JP3027658B2 - Method of forming inner projection of metal tube - Google Patents
Method of forming inner projection of metal tubeInfo
- Publication number
- JP3027658B2 JP3027658B2 JP4256203A JP25620392A JP3027658B2 JP 3027658 B2 JP3027658 B2 JP 3027658B2 JP 4256203 A JP4256203 A JP 4256203A JP 25620392 A JP25620392 A JP 25620392A JP 3027658 B2 JP3027658 B2 JP 3027658B2
- Authority
- JP
- Japan
- Prior art keywords
- tube
- welding
- raw
- peripheral surface
- metal tube
- 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
Links
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- Butt Welding And Welding Of Specific Article (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は、素管の内周面に対し、
螺旋状の突出部を形成する金属管の内面突出部の形成方
法に関する。BACKGROUND OF THE INVENTION The present invention relates to an inner peripheral surface of a raw pipe.
The present invention relates to a method for forming an inner surface protrusion of a metal tube that forms a spiral protrusion.
【0002】[0002]
【従来の技術】熱交換用管(即ち、種々の温度での熱交
換を主目的に使用される管)として、その内周面に螺旋
状の突出部を形成したものを使用した場合、その螺旋状
の突出部の存在によって、金属管内を層流状態で通流し
ようとする流体が乱流状態とされて流体の管内素通りが
防止され、しかも、その流体に対する金属管の反応表面
積も増大するので、熱交換が能率的に行われるようにな
る。2. Description of the Related Art When a heat exchange tube (that is, a tube mainly used for heat exchange at various temperatures) having a helical projection formed on an inner peripheral surface thereof is used. Due to the presence of the helical protrusion, the fluid which is going to flow through the metal pipe in a laminar flow state is made turbulent, and the fluid is prevented from passing through the pipe, and the reaction surface area of the metal pipe to the fluid also increases. Therefore, the heat exchange is performed efficiently.
【0003】そこで、各種金属管の内周面に螺旋状の突
出部を形成した突出部付きの金属管が実用化されてい
る。その螺旋状の突出部付き金属管の製造方法として
は、従来、適宜製法にて製造された円筒状のチューブを
素管として準備し、その素管に対して長手方向に直線状
にわたる突出部を管内周面に熱間押出成形によって形成
した第2の素管を先ず製造し、その第2の素管に対して
管周方向の捩り加工を施すことにより、螺旋状の突出部
付き金属管を製造することが考えられている(例えば、
特開昭58−173022号公報参照)。[0003] Therefore, a metal tube with a projection formed with a spiral projection on the inner peripheral surface of various metal tubes has been put to practical use. Conventionally, as a method of manufacturing the metal tube with the helical protrusion, a cylindrical tube manufactured by an appropriate manufacturing method is prepared as a raw tube, and a protrusion that extends linearly in the longitudinal direction with respect to the raw tube is provided. First, a second tube formed on the inner peripheral surface of the tube by hot extrusion is manufactured, and the second tube is subjected to a torsion process in a tube circumferential direction to form a metal tube having a helical protrusion. Is considered to be manufactured (for example,
See JP-A-58-173022).
【0004】[0004]
【発明が解決しようとする課題】しかしながら、突出部
を管内周面に形成するための熱間押出成形は、相当に過
酷な条件下で行われるため、その熱間押出成形が可能な
素管はその材質が成形性の良好なものに限定されてしま
う。例えば、炭素含有量が多い加工性の悪いものには適
用することができない。従って、熱間押出成形を用いる
従来方法では、成形性が悪い材質よりなる金属管に対し
て適用することができない、という加工性に係わる問題
があった。However, since the hot extrusion for forming the protruding portion on the inner peripheral surface of the tube is performed under considerably severe conditions, the raw tube which can be hot-extrusion-formed is The material is limited to those having good moldability. For example, it cannot be applied to those having a high carbon content and poor workability. Therefore, the conventional method using hot extrusion has a problem with workability that it cannot be applied to a metal pipe made of a material having poor formability.
【0005】また、従来方法によれば、前記第2の素管
を先ず製造した上でその第2の素管に対して管周方向の
捩り加工を施すので、最終的に得られる金属管に前記捩
り加工に基づく残留応力が発生することとなり、その残
留応力に基づいて、前記内面突出部付き金属管には使用
中に歪み等が発生する、という残留応力の問題があっ
た。更に、前記捩り加工を実際に行う過程において、捩
り過ぎによる管の変形・破断等の発生阻止を常に考慮し
なければならないため、螺旋状突出部の螺旋ピッチを小
さくするには一定の限界がある、という螺旋状突出部の
形状に係わる問題もあった。In addition, according to the conventional method, the second tube is manufactured first, and then the second tube is subjected to a torsion process in the circumferential direction of the tube. Residual stress is generated due to the torsion process, and there is a problem of residual stress that distortion and the like occur during use in the metal tube with the inner protruding portion based on the residual stress. Further, in the process of actually performing the torsion process, it is necessary to always consider prevention of deformation and breakage of the tube due to excessive torsion. Therefore, there is a certain limit to reducing the helical pitch of the helical protrusion. There is also a problem related to the shape of the spiral protrusion.
【0006】更に、熱交換用管は、高温に曝されるの
で、その素材として、高炭素(例えば、炭素含有量を
0.4〜0.5%)の耐熱素材を使用することが検討さ
れ、また、ケイ素も多く含有させた、高炭素且つ高ケイ
素の耐熱素材を使用することも検討されている。しか
し、前記高炭素(又は、高炭素且つ高ケイ素)の耐熱素
材は、延性が非常に乏しい材料であるので、前記素管自
体を熱間塑性加工で形成するのも比較的難しく、また、
前記素管が仮に形成できたとしても、その素管に対して
前記熱間押出成形を施して、管内面に前記突出部を形成
するのには、延性が不足して前記熱間押出成形が実質的
に実行できない。そこで、前記素管の形成は勿論のこ
と、前記突出部の熱間押出成形による形成も実質的に実
行できる条件まで、素材の炭素含有量を落とす(具体的
には、炭素含有量を0.1〜0.2%まで落とす)等の
対策が必要になる。しかし、炭素含有量の低下によって
管の高温強度が低下するので、その高温強度の低下を防
止するには、予め素材に高温強度確保に有効なTi,Z
r等の高価な合金元素を添加することが必要となり、最
終的に得られる熱交換用管のコストが割高になってしま
う、というコスト上の問題もあった。Further, since the heat exchange tube is exposed to a high temperature, the use of a heat-resistant material having a high carbon content (for example, a carbon content of 0.4 to 0.5%) has been studied. Also, the use of a high-carbon and high-silicon heat-resistant material containing a large amount of silicon has been studied. However, since the high-carbon (or high-carbon and high-silicon) heat-resistant material is a material having extremely poor ductility, it is relatively difficult to form the raw tube itself by hot plastic working, and
Even if the raw tube could be formed, the hot extrusion is insufficient for ductility to form the projecting portion on the inner surface of the tube by performing the hot extrusion on the raw tube. I can't practically do it. Therefore, the carbon content of the raw material is reduced to a condition under which not only the formation of the raw tube but also the formation of the projection by hot extrusion can be substantially performed (specifically, the carbon content is reduced to 0.1%). Countermeasures such as 1% to 0.2%). However, since the high-temperature strength of the pipe decreases due to the decrease in the carbon content, in order to prevent the decrease in the high-temperature strength, Ti, Z, which is effective in securing the high-temperature strength in advance, is added to the material.
It is necessary to add an expensive alloy element such as r, and there is also a cost problem that the cost of the finally obtained heat exchange tube is relatively high.
【0007】本発明は、上述の加工性・使用材料・製造
能力に係わる問題を解消し、また、残留応力・螺旋状突
出部の形状特性等の問題を解消しつつ、要求される特性
を備える熱交換用管を低コストにて製造する方法の提供
を目的としている。The present invention solves the above-mentioned problems relating to workability, materials used, and manufacturing capability, and also has the required characteristics while solving problems such as residual stress and the shape characteristics of the spiral projection. An object of the present invention is to provide a method for manufacturing a heat exchange tube at low cost.
【0008】[0008]
【課題を解決するための手段】本発明は、鋭意研究の結
果、管内面の螺旋状の突出部を、ビード幅を広くしなく
ても高い肉盛りビードを形成でき、しかも、小さなトー
チで肉盛り溶接できる粉体プラズマアーク溶接法の特性
に着目して、これを利用して形成することとしたもので
あり、本発明による内面突出部の形成方法は、素管の内
周面に対し、螺旋状の突出部を形成する金属管の内面突
出部の形成方法であって、前記素管を遠心力鋳造により
製造した後、前記突出部を粉体プラズマアーク溶接法に
よる肉盛ビードにより形成する点に特徴を有している。According to the present invention, as a result of intensive studies, it has been found that a helical protrusion on the inner surface of a pipe can be formed into a high build-up bead without increasing the bead width, and that a small torch is used to form a bead. Focusing on the characteristics of the powder plasma arc welding method that can be welded, it is to be formed using this, the method of forming the inner surface protruding portion according to the present invention, the inner peripheral surface of the raw tube, A method for forming an inner surface protruding portion of a metal tube that forms a helical protruding portion, wherein after manufacturing the raw tube by centrifugal force casting, the protruding portion is formed by a build-up bead by a powder plasma arc welding method. It is characterized by points.
【0009】[0009]
【作用】本発明の方法によれば、素管を遠心力鋳造によ
って製造するから、遠心力鋳造管を前記素管としてその
まま用いることができ、例えば炭素含有量が0.4%以
上の耐熱強度の高い素管を製造できる。そして、その素
管の内周面に対して、粉体プラズマアーク溶接法により
肉盛ビードを形成するから、ビード幅を広くすることな
く肉盛ビードを高く形成でき、その肉盛ビードによって
螺旋状の突出部を形成するので、塑性加工を施すことな
く前記突出部を所望の高さに形成することができる。こ
のように素管の内周面に螺旋状の突出部を形成すれば、
従来のように熱間押出成形のような塑性加工のための素
材の成形性を考慮しなくても済み、前記素管の素材の炭
素含有量を、加工性・成形性を維持するために低下させ
る必要がないから、高温強度が劣化するおそれがなく、
高温強度劣化を補うためにTi,Zr等の高価な合金元
素を素材に添加する必要がなくなる。According to the method of the present invention, since the raw tube is manufactured by centrifugal casting, the centrifugally cast tube can be used as it is as the raw tube, for example, a heat resistant strength having a carbon content of 0.4% or more. Can be manufactured. And, since the build-up bead is formed on the inner peripheral surface of the base tube by the powder plasma arc welding method, the build-up bead can be formed high without increasing the bead width, and the build-up bead forms a spiral shape. Since the protrusions are formed, the protrusions can be formed at a desired height without performing plastic working. By forming a helical protrusion on the inner peripheral surface of the raw pipe in this way,
It is not necessary to consider the formability of the material for plastic working such as hot extrusion molding as in the past, and the carbon content of the raw material of the raw tube is reduced in order to maintain workability and formability. Because there is no need to do, there is no risk of high temperature strength
It is not necessary to add expensive alloy elements such as Ti and Zr to the material in order to compensate for high-temperature strength deterioration.
【0010】[0010]
【発明の効果】本発明の方法によれば、素管に塑性加工
を施さないので、従来のように素管の素材の成形性等を
考慮しなくても済み、所望の強度特性を備える素材を用
いることが可能となり、残留応力の問題も解消される。
従って、素管の素材にTi,Zr等の高価な合金元素を
添加する必要もなく、内周面に螺旋状の突出部を備えた
熱交換用管を低コストにて製造できる。According to the method of the present invention, since no plastic working is performed on the raw tube, it is not necessary to consider the formability of the raw material of the raw tube as in the prior art, and a material having desired strength characteristics can be obtained. Can be used, and the problem of residual stress can be solved.
Therefore, it is not necessary to add expensive alloy elements such as Ti and Zr to the raw material of the raw tube, and a heat exchange tube having a spiral projection on the inner peripheral surface can be manufactured at low cost.
【0011】[0011]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。管内温度が800℃を越える高温となるように
(管自体は、1000℃を越える高温となるように)加
熱される金属管内に、ナフサ等の分解原料流体を通流さ
せ、その通流流体を前記高温で熱分解させてエチレン・
プロピレン等を製造することが行われている。Embodiments of the present invention will be described below with reference to the drawings. A decomposition raw material fluid such as naphtha is passed through a metal tube that is heated so that the temperature in the tube is higher than 800 ° C. (the tube itself is higher than 1000 ° C.). Pyrolyzed at the high temperature
Production of propylene and the like has been performed.
【0012】このような金属管は、1000℃を越える
高温で使用されるので、その素材として、1000℃を
越える高温での強度を確保すべく炭素含有量を適量増加
させた高炭素(例えば、炭素含有量:0.4〜0.5
%)の耐熱素材(例えば、高炭素の25Cr−20Ni
系Fe合金)が使用される。[0012] Since such a metal tube is used at a high temperature exceeding 1000 ° C, as a material thereof, a high carbon (for example, a high carbon steel having an appropriate amount of increased carbon content in order to secure strength at a high temperature exceeding 1000 ° C) is used. Carbon content: 0.4-0.5
% Of heat-resistant material (for example, 25Cr-20Ni of high carbon)
System Fe alloy) is used.
【0013】このような耐熱素材よりなる金属管におい
て、その内周面に、長手方向にわたって螺旋状の突出部
が形成されている場合、その突出部の存在によって、前
記金属管内を層流状態で通流しようとする流体が乱流状
態とされて前記流体の管内素通りが防止され、しかも、
その流体に対する前記金属管の反応表面積も増大するの
で、前記熱分解が能率的に行われるようになる。In a metal tube made of such a heat-resistant material, when a helical protrusion is formed on the inner peripheral surface in the longitudinal direction, the presence of the protrusion causes the inside of the metal tube to be in a laminar flow state. The fluid to be passed is set in a turbulent state to prevent the fluid from passing through the pipe, and
Since the reaction surface area of the metal tube with respect to the fluid is also increased, the thermal decomposition is efficiently performed.
【0014】図1には、螺旋状の突出部が管内周面に形
成された金属管を製造するのに、本発明方法を適用した
実施例が示されており、図2には、その方法にて製造さ
れた金属管の最終断面形状が示されている。FIG. 1 shows an embodiment in which the method of the present invention is applied to manufacture a metal tube having a spiral projecting portion formed on the inner peripheral surface of the tube, and FIG. 2 shows the method. 2 shows the final cross-sectional shape of the metal tube manufactured by the method described above.
【0015】図1における1は、前記金属管を製造する
ための素管であり、その素管1は、予め、前記高炭素の
25Cr−20Ni系Fe合金の溶湯を遠心力鋳造する
ことによって製造されている。そして、その素管1に対
しては、その内周面に引け巣等の欠陥が発生している可
能性があるため、その内周面を適宜厚さ分だけ除去すべ
く、内径ボーリング加工が施されている。Reference numeral 1 in FIG. 1 denotes a raw tube for manufacturing the metal tube. The raw tube 1 is manufactured by centrifugally casting a molten metal of the high-carbon 25Cr-20Ni-based Fe alloy in advance. Have been. Since there is a possibility that a defect such as a shrinkage cavity may occur on the inner peripheral surface of the raw tube 1, an inner diameter boring process is performed to remove the inner peripheral surface by an appropriate thickness. It has been subjected.
【0016】前記素管1は、公知の把持駆動手段(図
外)によって、管軸芯周りに回転自在に支持されてい
る。また、前記素管1の内部には、その素管1の内周面
にそれと同素材(又は相当素材)が突出形成されてなる
突出部2を形成すべく前記素材の肉盛ビードを前記内周
面に肉盛溶接するための溶接トーチ3が、前記素管1内
に、その管軸芯方向に延在する状態に支持され且つその
方向に移動自在に構成されたトーチ支持杆4を介して、
前記素管1に対して長手方向に平行移動自在に配置され
ている。従って、前記溶接トーチ3は、前記素管1に対
して長手方向及び周方向に相対移動させることができる
ように構成されている。The raw tube 1 is rotatably supported around the tube axis by known gripping driving means (not shown). In addition, inside the base tube 1, a build-up bead of the material is formed to form a protrusion 2 on the inner peripheral surface of the base tube 1 by protruding the same material (or equivalent material). A welding torch 3 for overlay welding on the peripheral surface is supported in the base tube 1 so as to extend in the tube axis direction and via a torch support rod 4 configured to be movable in that direction. hand,
It is arranged so as to be able to move parallel to the raw tube 1 in the longitudinal direction. Therefore, the welding torch 3 is configured to be able to move relatively to the raw tube 1 in the longitudinal direction and the circumferential direction.
【0017】前記溶接トーチ3は、具体的には、粉体プ
ラズマアーク溶接(プラズマパウダーアーク溶接)によ
る肉盛溶接を実行するための溶接装置のトーチであり、
その溶接トーチ3の部分には、前記粉体プラズマアーク
溶接に必要な粉体を絶えず送給するためのパウダー供給
管5(そのパウダー供給管5は、前記トーチ支持杆4に
沿って配管されている)の先端が接続されている。The welding torch 3 is, specifically, a torch of a welding apparatus for performing overlay welding by powder plasma arc welding (plasma powder arc welding).
A powder supply pipe 5 for continuously feeding powder required for the powder plasma arc welding is provided on the welding torch 3 (the powder supply pipe 5 is piped along the torch support rod 4). Is connected).
【0018】このように構成された溶接装置を用いて、
前記素管1の内周面に、前記突出部2を螺旋状に4条分
だけ形成する場合、先ず、前記把持駆動手段によって支
持した前記素管1を管軸芯周りに回転させつつ、前記素
管1を管軸芯方向に1回だけ平行移動させた状態で、前
記肉盛溶接を実行することにより、前記素管1の内周面
に前記突出部2を螺旋状に1条分だけ形成する。そし
て、この一連の操作を、前記突出部2の条数分だけ(即
ち、4回)繰り返すことにより、前記突出部2を螺旋状
に4条分だけ形成する。Using the welding apparatus thus configured,
When the projecting portion 2 is spirally formed on the inner peripheral surface of the raw tube 1 by four lines, first, while rotating the raw tube 1 supported by the gripping driving means around a tube axis, By performing the build-up welding in a state where the raw tube 1 is translated once in the tube axis direction, the projecting portion 2 is spirally formed on the inner peripheral surface of the raw tube 1 by one line. Form. Then, this series of operations is repeated by the number of the protrusions 2 (that is, four times), thereby forming the protrusions 2 in a spiral shape for four lines.
【0019】このような本発明方法によれば、前記素管
1の内周面に肉盛溶接によって肉盛ビードを形成し、そ
の肉盛ビードによって前記突出部2を形成するので、従
来の熱間押出成形を用いることなく前記突出部2を形成
することができ、従来のように熱間押出成形のための素
材の成形性を考慮しなくても済む。しかも、前記突出部
2を螺旋状に形成するのに、従来のように捩り加工を施
すことがないので、捩り加工に基づく残留応力が発生す
るのが回避されるようになる。更に、最終的に得られる
金属管における前記螺旋状に形成された突出部の螺旋ピ
ッチを自由に設定することができ、また、前記粉体を用
いて形成される肉盛ビードは、前記素管1の材質が同じ
ものであっても異なるものであっても、前記粉体の種類
を適宜選択することによって形成することができる。According to such a method of the present invention, a build-up bead is formed on the inner peripheral surface of the base tube 1 by build-up welding, and the protrusion 2 is formed by the build-up bead. The projecting portion 2 can be formed without using the hot extrusion, and it is not necessary to consider the formability of the material for the hot extrusion as in the related art. Further, since the projecting portion 2 is formed in a spiral shape, twisting is not performed as in the related art, so that generation of residual stress due to the twisting can be avoided. Further, the helical pitch of the helically formed protrusions in the finally obtained metal tube can be freely set, and the overlay bead formed by using the powder can be formed by the base tube. Regardless of whether the first material is the same or different, it can be formed by appropriately selecting the type of the powder.
【0020】更に、前記素管1が遠心力鋳造によって製
造され、且つ、螺旋状の突出部2が前記肉盛溶接によっ
て形成されるので、前記素管1を製造するのにも、螺旋
状の突出部2を形成するのにも、素材の加工性・成形性
を考慮する必要がなくなる。従って、従来のようにT
i,Zr等の高価な合金元素を素材に添加する必要がな
くなる。Further, since the raw tube 1 is manufactured by centrifugal force casting and the helical projection 2 is formed by the overlay welding, the helical tube is also manufactured for manufacturing the raw tube 1. In forming the protruding portion 2, it is not necessary to consider the workability and formability of the material. Therefore, as before, T
It is not necessary to add expensive alloy elements such as i and Zr to the material.
【0021】尚、本実施例においては、粉体プラズマア
ーク溶接を用いて肉盛溶接を行うから、以下に述べる種
々の利点が生じる。 (1)例えば、TIG溶接装置等に必要な溶接ワイヤの
成形が不可能な硬い肉盛材料(例えば、50Cr−50
Ni系の肉盛材料)を用いながら、その粉体を用いて肉
盛溶接することで、前記突出部2が容易に形成できる。 (2)粉体プラズマアーク溶接に使用する溶接トーチ3
は、コンパクトに設計することができ、こうした溶接ト
ーチ3を採用して、小径の素管1に対しても、前記突出
部2を形成できる (3)粉体プラズマアーク溶接による場合、溶接ビード
の溶け込みが浅く、肉盛溶接に適している。 (4)前記粉体にはアルミニウムやケイ素を多量に添加
することもできるので、それらを多量に添加した粉体を
用いた粉体プラズマアーク溶接によって、前記突出部2
の耐浸炭性を向上させることができる。 (5)プラズマ電流の調節により肉盛材料の溶着条件に
悪影響を及ぼすことなく肉盛ビードの温度を制御できる
から、例えば高クロム合金等の割れ感受性の高い肉盛材
料を肉盛溶接する際にも、溶着不良を防止しながら肉盛
ビードの割れを容易に防止できる。In this embodiment, since the build-up welding is performed using the powder plasma arc welding, the following various advantages are obtained. (1) For example, a hard overlay material (for example, 50Cr-50) that cannot form a welding wire necessary for a TIG welding device or the like.
The protruding portion 2 can be easily formed by overlay welding using the powder while using the Ni-based overlay material). (2) Welding torch 3 used for powder plasma arc welding
Can be designed to be compact, and by employing such a welding torch 3, the protruding portion 2 can be formed even with a small diameter pipe 1. (3) In the case of powder plasma arc welding, It has shallow penetration and is suitable for overlay welding. (4) Since a large amount of aluminum or silicon can be added to the powder, the protruding portion 2 is formed by powder plasma arc welding using a powder to which a large amount of these are added.
Can be improved in carburization resistance. (5) Since the temperature of the build-up bead can be controlled by adjusting the plasma current without adversely affecting the welding conditions of the build-up material, for example, when welding a build-up material with high crack sensitivity such as a high chromium alloy, etc. In addition, cracking of the overlay bead can be easily prevented while preventing poor welding.
【0022】次に、別実施例について説明する。図3に
示すように、前記トーチ支持杆4に対して、前記溶接ト
ーチ3を縦列4連状態に設けておけば、前記素管1の内
周面に前記突出部2を螺旋状に4条分だけ形成する場合
においても、前記溶接トーチ3の移動操作が1回で済む
ようになる。また、このような縦列4連式の溶接トーチ
3を用いる場合、前記素管1の内周面に前記突出部2を
螺旋状に8条分だけ形成する場合においても、前記溶接
トーチ3の移動操作が2回で済むようになる。このよう
に、前記溶接トーチ3の態様及び前記溶接トーチ3の移
動操作を変化させることにより、前記螺旋状の突出部2
の形成態様を種々に変更することができる。Next, another embodiment will be described. As shown in FIG. 3, if the welding torches 3 are provided in a tandem state with respect to the torch support rod 4, the projecting portions 2 are spirally formed on the inner peripheral surface of the raw tube 1 in four rows. Even in the case where the welding torch 3 is formed only for one minute, the moving operation of the welding torch 3 can be performed only once. In addition, when such a quadruple welding torch 3 is used, even when the projecting portion 2 is spirally formed on the inner peripheral surface of the base tube 1 by eight lines, the welding torch 3 moves. Only two operations are required. Thus, by changing the mode of the welding torch 3 and the operation of moving the welding torch 3, the spiral protrusion 2
Can be variously changed.
【0023】尚、特許請求の範囲の項に図面との対照を
便利にするために符号を記すが、該記入により本発明は
添付図面の構成に限定されるものではない。In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.
【図1】本発明方法の一実施例を示す説明図FIG. 1 is an explanatory view showing an embodiment of the method of the present invention.
【図2】その方法で製造された金属管を示す横断面図FIG. 2 is a cross-sectional view showing a metal tube manufactured by the method.
【図3】本発明方法の別実施例を示す説明図FIG. 3 is an explanatory view showing another embodiment of the method of the present invention.
1 素管 2 螺旋状の突出部 DESCRIPTION OF SYMBOLS 1 Base tube 2 Spiral protrusion
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭58−176077(JP,A) 特開 昭49−40227(JP,A) 特開 昭62−183967(JP,A) 特開 昭57−94470(JP,A) 特開 昭62−187572(JP,A) 特公 昭58−21056(JP,B2) 実公 昭64−6920(JP,Y2) (58)調査した分野(Int.Cl.7,DB名) B23K 9/00 F28F 1/40 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-176077 (JP, A) JP-A-49-40227 (JP, A) JP-A-62-183967 (JP, A) JP-A-57-167 94470 (JP, A) JP-A-62-187572 (JP, A) JP-B-58-21056 (JP, B2) JP-B-64-6920 (JP, Y2) (58) Fields investigated (Int. Cl. 7 , DB name) B23K 9/00 F28F 1/40
Claims (1)
出部(2)を形成する金属管の内面突出部の形成方法で
あって、 前記素管(1)を遠心力鋳造により製造した後、前記 突
出部(2)を粉体プラズマアーク溶接法による肉盛ビー
ドにより形成する金属管の内面突出部の形成方法。 A helical projection is formed on an inner peripheral surface of a base tube (1).
In the method of forming the protruding portion on the inner surface of the metal tube forming the protrusion (2)
There, after the raw tube (1) was prepared by centrifugal force casting, said protrusions (2) a method of forming the inner surface protruding portion of the metal tube formed by cladding bead by powder plasma arc welding method.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4256203A JP3027658B2 (en) | 1992-09-25 | 1992-09-25 | Method of forming inner projection of metal tube |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4256203A JP3027658B2 (en) | 1992-09-25 | 1992-09-25 | Method of forming inner projection of metal tube |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH06109392A JPH06109392A (en) | 1994-04-19 |
JP3027658B2 true JP3027658B2 (en) | 2000-04-04 |
Family
ID=17289354
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP4256203A Expired - Lifetime JP3027658B2 (en) | 1992-09-25 | 1992-09-25 | Method of forming inner projection of metal tube |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3027658B2 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CA2356583C (en) | 2001-03-28 | 2007-10-16 | Nippon Welding Rod Co., Ltd. | Torch for powder plasma buildup welding |
EP1561795B1 (en) * | 2002-11-15 | 2014-04-02 | Kubota Corporation | Cracking tube with spiral fin |
PL2037202T3 (en) * | 2006-07-05 | 2019-03-29 | Nippon Steel & Sumitomo Metal Corporation | Metal tube for thermal cracking reaction |
JP6041778B2 (en) * | 2013-09-19 | 2016-12-14 | 東京瓦斯株式会社 | Heat transfer tube and manufacturing method thereof |
JP6054274B2 (en) * | 2013-09-19 | 2016-12-27 | 東京瓦斯株式会社 | Metal member and manufacturing method thereof |
JP6824004B2 (en) | 2016-11-09 | 2021-02-03 | 株式会社クボタ | Casting product with an alumina barrier layer on the surface and its manufacturing method |
-
1992
- 1992-09-25 JP JP4256203A patent/JP3027658B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH06109392A (en) | 1994-04-19 |
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