JPS61212483A - Production of two phase stainless welding pipe having excellent corrosion resistance - Google Patents
Production of two phase stainless welding pipe having excellent corrosion resistanceInfo
- Publication number
- JPS61212483A JPS61212483A JP5510385A JP5510385A JPS61212483A JP S61212483 A JPS61212483 A JP S61212483A JP 5510385 A JP5510385 A JP 5510385A JP 5510385 A JP5510385 A JP 5510385A JP S61212483 A JPS61212483 A JP S61212483A
- Authority
- JP
- Japan
- Prior art keywords
- welding
- solution treatment
- upsetting
- stainless steel
- corrosion resistance
- 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.)
- Granted
Links
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- Heat Treatment Of Articles (AREA)
Abstract
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は石油または天然ガス用ラインパイプ。[Detailed description of the invention] (Industrial application field) The present invention is a line pipe for oil or natural gas.
油井管、原子力用、地熱用、化学プラント用、−設配管
用などに使用する二相ステンレス溶接管の製造法に関す
るものである。The present invention relates to a method for manufacturing two-phase stainless steel welded pipes used for oil country tubular goods, nuclear power, geothermal, chemical plants, installation piping, etc.
（従来の技術）
近年、上記各種用途に二相ステンレス溶接管が使用され
るようになシ、その溶接方法としては、ＴＩＧ 、 Ｓ
ＡＷ法が用いられている。ＴＩＧ溶接方法は比較的薄板
の溶接に用いられ、溶接速度が遅く、生産性が劣る。(Prior Art) In recent years, duplex stainless steel welded pipes have been used for the various purposes mentioned above, and the welding methods include TIG, S
The AW method is used. The TIG welding method is used for welding relatively thin plates, has a slow welding speed, and has poor productivity.
一方、ＳＡＷ溶接方法は、中、厚板に用いられ溶加材を
用いた大入熱による比較的高能率溶接法である。On the other hand, the SAW welding method is a relatively high-efficiency welding method that is used for medium to thick plates and uses a filler metal and uses a large heat input.
ＴＩＧ 、 ＳＡＷ法で溶接された溶接部組織を観察す
ると、熱影響部は粗大結晶粒の凝固組織であり、母材部
に比ベフェライト量が多くなる傾向にある。When observing the structure of a welded part welded by the TIG or SAW method, the heat-affected zone is a solidified structure of coarse crystal grains, and the amount of beferrite tends to be larger than that of the base metal.
溶接後、高温熱処理（以下溶体化処理と呼ぶ）を行って
も溶接部は再結晶が行われず粗大結晶粒の１１である。After welding, even if high-temperature heat treatment (hereinafter referred to as solution treatment) is performed, recrystallization is not performed in the welded portion, and the welded portion has coarse crystal grains.
そのため、耐食性、延性、靭性を損うという問題点があ
る。Therefore, there is a problem that corrosion resistance, ductility, and toughness are impaired.
なお、フェライト系ステンレス鋼の溶接鋼管では、この
他にアップセット溶接も行われ、特公昭５３−２８０１
４号公報で開示された製造法がある。しかし、この製造
法は、アップセット溶接部の結晶粒の細粒化の考えはな
く、素材成分であるＣ、Ｎ、Ｓ、Ｏを極力低下させるこ
とにより耐食性、冷間加工性の改善を狙ったものである
。In addition, upset welding is also performed for welded ferritic stainless steel pipes.
There is a manufacturing method disclosed in Publication No. 4. However, this manufacturing method does not consider the refinement of the crystal grains in the upset weld, and aims to improve corrosion resistance and cold workability by reducing the material components C, N, S, and O as much as possible. It is something that
（発明が解決しようとする問題点）
本発明は衝合部の成分調整することなく溶接後の溶接部
組織を母材部と同等またはそれ以上の細粒の結晶粒組織
となすことによって溶接部の耐食性、延性、靭性を改善
したフェライト相とオーステナイト相の二相ステンレス
溶接管を提供することを目的とするものでちる。(Problems to be Solved by the Invention) The present invention achieves a welded part by making the welded part structure after welding into a fine-grained crystal grain structure equivalent to or larger than that of the base metal part without adjusting the composition of the abutting part. The purpose of this invention is to provide a two-phase stainless steel welded pipe of ferrite and austenite phases with improved corrosion resistance, ductility, and toughness.
（問題点を解決するための手段）
本発明はフェライト相とオーステナイト相からなる二相
ステンレス鋼を非酸化性ガス雰囲気中にて溶加材を使用
せずにアップセット量を肉厚ＸＩ、４以上としてアップ
セット溶接し、その後、溶体化処理することを特徴とす
る耐食性の優れた二相ステンレス溶接管の製造方法であ
る。(Means for Solving the Problems) The present invention improves the upset amount of duplex stainless steel consisting of a ferrite phase and an austenite phase in a non-oxidizing gas atmosphere to a wall thickness of XI and 4 without using a filler metal. As described above, this is a method for manufacturing a duplex stainless steel welded pipe with excellent corrosion resistance, which is characterized by upset welding and then solution treatment.
本発明の構成要件の限定理由は次の通りである。The reasons for limiting the constituent elements of the present invention are as follows.
二相ステンレス鋼のアップセット溶接を非酸化性ガス雰
囲気中で行わない場合には、アップセ。Upset welding of duplex stainless steel is not performed in a non-oxidizing gas atmosphere.
ト溶接の加熱の際に接合面が酸化して緻密な酸化物が発
生し、これが溶接衝合部に残存して溶接欠陥となり耐食
性、延性、靭性を低下させる因子となる。そのため、溶
接欠陥発生防止のためには溶接雰囲気を非酸化性ガス雰
囲気にする必要がある。During heating during welding, the joint surface is oxidized and dense oxides are generated, which remain in the welded joint and become weld defects, causing a decrease in corrosion resistance, ductility, and toughness. Therefore, in order to prevent the occurrence of welding defects, it is necessary to make the welding atmosphere a non-oxidizing gas atmosphere.
そして該雰囲気中の酸素濃度は０．２％以下とすること
が好ましく、更に好ましい酸素濃度は０．０５−以下で
ある。The oxygen concentration in the atmosphere is preferably 0.2% or less, and more preferably 0.05% or less.
二相ステンレス鋼板を不活性ガス、還元性ガス等の非酸
化性ガス雰囲気中で高周波誘導加熱、高周波抵抗加熱、
アーク加熱により接合表面を加熱。Duplex stainless steel sheets are heated by high-frequency induction heating, high-frequency resistance heating, etc. in a non-oxidizing gas atmosphere such as inert gas or reducing gas.
The joint surface is heated by arc heating.
溶融後、アップセットし、溶接衝合部を形成する際、ア
ップセット量が肉厚×１／４以下では溶融金属が十分に
アワグセ、トされずビードが形成されないため、成形時
に生じた応力により溶接溶融部の外、内表面に微細なり
ラック状欠陥が発生するので、アップセット量の下限は
肉厚×１／４とした。After melting, when upsetting and forming a welding abutment, if the upsetting amount is less than 1/4 of the wall thickness, the molten metal will not be sufficiently warped and twisted, and no bead will be formed. Since fine rack-like defects occur on the inner surface outside the weld fusion zone, the lower limit of the upset amount was set to 1/4 of the wall thickness.
好ましいアップセット量の範囲は肉厚ｘ （１／’３〜
２Ａ ）である。The preferred range of upset amount is wall thickness x (1/'3~
2A).
アップセット溶接時に溶加棒を用いると、高速溶接を阻
害し、生産性を低下させるので溶加棒は使用しない。If a filler rod is used during upset welding, it will inhibit high-speed welding and reduce productivity, so do not use a filler rod.
アップセット溶接後、溶体化処理によシ溶接部の組織は
母材部と同等な細粒の結晶粒組織に再結晶するが、溶体
化処理温度が、９５０℃未満では析出物が固溶しなく、
また、１１５０℃を越えるとフェライト量が多くなるこ
と及び結晶粒が大きくなることより好ましい溶体化処理
温度は９５０〜１１５０℃である。After upset welding, the structure of the weld zone recrystallizes to a fine grain structure equivalent to that of the base metal due to solution treatment, but if the solution treatment temperature is lower than 950℃, the precipitates will dissolve into solid solution. Without,
In addition, if the temperature exceeds 1150°C, the amount of ferrite increases and the crystal grains become large, so the solution treatment temperature is preferably 950 to 1150°C.
（作用）
本発明の上記の如く構成したことによる特有の作用は次
の通りである。(Function) The unique effects of the above-described configuration of the present invention are as follows.
二相ステンレス鋼を非酸化性ガス雰囲気中にてアップセ
ット溶接するので、溶接衝合部にＣｒ、Ｍｎ。Since duplex stainless steel is upset welded in a non-oxidizing gas atmosphere, Cr and Mn are added to the weld abutment.
Ｓｉ等の酸化物が発生せず、溶接欠陥がなく溶接部の耐
食性、延性、靭性に悪影響を及ぼすことがない。このよ
うにして、酸化物のない溶融鋼を生成した後、溶接部を
アップセットした際、溶接部は大きな歪エネルギーを受
ける。この状態の溶接部組織は結晶粒界、格子欠陥等の
結晶の不連続部に濃縮したＣ ＊ Ｎ ＊ Ｃｒ等の偏
析が生じている。その後、溶体化処理による熱エネルギ
ーとアップセットの際に生じた歪エネルギーにより、溶
接部は整粒で、かつ、偏析のない細粒の結晶粒に再結晶
する。その際、溶体化処理温度を９５０〜１１５０℃に
設定すれば、フェライト量とオーステナイト量の比は母
材部と同等に保たれる。Oxides such as Si are not generated, there are no welding defects, and there is no adverse effect on the corrosion resistance, ductility, and toughness of the welded part. After producing oxide-free molten steel in this manner, the weld is subjected to large strain energies when the weld is upset. In the weld structure in this state, segregation of concentrated C*N*Cr and the like occurs at crystal discontinuities such as grain boundaries and lattice defects. Thereafter, due to the thermal energy from the solution treatment and the strain energy generated during the upset, the weld zone recrystallizes into fine crystal grains with regular grain size and no segregation. At that time, if the solution treatment temperature is set to 950 to 1150°C, the ratio of the amount of ferrite to the amount of austenite is kept equal to that of the base material.
このように、非酸化性雰囲気中でのアップセット溶接と
その後の溶体化処理の組合せにより溶接部の耐食性、延
性、靭性は母材部と同等な特性を具備した二相ステンレ
ス溶接管が得られる。In this way, by combining upset welding in a non-oxidizing atmosphere and subsequent solution treatment, it is possible to obtain a duplex stainless steel welded pipe whose corrosion resistance, ductility, and toughness of the welded part are equivalent to those of the base metal. .
（実施例） 表１に示すように本発明例の溶接部の耐食性。(Example) As shown in Table 1, the corrosion resistance of the welded parts of the examples of the present invention.
延性、低温靭性は従来例に比較し、優れた特性を示す。It exhibits superior ductility and low-temperature toughness compared to conventional examples.
特に本発明例は従来例の高周波抵抗溶接材に比し、その
効果は顕著である。更に、本発明例の溶接速度は従来例
のＴＩＧ、ＳＡＷ法に比し数十倍でおり、生産性からも
優れている。In particular, the effects of the present invention are remarkable compared to conventional high-frequency resistance welding materials. Furthermore, the welding speed of the example of the present invention is several tens of times faster than that of the conventional TIG and SAW methods, and it is also superior in terms of productivity.
本発明例（憲３）の全体像、溶接部、および母材部の顕
微鏡金属組織写真を夫々第１図、第２図。FIGS. 1 and 2 are microscopic metallographic photographs of the overall image, welded area, and base material of the present invention example (Ken 3), respectively.
第３図で示し、従来例（Ａ８）の全体像、溶接部。Fig. 3 shows the overall view of the conventional example (A8) and the welded part.
および母材部の顕微鏡金属組織写真を夫々第４図。and Fig. 4 shows microscopic metallographic photographs of the base material.
第５図、第６図に示す。本発明例の溶体化処理後の溶接
部組織は母材部と同等な細粒組織を呈する・これに対し
、Ｓ、ＡＷ法による溶接部組織は粗粒組織である。It is shown in FIGS. 5 and 6. The weld structure after solution treatment in the example of the present invention exhibits a fine-grain structure equivalent to that of the base metal.In contrast, the weld structure obtained by the S and AW methods has a coarse-grain structure.
（発明の効果） 本発明の効果は以下の通りである。(Effect of the invention) The effects of the present invention are as follows.
（１） 溶体化処理後の溶接部組織は母材部と同等な
細粒の再結晶組織となシ、耐食性、延性、低温靭性の品
質特性が母材部と同等となる。これにより溶接部と母材
部間で品質特性の均一化がはかられる。(1) The structure of the weld after solution treatment is a fine-grained recrystallized structure equivalent to that of the base metal, and the quality characteristics of corrosion resistance, ductility, and low-temperature toughness are equivalent to those of the base metal. This ensures uniformity of quality characteristics between the welded part and the base metal part.
（２）溶接速度が従来例のＴＩＧ、ＳＡＷ法に比較し速
く、かつ、上記（１）の理由から溶接部品質の優れた二
相ステンレス溶接管を安価に製造できる。(2) The welding speed is faster than that of conventional TIG and SAW methods, and for the reason of (1) above, a duplex stainless steel welded pipe with excellent weld quality can be manufactured at low cost.
第１図乃至第６図は、本発明実施例（ム３）の高周波抵
抗溶接法、および従来例（Ａ８）のＳＡＷ法で製造し、
その後、溶体化処理したものの顕微鏡金属組織を示す写
真であり、第１図、第２図。
第３図は本発明実施例の全体像、溶接部、母材部を示し
、第４図、第５図、第６図は従来例（ム８）の全体像、
溶接部、母材部を示す。
ｊ１１図
〉□ｌ
第２図
第３図
手続補正書
昭和６０年蓼月ｌ 日
４．−□１
！１【件との関係 出 願 人
表代理人
住 所 東京都千代１１区丸の内２丁目６番２号丸の
内へ重洲ビル３３０、 ゛
補 正 書
本願明細書中下記事項を補正いたします。
４」の項に
「高周波抵抗溶接」とあるを
「高周波誘導溶接」と訂正する。
代理人 谷 山 輝 雄ｊ゛“コ
ニ ｊ
今□−９，□１−Figures 1 to 6 show the products manufactured by the high-frequency resistance welding method of the embodiment of the present invention (Mo. 3) and the SAW method of the conventional example (A8).
FIGS. 1 and 2 are photographs showing the microscopic metal structure of the product which was then subjected to solution treatment. FIG. 3 shows the overall image, welded part, and base metal part of the embodiment of the present invention, and FIGS. 4, 5, and 6 show the overall image of the conventional example (Mo.
The welded part and base metal part are shown. Figure 11〉□l Figure 2 Figure 3 Procedural amendment 1985 1 Day 4. -□1! 1 [Relationship with the matter] Application Name and address of agent Address: 330 Marunouchi Shigesu Building, 2-6-2 Marunouchi, Chiyo 11-ku, Tokyo ゛Amendment The following matters in the specification of this application are amended. In section 4, the phrase “high-frequency resistance welding” is corrected to “high-frequency induction welding.” Agent Teru Taniyama Koni j Ima□−9,□1−
Claims (1)
ス鋼を非酸化性ガス雰囲気中にて溶加材を使用せずに、
アップセット量を肉厚×１／４以上としてアップセット
溶接し、その後、溶体化処理することを特徴とする耐食
性の優れた二相ステンレス溶接管の製造方法。Duplex stainless steel consisting of ferrite and austenite phases is processed in a non-oxidizing gas atmosphere without using filler metal.
A method for manufacturing a duplex stainless steel welded pipe with excellent corrosion resistance, characterized by performing upset welding with an upset amount of 1/4 or more of the wall thickness, and then subjecting it to solution treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5510385A JPS61212483A (en) | 1985-03-19 | 1985-03-19 | Production of two phase stainless welding pipe having excellent corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5510385A JPS61212483A (en) | 1985-03-19 | 1985-03-19 | Production of two phase stainless welding pipe having excellent corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61212483A true JPS61212483A (en) | 1986-09-20 |
| JPH0333071B2 JPH0333071B2 (en) | 1991-05-15 |
Family
ID=12989410
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5510385A Granted JPS61212483A (en) | 1985-03-19 | 1985-03-19 | Production of two phase stainless welding pipe having excellent corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61212483A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51145454A (en) * | 1975-06-10 | 1976-12-14 | Nippon Steel Corp | Method for manufacture of electriccweld steel pipe |
| JPS5550757A (en) * | 1978-10-06 | 1980-04-12 | Hitachi Denshi Ltd | Signal change-over control device |
-
1985
- 1985-03-19 JP JP5510385A patent/JPS61212483A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS51145454A (en) * | 1975-06-10 | 1976-12-14 | Nippon Steel Corp | Method for manufacture of electriccweld steel pipe |
| JPS5550757A (en) * | 1978-10-06 | 1980-04-12 | Hitachi Denshi Ltd | Signal change-over control device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0333071B2 (en) | 1991-05-15 |
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