JP2021123781A - Repair method of weld bead cutting part of electroseamed steel pipe, and manufacturing method of electroseamed steel pipe - Google Patents
Repair method of weld bead cutting part of electroseamed steel pipe, and manufacturing method of electroseamed steel pipe Download PDFInfo
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 57
- 239000011324 bead Substances 0.000 title claims abstract description 57
- 239000010959 steel Substances 0.000 title claims abstract description 57
- 238000005520 cutting process Methods 0.000 title claims abstract description 56
- 238000000034 method Methods 0.000 title claims abstract description 40
- 238000004519 manufacturing process Methods 0.000 title claims description 8
- 238000005507 spraying Methods 0.000 claims abstract description 61
- 238000007747 plating Methods 0.000 claims abstract description 24
- 239000000956 alloy Substances 0.000 claims abstract description 16
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 16
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 15
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 14
- 238000005260 corrosion Methods 0.000 abstract description 23
- 230000007797 corrosion Effects 0.000 abstract description 23
- 239000007789 gas Substances 0.000 description 58
- 238000007751 thermal spraying Methods 0.000 description 52
- 239000000463 material Substances 0.000 description 21
- 230000000052 comparative effect Effects 0.000 description 18
- 239000007921 spray Substances 0.000 description 15
- 238000012360 testing method Methods 0.000 description 12
- 229910007570 Zn-Al Inorganic materials 0.000 description 7
- 238000011156 evaluation Methods 0.000 description 5
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 229920000298 Cellophane Polymers 0.000 description 4
- 238000010289 gas flame spraying Methods 0.000 description 4
- 238000003466 welding Methods 0.000 description 4
- 238000001000 micrograph Methods 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 238000010891 electric arc Methods 0.000 description 2
- 238000009958 sewing Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
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- Coating By Spraying Or Casting (AREA)
Abstract
Description
本発明は、電縫鋼管の溶接ビード切削部の補修方法、及び電縫鋼管の製造方法に関する。 The present invention relates to a method for repairing a weld bead cutting portion of an electric resistance-sewn steel pipe and a method for manufacturing an electric resistance-sewn steel pipe.
Ａｌめっき層、Ｚｎめっき層、又はＡｌ及びＺｎの少なくとも１種を含む合金めっき層を表面に有する電縫鋼管は、耐食性、耐候性及び耐熱性に優れていることから、建築材料、自動車部品、電気機器材料などにおいて広く用いられている。この電縫鋼管は、Ａｌめっき層、Ｚｎめっき層、又はＡｌ及びＺｎの少なくとも１種を含む合金めっき層を表面に形成した鋼帯の幅方向両端部を突き合わせて管状に成形した後、突き合せ部を電縫溶接することによって製造されている。電縫溶接では溶接ビードが形成されるため、溶接ビードを切削することが一般に行われている。溶接ビードを切削すると、めっき層が除去されるため、溶射によって切削部が補修されている。 An electro-sewn steel pipe having an Al-plated layer, a Zn-plated layer, or an alloy-plated layer containing at least one of Al and Zn on its surface is excellent in corrosion resistance, weather resistance, and heat resistance. Widely used in electrical equipment materials. This electrosewn steel pipe is formed into a tubular shape by abutting both ends in the width direction of a steel strip having an Al-plated layer, a Zn-plated layer, or an alloy-plated layer containing at least one of Al and Zn on the surface, and then butt-butting. Manufactured by electrostitching the parts. Since a weld bead is formed in electric sewing welding, it is common practice to cut the weld bead. When the weld bead is cut, the plating layer is removed, so the cut portion is repaired by thermal spraying.
切削部の補修方法としては、例えば、特許文献１には、切削部をアーク溶射によって補修する方法が提案されている。
しかしながら、アーク溶射は、一般に、切削部に形成される補修層（アーク溶射層）の厚みが長手方向でばらつき易い。そのため、特許文献１の方法は、補修層の厚みが小さい部分が腐食の起点となり易く、耐食性を十分に確保することができない。
As a method for repairing a cut portion, for example, Patent Document 1 proposes a method for repairing a cut portion by arc spraying.
However, in arc spraying, in general, the thickness of the repair layer (arc spraying layer) formed in the cutting portion tends to vary in the longitudinal direction. Therefore, in the method of Patent Document 1, the portion where the thickness of the repair layer is small tends to be the starting point of corrosion, and sufficient corrosion resistance cannot be ensured.
また、特許文献２には、切削部に対してＡｌをガスフレーム溶射した後、Ｚｎ又はＺｎ−Ａｌ合金をガスフレーム溶射して補修する方法が提案されている。
しかしながら、ガスフレーム溶射は、一般に、補修層（ガスフレーム溶射層）の厚みを大きくすることが難しい。そのため、特許文献２の方法は、耐食性を確保するために、溶射時のラインスピードを低下させて補修層の厚みを確保する必要があり、電縫鋼管の生産性が低下し易い。
Further, Patent Document 2 proposes a method of repairing a cutting portion by spraying Al on a gas frame and then spraying a Zn or Zn—Al alloy on the gas frame.
However, in gas frame thermal spraying, it is generally difficult to increase the thickness of the repair layer (gas frame thermal spraying layer). Therefore, in the method of Patent Document 2, in order to secure corrosion resistance, it is necessary to reduce the line speed at the time of thermal spraying to secure the thickness of the repair layer, and the productivity of the electrosewn steel pipe tends to decrease.
さらに、特許文献３には、切削部をガスフレーム溶射した後、アーク溶射して補修する方法が提案されている。 Further, Patent Document 3 proposes a method of repairing a cut portion by spraying a gas frame and then spraying an arc.
特許文献３の方法は、アーク溶射とガスフレーム溶射とを組み合わせることにより、各溶射方法の欠点を解消することができると考えられる。
しかしながら、ガスフレーム溶射を行った後にアーク溶射を行う特許文献３の方法は、ガスフレーム溶射によって形成される補修層（ガスフレーム溶射層）とアーク溶射によって形成される補修層（アーク溶射層）との密着性が悪く、その後の加工処理などで補修層が剥離し易い。
It is considered that the method of Patent Document 3 can eliminate the drawbacks of each thermal spraying method by combining arc thermal spraying and gas frame thermal spraying.
However, the method of Patent Document 3 in which arc spraying is performed after gas flame spraying is performed with a repair layer (gas frame spraying layer) formed by gas flame spraying and a repair layer (arc spraying layer) formed by arc spraying. Adhesion is poor, and the repair layer is easily peeled off in the subsequent processing.
本発明は、上記のような問題を解決するためになされたものであり、アーク溶射層とガスフレーム溶射層との密着性が高く、且つ耐食性に優れる補修層を形成することが可能な電縫鋼管の溶接ビード切削部の補修方法、及び電縫鋼管の製造方法を提供することを目的とする。 The present invention has been made to solve the above problems, and is capable of forming a repair layer having high adhesion between the arc sprayed layer and the gas frame sprayed layer and excellent corrosion resistance. It is an object of the present invention to provide a method for repairing a welded bead cutting portion of a steel pipe and a method for manufacturing an electrosewn steel pipe.
本発明者らは、上記のような問題を解決すべく鋭意研究を行った結果、所定のめっき層を表面に有する電縫鋼管の溶接ビード切削部に対して、アーク溶射を行ってアーク溶射層を形成した後にガスフレーム溶射を行ってガスフレーム溶射層を形成することにより、アーク溶射層とガスフレーム溶射層との密着性が高く、且つ耐食性に優れる補修層を形成し得ることを見出し、本発明を完成するに至った。 As a result of diligent research to solve the above problems, the present inventors performed arc spraying on the weld bead cutting portion of an electrosewn steel pipe having a predetermined plating layer on the surface to perform an arc spraying layer. By forming a gas frame sprayed layer by performing gas frame spraying after forming the above, it was found that a repair layer having high adhesion between the arc sprayed layer and the gas frame sprayed layer and excellent corrosion resistance can be formed. The invention was completed.
すなわち、本発明は、Ａｌめっき層、Ｚｎめっき層、又はＡｌ及びＺｎの少なくとも１種を含む合金めっき層を表面に有する電縫鋼管の溶接ビード切削部に対して、アーク溶射を行ってアーク溶射層を形成した後、前記アーク溶射層上にガスフレーム溶射を行ってガスフレーム溶射層を形成する、電縫鋼管の溶接ビード切削部の補修方法である。 That is, in the present invention, arc spraying is performed on a weld bead cutting portion of an electrosewn steel pipe having an Al plating layer, a Zn plating layer, or an alloy plating layer containing at least one of Al and Zn on the surface. This is a method of repairing a weld bead cutting portion of an electrosewn steel pipe, in which a gas frame sprayed layer is formed by performing gas frame spraying on the arc sprayed layer after the layer is formed.
また、本発明は、前記補修方法を含む、電縫鋼管の製造方法である。 Further, the present invention is a method for manufacturing an electric resistance welded steel pipe, including the above-mentioned repair method.
本発明によれば、アーク溶射層とガスフレーム溶射層との密着性が高く、且つ耐食性に優れる補修層を形成することが可能な電縫鋼管の溶接ビード切削部の補修方法、及び電縫鋼管の製造方法を提供することができる。 According to the present invention, a method for repairing a welded bead cutting portion of an electrosewn steel pipe capable of forming a repair layer having high adhesion between an arc sprayed layer and a gas frame sprayed layer and excellent corrosion resistance, and an electrosewn steel pipe. Manufacturing method can be provided.
以下、本発明の実施形態について具体的に説明する。本発明は以下の実施形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で、当業者の通常の知識に基づいて、以下の実施形態に対し変更、改良などが適宜加えられたものも本発明の範囲に入ることが理解されるべきである。 Hereinafter, embodiments of the present invention will be specifically described. The present invention is not limited to the following embodiments, and changes, improvements, etc. have been appropriately added to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that things also fall within the scope of the present invention.
本発明の実施形態に係る電縫鋼管の溶接ビード切削部の補修方法（以下、「補修方法」と略すことがある）は、めっき層を有する電縫鋼管の溶接ビード切削部に対して、アーク溶射を行ってアーク溶射層を形成した後、アーク溶射層上にガスフレーム溶射を行ってガスフレーム溶射層を形成することを含む。 The method for repairing a welded bead cut portion of an electrosprayed steel pipe according to an embodiment of the present invention (hereinafter, may be abbreviated as “repair method”) is an arc with respect to a welded bead cut portion of an electrosprayed steel pipe having a plating layer. This includes performing gas flame spraying on the arc sprayed layer to form a gas frame sprayed layer after performing thermal spraying to form an arc sprayed layer.
ここで、本明細書において「アーク溶射」とは、溶射ガンから連続的に送給される２本の溶射材料（ワイヤ）の先端で直流アーク放電を発生させ、溶融した金属を圧縮空気などで吹き飛ばす溶射法を意味する。また、本明細書において「ガスフレーム溶射」とは、燃料と酸素ガスが充満した燃焼フレーム内に溶射ガンから溶射材料（ワイヤ）を連続的に供給し、フレーム内で溶融した材料を圧縮空気などで吹き飛ばす溶射法を意味する。 Here, in the present specification, "arc spraying" means that a DC arc discharge is generated at the tips of two thermal spraying materials (wires) continuously supplied from a thermal spray gun, and the molten metal is blown with compressed air or the like. It means a thermal spraying method that blows away. Further, in the present specification, "gas frame thermal spraying" means that a thermal spray material (wire) is continuously supplied from a thermal spray gun into a combustion frame filled with fuel and oxygen gas, and the material melted in the frame is compressed air or the like. It means the thermal spraying method to blow off with.
アーク溶射によって形成されるアーク溶射層は、ガスフレーム溶射によって形成されるガスフレーム溶射層に比べて、溶射された溶融金属の温度が高いため、溶接ビード切削部に対する密着強度が高い。そのため、溶接ビード切削部に対し、最初にアーク溶射を行ってアーク溶射層を形成することにより、溶接ビード切削部とアーク溶射層との密着性を高めることができる。
また、アーク溶射は、ガスフレーム溶射に比べて、溶射ワイヤを溶融させるためのエネルギー密度が高く、皮膜形成速度が速い。そのため、アーク溶射を行うことにより、厚みが大きいアーク溶射層（補修層）を形成し、補修層の耐食性を高めることができる。
The arc sprayed layer formed by arc spraying has a higher temperature of the molten metal sprayed than the gas flame sprayed layer formed by gas flame spraying, so that the adhesion strength to the weld bead cut portion is high. Therefore, by first performing arc spraying on the weld bead cutting portion to form an arc sprayed layer, the adhesion between the weld bead cutting portion and the arc sprayed layer can be improved.
Further, in the arc spraying, the energy density for melting the sprayed wire is higher and the film forming speed is faster than in the gas frame spraying. Therefore, by performing arc spraying, a large arc spraying layer (repair layer) can be formed, and the corrosion resistance of the repair layer can be improved.
一方、アーク溶射層では、溶射ワイヤの先端部での間欠的なアーク放電により溶融された金属が粒子となって基板表面に溶着するため、溶接ビード切削部の長手方向で厚みがばらつき易く、厚みが小さい部分が腐食の起点となって耐食性が低下する恐れがある。そこで、アーク溶射層上にガスフレーム溶射を行ってガスフレーム溶射層を形成することにより、溶接ビード切削部の長手方向におけるアーク溶射層の厚みのばらつきを少なくし、補修層全体としての耐食性を安定して高めることができる。
また、アーク溶射層は、ガスフレーム溶射層に比べて表面が粗い。そのため、アーク溶射層上にガスフレーム溶射層を形成することにより、アンカー効果によってアーク溶射層とガスフレーム溶射層との密着性を高めることもできる。
On the other hand, in the arc sprayed layer, the metal melted by the intermittent arc discharge at the tip of the sprayed wire becomes particles and welds to the substrate surface, so that the thickness tends to vary in the longitudinal direction of the weld bead cutting portion, and the thickness. The small part may become the starting point of corrosion and the corrosion resistance may decrease. Therefore, by performing gas frame spraying on the arc sprayed layer to form the gas frame sprayed layer, the variation in the thickness of the arc sprayed layer in the longitudinal direction of the weld bead cutting portion is reduced, and the corrosion resistance of the entire repair layer is stabilized. Can be enhanced.
Further, the surface of the arc sprayed layer is rougher than that of the gas frame sprayed layer. Therefore, by forming the gas frame sprayed layer on the arc sprayed layer, the adhesion between the arc sprayed layer and the gas frame sprayed layer can be improved by the anchor effect.
アーク溶射層の材質としては、特に限定されず、耐食性を有する各種金属を用いることができる。アーク溶射層の材質の例としては、Ａｌ、Ｚｎ、これらの元素を含む合金（Ｚｎ−Ａｌ合金など）などが挙げられる。その中でも、アーク溶射層は、Ａｌを含むことが好ましく、Ａｌ単体から形成されていることが好ましい。
アーク溶射層は、２本の溶射材料（ワイヤ）の種類を適宜選択することにより、各種材質のアーク溶射層を形成することができる。例えば、材質がＡｌのアーク溶射層を形成する場合、２本の溶射材料としてＡｌワイヤを選択すればよい。また、材質がＺｎ−Ａｌ合金のアーク溶射層を形成する場合、２本の溶射材料としてＺｎ−Ａｌ合金ワイヤを用いるか、又はＺｎワイヤとＡｌワイヤとを組み合わせて用いればよい。ただし、ＺｎワイヤとＡｌワイヤとを組み合わせて用いた場合、アーク溶射層でＺｎ及びＡｌが均一に分布し難く、所望の耐食性が得られ難いため、２本の溶射材料（ワイヤ）は同一成分であることが好ましい。
The material of the arc sprayed layer is not particularly limited, and various metals having corrosion resistance can be used. Examples of the material of the arc sprayed layer include Al, Zn, and alloys containing these elements (Zn—Al alloy, etc.). Among them, the arc sprayed layer preferably contains Al, and is preferably formed from Al alone.
As the arc sprayed layer, the arc sprayed layer of various materials can be formed by appropriately selecting the types of the two thermal spraying materials (wires). For example, when forming an arc sprayed layer whose material is Al, Al wire may be selected as the two sprayed materials. When forming an arc sprayed layer made of a Zn—Al alloy, the Zn—Al alloy wire may be used as the two sprayed materials, or the Zn wire and the Al wire may be used in combination. However, when a Zn wire and an Al wire are used in combination, it is difficult to uniformly distribute Zn and Al in the arc sprayed layer, and it is difficult to obtain the desired corrosion resistance. Therefore, the two sprayed materials (wires) have the same component. It is preferable to have.
アーク溶射層の平均厚みは、特に限定されないが、好ましくは１０〜８０μｍである。このような範囲に平均厚みを制御することにより、補修層全体としての厚みを十分に確保することができるため、補修層の耐食性を高めることができる。
ここで、本明細書において「アーク溶射層の平均厚み」とは、溶接ビード切削部に形成されたアーク溶射層及びガスフレーム溶射層の補修層断面の顕微鏡写真において、電縫鋼管の円周方向（Ｃ方向）で測定されたアーク溶射層の厚みの平均値を意味する。
The average thickness of the arc sprayed layer is not particularly limited, but is preferably 10 to 80 μm. By controlling the average thickness within such a range, the thickness of the repair layer as a whole can be sufficiently secured, so that the corrosion resistance of the repair layer can be improved.
Here, in the present specification, the "average thickness of the arc sprayed layer" is the circumferential direction of the electrosewn steel pipe in the micrograph of the repair layer cross section of the arc sprayed layer and the gas frame sprayed layer formed in the weld bead cutting portion. It means the average value of the thickness of the arc sprayed layer measured in (C direction).
アーク溶射の条件は、使用する溶射装置及び溶射材料の種類などに応じて適宜調整すればよく、特に限定されない。
なお、アーク溶射を行う際に溶接ビード切削部を加熱してもよい。溶射材料の種類にもよるが、例えば、２００〜３５０℃に溶接ビード切削部を加熱してアーク溶射を行うことにより、溶接ビード切削部とアーク溶射層との密着性を高めることができる。
The conditions for arc spraying may be appropriately adjusted according to the type of spraying device and spraying material used, and are not particularly limited.
The weld bead cutting portion may be heated when performing arc spraying. Although it depends on the type of thermal spraying material, for example, by heating the weld bead cutting portion to 200 to 350 ° C. and performing arc spraying, the adhesion between the weld bead cutting portion and the arc sprayed layer can be improved.
ガスフレーム溶射層の材質としては、特に限定されないが、Ｚｎ及びＡｌを含むことが好ましい。ガスフレーム溶射層の材質の例としては、Ｚｎ−Ａｌ合金が挙げられる。
ガスフレーム溶射層は、１本の溶射材料（ワイヤ）の種類を適宜選択することにより、各種材質のガスフレーム溶射層を形成することができる。例えば、材質がＺｎ−Ａｌ合金のガスフレーム溶射層を形成する場合、１本の溶射材料としてＺｎ−Ａｌ合金ワイヤを用いればよい。
The material of the gas frame sprayed layer is not particularly limited, but preferably contains Zn and Al. An example of the material of the gas frame sprayed layer is a Zn—Al alloy.
As the gas frame spraying layer, a gas frame spraying layer of various materials can be formed by appropriately selecting the type of one spraying material (wire). For example, when forming a gas frame thermal spraying layer made of a Zn—Al alloy, a Zn—Al alloy wire may be used as one thermal spraying material.
ガスフレーム溶射層の平均厚みは、特に限定されないが、好ましくは３〜３０μｍである。このような範囲に平均厚みを制御することにより、アーク溶射層の厚みのばらつきを安定的に低減させることができる。
ここで、本明細書において「ガスフレーム溶射層の平均厚み」とは、溶接ビード切削部に形成されたアーク溶射層及びガスフレーム溶射層の補修層断面の顕微鏡写真において、電縫鋼管の円周方向（Ｃ方向）で測定されたガスフレーム溶射層の厚みの平均値を意味する。
The average thickness of the gas frame sprayed layer is not particularly limited, but is preferably 3 to 30 μm. By controlling the average thickness within such a range, it is possible to stably reduce the variation in the thickness of the arc sprayed layer.
Here, in the present specification, the "average thickness of the gas frame sprayed layer" is the circumference of the electric resistance welded steel pipe in the micrograph of the arc sprayed layer formed in the weld bead cutting portion and the repair layer cross section of the gas frame sprayed layer. It means the average value of the thickness of the gas frame sprayed layer measured in the direction (C direction).
ガスフレーム溶射の条件は、使用する溶射装置及び溶射材料の種類などに応じて適宜調整すればよく、特に限定されない。 The conditions for gas frame thermal spraying may be appropriately adjusted according to the type of thermal spraying device and thermal spraying material used, and are not particularly limited.
本発明の実施形態に係る補修方法は、各種めっき層を表面に有する電縫鋼管の溶接ビード切削部に適用することができるが、めっき層は、電縫鋼管の耐食性の観点から、Ａｌめっき層、Ｚｎめっき層、又はＡｌ及びＺｎの少なくとも１種を含む合金めっき層から選択される。その中でも、めっき層は、Ａｌ、Ｚｎ及びＭｇを含む合金めっき層であることが好ましい。 The repair method according to the embodiment of the present invention can be applied to a weld bead cutting portion of an electrosewn steel pipe having various plating layers on its surface, but the plating layer is an Al plating layer from the viewpoint of corrosion resistance of the electrosewn steel pipe. , Zn plating layer, or alloy plating layer containing at least one of Al and Zn. Among them, the plating layer is preferably an alloy plating layer containing Al, Zn and Mg.
本発明の実施形態に係る電縫鋼管の製造方法は、上記の補修方法を含む。
補修方法以外の工程は、特に限定されず、当該技術分野において公知の方法に準じて行うことができる。具体的には、次のようにして電縫鋼管を製造することができる。まず、Ａｌめっき層、Ｚｎめっき層、又はＡ１及びＺｎの少なくとも１種を含む合金めっき層を表面に有するめっき鋼帯の幅方向両端部を突き合わせて管状にロール成形した後、突き合せ部を電縫溶接する。次に、溶接ビードを切削し、溶接ビード切削部に上記の補修方法によって補修層を形成することにより、電縫鋼管を得ることができる。なお、電縫鋼管は、補修層の形成後に、サイジングロールを用いて所望のサイズに調整することができる。
The method for manufacturing an electrosewn steel pipe according to an embodiment of the present invention includes the above-mentioned repair method.
The steps other than the repair method are not particularly limited, and can be performed according to a method known in the art. Specifically, the electric resistance welded steel pipe can be manufactured as follows. First, both ends in the width direction of a plated steel strip having an Al plating layer, a Zn plating layer, or an alloy plating layer containing at least one of A1 and Zn on the surface are butted to form a tubular roll, and then the butted portion is electrocuted. Sewing and welding. Next, the welded steel pipe can be obtained by cutting the weld bead and forming a repair layer on the weld bead cutting portion by the above-mentioned repair method. The electrosewn steel pipe can be adjusted to a desired size using a sizing roll after the repair layer is formed.
以下に、実施例を挙げて本発明の内容を詳細に説明するが、本発明はこれらに限定して解釈されるものではない。 Hereinafter, the contents of the present invention will be described in detail with reference to examples, but the present invention is not construed as being limited thereto.
（実施例１）
Ａｌ、Ｚｎ及びＭｇを含む合金めっき層を表面に有する電縫鋼管（外径４２．７ｍｍ×厚み２．３ｍｍ）の溶接ビード切削部に対して、Ａｌワイヤ（径１．４ｍｍ）２本を用いてアーク溶射（第１溶射工程）を行った後に、ＺｎＡｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第２溶射工程）を行うことにより、溶接ビード切削部の補修を行った。溶射工程では、電縫鋼管の搬送速度を８０ｍ／分、アーク溶射ガンとガスフレーム溶射ガンとの間の距離を４００ｍｍとした。アーク溶射では、高速インバータドライブ溶射装置（ディーテック株式会社製ＡＲＣ−ＢＯＹ Ａ４００；以下の実施例及び比較例でも同じ装置を使用した）を用い、２本のワイヤの送給速度をいずれも１３ｍ／分、圧縮空気の圧力を０．５２ＭＰａ、電圧を２１．４Ｖ、電流を１７０Ａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。ガスフレーム溶射では、ガス式メタライジング溶射機（コーケン・テクノ株式会社製ＣＤ−３型ガス・フレーム式金属ワイヤー溶射機；以下の実施例及び比較例でも同じ装置を使用）を用い、ワイヤの送給速度を４．２ｍ／分、圧縮空気の圧力を０．４ＭＰａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。
(Example 1)
Two Al wires (1.4 mm in diameter) are used for the weld bead cutting part of an electrosewn steel pipe (outer diameter 42.7 mm x 2.3 mm thickness) having an alloy plating layer containing Al, Zn and Mg on the surface. After performing arc spraying (first spraying step), the weld bead cutting portion was repaired by performing gas frame spraying (second spraying step) using one ZnAl wire (diameter 1.4 mm). .. In the thermal spraying step, the transfer speed of the electrosewn steel pipe was set to 80 m / min, and the distance between the arc thermal spray gun and the gas frame thermal spray gun was set to 400 mm. For arc spraying, a high-speed inverter drive spraying device (ARC-BOY A400 manufactured by D-Tech Co., Ltd .; the same device was used in the following examples and comparative examples) was used, and the feeding speed of the two wires was 13 m / The pressure of the compressed air was 0.52 MPa, the voltage was 21.4 V, the current was 170 A, and the distance between the thermal spray gun and the weld bead cutting part was 30 mm. In gas frame spraying, a gas type metallizing sprayer (CD-3 type gas frame type metal wire sprayer manufactured by Koken Techno Co., Ltd .; the same device is used in the following examples and comparative examples) is used to feed the wire. The feeding speed was 4.2 m / min, the pressure of the compressed air was 0.4 MPa, and the distance between the thermal spray gun and the weld bead cutting portion was 30 mm.
（実施例２）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、Ａｌワイヤ（径１．４ｍｍ）２本を用いてアーク溶射（第１溶射工程）を行った後に、ＺｎＡｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第２溶射工程）を行うことにより、溶接ビード切削部の補修を行った。溶射工程では、アーク溶接における２本のワイヤの送給速度をいずれも８ｍ／分としたこと以外は、実施例１と同様にした。
(Example 2)
A ZnAl wire (diameter 1. The weld bead cutting portion was repaired by performing gas frame thermal spraying (second thermal spraying step) using one 4 mm) wire. In the thermal spraying step, the same as in Example 1 was carried out except that the feeding speeds of the two wires in arc welding were both set to 8 m / min.
（比較例１）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、Ａｌワイヤ（径１．４ｍｍ）２本を用いてアーク溶射（第１溶射工程）を行うことにより、溶接ビード切削部の補修を行った。アーク溶射の条件は、実施例１と同様にした。また、溶射工程におけるその他の条件は実施例１と同様にした。
(Comparative Example 1)
Repair of the weld bead cutting part by performing arc spraying (first spraying step) using two Al wires (diameter 1.4 mm) on the weld bead cutting part of the electric resistance welded steel pipe similar to Example 1. Was done. The conditions for arc spraying were the same as in Example 1. In addition, other conditions in the thermal spraying step were the same as in Example 1.
（比較例２）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、Ａｌワイヤ（径１．４ｍｍ）２本を用いてアーク溶射（第１溶射工程）を行うことにより、溶接ビード切削部の補修を行った。アーク溶射の条件は、実施例２と同様にした。また、溶射工程におけるその他の条件は実施例１と同様にした。
(Comparative Example 2)
Repair of the weld bead cutting part by performing arc spraying (first spraying step) using two Al wires (diameter 1.4 mm) on the weld bead cutting part of the electric resistance welded steel pipe similar to Example 1. Was done. The conditions for arc spraying were the same as in Example 2. In addition, other conditions in the thermal spraying step were the same as in Example 1.
（比較例３）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、ＺｎＡｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第１溶射工程）を行った後に、Ａｌワイヤ（径１．４ｍｍ）２本を用いてアーク溶射（第２溶射工程）を行うことにより、溶接ビード切削部の補修を行った。ガスフレーム溶射では、ワイヤの送給速度を４．２ｍ／分、圧縮空気の圧力を０．４ＭＰａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。また、アーク溶射では、２本のワイヤの送給速度をいずれも１３ｍ／分、圧縮空気の圧力を０．５２ＭＰａ、電圧を２１．４Ｖ、電流を１７０Ａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。溶射工程におけるその他の条件は実施例１と同様にした。
(Comparative Example 3)
After performing gas frame thermal spraying (first thermal spraying step) using one ZnAl wire (diameter 1.4 mm) on the weld bead cutting portion of the electrosewn steel pipe similar to Example 1, the Al wire (diameter 1). The weld bead cutting portion was repaired by performing arc spraying (second thermal spraying step) using two .4 mm) wires. In the gas frame thermal spraying, the wire feeding speed was 4.2 m / min, the pressure of the compressed air was 0.4 MPa, and the distance between the thermal spray gun and the weld bead cutting portion was 30 mm. In arc spraying, the feed rate of the two wires is 13 m / min, the pressure of compressed air is 0.52 MPa, the voltage is 21.4 V, the current is 170 A, and between the thermal spray gun and the weld bead cutting part. The distance was 30 mm. Other conditions in the thermal spraying step were the same as in Example 1.
（比較例４）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、ＺｎＡｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第１溶射工程）を行った後に、Ａｌワイヤ（径１．４ｍｍ）２本を用いてアーク溶射（第２溶射工程）を行うことにより、溶接ビード切削部の補修を行った。溶射工程では、アーク溶接における２本のワイヤの送給速度をいずれも８ｍ／分としたこと以外は、比較例３と同様にした。
(Comparative Example 4)
After performing gas frame thermal spraying (first thermal spraying step) using one ZnAl wire (diameter 1.4 mm) on the weld bead cutting portion of the electrosewn steel pipe similar to Example 1, the Al wire (diameter 1). The weld bead cutting portion was repaired by performing arc spraying (second thermal spraying step) using two .4 mm) wires. The thermal spraying step was the same as in Comparative Example 3 except that the feeding speeds of the two wires in arc welding were both set to 8 m / min.
（比較例５）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、ＺｎＡｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第１溶射工程）を行うことにより、溶接ビード切削部の補修を行った。ガスフレーム溶射の条件は、比較例３及び４と同様にした。溶射工程におけるその他の条件は実施例１と同様にした。
(Comparative Example 5)
By performing gas frame thermal spraying (first thermal spraying step) using one ZnAl wire (diameter 1.4 mm) on the weld bead cutting portion of the electrosewn steel pipe similar to Example 1, the weld bead cutting portion of the weld bead cutting portion. Repaired. The conditions for gas frame thermal spraying were the same as in Comparative Examples 3 and 4. Other conditions in the thermal spraying step were the same as in Example 1.
（比較例６）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、Ａｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第１溶射工程）を行うことにより、溶接ビード切削部の補修を行った。ガスフレーム溶射では、ワイヤの送給速度を２．８ｍ／分、圧縮空気の圧力を０．４ＭＰａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。溶射工程におけるその他の条件は実施例１と同様にした。
(Comparative Example 6)
By performing gas frame thermal spraying (first thermal spraying step) using one Al wire (diameter 1.4 mm) on the weld bead cutting portion of the electrosewn steel pipe similar to Example 1, the weld bead cutting portion of the weld bead cutting portion. Repaired. In the gas frame spraying, the wire feeding speed was set to 2.8 m / min, the pressure of the compressed air was set to 0.4 MPa, and the distance between the spray gun and the weld bead cutting portion was set to 30 mm. Other conditions in the thermal spraying step were the same as in Example 1.
（比較例７）
実施例１と同様の電縫鋼管の溶接ビード切削部に対して、Ａｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第１溶射工程）を行った後に、ＺｎＡｌワイヤ（径１．４ｍｍ）１本を用いてガスフレーム溶射（第２溶射工程）を更に行うことより、溶接ビード切削部の補修を行った。溶射工程では、電縫鋼管の搬送速度を８０ｍ／分、２つのガスフレーム溶射ガンとの間の距離を４００ｍｍとした。最初のガスフレーム溶射では、ワイヤの送給速度を２．８ｍ／分、圧縮空気の圧力を０．４ＭＰａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。また、後のガスフレーム溶射では、ワイヤの送給速度を４．２ｍ／分、圧縮空気の圧力を０．４ＭＰａ、溶射ガンと溶接ビード切削部との間の距離を３０ｍｍとした。
なお、上記の実施例及び比較例における主要な溶射条件を表１に示す。
(Comparative Example 7)
After performing gas frame thermal spraying (first thermal spraying step) using one Al wire (diameter 1.4 mm) on the weld bead cutting portion of the electrosewn steel pipe similar to Example 1, ZnAl wire (diameter 1) The weld bead cutting portion was repaired by further performing gas frame thermal spraying (second thermal spraying step) using one .4 mm) wire. In the thermal spraying step, the transfer speed of the electrosewn steel pipe was set to 80 m / min, and the distance between the two gas frame thermal spray guns was set to 400 mm. In the first gas frame spraying, the wire feeding speed was set to 2.8 m / min, the pressure of the compressed air was set to 0.4 MPa, and the distance between the spray gun and the weld bead cutting portion was set to 30 mm. In the later gas frame spraying, the wire feeding speed was set to 4.2 m / min, the pressure of the compressed air was set to 0.4 MPa, and the distance between the spray gun and the weld bead cutting portion was set to 30 mm.
Table 1 shows the main thermal spraying conditions in the above Examples and Comparative Examples.
上記の実施例及び比較例で補修した電縫鋼管について、以下の評価を行った。 The electric pipes repaired in the above Examples and Comparative Examples were evaluated as follows.
（補修層（溶射層）の厚み）
電縫鋼管の補修層が形成された位置を切断した。切断方向は、電縫鋼管の円周方向（Ｃ方向）とした。切断面について顕微鏡観察（４００倍）を行い、顕微鏡写真において、任意の１０点で補修層の厚みを測定し、その平均を平均厚みとした。
なお、この評価において、第１溶射工程で得られた層を第１溶射層、第２溶射工程で得られた層を第２溶射層と表す。
(Thickness of repair layer (sprayed layer))
The position where the repair layer of the electric resistance pipe was formed was cut. The cutting direction was the circumferential direction (C direction) of the electrosewn steel pipe. The cut surface was observed under a microscope (400 times), and the thickness of the repair layer was measured at any 10 points in the micrograph, and the average was taken as the average thickness.
In this evaluation, the layer obtained in the first thermal spraying step is referred to as a first thermal spraying layer, and the layer obtained in the second thermal spraying step is referred to as a second thermal spraying layer.
（補修層の密着性）
補修層の密着性は、直管の（曲げ加工していない）電縫鋼管及び曲げ加工した後の電縫鋼管の両方において評価した。
直管の電縫鋼管における補修層の密着性は、電縫鋼管の補修層の表面に市販のセロテープ（登録商標）を貼り、セロテープ（登録商標）を剥がした時の補修層の剥離の有無を評価した。
曲げ加工した電縫鋼管における補修層の密着性は、電縫鋼管を二次元曲げ加工した後、曲げ部の補修層の表面に市販のセロテープ（登録商標）を貼り、セロテープ（登録商標）を剥がした時の補修層の剥離の有無を評価した。
これらの評価において、補修層の剥離がなかったものを〇、補修層の一部の剥離があったものを×と表す。
(Adhesion of repair layer)
The adhesion of the repair layer was evaluated for both the straight pipe (unbent) and the bent steel pipe.
The adhesion of the repair layer in the straight pipe electric pipe is determined by the presence or absence of peeling of the repair layer when commercially available cellophane tape (registered trademark) is attached to the surface of the repair layer of the electric pipe and the cellophane tape (registered trademark) is peeled off. evaluated.
For the adhesion of the repair layer in the bent steel pipe, after the electric resistance pipe is two-dimensionally bent, a commercially available cellophane tape (registered trademark) is attached to the surface of the repair layer at the bent portion, and the cellophane tape (registered trademark) is peeled off. The presence or absence of peeling of the repair layer at that time was evaluated.
In these evaluations, those in which the repair layer was not peeled off are marked with 〇, and those in which the repair layer was partially peeled off are marked with x.
（補修層の耐食性）
１．ＣＣＴ試験（塩乾湿複合サイクル試験）
ＣＣＴ試験は、補修した電縫鋼管を所定の長さに切断した試験片で行った。
ＣＣＴ試験は以下の（１）〜（３）を１サイクルとして、６６０サイクル繰り返した。
（１）塩水噴霧（３５℃、５％ＮａＣｌ、１５分）
（２）乾燥（６０℃、３０％ＲＨ、６０分）
（３）湿潤（５０℃、９５％ＲＨ、３時間）
ＣＣＴ試験の評価において、溶射部に赤錆がないものを〇、赤錆が発生したものを×と表す。
(Corrosion resistance of repair layer)
1. 1. CCT test (salt-dry-wet composite cycle test)
The CCT test was carried out with a test piece obtained by cutting the repaired electric resistance steel pipe to a predetermined length.
The CCT test was repeated for 660 cycles with the following (1) to (3) as one cycle.
(1) Salt spray (35 ° C, 5% NaCl, 15 minutes)
(2) Drying (60 ° C, 30% RH, 60 minutes)
(3) Wet (50 ° C, 95% RH, 3 hours)
In the evaluation of the CCT test, the one without red rust on the sprayed part is indicated by 〇, and the one with red rust is indicated by ×.
２．ＢＢＴ試験（湿潤試験）
ＢＢＴ試験は、補修した電縫鋼管を所定の長さに切断した試験片で行った。
ＢＢＴ試験は、温度５０℃、湿度９８％ＲＨの環境下で３５００時間放置することによって行った。
ＢＢＴ試験の評価において、表面に赤錆が発生していないものを〇、赤錆が発生したものを×と表す。
2. BBT test (wet test)
The BBT test was carried out with a test piece obtained by cutting the repaired electric resistance steel pipe to a predetermined length.
The BBT test was carried out by leaving it for 3500 hours in an environment of a temperature of 50 ° C. and a humidity of 98% RH.
In the evaluation of the BBT test, the one without red rust on the surface is indicated by 〇, and the one with red rust is indicated by ×.
上記の各評価結果を表２に示す。 The results of each of the above evaluations are shown in Table 2.
表２に示されるように、アーク溶射を行った後にガスフレーム溶射を行うことで補修層を形成した実施例１及び２の電縫鋼管は密着性が良好であり、実施例１の電縫鋼管は耐食性も良好であった。
これに対して比較例１及び５〜７の電縫鋼管は、密着性は良好であったものの、耐食性が十分でなかった。例えば、アーク溶射のみで補修層を形成した比較例１の電縫鋼管は、補修層（溶射層）の厚みは大きかったものの、その厚みのバラツキが大きく、耐食性が十分でなかった。特に、厚みが小さい箇所で赤錆の発生が確認された。また、ガスフレーム溶射のみで補修層を形成した比較例５及び６の電縫鋼管は、補修層の厚みが小さく、耐食性が十分でなかった。さらに、異なる溶射材でガスフレーム溶射を２回行うことで補修層を形成した比較例７の電縫鋼管は、補修層の厚みが依然として十分でなく、耐食性が十分でなかった。
ガスフレーム溶射を行った後にアーク溶射を行うことで補修層を形成した比較例３及び４の電縫鋼管は、曲げ加工後の補修層の密着性が不十分であり、補修層の部分的な剥離が観察された。剥離した部分について分析した結果、第１溶射層（ガスフレーム溶射層）と第２溶射層（アーク溶射層）との間で剥離していることが確認された。
As shown in Table 2, the electric resistance pipes of Examples 1 and 2 in which the repair layer was formed by performing gas frame spraying after the arc spraying had good adhesion, and the electric resistance pipe of Example 1 was formed. Also had good corrosion resistance.
On the other hand, the electrosewn steel pipes of Comparative Examples 1 and 5 to 7 had good adhesion, but did not have sufficient corrosion resistance. For example, in the electric resistance welded steel pipe of Comparative Example 1 in which the repair layer was formed only by arc spraying, the thickness of the repair layer (sprayed layer) was large, but the thickness varied widely and the corrosion resistance was not sufficient. In particular, the occurrence of red rust was confirmed in places where the thickness was small. Further, in the electric resistance welded steel pipes of Comparative Examples 5 and 6 in which the repair layer was formed only by gas frame thermal spraying, the thickness of the repair layer was small and the corrosion resistance was not sufficient. Further, in the electric resistance welded steel pipe of Comparative Example 7 in which the repair layer was formed by performing gas frame spraying twice with different thermal spray materials, the thickness of the repair layer was still insufficient and the corrosion resistance was not sufficient.
In the electrosewn steel pipes of Comparative Examples 3 and 4 in which the repair layer was formed by performing arc spraying after performing gas frame spraying, the adhesion of the repair layer after bending was insufficient, and the repair layer was partially sprayed. Detachment was observed. As a result of analyzing the peeled portion, it was confirmed that the peeled portion was peeled between the first sprayed layer (gas frame sprayed layer) and the second sprayed layer (arc sprayed layer).
以上の結果からわかるように、本発明によれば、アーク溶射層とガスフレーム溶射層との密着性が高く、且つ耐食性に優れる補修層を形成することが可能な電縫鋼管の溶接ビード切削部の補修方法、及び電縫鋼管の製造方法を提供することができる。 As can be seen from the above results, according to the present invention, a welded bead cutting portion of an electrosewn steel pipe capable of forming a repair layer having high adhesion between the arc sprayed layer and the gas frame sprayed layer and excellent corrosion resistance. A method for repairing the above and a method for manufacturing an electric resistance sewn steel pipe can be provided.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5985369A (en) * | 1982-11-09 | 1984-05-17 | Kawasaki Steel Corp | Arc and gas mixed melt spraying repairing method of metallic object |
| JPH08127855A (en) * | 1994-09-09 | 1996-05-21 | Nisshin Steel Co Ltd | Method for touching-up surface of plated steel and device therefor |
| JP2004292897A (en) * | 2003-03-27 | 2004-10-21 | Nippon Steel Corp | Electroseamed steel pipe having damping property, and its production method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5985369A (en) * | 1982-11-09 | 1984-05-17 | Kawasaki Steel Corp | Arc and gas mixed melt spraying repairing method of metallic object |
| JPH08127855A (en) * | 1994-09-09 | 1996-05-21 | Nisshin Steel Co Ltd | Method for touching-up surface of plated steel and device therefor |
| JP2004292897A (en) * | 2003-03-27 | 2004-10-21 | Nippon Steel Corp | Electroseamed steel pipe having damping property, and its production method |
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