JPH09229248A - Socket welding piping fitting - Google Patents
Socket welding piping fittingInfo
- Publication number
- JPH09229248A JPH09229248A JP3788696A JP3788696A JPH09229248A JP H09229248 A JPH09229248 A JP H09229248A JP 3788696 A JP3788696 A JP 3788696A JP 3788696 A JP3788696 A JP 3788696A JP H09229248 A JPH09229248 A JP H09229248A
- Authority
- JP
- Japan
- Prior art keywords
- socket
- welding
- weld
- residual stress
- pipe
- 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.)
- Withdrawn
Links
Landscapes
- Butt Welding And Welding Of Specific Article (AREA)
- Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、配管を互いに溶接
により継ぎ合わせる場合などに適用されるソケット溶接
配管継手に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a socket welded pipe joint applied when pipes are joined together by welding.
【０００２】[0002]
【従来の技術】図５および図６は配管を互いに溶接によ
り継ぎ合わせる場合などに使用されている従来のソケッ
ト溶接継手の説明図である。図において、高エネルギー
を発生させる各種プラントなどにおいては配管を使用し
て高温高圧の流体を循環させるなどしており、ソケット
溶接継手１などを使用して配管同士を互いに結合させて
いる。ソケット溶接継手１は高温高圧の流体が漏れない
ように配管２をソケット３に差し込み、配管２とソケッ
ト３とを溶接４により結合して配管２同士を互いに継ぎ
合わせるようになっている。2. Description of the Related Art FIGS. 5 and 6 are explanatory views of a conventional socket welded joint used when joining pipes to each other by welding. In the figure, pipes are used to circulate high-temperature and high-pressure fluid in various plants that generate high energy, and socket weld joints 1 are used to connect pipes to each other. The socket welded joint 1 is configured such that the pipe 2 is inserted into the socket 3 so that the high-temperature and high-pressure fluid does not leak, the pipe 2 and the socket 3 are joined by welding 4, and the pipes 2 are joined together.
【０００３】[0003]
【発明が解決しようとする課題】上記のように、従来の
ソケット溶接継手においては配管２とソケット３とを溶
接４により結合しているが、溶接４の熱によって高温領
域が溶接部の近傍に発生したり溶接４後に溶接材が冷却
して凝固したりするのに伴ない、高引張り残留応力がソ
ケット溶接継手１の溶接ルート部７に生じる。As described above, in the conventional socket welded joint, the pipe 2 and the socket 3 are joined by the weld 4, but the heat of the weld 4 causes the high temperature region to be in the vicinity of the welded portion. High tensile residual stress is generated in the welding root portion 7 of the socket weld joint 1 as the welding material cools and solidifies after the welding 4 after the welding.
【０００４】即ち、ソケット溶接継手１のソケット３に
配管２を差し込んだ後に溶接４を施工すると、図６
（ａ）に示すように溶接材は高温により伸びようとする
が配管２、ソケット３に拘束されて伸びきれず、圧縮の
残留応力を生ずる。このとき、溶接４近傍の配管２、ソ
ケット３は引張り張力を受けている。この溶接４の終了
後は、同図（ｂ）に示すように溶接材が冷却することに
より溶接４時に伸びきれなかった分が収縮していくた
め、配管２は溶接４前の状態に戻ろうとしても溶接材が
拘束しているために戻どりきれず、半径方向に突出した
形状１７に落ち着く。ソケット３は溶接材の収縮に合わ
せて引張られ、溶接４前の状態から伸びきった状態にな
る。配管２とソケット３との間の隙間８は溶接４施工時
はソケット３の動きに合わせて狭められていくが、溶接
４終了後は逆に開いていき、溶接ルート部７に高引張り
残留応力が生じる。That is, when the welding 4 is carried out after inserting the pipe 2 into the socket 3 of the socket welded joint 1, as shown in FIG.
As shown in (a), the welding material tries to expand due to high temperature, but it is constrained by the pipe 2 and the socket 3 so that it cannot be fully expanded, and a compressive residual stress is generated. At this time, the pipe 2 and the socket 3 near the weld 4 are under tensile tension. After the completion of this welding 4, as the welding material cools as shown in FIG. 4B, the part that could not be fully expanded at the time of welding 4 contracts, so the pipe 2 will return to the state before welding 4. However, since the welding material is restrained, it cannot be returned and settles into the shape 17 protruding in the radial direction. The socket 3 is pulled in accordance with the contraction of the welding material, and is in a fully extended state from the state before the welding 4. The gap 8 between the pipe 2 and the socket 3 is narrowed in accordance with the movement of the socket 3 during the welding 4, but after the welding 4 is finished, the gap 8 is opened in reverse and the high tensile residual stress is applied to the welding root 7. Occurs.
【０００５】このような溶接４後の高引張り残留応力は
溶接材によっては応力腐食割れ、或いは疲労亀裂などの
原因となり、高温割れ５を生じてそれが大きく生長する
と配管２内部の高温、高圧の流体がこの高温割れ５の部
分を通って外部へ漏れる漏洩事故などを起こすことがあ
る。The high tensile residual stress after the welding 4 causes stress corrosion cracking or fatigue cracking depending on the welding material, and if a high temperature crack 5 is generated and grows significantly, high temperature and high pressure inside the pipe 2 may occur. There may be a leakage accident in which the fluid leaks to the outside through the high temperature crack 5.
【０００６】[0006]
【課題を解決するための手段】本発明に係るソケット溶
接配管継手は上記課題の解決を目的にしており、配管端
部をソケットに差し込み溶接により配管を互いに継ぐソ
ケット溶接配管継手における上記ソケットに溶接により
上記配管を結合した後に溶接部近傍の上記ソケットの端
部外周が削除される。従来のソケット溶接配管継手にお
いては溶接の熱により溶接部近傍の特に溶接ルート部に
高引張り残留応力が生じて溶接材に高温割れが発生する
ことがあるが、本ソケット溶接配管継手においては溶接
後にソケットの端部外周を例えば砲弾砥石などを用いて
削除することによりソケットの剛性が下がり、溶接の熱
により溶接ルート部に発生する高引張り残留応力が圧縮
応力へ移行して高引張り残留応力が低減する。SUMMARY OF THE INVENTION A socket welded pipe joint according to the present invention is intended to solve the above-mentioned problems and is welded to the socket in a socket welded pipe joint in which pipe ends are inserted into a socket to join pipes by welding. After connecting the pipes, the outer periphery of the end portion of the socket near the weld is removed. With conventional socket welded pipe joints, high tensile residual stress may occur in the weld material near the weld, especially at the weld root, and hot cracking may occur in the welded material due to the heat of welding. By removing the outer circumference of the end of the socket using, for example, a bullet grindstone, the rigidity of the socket is reduced, and the high tensile residual stress generated at the welding root due to the heat of welding shifts to compressive stress and the high tensile residual stress is reduced. To do.
【０００７】[0007]
【発明の実施の形態】図１乃至図４は本発明の実施の一
形態に係るソケット溶接継手の説明図である。図におい
て、本実施の形態に係るソケット溶接継手は配管を互い
に継ぎ合わせる場合などに使用されるもので、図に示す
ように配管２をソケット３に差し込み、配管２とソケッ
ト３とを溶接４により結合して配管２同士を互いに継ぎ
合わせるようになっているが、この溶接４の熱により溶
接４の特に溶接ルート部７に高引張り残留応力が生じて
高温割れが発生することが考えられるため、図１に示す
ように溶接４後にソケット３の端部外周（コーナ）１３
を砲弾砥石１４などで削除することにより溶接４時の熱
による残留応力を低減させて高温割れを抑制するように
なっている。1 to 4 are explanatory views of a socket welded joint according to an embodiment of the present invention. In the figure, the socket welded joint according to the present embodiment is used when, for example, joining pipes to each other. As shown in the figure, the pipe 2 is inserted into the socket 3, and the pipe 2 and the socket 3 are welded 4 together. The pipes 2 are joined together and spliced to each other. However, it is considered that the heat of the weld 4 causes high tensile residual stress in the weld 4 particularly in the weld root portion 7 to cause hot cracking. As shown in FIG. 1, the outer periphery (corner) 13 of the end portion of the socket 3 after welding 4
Is removed by a bullet grindstone 14 or the like, the residual stress due to heat at the time of welding 4 is reduced and hot cracking is suppressed.
【０００８】本ソケット溶接継手１は配管２がＳＴＰＴ
４２材、ソケット３がＳ２５Ｃ材、溶接４がＴＧＳ−５
材で形成されており、図２に示すように管径は配管２が
ｄ1＝１９．４mm、ソケット３がｄ2 ＝２１．４mm、板
厚は配管２がｔ1 ＝３．９mm、ソケット３がｔ2 ＝５．
６５mmで、両者のギャップ量をＧ＝２mm設けている。溶
接４の条件は電流Ｉ＝１００Ａ、電圧＝１４Ｖ、溶接速
度υ＝４．５ｍ／min、層間の温度は１００℃以下で、
同図（ｂ）に示すように従来のソケット溶接継手と同様
に３層、８パスにて配管２の板厚ｔ1 ＝３．９mmに見合
う程度に１．０ｔ1 で溶接を行った後、同図（ａ）に示
すように従来のソケット溶接継手と同様に肉盛中心（４
５°）から０．８５ｔ1 までソケット３に向かって砲弾
砥石１４によってのど厚加工１５が行われている。In this socket welded joint 1, the pipe 2 is STPT
42 materials, socket 3 is S25C material, welding 4 is TGS-5
2, the pipe diameter is d 1 = 19.4 mm for the pipe 2, the socket 3 is d 2 = 21.4 mm, and the plate thickness is the pipe 2 for t 1 = 3.9 mm, the socket is as shown in FIG. 3 is t 2 = 5.
It is 65 mm, and the gap amount between them is G = 2 mm. The conditions for welding 4 are current I = 100 A, voltage = 14 V, welding speed υ = 4.5 m / min, and the temperature between layers is 100 ° C. or less.
After welding 1.0 t 1 to an extent commensurate with FIG conventional socket welded joint as well as three-layer (b), the thickness t of the pipe 2 at 8 pass 1 = 3.9 mm, As shown in FIG. 4A, the overlay center (4
Throat thickness processing 15 is performed from 5 °) to 0.85 t 1 toward the socket 3 by the shell grindstone 14.
【０００９】さらに、本ソケット溶接継手においては、
のど厚の加工後に図３に示すようにソケット３の端部外
周１３を幅１．８mm、長さ６．３mmの大きさに砲弾砥石
１４などを用いて削除しており、ソケット３の端部外周
１３を削除することによりソケット３の剛性が下がって
隙間が閉じられ、溶接ルート部７における高引張り残留
応力が低減して従来の溶接ルート部に発生する高温割れ
を抑制することができる。Further, in the present socket welded joint,
After processing the throat thickness, as shown in FIG. 3, the outer periphery 13 of the end portion of the socket 3 is removed to a size of width 1.8 mm and length 6.3 mm by using a bullet grindstone 14 etc., and the end portion of the socket 3 is removed. By deleting the outer periphery 13, the rigidity of the socket 3 is reduced and the gap is closed, the high tensile residual stress in the welding root portion 7 is reduced, and high temperature cracking that occurs in the conventional welding root portion can be suppressed.
【００１０】図４は溶接の熱による残留応力の解析結果
を示しており、解析モデルは軸対称要素モデルで中心線
を基準に断面の一部をモデル化している。溶接の熱によ
り入る熱量は溶接条件の電流、電圧、溶接の速度を基に
換算し、溶接材に単位時間（１sec ）に一度に入熱を行
い、その後に冷却させる方法を採っている。これによる
と、本ソケット溶接継手における軸方向の残留応力、半
径方向の残留応力の分布は、従来のソケット溶接継手に
おける軸方向の残留応力、半径方向の残留応力に比べて
溶接ルート部７において高引張り応力が１０％〜２０％
程度低下する。FIG. 4 shows the result of analysis of residual stress due to welding heat. The analysis model is an axisymmetric element model in which a part of the cross section is modeled with the center line as a reference. The amount of heat input by the heat of welding is converted based on the current, voltage, and welding speed of the welding conditions, and the heat is applied to the welding material once per unit time (1 sec) and then cooled. According to this, the distribution of the residual stress in the axial direction and the residual stress in the radial direction in this socket welded joint is higher in the welding root portion 7 than the residual stress in the axial direction and the residual stress in the radial direction in the conventional socket welded joint. Tensile stress is 10% to 20%
To some extent.
【００１１】従来のソケット溶接継手においては配管と
ソケットとを溶接により結合しているが、溶接の熱によ
って高温領域が溶接部の近傍に発生したり溶接後に溶接
材が冷却して凝固したりするのに伴ない、高引張り残留
応力がソケット溶接継手の溶接ルート部に生じる。この
ような溶接後の高引張り残留応力は溶接材によっては応
力腐食割れ、或いは疲労亀裂などの原因となり、高温割
れを生じてそれが大きく生長すると配管内部の高温、高
圧の流体がこの高温割れの部分を通って外部へ漏れる漏
洩事故などを起こすことがあるが、本ソケット溶接継手
においてはソケット溶接継手１の溶接ルート部７に存在
する高引張り残留応力を低減させて使用中の応力腐食割
れの発生や進展などを防止するため、配管２をソケット
３に差し込んで溶接４により結合し、溶接４におけるの
ど厚の加工後にソケット３の端部外周１３を砲弾砥石１
４などを用いて削除することにより、ソケット３の剛性
が下がって隙間が閉じられ、高引張り残留応力が発生し
ている部分が圧縮応力へ移行して溶接ルート部７におけ
る高引張り残留応力が低減し、溶接材における高温割れ
の発生、進展などが抑制される。In the conventional socket welded joint, the pipe and the socket are joined by welding, but a high temperature region is generated in the vicinity of the welded portion due to the heat of welding, or the welded material cools and solidifies after welding. As a result, high tensile residual stress occurs in the weld root of the socket weld joint. Such high tensile residual stress after welding causes stress corrosion cracking, fatigue cracking, etc. depending on the welding material, and if hot cracking occurs and grows significantly, the high temperature and high pressure fluid inside the pipe will cause this hot cracking. Although there may be a leakage accident such as leakage through the portion to the outside, in this socket welded joint, the high tensile residual stress existing in the welding root portion 7 of the socket welded joint 1 is reduced to prevent stress corrosion cracking during use. In order to prevent generation and progress, the pipe 2 is inserted into the socket 3 and joined by the welding 4, and after processing the throat thickness in the welding 4, the outer periphery 13 of the end of the socket 3 is replaced by the shell grindstone 1.
By using 4 etc., the rigidity of the socket 3 is reduced and the gap is closed, the part where high tensile residual stress is generated is transferred to compressive stress, and the high tensile residual stress in the welding root 7 is reduced. However, the occurrence and development of high temperature cracks in the weld material are suppressed.
【００１２】[0012]
【発明の効果】本発明に係るソケット溶接配管継手は前
記のように構成されており、溶接後にソケットの端部外
周を削除することによりソケットの剛性が下がり、溶接
の熱により溶接ルート部に発生する高引張り残留応力が
圧縮応力へ移行して高引張り残留応力が低減するので、
溶接材における高温割れの発生および進展が抑制されて
配管内部の流体が高温割れの部分を通って外部へ漏れる
漏洩事故などを起こすことがなくなる。The socket welded pipe joint according to the present invention is constructed as described above, and the rigidity of the socket is reduced by removing the outer periphery of the end portion of the socket after welding, and the heat of welding causes the weld root portion to generate. As the high tensile residual stress is transferred to the compressive stress and the high tensile residual stress is reduced,
The occurrence and development of hot cracking in the welded material are suppressed, and the fluid inside the pipe does not leak to the outside through the hot cracking portion.
【図１】図１は本発明の実施の一形態に係るソケット溶
接継手の断面図である。FIG. 1 is a sectional view of a socket welded joint according to an embodiment of the present invention.
【図２】図２（ａ），（ｂ）はその加工説明図である。FIG. 2A and FIG. 2B are explanatory views of the processing.
【図３】図３もその加工説明図である。FIG. 3 is also an explanatory view of the processing.
【図４】図４はその作用説明図である。FIG. 4 is an explanatory view of its operation.
【図５】図５（ａ），（ｂ）は従来のソケット溶接継手
の断面図である。5 (a) and 5 (b) are sectional views of a conventional socket welded joint.
【図６】図６はその作用説明図である。FIG. 6 is an explanatory view of its operation.
１ ソケット溶接継手 ２ 配管 ３ ソケット ４ 溶接 ５ 高温割れ ７ 溶接ルート部 １３ 端部外周 １４ 砲弾砥石 １５ のど厚加工 1 Socket Welding Joint 2 Piping 3 Socket 4 Welding 5 High Temperature Cracking 7 Welding Root 13 Outer Perimeter 14 Shell Whetstone 15 Throat Processing
Claims (1)
り配管を互いに継ぐソケット溶接配管継手において、溶
接により上記配管を上記ソケットに結合した後に溶接部
近傍の上記ソケットの端部外周を削除したことを特徴と
するソケット溶接配管継手。1. A socket welded pipe joint in which pipe ends are inserted into a socket to join pipes together by welding, and after the pipes are joined to the sockets by welding, the outer periphery of the end of the socket near the welded portion is deleted. Characteristic socket welding pipe joint.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3788696A JPH09229248A (en) | 1996-02-26 | 1996-02-26 | Socket welding piping fitting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3788696A JPH09229248A (en) | 1996-02-26 | 1996-02-26 | Socket welding piping fitting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09229248A true JPH09229248A (en) | 1997-09-05 |
Family
ID=12510028
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3788696A Withdrawn JPH09229248A (en) | 1996-02-26 | 1996-02-26 | Socket welding piping fitting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09229248A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101303209B1 (en) * | 2013-06-19 | 2013-09-03 | 주식회사 코스 | Refrigerant pipe fixing structure of air conditioner |
-
1996
- 1996-02-26 JP JP3788696A patent/JPH09229248A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101303209B1 (en) * | 2013-06-19 | 2013-09-03 | 주식회사 코스 | Refrigerant pipe fixing structure of air conditioner |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20030506 |