JPS63317204A - Manufacture of two-phase stainless steel tube excellent in corrosion resistance - Google Patents
Manufacture of two-phase stainless steel tube excellent in corrosion resistanceInfo
- Publication number
- JPS63317204A JPS63317204A JP15423487A JP15423487A JPS63317204A JP S63317204 A JPS63317204 A JP S63317204A JP 15423487 A JP15423487 A JP 15423487A JP 15423487 A JP15423487 A JP 15423487A JP S63317204 A JPS63317204 A JP S63317204A
- Authority
- JP
- Japan
- Prior art keywords
- stainless steel
- less
- rolling
- duplex stainless
- phases
- 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
- 230000007797 corrosion Effects 0.000 title claims abstract description 28
- 238000005260 corrosion Methods 0.000 title claims abstract description 28
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 229910001220 stainless steel Inorganic materials 0.000 title abstract description 9
- 239000010935 stainless steel Substances 0.000 title abstract description 5
- 238000005096 rolling process Methods 0.000 claims abstract description 29
- 229910001566 austenite Inorganic materials 0.000 claims abstract description 15
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 10
- 238000005098 hot rolling Methods 0.000 claims abstract description 6
- 229910001039 duplex stainless steel Inorganic materials 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 23
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 229910052720 vanadium Inorganic materials 0.000 claims description 4
- 239000012535 impurity Substances 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 229910052804 chromium Inorganic materials 0.000 claims description 2
- 229910052748 manganese Inorganic materials 0.000 claims description 2
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 229910052757 nitrogen Inorganic materials 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims 1
- 229910052750 molybdenum Inorganic materials 0.000 claims 1
- 238000005336 cracking Methods 0.000 abstract description 12
- 239000000463 material Substances 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 239000012809 cooling fluid Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 238000001192 hot extrusion Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000004881 precipitation hardening Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、耐食性、特に耐応力腐食割れ性に優れた二相
ステンレス鋼継目無管の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a duplex stainless steel seamless pipe having excellent corrosion resistance, particularly stress corrosion cracking resistance.
（従来の技術とその問題点）
フェライトとオーステナイトの二相Ｎｉ織から成る二相
ステンレス鋼は、フェライトステンレス鋼とオーステナ
イトステンレス鋼の長所を合わせ持ち、特に耐応力腐食
割れ性に優れているところから、Ｃｒ−を含む厳しい腐
食環境下での高耐食性材料として広く使用されるように
なってきたおり、高級油井管や熱交換チューブ用の二相
ステンレス鋼継目無管も近年その使用量が増えつつある
。(Conventional technology and its problems) Duplex stainless steel consisting of a dual-phase Ni weave of ferrite and austenite combines the advantages of ferritic stainless steel and austenitic stainless steel, and is especially excellent in stress corrosion cracking resistance. It has become widely used as a highly corrosion-resistant material in harsh corrosive environments containing Cr-, and duplex stainless steel seamless pipes for high-grade oil country tubular goods and heat exchange tubes have also been increasing in use in recent years. be.
しかしながら、従来の二相ステンレス鋼継目無管は、必
ずしも二相ステンレス鋼本来の優れた耐応力腐食割れ性
を発揮しているとは言い難い、その理由は、熱間圧延に
よる継目無管の製造工程、特にその圧延温度にあるもの
と考えられる。However, it cannot be said that conventional duplex stainless steel seamless pipes necessarily exhibit the excellent stress corrosion cracking resistance inherent to duplex stainless steels.The reason is that seamless pipes are manufactured by hot rolling. This is thought to be due to the rolling process, especially the rolling temperature.
例えば、傾斜穿孔圧延法（マンネスマン製管法）によっ
て継目無管を製造する場合、素材ビレットは１３００℃
前後に加熱されて圧延に供されるが、各圧延スタンドで
は管内面とプラグ等との摩擦により実際の圧延温度はか
なり高（なる、従って、圧延は殆どフェライト単相域で
実施されることになる。上記圧延過程で発生する加工熱
による温度上昇があるため、被圧延材のトップからボト
ムに温度勾配が生じ、仮りに圧延トップがα＋Ｔ二相域
圧延であってもボトムはより高温のα域圧延になってし
まう。For example, when manufacturing seamless pipes by the inclined perforation rolling method (Mannesmann pipe manufacturing method), the material billet is heated to 1300°C.
Although the tube is heated back and forth and subjected to rolling, the actual rolling temperature is quite high due to the friction between the inner surface of the tube and the plugs in each rolling stand. Since there is a temperature rise due to processing heat generated in the above rolling process, a temperature gradient occurs from the top to the bottom of the rolled material, and even if the top of rolling is α + T two-phase region rolling, the bottom is α which is higher temperature. This results in area rolling.
第１図は、後述する実施例で用いた従来の圧延法により
フェライト単相、または大部分がフェライト相である頭
載で圧延された二相ステンレス鋼管のミクロ組織（倍率
： １００）の−例である。このミクロ組織をみればγ
相は掻くランダムにα相と混合していることが分かる。FIG. 1 shows an example of the microstructure (magnification: 100) of a duplex stainless steel tube that was rolled with a single ferrite phase or with a mostly ferrite phase over head by the conventional rolling method used in the examples described later. It is. Looking at this microstructure, γ
It can be seen that the phase is randomly mixed with the α phase.
このような組織になるのは、圧延過程で加工を受けたα
相が、α−α十γと相変態するときに生じるオーステナ
イトが方向性のないランダムなものであることが原因で
あると考えられる。This type of structure is created by α processed during the rolling process.
This is thought to be due to the fact that the austenite produced when the phase transforms into α-α+γ is random and has no directionality.
二相ステンレス鋼の優れた耐応力腐食割れ性は、フェラ
イト相を伝播していく応力腐食の亀裂がオーステナイト
相で止められるためであるが、第１図のような組織では
、亀裂は連続したα相またはα相とγ相の界面を伝って
進展していくものと考えられ、これが二相ステンレス鋼
管の耐応力腐食割れ性が不十分な原因と推定される。The excellent stress corrosion cracking resistance of duplex stainless steel is due to the fact that stress corrosion cracks that propagate through the ferrite phase are stopped by the austenite phase. It is thought that the corrosion propagates along the phase or the interface between the α phase and the γ phase, and this is presumed to be the reason why the stress corrosion cracking resistance of the duplex stainless steel pipe is insufficient.
（問題点を解決するための手段）
本発明者は、最終的に得られる製品のミクロ組織中でフ
ェライト相とオーステナイト相とが圧延方向に平行に層
状に分布している場合に、二相ステンレス鋼管の耐応力
腐食割れ性が著しく改善されることを確認した。そして
、このようなミクロ＆［ｌ織を得るため、圧延工程の改
善を試み本発明に到った。(Means for Solving the Problems) The present inventor has proposed that when a ferrite phase and an austenite phase are distributed in layers parallel to the rolling direction in the microstructure of the final product, two-phase stainless steel It was confirmed that the stress corrosion cracking resistance of steel pipes was significantly improved. In order to obtain such a micro weave, an attempt was made to improve the rolling process and the present invention was achieved.
本発明の要旨は、ｒ熱間圧延をオーステナイトとフェラ
イトの二相温度域で行うことを特徴とする耐食性に優れ
た二相ステンレス＄４継目無管の製造方法」にある。The gist of the present invention is a method for producing a seamless two-phase stainless steel pipe with excellent corrosion resistance, characterized in that hot rolling is carried out in the two-phase temperature range of austenite and ferrite.
継目無管の素材となる二相ステンレス鋼は種々あるが、
本発明はその種類を問わない。しかし、広く継目無管に
要求される機械的強度や耐応力腐食割れ性をはじめとす
る耐食性、溶接性を考慮して、望ましい二相ステンレス
鋼として、次のものがある。即ち、
重置％で、Ｃ： ｏ、ｏｓ％以下、Ｓｉ ： ０．０８
％以下、Ｍｎ： ０．２０〜２．００％、Ｃｒ ： １
８〜２７％、ｌ’ｌｏ ： １．４０〜４．５０、Ｎｉ
： ３．００〜８．００％、Ｎ： ０．０４〜０．２
０％を含有する二相ステンレス鋼である。There are various duplex stainless steels that can be used as materials for seamless pipes.
The present invention is not limited to any type. However, in consideration of mechanical strength, corrosion resistance including stress corrosion cracking resistance, and weldability that are widely required for seamless pipes, the following are desirable duplex stainless steels. That is, in overlay %, C: o, os% or less, Si: 0.08
% or less, Mn: 0.20-2.00%, Cr: 1
8-27%, l'lo: 1.40-4.50, Ni
: 3.00~8.00%, N: 0.04~0.2
It is a duplex stainless steel containing 0%.
上記の二相ステンレス鋼は、残部が実賞的にＦｅから成
り、外に特定の合金元素を含有しないものであってもよ
く、また、例えば析出硬化による強度の向上、耐食性の
向上のために、Ｃｕ ： ２．５０％以下、Ｎｂ；１．
００％以下、Ｖ ： １．００％以下、Ｔｉ ： ０．
５Ｑ％以下、Ｚｒ ： １．００％以下の１種以上を含
むものであってもよい。The above-mentioned duplex stainless steel may be one in which the remainder is actually Fe and does not contain any other specific alloying elements, and may also be used, for example, to improve strength and corrosion resistance by precipitation hardening. , Cu: 2.50% or less, Nb; 1.
00% or less, V: 1.00% or less, Ti: 0.00% or less, V: 1.00% or less, Ti: 0.
It may contain one or more of 5Q% or less and Zr: 1.00% or less.
上記のような二相ステンレス鋼では、α→α＋Ｔの変態
温度はおよそ１２６０℃前後であるから、穿孔圧延をは
じめとする熱間圧延は１０００℃から１２６０℃の範囲
で行う、下限の１０００℃は、実操業上圧延の可能な限
界温度である。In the above-mentioned duplex stainless steel, the transformation temperature of α→α+T is around 1260°C, so hot rolling including piercing rolling is performed in the range of 1000°C to 1260°C, with the lower limit of 1000°C being , is the limit temperature at which rolling can be carried out in actual operation.
製管方法としては、継目無製管法と総称されるマンドレ
ルミル方式、プラグミル方式、プレスピアシング方式等
の穿孔圧延法が採用される。その他、熱間押出法、熱間
押抜き法等の各種の継目無管製造方法が採用できる。As the pipe manufacturing method, a piercing rolling method such as a mandrel mill method, a plug mill method, a press piercing method, etc., collectively referred to as a seamless pipe manufacturing method, is adopted. In addition, various seamless pipe manufacturing methods such as hot extrusion method and hot punching method can be adopted.
製管工程に先立つビレットの加熱は、二相ステンレス鋼
が比較的熱間加工の困難な材料であることを考慮して、
従来どおり１３００℃前後の温度とするのがよい、圧延
工程における温度の制御には、プラグ先端から水や空気
、窒素ガス等の冷却用流体を流す方法、プラグを熱伝導
性の良い材料で製作しプラグを強冷する方法などが採用
される。The heating of the billet prior to the pipe-making process takes into account that duplex stainless steel is a material that is relatively difficult to hot-work.
It is best to keep the temperature around 1300℃ as usual.To control the temperature in the rolling process, there are two methods: to flow a cooling fluid such as water, air, or nitrogen gas from the tip of the plug, and to make the plug from a material with good thermal conductivity. Methods such as strongly cooling the plug are used.
製管後の熱処理は、従来のとおり溶体化処理を行えばよ
い、前述の本発明方法の対象として望ましい二相ステン
レス鋼の場合、溶体化処理は、およそ１０００〜１２０
０℃での加熱の後、水冷する。For heat treatment after pipe making, solution treatment may be performed as in the conventional method. In the case of duplex stainless steel, which is desirable as a target for the method of the present invention described above, solution treatment requires approximately 1000 to 120
After heating at 0°C, it is water cooled.
（作用）
本発明の製管方法によれば、素材二相ステンレス鋼の圧
延はα＋γの二相域で行われる。従って、圧延によって
延伸されたオーステナイト相はそのまま圧延方向に平行
に残り、その間にフェライト相が分散したｍ織となる。(Function) According to the pipe manufacturing method of the present invention, rolling of the material duplex stainless steel is performed in the α+γ two-phase region. Therefore, the austenite phase stretched by rolling remains parallel to the rolling direction, and the ferrite phase is dispersed therebetween to form an m-weave.
このような組織の管では、仮に一部に応力腐食割れが発
生しても亀裂の進展はオーステナイト相で阻止され、肉
厚方向に貫通する割れには到らない。In a pipe with such a structure, even if stress corrosion cracking occurs in a portion, the crack propagation is inhibited by the austenite phase and does not result in a crack penetrating through the wall thickness.
なお、本発明方法の対象として望ましいものとして挙げ
た前記の二相ステンレス鋼の成分含有量の限定理由を略
述すれば、次のとおりである。The reason for limiting the component content of the duplex stainless steel mentioned above as a desirable target for the method of the present invention is as follows.
ＣＴＣ量が多くなるとＣｒ炭化物が析出し粒界腐食と孔
食の感受性が増大するので上限を０．０８％とした。As the amount of CTC increases, Cr carbide precipitates and susceptibility to intergranular corrosion and pitting corrosion increases, so the upper limit was set at 0.08%.
Ｓｉ：Ｓｉは脱酸のため必要な元素であるが、Ｓｉ量が
多くなると靭性が劣化するので上限を０．８０％とした
。Si: Si is a necessary element for deoxidation, but as the amount of Si increases, toughness deteriorates, so the upper limit was set at 0.80%.
Ｍｎ ： Ｍｎはオーステナイトを安定させる元素であ
り強度上昇にも効果があるが、０．２０％未満ではその
効果は少なく 、２．００％を超えると靭性を劣化させ
る。Mn: Mn is an element that stabilizes austenite and is effective in increasing strength, but if it is less than 0.20%, the effect is small, and if it exceeds 2.00%, it deteriorates toughness.
Ｃｒ ： Ｃｒは２相ステンレス鋼の基本成分であり耐
食性向上に効果があるが、１８％未満ではその効果は小
さり、２７％を超えるとオーステナイトが出現しにくく
なり高価なＮｉを多量に使用しなければならない、また
、溶接性も劣化する。Cr: Cr is a basic component of duplex stainless steel and is effective in improving corrosion resistance, but if it is less than 18%, the effect is small, and if it exceeds 27%, it becomes difficult for austenite to appear, making it necessary to use large amounts of expensive Ni. In addition, weldability also deteriorates.
Ｍｏ ： Ｍｏは炭化物を形成して高温強度を高め、耐
孔食性を含め耐食性を改善する元素であるが、１゜４０
％未満ではその効果は小さく 、４．５０％を超えると
オーステナイトが出現しにくくなり高価なＮｉを多量に
使用しなければならなくなる。Mo: Mo is an element that forms carbides to increase high temperature strength and improve corrosion resistance including pitting corrosion resistance.
If it is less than 4.50%, the effect will be small, and if it exceeds 4.50%, austenite will hardly appear and a large amount of expensive Ni will have to be used.
Ｎｉ ： Ｎｉはオーステナイト安定化元素で２相ステ
ンレス鋼の基本成分であるが、３％未満ではその効果が
少なく、８％を超えると経済上好ましくない。Ni: Ni is an austenite stabilizing element and is a basic component of duplex stainless steel, but if it is less than 3%, its effect is small, and if it exceeds 8%, it is economically unfavorable.
ＮＵＮは溶解中に大気から侵入してくる元素で特に有害
ではないが、０６０４％未満にはＮＮを低下しにくく、
かつ結晶粒微細化効果が少な（なるため下限を０．０４
％とし、０．２０％を超えると加窒しなければならなく
工数が増大し経済上好ましくない。NUN is an element that enters from the atmosphere during melting and is not particularly harmful, but it is difficult to reduce the NN to less than 0.604%.
and the grain refining effect is small (so the lower limit is set to 0.04
%, and if it exceeds 0.20%, it is necessary to perform nitriding, which increases the number of man-hours and is economically unfavorable.
これらの成分の外に、脱酸剤として使用される＾ｌは、
ｓｏｌ、 Ａｌとして０．１０％まで含有されていても
よい、また、不純物であるＳとＰはそれぞれ０．０１０
％以下、０．０３５％以下に抑えるべきである。In addition to these ingredients, ^l used as a deoxidizer is:
sol, Al may be contained up to 0.10%, and the impurities S and P are each 0.010%.
% or less, and should be suppressed to 0.035% or less.
更に、特定の性質の向上のために必要に応じて添加され
る成分とその含有量の限定理由は下記の通りである。Furthermore, the components added as necessary to improve specific properties and the reasons for limiting their contents are as follows.
Ｃｕ：耐食性の向上のために添加するが、靭性劣化を防
ぐため含有量の上限を２．５０％とする。Cu: Added to improve corrosion resistance, but the upper limit of the content is set at 2.50% to prevent toughness deterioration.
Ｎｂ％Ｖ、 Ｔｉ、 Ｚｒ ：これらは、析出強化によ
る強度上界のため添加されるが、含有量が多すぎると析
出物が粗大化して好ましくない、従って、それぞれ上限
を１．００％、１．００％、０．５０％、１．００％と
する。Nb%V, Ti, Zr: These are added because of the upper limit of strength due to precipitation strengthening, but if the content is too large, the precipitates will become coarse, which is undesirable. Therefore, the upper limit is set to 1.00% and 1. .00%, 0.50%, 1.00%.
次に、本発明を実施例によってさらに具体的に説明する
。Next, the present invention will be explained in more detail with reference to Examples.
（実施例）
第１表記載の組成をもつ二相ステンレス鋼を電気炉−＾
ＯＤで溶製し、連続鋳造ブルームから分塊圧延して２１
３ｍ径の丸ビレットとした。これを素材として下記の条
件で２３１．６＋ｎ径Ｘ １５．８ｎ厚の継目無管を製
造した。(Example) Duplex stainless steel having the composition listed in Table 1 was heated in an electric furnace.
Molten with OD and bloomed from continuous casting bloom to 21
It was made into a round billet with a diameter of 3 m. Using this material as a raw material, a seamless pipe with a diameter of 231.6+n and a thickness of 15.8n was manufactured under the following conditions.
ビレット加熱温度・・・・・・１３００ ℃第１穿孔
圧延温度・・・・・・１１４０ ℃第２穿孔圧延温度
・・・・・・１１２０ ℃プラグミル圧延温度・・・
・・１１００ ℃サイザー圧延温度・・・・・・８０
０ ℃熱処理・・・・・・・・１０５０℃加熱、水冷
（温度は全て外面温度の測定値）
第１表
上記によって得られた鋼管から６龍径×３０１Ｇ、Ｌ、
の試験片を採り、引張り試験と応力腐食割れ試験を行っ
た。その結果を第２表に掲げる。Billet heating temperature...1300°C First piercing rolling temperature...1140°C Second piercing rolling temperature...1120°C Plug mill rolling temperature...
...1100℃ Sizer rolling temperature...80
0℃ heat treatment・・・・・・Heating at 1050℃, water cooling (all temperatures are measured values of external surface temperature) Table 1 From the steel pipe obtained above, 6 diameter x 301G, L,
A test piece was taken and subjected to a tensile test and a stress corrosion cracking test. The results are listed in Table 2.
（第２表に、比較例として同しビレットから従来のＷＡ
前管法製造した継目無管の性質を併記した。）第２表
第１図に上記比較例によって得られた鋼管のミクロ組織
、第２図に本発明の実施例によってえられた鋼管のミク
ロ＆ｌＩ織（倍率はいずれも１００倍）を示す。第２図
に明らかなように、本発明方法によって製造された鋼管
ではオーステナイト結晶粒が圧延方向に大きく伸びて層
状に分布している。(Table 2 shows a conventional WA from the same billet as a comparative example.
The properties of seamless pipes manufactured by the front pipe method are also listed. ) Table 2 FIG. 1 shows the microstructure of the steel pipe obtained by the above comparative example, and FIG. 2 shows the microstructure of the steel pipe obtained by the example of the present invention (all magnifications are 100x). As is clear from FIG. 2, in the steel pipe manufactured by the method of the present invention, austenite crystal grains are largely elongated in the rolling direction and distributed in layers.
こようなＭＥ織であれば、フェライト粒に発生した亀裂
もオーステナイト粒によって効果的に阻止されるから、
これが第２表に示される優れた耐応力腐食割れ性を生む
のである。なお、本発明方法で製造された鋼管の機械的
性質は、第２表に示すとおり、従来方法によるものと何
ら差違はない。With this kind of ME weave, cracks that occur in ferrite grains are effectively blocked by austenite grains, so
This produces the excellent stress corrosion cracking resistance shown in Table 2. Note that, as shown in Table 2, the mechanical properties of the steel pipe manufactured by the method of the present invention are no different from those manufactured by the conventional method.
（発明の効果）
実施例からも明らかなとおり、本発明方法によって製造
される二相ステンレス鋼継目無管は、従来の製造方法に
よるものと比較して、極めて優れた耐応力腐食割れ性を
持つ。かかる二相ステンレス鋼継目無管は、ますます苛
酷になる腐食環境下でも高い信軌性をもって使用できる
ものである。(Effects of the invention) As is clear from the examples, the duplex stainless steel seamless pipe manufactured by the method of the present invention has extremely superior stress corrosion cracking resistance compared to that manufactured by the conventional manufacturing method. . Such duplex stainless steel seamless pipes can be used with high reliability even in increasingly severe corrosive environments.
第１図および第２図は、それぞれ従来法および本発明法
によって製造された二相ステンレス！１継目無管のミク
ロ′ａ織の顕微鏡写真（ｘｌＯＯ）である。Figures 1 and 2 show duplex stainless steel produced by the conventional method and the method of the present invention, respectively! This is a micrograph (xlOO) of a seamless micro-a weave.
Claims (5)
度域で行うことを特徴とする耐食性に優れた二相ステン
レス鋼継目無管の製造方法。(1) A method for producing a seamless duplex stainless steel pipe with excellent corrosion resistance, characterized in that hot rolling is carried out in the two-phase temperature range of austenite and ferrite.
％以下、Ｍｎ：０．２０〜２．００％、Ｃｒ：１８〜２
７％、Ｍｏ：１．４０〜４．５０、Ｎｉ：３〜８％、Ｎ
：０．０４〜０．２０％を含有する二相ステンレス鋼を
、１０００〜１２６０℃で圧延する特許請求の範囲第１
項記載の継目無管の製造方法。(2) In weight%, C: 0.08% or less, Si: 0.08
% or less, Mn: 0.20-2.00%, Cr: 18-2
7%, Mo: 1.40-4.50, Ni: 3-8%, N
Claim 1: Duplex stainless steel containing 0.04 to 0.20% is rolled at 1000 to 1260°C.
The method for manufacturing the seamless pipe described in Section 1.
および不可避不純物から成るものである特許請求の範囲
第２項記載の継目無管の製造方法。(3) Duplex stainless steel has the above components and the remainder is Fe.
and unavoidable impurities.
成分の外、Ｃｕ：２．５０％以下、Ｎｂ：１．００％以
下、Ｖ：１．００％以下、Ｔｉ：０．５０％以下、Ｚｒ
：１．００％以下の１種以上を含有し、残部がＦｅおよ
び不可避不純物から成るものである特許請求の範囲第２
項記載の継目無管の製造方法。(4) The duplex stainless steel contains, in addition to the components set forth in claim 2, Cu: 2.50% or less, Nb: 1.00% or less, V: 1.00% or less, Ti: 0.50. % or less, Zr
: 1.00% or less of one or more types, with the remainder consisting of Fe and unavoidable impurities.
The method for manufacturing the seamless pipe described in Section 1.
第１項、第２項、第３項、または第４項記載の継目無管
の製造方法。(5) The method for manufacturing a seamless pipe according to claim 1, 2, 3, or 4, wherein the hot rolling is an inclined piercing rolling method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62154234A JPH069693B2 (en) | 1987-06-20 | 1987-06-20 | Method for producing duplex stainless steel pipe with excellent corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62154234A JPH069693B2 (en) | 1987-06-20 | 1987-06-20 | Method for producing duplex stainless steel pipe with excellent corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63317204A true JPS63317204A (en) | 1988-12-26 |
| JPH069693B2 JPH069693B2 (en) | 1994-02-09 |
Family
ID=15579781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62154234A Expired - Lifetime JPH069693B2 (en) | 1987-06-20 | 1987-06-20 | Method for producing duplex stainless steel pipe with excellent corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH069693B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016117944A (en) * | 2014-12-18 | 2016-06-30 | Ｊｆｅスチール株式会社 | Method of producing two-phase stainless seamless steel tube |
| JP2016164288A (en) * | 2015-03-06 | 2016-09-08 | Ｊｆｅスチール株式会社 | Method for producing high strength stainless seamless steel pipe for oil well |
| US9771628B2 (en) | 2011-02-14 | 2017-09-26 | Nippon Steel & Sumitomo Metal Corporation | Duplex stainless steel and production method therefor |
| CN115584443A (en) * | 2021-07-05 | 2023-01-10 | 中国石油天然气集团有限公司 | Copper-containing antibacterial duplex stainless steel continuous tube and processing method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS612743A (en) * | 1984-06-15 | 1986-01-08 | Mitsubishi Rayon Co Ltd | Porous membrane |
-
1987
- 1987-06-20 JP JP62154234A patent/JPH069693B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS612743A (en) * | 1984-06-15 | 1986-01-08 | Mitsubishi Rayon Co Ltd | Porous membrane |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9771628B2 (en) | 2011-02-14 | 2017-09-26 | Nippon Steel & Sumitomo Metal Corporation | Duplex stainless steel and production method therefor |
| JP2016117944A (en) * | 2014-12-18 | 2016-06-30 | Ｊｆｅスチール株式会社 | Method of producing two-phase stainless seamless steel tube |
| JP2016164288A (en) * | 2015-03-06 | 2016-09-08 | Ｊｆｅスチール株式会社 | Method for producing high strength stainless seamless steel pipe for oil well |
| CN115584443A (en) * | 2021-07-05 | 2023-01-10 | 中国石油天然气集团有限公司 | Copper-containing antibacterial duplex stainless steel continuous tube and processing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH069693B2 (en) | 1994-02-09 |
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