JPH0941092A - High corrosion resistance martensitic stainless steel reduced in hardness in weld zone - Google Patents
High corrosion resistance martensitic stainless steel reduced in hardness in weld zoneInfo
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- JPH0941092A JPH0941092A JP19192895A JP19192895A JPH0941092A JP H0941092 A JPH0941092 A JP H0941092A JP 19192895 A JP19192895 A JP 19192895A JP 19192895 A JP19192895 A JP 19192895A JP H0941092 A JPH0941092 A JP H0941092A
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は優れた耐ＣＯ2 腐食
特性を有する溶接部硬さの低いマルテンサイト系ステン
レス鋼に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a martensitic stainless steel having a low weld hardness and having excellent CO 2 corrosion resistance.
【０００２】[0002]
【従来の技術】近年、ＣＯ2 を多量に含むガスを生産す
るガス井が開発され、また、ＣＯ2 インジェクションが
広く行われるようになっている。このような環境では腐
食が激しいため、ＡＩＳＩ４２０鋼に代表されるような
耐ＣＯ2 腐食特性にすぐれた１３％Ｃｒマルテンサイト
系ステンレス鋼の油井管が使用されている。地表に出て
からのラインパイプは溶接で継がれるために、溶接性を
考慮していない油井管に使用されるような材料は使用出
来ない。従って、止むなく更に高級な二相ステンレス鋼
のラインパイプが使用されている。しかし、経済性の観
点からは１３％Ｃｒ鋼程度の材料をラインパイプに適用
することが望まれている。2. Description of the Related Art In recent years, a gas well for producing a gas containing a large amount of CO 2 has been developed, and CO 2 injection has been widely performed. Since corrosion is severe in such an environment, 13% Cr martensitic stainless steel oil country tubular goods having excellent CO 2 corrosion resistance as represented by AISI 420 steel are used. Since the line pipes that appear on the surface of the earth are welded together, the materials used for oil well pipes that do not take into account weldability cannot be used. Therefore, higher grade duplex stainless steel line pipes are used unavoidably. However, from the viewpoint of economy, it is desired to apply a material of about 13% Cr steel to the line pipe.
【０００３】溶接性を向上させるためには一般にＣを低
減することが必要であり、マルテンサイト系ステンレス
鋼でＣを低減し溶接性を向上させた材料が、例えば特開
平４−９９１２８号公報、特開平４−９９１２７号公報
などに挙げられている。しかし、これらの鋼も溶接部が
硬く、特性上問題が多い。何よりも、その硬さのために
耐硫化物応力割れ性が十分でなかったりして二相ステン
レス鋼の代わりに使える水準までは達していない。そこ
で、ラインパイプの使用温度でのＣＯ2 耐食性と母材並
の溶接部硬さが得られる鋼が必要とされている。In order to improve weldability, it is generally necessary to reduce C, and a martensitic stainless steel material having reduced C and improved weldability is disclosed in, for example, Japanese Patent Laid-Open No. 4-99128. It is listed in, for example, JP-A-4-99127. However, these steels also have hard welds and have many problems in terms of properties. Above all, due to its hardness, sulfide stress cracking resistance is not sufficient, and it has not reached a level where it can be used in place of duplex stainless steel. Therefore, there is a need for steel that can obtain CO 2 corrosion resistance at the operating temperature of the line pipe and a weld hardness comparable to that of the base metal.
【０００４】[0004]
【発明が解決しようとする課題】本発明は、上記したよ
うな従来の問題を解決しようとするものであって、特定
の成分に調整することにより、良好な耐ＣＯ2 腐食特性
と母材相当の硬さおよび特性となる溶接熱影響部を有す
るマルテンサイト系ステンレス鋼を提供することを目的
とする。DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and by adjusting to specific components, good CO 2 corrosion resistance and equivalent base material can be obtained. It is an object of the present invention to provide a martensitic stainless steel having a weld heat affected zone having the hardness and properties of.
【０００５】[0005]
【課題を解決するための手段】本発明者は多くの実験結
果から、耐ＣＯ2 腐食特性は、ＣｒまたはＣｒ＋１．６
Ｍｏが９重量％（以下％は重量％を示す）以上でないと
典型的なラインパイプの環境である６０〜８０℃のよう
な比較的低い温度において良好とならないことを見いだ
した。図１は８０℃でのＣｒ量と湿潤炭酸ガス環境での
腐食速度との関係を示したものである。Ｃｒが９％を下
回ると、急激に腐食速度が大きくなることが分かる。一
般に、腐食速度が０．１mm/yより小さければ耐食性が良
いと見なされる。一方、材料の熱間加工性、耐溶接割れ
性、溶接熱影響部の靭性等を考慮すると、δフェライト
相を含有しないマルテンサイト相（高温ではオーステナ
イト相）でなければならず、その為にはＮｉ等のオース
テナイト相形成元素の添加が必要となる。From the results of many experiments, the present inventor has found that the CO 2 corrosion resistance is Cr or Cr + 1.6.
It has been found that when the content of Mo is not more than 9% by weight (hereinafter,% means% by weight), it is not good at a relatively low temperature such as 60 to 80 ° C. which is a typical line pipe environment. FIG. 1 shows the relationship between the Cr content at 80 ° C. and the corrosion rate in a wet carbon dioxide gas environment. It can be seen that when Cr is less than 9%, the corrosion rate rapidly increases. Generally, if the corrosion rate is less than 0.1 mm / y, the corrosion resistance is considered to be good. On the other hand, considering the hot workability of the material, the resistance to weld cracking, the toughness of the weld heat affected zone, etc., it must be a martensite phase containing no δ ferrite phase (austenite phase at high temperatures). It is necessary to add an austenite phase forming element such as Ni.
【０００６】このような鋼では溶接熱影響部は溶接入熱
に関わりなくマルテンサイト変態するため、その部分の
硬さはマルテンサイトの硬さとなり、高くなる。マルテ
ンサイトの硬さはＣとＮの量で決まるため、硬さを低く
するためにはこれらの元素を低減する必要がある。図２
は再現熱サイクル試験で得た溶接熱影響部の硬さおよび
母材の熱処理後の硬さにおよぼすＣ量の影響を示してい
る。Ｃ量をある水準まで低減すると両者の硬さがほぼ同
じになることを見いだした。溶接熱影響部は高温に加熱
されるため炭化物形成による固溶Ｃの低減は一般には有
効でない。このような極低Ｃで且つδフェライト相が出
現しないような化学成分を得る条件を実験的に見いだ
し、これらの知見を組み合わせることで溶接熱影響部の
硬さが低く耐食性の良いマルテンサイト系ステンレス鋼
が得られることが分かった。[0006] In such a steel, the weld heat affected zone undergoes martensite transformation regardless of the welding heat input, so that the hardness of that portion becomes that of martensite and becomes high. Since the hardness of martensite is determined by the amounts of C and N, it is necessary to reduce these elements in order to lower the hardness. FIG.
Shows the effect of the amount of C on the hardness of the weld heat affected zone and the hardness after heat treatment of the base material obtained in the simulated heat cycle test. It was found that when the C content was reduced to a certain level, the hardness of both became almost the same. Since the weld heat affected zone is heated to a high temperature, the reduction of solid solution C due to the formation of carbides is not generally effective. We have experimentally found the conditions for obtaining such a chemical composition that the extremely low C and the δ ferrite phase do not appear, and by combining these findings, the martensitic stainless steel with low hardness in the weld heat affected zone and good corrosion resistance It was found that steel was obtained.
【０００７】このように、本発明は以上述べてきた知見
を組み合わせて構成したものであって、その要旨とする
ところは以下の通りである。すなわち本発明は、合金成
分として重量％で、Ｃ ：０．００５％以下、
Ｓｉ：０．５０％以下、Ｍｎ：０．１〜１．０％、
Ｐ ：０．０３％以下、Ｓ ：０．００５％以下、
Ｃｒ：８．２〜１３％、Ｎｉ：１．５〜５％、
Ａｌ：０．０６％以下、Ｎ ：０．００８
％以下また、必要に応じてＭｏ：０．５〜２．０％を含
有し、それらの成分間に式 Ｃｒ＋１．６Ｍｏ≧９％ を満足し、更に式 ４０Ｃ＋３４Ｎ＋Ｎｉ−１．１Ｃｒ−１．８Ｍｏ≧−１
０．５ を満足する関係を有し、更に必要に応じてＴｉ：０．０
０５〜０．１％、Ｚｒ：０．０１〜０．２％のうちの１
種または２種、或いは更に必要に応じてＣａ：０．００
１〜０．０２％、ＲＥＭ：０．００３〜０．４％のうち
の１種または２種を含有してもよく、残部が実質的にＦ
ｅからなるマルテンサイト組織を呈することを特徴とす
る溶接部硬さの低い高耐食マルテンサイト系ステンレス
鋼である。また、この鋼をＡｃ3 変態点以上の温度に加
熱し冷却した後、焼戻し、または二相域焼戻しを施して
もよい。As described above, the present invention is constructed by combining the findings described above, and the gist thereof is as follows. That is, in the present invention, C: 0.005% or less by weight% as an alloy component,
Si: 0.50% or less, Mn: 0.1 to 1.0%,
P: 0.03% or less, S: 0.005% or less,
Cr: 8.2 to 13%, Ni: 1.5 to 5%,
Al: 0.06% or less, N: 0.008
% Or less, and if necessary, Mo: 0.5 to 2.0% is contained, the formula Cr + 1.6Mo ≧ 9% is satisfied between these components, and the formula 40C + 34N + Ni-1.1Cr-1.8Mo ≧ -1
It has a relationship of satisfying 0.5, and if necessary, Ti: 0.0
05-0.1%, Zr: 1 of 0.01-0.2%
Seed or two, or if necessary, Ca: 0.00
1 to 0.02%, REM: 0.003 to 0.4%, and may contain 1 type or 2 types, and the balance is substantially F.
It is a highly corrosion-resistant martensitic stainless steel with a low weld hardness, which is characterized by exhibiting a martensitic structure composed of e. Further, this steel may be heated to a temperature not lower than the Ac 3 transformation point and cooled, and then tempered or two-phase region tempered.
【０００８】[0008]
【発明の実施の形態】以下に本発明について詳細に説明
する。 Ｃ：強化に有効であり、且つ強力なオーステナイト形成
元素であって、δフェライト相の形成を抑制する効果が
ある。しかし、低Ｃ化により溶接熱影響部の靭性を高
め、更に図２で示したように溶接熱影響部の硬さを母材
並に低減させるためには０．００５％以下に制限する必
要がある。下限は必ずしも明らかではないが０．００１
％でもまだ有効である。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. C: A strong austenite forming element which is effective for strengthening and has an effect of suppressing the formation of the δ ferrite phase. However, in order to increase the toughness of the weld heat affected zone by lowering C and further reduce the hardness of the weld heat affected zone to the level of the base metal as shown in FIG. 2, it is necessary to limit it to 0.005% or less. is there. The lower limit is not always clear, but 0.001
% Is still valid.
【０００９】Ｓｉ：製鋼上脱酸材として添加され残有し
ているもので、鋼の中に０．５０％を超えて含有してい
ると靭性および耐硫化物応力割れ性を低下させるため、
０．５０％以下とした。Si: It is added as a deoxidizing agent on steelmaking and remains. If it is contained in the steel in an amount of more than 0.50%, toughness and sulfide stress cracking resistance are deteriorated.
0.50% or less.
【００１０】Ｍｎ：粒界強度を低下させて腐食環境下で
の割れ抵抗性を損なう元素である。しかし、ＭｎＳを形
成してＳの無害化を進め、また、オーステナイト単相化
に有効で有用な元素であるので、添加する。ただし、含
有量が０．１％未満では効果が無く、１．０％を超える
と粒界強度の低下が著しくなるので、Ｍｎの含有量は
０．１〜１．０％とした。Mn: An element that lowers the grain boundary strength and impairs crack resistance in a corrosive environment. However, MnS is added to promote detoxification of S and is an element that is effective and useful for forming a single phase of austenite, so is added. However, if the content is less than 0.1%, there is no effect, and if it exceeds 1.0%, the grain boundary strength decreases significantly, so the Mn content was made 0.1 to 1.0%.
【００１１】Ｐ：粒界に偏析して粒界強度を弱め、耐硫
化物応力割れ性、および低温靭性を低下させるので０．
０３％以下とした。 Ｓ：硫化物系の介在物を形成し、熱間加工性、および延
靭性を低下させるため、その上限を０．００５％とし
た。P: Segregated at the grain boundaries to weaken the grain boundary strength and reduce the sulfide stress cracking resistance and the low temperature toughness.
03% or less. S: The upper limit was made 0.005% in order to form sulfide-based inclusions and reduce hot workability and ductility.
【００１２】Ｎｉ：強力なオーステナイト生成元素であ
るので、マルテンサイト組織の実現、熱間加工性の向上
に有用である。更に、低Ｃのマルテンサイト組織である
溶接熱影響部の靭性を高める役割がある。含有量が１．
５％未満では効果が十分でなく、また、５％を超えて含
有するとＡｃ1 変態点が低くなり過ぎ、調質が困難にな
るので、その限定範囲を１．５〜５％とした。Ni: A strong austenite-forming element, which is useful for realizing a martensite structure and improving hot workability. Further, it has a role of increasing the toughness of the weld heat affected zone which is a low C martensitic structure. Content is 1.
If it is less than 5%, the effect is not sufficient, and if it exceeds 5%, the Ac 1 transformation point becomes too low and the tempering becomes difficult, so the limiting range was made 1.5 to 5%.
【００１３】Ａｌ：Ｓｉと同様に脱酸材として添加され
残有しているもので、含有量が０．０６％を超えるとＡ
ＩＮが多量に形成され、靭性が低下する。従って、含有
量の上限を０．０６％とした。 Ｎ：鋼に不可避的に含有される元素であるが、溶接熱影
響部の硬さを高めて靭性を劣化させるので、最大０．０
０８％とした。Similar to Al: Si, it is added as a deoxidizing agent and remains. If the content exceeds 0.06%, A
A large amount of IN is formed and the toughness decreases. Therefore, the upper limit of the content is set to 0.06%. N: It is an element that is inevitably contained in steel, but since it increases the hardness of the weld heat affected zone and deteriorates the toughness, the maximum is 0.0.
It was set to 08%.
【００１４】Ｃｒ：耐ＣＯ2 腐食特性を向上させる最も
重要な元素である。Ｃｒ単独添加で含有量が９％未満の
ときには耐食性が十分ではなく、一方１３％を超えると
δフェライト相が生成し易くなる。従って、９〜１３％
とした。また、上記のようにＭｏも同様な働きをし、そ
の寄与率は実験的に求めた結果Ｃｒの１．６倍である。
従ってＣｒ単独ではなく、Ｍｏも含有する場合にはＣｒ
＋１．６Ｍｏを９％以上とし、Ｃｒの下限を８．２％と
した。Cr: The most important element for improving the CO 2 corrosion resistance. If the content of Cr alone is less than 9%, the corrosion resistance is not sufficient, while if it exceeds 13%, the δ ferrite phase is likely to be formed. Therefore, 9-13%
And In addition, as described above, Mo also has a similar function, and its contribution rate is 1.6 times that of Cr as a result of experimental determination.
Therefore, when not only Cr but also Mo is contained, Cr
+ 1.6Mo was set to 9% or more, and the lower limit of Cr was set to 8.2%.
【００１５】Ｍｏ：前記のＣｒと同様、耐ＣＯ2 腐食特
性を向上させ、更にＳＳＣ性を改善する効果を有するの
で必要に応じて添加する。含有量が０．５％未満では効
果がないので０．５％以上となるよう添加することとし
た。一方、多量に添加してもその効果が飽和し、且つ熱
間変形抵抗が増して熱間加工性が低下するので上限を２
％とした。Mo: Like the above-mentioned Cr, it has the effect of improving the CO 2 corrosion resistance and improving the SSC property, so it is added if necessary. If the content is less than 0.5%, there is no effect, so the content was determined to be 0.5% or more. On the other hand, even if added in a large amount, the effect saturates, and the hot deformation resistance increases and the hot workability decreases, so the upper limit is 2
%.
【００１６】以上述べたような成分範囲の鋼は、良好な
耐ＣＯ2 腐食特性を示す。しかし、Ｃｒ，Ｍｏ等のフェ
ライト生成元素の多い成分では、溶接熱影響部にフェラ
イト相が生成して靭性が劣化する。従って、フェライト
生成元素の含有量を制限する必要がある。従来の知見か
ら、Ｃ，Ｎ，Ｎｉはフェライト相の生成を抑制し、Ｃ
ｒ，Ｍｏは促進する。各元素濃度を変化させた鋼を溶製
し実験的に各々の寄与率Ｉpsを決定した。その結果、下
記の式 Ｉps＝４０Ｃ＋３４Ｎ＋Ｎｉ−１．１Ｃｒ−１．８Ｍｏ
≧−１０．５ を満足すればフェライト相は生成せず、マルテンサイト
単相となることが分かったので、Ｃ，Ｎ，Ｎｉ，Ｃｒ，
Ｍｏはこの関係を満足する必要がある。The steel having the above-mentioned compositional range exhibits good CO 2 corrosion resistance. However, with a component containing a large amount of ferrite forming elements such as Cr and Mo, a ferrite phase is formed in the weld heat affected zone and the toughness deteriorates. Therefore, it is necessary to limit the content of the ferrite forming element. From the conventional knowledge, C, N and Ni suppress the generation of ferrite phase,
r and Mo accelerate. Steel with different element concentrations was melted and the respective contribution rates I ps were experimentally determined. As a result, the following formula I ps = 40C + 34N + Ni-1.1Cr-1.8Mo
If ≧ -10.5 is satisfied, it was found that the ferrite phase was not generated and the single phase was martensite. Therefore, C, N, Ni, Cr,
Mo needs to satisfy this relationship.
【００１７】Ｔｉ：ＴｉＮやＴｉ酸化物として分散し、
溶接熱影響部の粒成長を抑制して、靭性の劣化を抑制す
るために必要に応じて含有させる。少なすぎると効果が
無く、過剰に添加するとＴｉＣが析出して靭性を却って
劣化させる。従って、Ｔｉを添加する場合、Ｔｉ：０．
００５〜０．１％とした。Ti: dispersed as TiN or Ti oxide,
It is contained as necessary in order to suppress the grain growth of the weld heat affected zone and suppress the deterioration of toughness. If it is too small, there is no effect, and if it is added excessively, TiC precipitates and rather deteriorates the toughness. Therefore, when Ti is added, Ti: 0.
It was set to 005 to 0.1%.
【００１８】Ｚｒ：Ｔｉと同様に必要に応じて含有させ
る。すなわち耐硫化物応力割れ性に対して有害なＰとの
間で安定な化合物を形成し、固溶Ｐを減少させて実質的
な低Ｐ化を図る効果を有する。少量では効果が無く、多
すぎると粗大な酸化物を形成して却って靭性や耐硫化物
応力割れ性を低下させるので、０．０１〜０．２％とし
た。Like Zr: Ti, it is contained if necessary. That is, it has the effect of forming a stable compound with P that is harmful to sulfide stress cracking resistance, and reducing the solid solution P to substantially reduce P. If the amount is too small, there is no effect, and if the amount is too large, coarse oxides are formed and the toughness and sulfide stress cracking resistance are reduced, so the content was made 0.01 to 0.2%.
【００１９】Ｃａ，ＲＥＭ：介在物の形態を球状化させ
て無害化するのに有効な元素であり、必要に応じて添加
する。少なすぎるとその効果が無く、多すぎると介在物
を増加させて耐硫化物応力割れ抵抗性を低下させるので
各々０．００１〜０．０２％、０．００３〜０．４％と
した。Ca, REM: An element effective in making the morphology of inclusions spherical to render them harmless, and is added as necessary. If it is too small, the effect is not obtained, and if it is too large, inclusions are increased and the resistance to sulfide stress cracking is lowered, so 0.001 to 0.02% and 0.003 to 0.4% respectively.
【００２０】以上のような成分を有する鋼は、熱間加工
ままで、または、Ａｃ3 変態点以上に再加熱および冷却
した後はマルテンサイト組織である。冷却は空冷ないし
水冷で行うのが好ましい。しかし、組織がマルテンサイ
トままでは変形能が十分でない場合があるので、必要に
応じて焼戻し、または二相域焼戻しを行う。このような
本発明（低Ｃ）鋼では焼戻しを行っても強度の変化は小
さいが、残留応力が低減され、伸びも改善されて変形能
が高まる。二相域焼戻しを行うと、焼戻しマルテンサイ
トとマルテンサイト、更に場合によってはオーステナイ
トとの混合組織となり、組織が微細となって靭性や伸び
が更に改善される。The steel having the above components has a martensitic structure in the as-hot-worked state or after being reheated and cooled to the Ac 3 transformation point or higher. Cooling is preferably performed by air cooling or water cooling. However, if the structure remains martensite, the deformability may not be sufficient, so tempering or two-phase region tempering is performed as necessary. In such a steel of the present invention (low C), the strength change is small even if tempered, but the residual stress is reduced, the elongation is improved, and the deformability is increased. When the two-phase region tempering is performed, a mixed structure of tempered martensite, martensite, and in some cases austenite is formed, and the structure becomes finer to further improve toughness and elongation.
【００２１】[0021]
【実施例】まず表１に示す化学成分の鋼を溶製・鋳造し
た後、モデル圧延機で継目無鋼管を製造し、必要に応じ
て熱処理を施した。耐ＣＯ2 腐食特性は、４０atm のＣ
Ｏ2 ガスと平衡状態にある８０℃の人口海水中に試験片
を浸漬し、腐食減量から腐食速度を測定した。耐硫化物
応力割れ性は、１規定の酢酸と１mol/ｌの酢酸ナトリウ
ムを混合してｐＨ：４．５に調整し、１％硫化水素＋９
９％窒素ガスの混合ガスを飽和させた液中で平滑丸棒試
験片（平行部径６．４mm、平行部長さ２５mm）に降伏強
度の７０％と９０％に相当する引張応力を付与して７２
０時間の引張試験を行い、破断の有無を観察した。ま
た、入熱２kJ／mm相当の再現熱サイクル試験を行い、硬
さおよびＪＩＳ４号シャルピー試験片による遷移温度
（ｖＴｒｓ）の測定を行った。表２に試験結果を示す。Example First, steel having the chemical composition shown in Table 1 was melted and cast, and then a seamless steel pipe was manufactured by a model rolling machine and heat-treated as required. CO 2 corrosion resistance is 40 atm C
The test piece was immersed in artificial seawater at 80 ° C. in equilibrium with O 2 gas, and the corrosion rate was measured from the corrosion weight loss. The resistance to sulfide stress cracking is adjusted to pH: 4.5 by mixing 1N acetic acid and 1mol / l sodium acetate, and 1% hydrogen sulfide +9
Applying tensile stress equivalent to 70% and 90% of the yield strength to a smooth round bar test piece (parallel part diameter 6.4 mm, parallel part length 25 mm) in a liquid saturated with a mixed gas of 9% nitrogen gas. 72
A 0-hour tensile test was performed and the presence or absence of breakage was observed. In addition, a reproduction heat cycle test corresponding to a heat input of 2 kJ / mm was performed to measure hardness and transition temperature (vTrs) using a JIS No. 4 Charpy test piece. Table 2 shows the test results.
【００２２】[0022]
【表１】 [Table 1]
【００２３】[0023]
【表２】 [Table 2]
【００２４】[0024]
【発明の効果】以上のように本発明によれば、鋼成分を
特定し、鋼組織を特定したマルテンサイト系ステンレス
鋼は、溶接部硬さが母材と同等で且つ優れた耐ＣＯ2 腐
食特性を有している。As described above, according to the present invention, the martensitic stainless steel in which the steel composition is specified and the steel structure is specified has the same weld hardness as the base metal and excellent CO 2 corrosion resistance. It has characteristics.
【図１】湿潤炭酸ガス環境での腐食速度におよぼすＣｒ
量の影響を示す図。FIG. 1 Cr influences corrosion rate in wet carbon dioxide environment
The figure which shows the influence of quantity.
【図２】溶接熱影響部の硬さと焼戻し後の硬さにおよぼ
すＣ量の影響を示す図。FIG. 2 is a diagram showing the effect of the amount of C on the hardness of the heat-affected zone of welding and the hardness after tempering.
Claims (5)
０５％以下、 Ｓｉ：０．５０％以下、 Ｍｎ：０．１〜１．０％、 Ｐ ：０．０３％以下、 Ｓ ：０．００５％以下、 Ｃｒ：９〜１３％、 Ｎｉ：１．５〜５％、 Ａｌ：０．０６％以下、 Ｎ ：０．００８％以下を含有し、それらの成分間に式 ４０Ｃ＋３４Ｎ＋Ｎｉ−１．１Ｃｒ≧−１０．５ を満足する関係を有し、且つ、残部が実質的にＦｅから
なるマルテンサイト組織を呈することを特徴とする溶接
部硬さの低い高耐食マルテンサイト系ステンレス鋼。1. As an alloying component, C: 0.0% by weight.
05% or less, Si: 0.50% or less, Mn: 0.1 to 1.0%, P: 0.03% or less, S: 0.005% or less, Cr: 9 to 13%, Ni: 1. 5 to 5%, Al: 0.06% or less, N: 0.008% or less are contained, and there is a relationship satisfying the formula 40C + 34N + Ni-1.1Cr ≧ -10.5 between these components, and A highly corrosion-resistant martensitic stainless steel having a low weld hardness, which has a martensitic structure with the balance being substantially Fe.
０５％以下、 Ｓｉ：０．５０％以下、 Ｍｎ：０．１〜１．０％、 Ｐ ：０．０３％以下、 Ｓ ：０．００５％以下、 Ｃｒ：８．２〜１３％、 Ｍｏ：０．５〜２．０％、 Ｎｉ：１．５〜５％、 Ａｌ：０．０６％以下、 Ｎ ：０．００８％以下を含有し、それらの成分間に式 Ｃｒ＋１．６Ｍｏ≧９％ を満足し、更に式 ４０Ｃ＋３４Ｎ＋Ｎｉ−１．１Ｃｒ−１．８Ｍｏ≧−１
０．５ を満足する関係を有し、且つ、残部が実質的にＦｅから
なるマルテンサイト組織を呈することを特徴とする溶接
部硬さの低い高耐食マルテンサイト系ステンレス鋼。2. As an alloying component, C: 0.0% by weight.
05% or less, Si: 0.50% or less, Mn: 0.1 to 1.0%, P: 0.03% or less, S: 0.005% or less, Cr: 8.2 to 13%, Mo: 0.5 to 2.0%, Ni: 1.5 to 5%, Al: 0.06% or less, N: 0.008% or less, and the formula Cr + 1.6Mo ≧ 9% between these components. Satisfaction, and further, the formula 40C + 34N + Ni-1.1Cr-1.8Mo ≧ -1
A highly corrosion-resistant martensitic stainless steel having a low weld hardness, which has a relationship satisfying 0.5 and has a martensitic structure in which the balance is substantially Fe.
金成分として更に、重量％で、 Ｔｉ：０．００５〜０．１％、 Ｚｒ：０．０１〜０．２％のうちの１種または２種を含
有することを特徴とする溶接部硬さの低い高耐食マルテ
ンサイト系ステンレス鋼。3. The steel according to claim 1 or 2, further comprising, as an alloy component, one of Ti: 0.005 to 0.1% and Zr: 0.01 to 0.2% by weight. Alternatively, a high corrosion-resistant martensitic stainless steel having a low weld hardness, which contains two kinds.
の鋼において、合金成分として更に、重量％で、 Ｃａ：０．００１〜０．０２％、 ＲＥＭ：０．００３〜０．４％のうちの１種または２種
を含有することを特徴とする溶接部硬さの低い高耐食マ
ルテンサイト系ステンレス鋼。4. The steel according to claim 1, 2 or 3, further comprising, as alloy components, in weight% Ca: 0.001 to 0.02%, REM: 0.003 to 0.4. %, A high corrosion resistant martensitic stainless steel having a low weld hardness.
記載の成分を有する鋼を、Ａｃ3 変態点以上の温度に加
熱、冷却した後、焼戻しまたは二相域焼戻しを施してな
ることを特徴とする溶接部硬さの低い高耐食マルテンサ
イト系ステンレス鋼。5. A steel having the composition according to any one of claims 1, 2, 3 or 4 is heated to a temperature of an Ac 3 transformation point or higher and cooled, and then tempered or two-phase region tempered. High corrosion resistance martensitic stainless steel with low weld hardness.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19192895A JP3422877B2 (en) | 1995-07-27 | 1995-07-27 | High corrosion resistance martensitic stainless steel with low weld hardness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19192895A JP3422877B2 (en) | 1995-07-27 | 1995-07-27 | High corrosion resistance martensitic stainless steel with low weld hardness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0941092A true JPH0941092A (en) | 1997-02-10 |
| JP3422877B2 JP3422877B2 (en) | 2003-06-30 |
Family
ID=16282783
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19192895A Expired - Fee Related JP3422877B2 (en) | 1995-07-27 | 1995-07-27 | High corrosion resistance martensitic stainless steel with low weld hardness |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3422877B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1070763A1 (en) * | 1999-02-02 | 2001-01-24 | Kawasaki Steel Corporation | HIGH Cr STEEL PIPE FOR LINE PIPE |
| JP2002249854A (en) * | 2001-02-23 | 2002-09-06 | Nkk Corp | LOW Mo TYPE CORROSION-RESISTANT MARTENSITIC STAINLESS STEEL |
| US8163233B2 (en) | 2006-08-31 | 2012-04-24 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel for welded structures |
-
1995
- 1995-07-27 JP JP19192895A patent/JP3422877B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1070763A1 (en) * | 1999-02-02 | 2001-01-24 | Kawasaki Steel Corporation | HIGH Cr STEEL PIPE FOR LINE PIPE |
| EP1070763A4 (en) * | 1999-02-02 | 2002-05-29 | Kawasaki Steel Co | HIGH Cr STEEL PIPE FOR LINE PIPE |
| US6464802B1 (en) | 1999-02-02 | 2002-10-15 | Kawasaki Steel Corporation | High Cr steel pipe for line pipe |
| JP2002249854A (en) * | 2001-02-23 | 2002-09-06 | Nkk Corp | LOW Mo TYPE CORROSION-RESISTANT MARTENSITIC STAINLESS STEEL |
| US8163233B2 (en) | 2006-08-31 | 2012-04-24 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel for welded structures |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3422877B2 (en) | 2003-06-30 |
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