heat treatment, so that there is no occurrence of weld defects and pipe bending, and the strength, toughness, etc. of the welded portion. A welded steel pipe with excellent material properties can be provided.
つぎに、本発明の溶接鋼管の熱処理方法および熱処理装置について、実施例により具体的に説明する。
まず、鋼板強度；８２９〜１０８１（ＭＰａ）の鋼板を、ＵＯＥ方式で成形し、Ｏ成形後、サブマージドアーク溶接により内外各一層の条件でシーム溶接を行い、鋼管外径；７１１．２（ｍｍ）〜１２１９．２（ｍｍ）、鋼管肉厚；１２（ｍｍ）〜２０（ｍｍ）、長さ；１２０００（ｍｍ）の種々のサイズの溶接鋼管を製造した。
Next, the heat treatment method and heat treatment apparatus for the welded steel pipe of the present invention will be specifically described with reference to examples.
First, a steel plate having a strength of 829 to 1081 (MPa) was formed by the UOE method, and after O forming, seam welding was performed by submerged arc welding under the conditions of the inner and outer layers, and the outer diameter of the steel pipe: 711.2 (mm ) To 1219.2 (mm), steel pipe wall thickness; 12 (mm) to 20 (mm), and length: 12000 (mm).
上記溶接鋼管を、図１に示す熱処理装置上に載置して加熱保持時間、加熱保持温度を変えた各種の熱処理を行い、本発明溶接鋼管１〜４２を得た。
それぞれの鋼管サイズと熱処理条件を表１に示す。
なお、図１に示す熱処理装置において、加熱装置は４分割された加熱エレメントからなり、また、加熱エレメントに装着されたシリンダを伸縮させて、加熱エレメントを必要量だけ回動させ、溶接鋼管の形状に対応させて、加熱エレメントに装着された間隔保持脚が溶接鋼管の周面に接触するように調節し、溶接部と加熱エレメントの間隔が、常に一定の距離に保つように調整した。
また、加熱保持温度（℃）については、目標とする加熱保持温度値を狙い値で示し、鋼管溶接部のＴｏｐ，Ｍｉｄ，Ｂｏｔ部の３箇所で測定した温度のうちの最高温度値をＭＡＸ値、最低温度値をＭＩＮ値として表１に示した。
表２には、熱処理した後の本発明例溶接鋼管１〜４２の諸特性（鋼板強度、溶接鋼管の引張強さ、強度落ち代、溶接部の衝撃値、溶接割れの有無、パイプ曲がり搬送不良の有無）を示す。
なお、強度落ち代（ＭＰａ）とは、溶接鋼管を熱処理したことに伴う引張強さの低下量（＝鋼板の引張強さ（鋼板強度（ＭＰａ））−熱処理後の溶接鋼管の引張強さ（ＭＰａ））をいう。
The said welded steel pipe was mounted on the heat processing apparatus shown in FIG. 1, and various heat processing which changed the heating holding time and the heating holding temperature was performed, and this invention welded steel pipes 1-42 were obtained.
Each steel pipe size and heat treatment conditions are shown in Table 1.
In the heat treatment apparatus shown in FIG. 1, the heating apparatus is composed of four heating elements, and the cylinder mounted on the heating element is expanded and contracted to rotate the heating element by a necessary amount, thereby forming the shape of the welded steel pipe. Corresponding to the above, the distance maintaining leg mounted on the heating element was adjusted so as to come into contact with the peripheral surface of the welded steel pipe, and the distance between the welded portion and the heating element was adjusted so as to always keep a constant distance.
Moreover, about heating holding temperature (degreeC), the target heating holding temperature value is shown with a target value, and the maximum temperature value among the temperatures measured at the Top, Mid, and Bot portions of the steel pipe welded portion is the MAX value. The minimum temperature value is shown in Table 1 as the MIN value.
Table 2 shows characteristics of the present invention welded steel pipes 1 to 42 after heat treatment (steel sheet strength, tensile strength of welded steel pipe, strength drop, weld impact value, presence or absence of weld cracks, poor pipe bending conveyance Presence or absence).
Note that the strength drop allowance (MPa) is the amount of decrease in tensile strength associated with heat treatment of the welded steel pipe (= tensile strength of the steel plate (steel plate strength (MPa)) − tensile strength of the welded steel pipe after heat treatment ( MPa)).
比較のために、溶接鋼管に熱処理を施さなかったもの（比較例４３）、溶接鋼管に誘導加熱による連続熱処理を施したもの（比較例４４〜６２）、溶接鋼管にバーナー加熱により熱処理を施したもの（比較例６３〜８２）を、比較例溶接鋼管４３〜８２として製造した。
それぞれの鋼管サイズ、熱処理条件を表３に、また、比較例溶接鋼管４３〜８２の諸特性を表４に示す。
For comparison, the welded steel pipe was not subjected to heat treatment (Comparative Example 43), the welded steel pipe was subjected to continuous heat treatment by induction heating (Comparative Examples 44 to 62), and the welded steel pipe was subjected to heat treatment by burner heating. The thing (Comparative Examples 63-82) was manufactured as Comparative Example welded steel pipes 43-82.
The respective steel pipe sizes and heat treatment conditions are shown in Table 3, and the characteristics of the comparative welded steel pipes 43 to 82 are shown in Table 4.
表１に示されるように、本発明によれば、種々のサイズの溶接鋼管について、溶接部の全領域のみを、同時に、目標とする加熱保持温度で均一に熱処理すること（即ち、加熱保持温度の狙い値、ＭＡＸ値、ＭＩＮ値のいずれもが１００〜５００℃の温度範囲内の温度であって、かつ、（ＭＡＸ値−ＭＩＮ値）＜１００℃）ができる。
そして、表２からも明らかなように、本発明の熱処理を施した本発明溶接鋼管１〜４２は、溶接部のガス成分の除去が十分に行われるため溶接部の衝撃値は約１００〜２００の値を示し、溶接部がすぐれた靭性を備えるものであり、また、強度落ち代が−１０〜−２９（ＭＰａ）を示すことから、溶接部ばかりか溶接鋼管全体としての大幅な引張強さの向上が認められ、さらに、溶接割れ及びパイプ曲がり搬送不良が全く生じないものであった。
したがって、本発明によれば、溶接欠陥の発生、形状不良がなく、強度・靭性に優れた高品質の溶接鋼管が得られることがわかる。
As shown in Table 1, according to the present invention, with respect to welded steel pipes of various sizes, only the entire region of the welded portion is simultaneously heat-treated uniformly at the target heating holding temperature (that is, the heating holding temperature). The target value, the MAX value, and the MIN value are within the temperature range of 100 to 500 ° C., and (MAX value−MIN value) <100 ° C.).
As is apparent from Table 2, the welded steel pipes 1 to 42 of the present invention subjected to the heat treatment of the present invention are sufficiently removed of the gas component of the welded portion, and therefore the impact value of the welded portion is about 100 to 200. The welded portion has excellent toughness, and the strength drop allowance is −10 to −29 (MPa). Therefore, the tensile strength of not only the welded portion but also the entire welded steel pipe is large. In addition, no weld cracking or pipe bending conveyance failure occurred.
Therefore, according to this invention, it turns out that there is no generation | occurrence | production of a welding defect and a shape defect, and the high quality welded steel pipe excellent in intensity | strength and toughness is obtained.
一方、表３中の、溶接部に対して熱処理を施さなかった比較例溶接鋼管４３については、表４に示されるように溶接割れが発生し、使用に耐えるものとはなりえなかった。
また、表３中の比較例溶接鋼管４４〜６２については、誘導加熱で急速加熱したため、加熱時間は非常に短時間（４０秒以下）ですんだが、その反面、急速加熱であるがために、加熱保持温度の狙い値が５００℃以下であったとしても、実際には、ＭＡＸ値が５００℃を超える値となってしまい、さらに、ＭＡＸ値−ＭＩＮ値の値が１００（℃）を超え、本発明の「溶接鋼管の溶接部の全領域のみを、同時に、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱する」という熱処理条件から外れた結果、表４に示される通り、形状不良のない安定した特性を有する溶接鋼管を得ることはできなかった。
例えば、比較例溶接鋼管４５、４７、４９、５３、５７では、加熱保持温度の狙い値は比較的低く本発明で規定する１００〜５００℃の範囲内となっており（但し、実際のＭＡＸ値は５００℃を超えている）、また、加熱時間も１０秒以内という短時間で熱処理されたものであるため、溶接鋼管の引張強さは向上し、溶接部の衝撃値も高い値となったが、溶接部に残存する水素の除去が不十分であることにより溶接割れを発生し、パイプ曲がりも生じたため、品質が不良なものであった。
また、例えば、比較例溶接鋼管４６、５１、５２、５４、５６、６０、６１、６２では、加熱保持温度が高く（狙い値が５００℃超）、加熱保持時間が長いため、水素除去が十分に行われ、その結果、溶接割れの発生はみられなくなったものの、溶接鋼管の引張強さは大幅に低下し、溶接部の衝撃値も小さな値となり靭性の低下を示し、さらにパイプ曲がりも生じたため、やはり品質が不良なものであった。
On the other hand, in Comparative Example welded steel pipe 43 in which heat treatment was not performed on the welded portion in Table 3, weld cracking occurred as shown in Table 4, and it could not endure use.
Moreover, since the comparative example welded steel pipes 44 to 62 in Table 3 were rapidly heated by induction heating, the heating time was very short (40 seconds or less), but on the other hand, because it was rapid heating, Even if the target value of the heating and holding temperature is 500 ° C. or lower, the MAX value actually exceeds 500 ° C., and the MAX value−MIN value exceeds 100 (° C.). In the present invention, “only the entire region of the welded portion of the welded steel pipe is simultaneously heated to a temperature within a temperature range of 100 to 500 ° C., and the difference between the maximum value and the minimum value of the heating temperature is within 100 ° C. As a result of deviating from the heat treatment condition of “to do”, as shown in Table 4, it was not possible to obtain a welded steel pipe having a stable characteristic without a shape defect.
For example, in the comparative example welded steel pipes 45, 47, 49, 53, 57, the target value of the heating and holding temperature is relatively low and within the range of 100 to 500 ° C. defined in the present invention (however, the actual MAX value) Is over 500 ° C), and the heat treatment time is within 10 seconds, so the tensile strength of the welded steel pipe is improved and the impact value of the welded part is also high. However, due to insufficient removal of hydrogen remaining in the welded portion, weld cracking occurred and pipe bending occurred, resulting in poor quality.
Further, for example, in the comparative example welded steel pipes 46, 51, 52, 54, 56, 60, 61, and 62, the heating and holding temperature is high (target value is over 500 ° C.), and the heating and holding time is long. As a result, although the occurrence of weld cracking was not observed, the tensile strength of the welded steel pipe was greatly reduced, the impact value of the welded part was also reduced, indicating a decrease in toughness, and pipe bending was also caused. As a result, the quality was still poor.
比較溶接鋼管６３〜８２については、表５に示すように、加熱保持温度（狙い値、ＭＡＸ値、ＭＩＮ値の全て）が本発明で規定する１００〜５００℃の範囲内となるように、さらに、本発明溶接鋼管１〜４２の場合と同程度の加熱保持時間になるようにバーナー加熱を行ったが、加熱保持温度のＭＡＸ値−ＭＩＮ値の値が１００℃を超えていたため、溶接部の全領域に亘って均一な加熱を行うことはできなかった。
そして、表６に示されるように、熱処理後の比較例溶接鋼管６３〜８２は、溶接部の衝撃値は高く、また、溶接割れの発生もなく引張強度の改善が見られることから、溶接鋼管としての機械的特性には優れるものの、溶接部の全領域に亘ってＭＡＸ値−ＭＩＮ値の値が１００℃以内となるような均一加熱ができなかったために、パイプ曲がりによる形状不良を生じた。
For the comparative welded steel pipes 63 to 82, as shown in Table 5, the heating and holding temperature (all of the target value, the MAX value, and the MIN value) is within the range of 100 to 500 ° C. defined in the present invention. The burner was heated so that the heating and holding time was about the same as in the case of the welded steel pipes 1 to 42 of the present invention, but the MAX value-MIN value of the heating and holding temperature exceeded 100 ° C. Uniform heating could not be performed over the entire region.
And as Table 6 shows, since the comparative example welded steel pipes 63-82 after heat processing have a high impact value of a weld part, and the improvement of tensile strength is seen without generation | occurrence | production of a weld crack, welded steel pipe However, since the uniform heating was not possible so that the MAX value−MIN value was within 100 ° C. over the entire area of the welded portion, a shape defect due to pipe bending occurred.
以上述べたように、本発明の溶接鋼管の熱処理方法および熱処理装置によれば、溶接鋼管の熱処理に際し、溶接鋼管の形状（変形）に追従対応させて、その溶接部のみを、高精度で均一に、かつ、効率的に熱処理することができるため、健全な溶接部と、溶接部長手方向の全体に亘って均質な機械的特性（強度、靭性等）を備え、かつ、形状不良のない溶接鋼管を効率的に製造することができる。 As described above, according to the heat treatment method and heat treatment apparatus for welded steel pipes of the present invention, when heat treating the welded steel pipes, the welded steel pipes are made to follow the shape (deformation) of the welded steel pipes, and only the welded portions thereof are uniform with high accuracy. In addition, since the heat treatment can be performed efficiently, the weld has a sound weld and uniform mechanical properties (strength, toughness, etc.) over the entire length of the weld, and has no defective shape. A steel pipe can be manufactured efficiently.
Claims (6)
前記筒状に成形した鋼板の相対向する鋼板端部を突合せて溶接した直後に、前記溶接鋼管の溶接部の全領域のみを、同時に、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱することを特徴とする溶接鋼管の熱処理方法。 After the steel sheet edge portions facing each of the shaped steel plate into a cylindrical shape butt welded and molded welded steel pipe having a weld, the heat treatment method of heat-treating the welded steel pipe,
Immediately after butt-welding opposite steel plate ends of the steel plate formed into a cylindrical shape, only the entire area of the welded portion of the welded steel pipe is simultaneously at a temperature within a temperature range of 100 to 500 ° C, and A method for heat treatment of a welded steel pipe, characterized by heating so that a difference between a maximum value and a minimum value of the heating temperature is within 100 ° C.
前記溶接鋼管の溶接部の全領域のみを、同時に、溶接部の全領域に亘って、１００〜５００℃の温度範囲内の温度に、かつ、加熱温度の最高値と最低値の差が１００℃以内となるように加熱する溶接部加熱手段を備え、該溶接部加熱手段は、
前記溶接鋼管の溶接部の全領域を覆う加熱装置を有し、前記加熱装置は、前記溶接鋼管の長手方向に複数に分割された加熱エレメントを含み、さらに、前記加熱エレメントは、前記溶接鋼管と前記加熱エレメントとの間隔を一定に保つための間隔保持脚を有することを特徴とする溶接鋼管の熱処理装置。 In the heat treatment apparatus for a welded steel pipe having a welded portion where the opposite ends of the steel plates formed into a cylindrical shape are welded to face each other,
Only the entire region of the welded portion of the welded steel pipe is simultaneously subjected to a temperature within a temperature range of 100 to 500 ° C over the entire region of the welded portion, and the difference between the maximum value and the minimum value of the heating temperature is 100 ° C. A welding part heating means for heating to be within , the welding part heating means,
A heating device that covers the entire area of the welded portion of the welded steel pipe, and the heating device includes a heating element that is divided into a plurality of lengths in the longitudinal direction of the welded steel pipe; An apparatus for heat treatment of a welded steel pipe, comprising a distance maintaining leg for maintaining a constant distance from the heating element .
該温度検知器で加熱対象域のそれぞれに存在する溶接部の温度を測定し、
その測定温度実績値を前記加熱エレメントにフィードバックするようにしたことを特徴とする請求項２記載の溶接鋼管の熱処理装置。 A temperature detector is provided in each of the heating target areas of the heating element divided into a plurality of claim 2 ,
The temperature detector measures the temperature of the weld that exists in each of the heating target areas,
3. The heat treatment apparatus for welded steel pipe according to claim 2 , wherein the measured temperature actual value is fed back to the heating element.
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| CN107723454A (en) * | 2017-11-28 | 2018-02-23 | 哈电集团（秦皇岛）重型装备有限公司 | A kind of tube sheet component and low head component girth joint localized heat treatment process |
| CN109623209A (en) * | 2018-12-29 | 2019-04-16 | 张家港市江南锅炉压力容器有限公司 | A kind of preheating device for heat exchange pipe head welding |
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| JPS52142612A (en) * | 1976-05-24 | 1977-11-28 | Nippon Steel Corp | Postannealer using high frequency induction heating |
| JPS55161589A (en) * | 1979-06-01 | 1980-12-16 | Nippon Steel Corp | Position control method of welded steel heat treatment equipment |
| JPS61190019A (en) * | 1985-02-19 | 1986-08-23 | Nippon Steel Corp | Electric welded steel pipe having excellent sour resistance in electric weld zone |
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