JPH08120415A - Martensitic stainless steel for oil well pipe, excellent in toughness - Google Patents
Martensitic stainless steel for oil well pipe, excellent in toughnessInfo
- Publication number
- JPH08120415A JPH08120415A JP25526394A JP25526394A JPH08120415A JP H08120415 A JPH08120415 A JP H08120415A JP 25526394 A JP25526394 A JP 25526394A JP 25526394 A JP25526394 A JP 25526394A JP H08120415 A JPH08120415 A JP H08120415A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- toughness
- oil well
- less
- strength
- 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
Landscapes
- Heat Treatment Of Articles (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、油井管用鋼、特に油
井、ガス井用のケーシング、チュービング、ドリルパイ
プ、その他石油、天然ガス生産用パイプ類等（以下、油
井管と総称する）に使用される、降伏強度が５５２ＭＰ
ａ（８０ｋｓｉ）以上の高強度でかつ靭性に優れたマル
テンサイト系ステンレス鋼の組成、組織に関する。INDUSTRIAL FIELD OF APPLICATION The present invention is used for oil well pipe steel, particularly for oil well and gas well casings, tubing, drill pipes, and other petroleum and natural gas production pipes (hereinafter collectively referred to as oil well pipes). The yield strength is 552MP
It relates to the composition and structure of martensitic stainless steel having a high strength of a (80 ksi) or more and excellent toughness.
【０００２】[0002]
【従来の技術】近年、原油、天然ガスを採取するための
油井管として、炭酸ガス環境、いわゆるスウィート環境
で優れた耐食性を有する鋼が求められるようになり、い
わゆるマルテンサイト系ステンレス鋼であるＡＩＳＩ４
２０タイプの１３％Ｃｒ鋼の需要が増大している。炭酸
ガス環境で現在活発な石油・ガス掘削活動が展開されて
いる代表的な油田地域は、北海地区であるが、このよう
な冬季に極寒となる地域で使用される油井管は、耐食
性、強度はもちろんのこと、併せて靭性に優れることが
要求される。2. Description of the Related Art In recent years, as oil well pipes for collecting crude oil and natural gas, steel having excellent corrosion resistance in a carbon dioxide gas environment, a so-called sweet environment, has been demanded, and so-called martensitic stainless steel AISI4.
Demand for 20 type 13% Cr steel is increasing. The typical oil field area where active oil and gas drilling activities are currently underway in the carbon dioxide environment is the North Sea area, but the oil well pipes used in areas where it is extremely cold in the winter have corrosion resistance and strength. Needless to say, it is also required to have excellent toughness.
【０００３】ＡＩＳＩ４２０タイプの１３％Ｃｒ油井管
は、金属組織としては、いわゆる焼ならし、焼戻しによ
って得られる、焼戻しマルテンサイト組織で使用し高強
度を得ている。ところが、このタイプの１３％Ｃｒ鋼
は、約０．２％のＣを含有するため、焼きならし時に旧
オーステナイト結晶粒界やマルテンサイトの下部構造で
あるパケット境界にＣｒ23Ｃ6 を主体とする炭化物が析
出するため、油井管として必要な５５２ＭＰａ（８０ｋ
ｓｉ）以上の高降伏強度を得ようとすると、北海での使
用に耐えるような高靭性を得がたいのが現状である。The AISI 420 type 13% Cr oil country tubular goods has a high strength when used as a tempered martensite structure obtained by so-called normalization and tempering. However, this type of 13% Cr steel contains approximately 0.2% C, so that when normalizing, the main component is Cr 23 C 6 at the packet boundary, which is the substructure of the former austenite grain boundaries and martensite. Since the carbides that deposit are deposited, 552 MPa (80 k
At present, it is difficult to obtain high toughness that can withstand use in the North Sea if high yield strength of si) or higher is to be obtained.
【０００４】ＡＩＳＩ４２０タイプの１３％Ｃｒ鋼の靭
性を高めるために、従来から、いわゆるオースフォーミ
ングを適用する方法が開示され、高強度でかつ高靭性化
に寄与することが知られている（例えば、特開昭６３−
２３８２１７号公報）。本方法はＣｒ23Ｃ6 を主体とす
る炭化物が析出して靭性が低下してしまう、ＡＩＳＩ４
２０タイプの１３％Ｃｒ鋼にあっても、マルテンサイト
変態前に、オースフォーミングにより、準安定状態のオ
ーステナイトを加工し、旧オーステナイトを十分に細粒
化したうえで、焼戻しマルテンサイト組織を得れば、高
い靭性が得られるという方法である。In order to enhance the toughness of AISI 420 type 13% Cr steel, a method of applying so-called ausforming has been disclosed so far, and it is known that it has high strength and contributes to high toughness (for example, JP 63-
238217 publication). In this method, carbides mainly composed of Cr 23 C 6 are precipitated and the toughness is lowered.
Even for 20-type 13% Cr steel, before martensitic transformation, austenite in a metastable state is processed by ausforming, and old austenite is sufficiently fine-grained to obtain a tempered martensite structure. If so, high toughness is obtained.
【０００５】[0005]
【発明が解決しようとする課題】上記従来技術は、旧オ
ーステナイトの細粒化により靭性を高める効果が認めら
れるものの、１３％Ｃｒ油井管にオースフォーミングを
適用するには実用上以下のような問題点がある。マルテ
ンサイト変態前のオーステナイトを準安定領域で加工す
るためには、オーステナイト化された油井管を例えば５
００℃程度の低温まで冷却し、しかる後に、さらに鋼管
の温度が低下してマルテンサイト変態が開始する以前に
成形加工をしなければならない。１３％Ｃｒ鋼は、普通
炭素鋼よりも変形抵抗が大きい上、温間加工しなければ
ならないから、負荷限界の大きい加工装置の設置が必要
になる。温間加工用の成形機としては、温間サイザーや
温間矯正機が用いられているが、これらの成形機の加工
量には当然限界があり、到底準安定オーステナイトの細
粒化が達成できるような加工を施すことは困難である。
従って、ＡＩＳＩ４２０タイプの１３％Ｃｒ鋼にオース
フォーミングを適用することは、冶金学的には極めて魅
力的であるけれども、実鋼管の製造を想定すれば、到底
実用的とはなり得ない。Although the above-mentioned prior art is recognized to have the effect of increasing the toughness by refining the former austenite, it is practically problematic to apply the ausforming to the 13% Cr oil country tubular goods. There is a point. In order to process the austenite before martensitic transformation in the metastable region, an austenized oil country tubular good is used, for example.
It has to be cooled to a low temperature of about 00 ° C., and then, before the temperature of the steel pipe further decreases and the martensitic transformation starts, the forming process must be performed. Since 13% Cr steel has a larger deformation resistance than ordinary carbon steel and must be warm-worked, it is necessary to install a processing device with a large load limit. As a molding machine for warm working, warm sizers and warm straightening machines are used, but the processing amount of these molding machines is naturally limited, and it is possible to achieve fine graining of metastable austenite. It is difficult to perform such processing.
Therefore, although applying the ausforming to the AISI 420 type 13% Cr steel is extremely attractive from a metallurgical point of view, it cannot be practically considered when manufacturing a real steel pipe.
【０００６】かかる事情を鑑み、本発明が解決しようと
する課題は、オースフォーミングのような極めて特殊な
加工熱処理を適用するのではなく、１３％Ｃｒ鋼の成
分、組織を厳密に制御することにより、高強度を保った
上で、一定以上の靭性を確保することである。In view of such circumstances, the problem to be solved by the present invention is not to apply a very special thermomechanical treatment such as ausforming, but to strictly control the composition and structure of 13% Cr steel. , While maintaining high strength, toughness above a certain level.
【０００７】[0007]
【課題を解決するための手段】本発明者らは、ＡＩＳＩ
４２０タイプの１３％Ｃｒ鋼の成分と熱処理条件が強度
及び靭性に及ぼす影響を鋭意研究し、同鋼の靭性支配冶
金因子を解明した。本発明者らは、ＡＩＳＩ４２０タイ
プの１３％Ｃｒ鋼の靭性支配冶金因子として、従来から
明らかになっている、旧オーステナイト結晶粒径、Ｃｒ
23Ｃ6 を主体とする炭化物に加えて、Ｃｒ2 Ｎを主体と
する窒化物、ＡＩＮが重要な役割を果たすことを見いだ
した。この結果、Ａｌ，Ｎ量、及びＡｌとＮのバランス
を制御することと、焼きならし温度を制御することで、
ＡＩＳＩ４２０タイプの１３％Ｃｒ鋼の靭性を高めるこ
とができることを知見した。The present inventors have found that AISI
The effects of the composition and heat treatment conditions of 420 type 13% Cr steel on the strength and toughness were studied intensively, and the metallurgical factors governing the toughness of the steel were clarified. The inventors of the present invention have found that the former austenite grain size, Cr, which has been clarified as a metallurgical factor controlling the toughness of 13% Cr steel of AISI 420 type
In addition to the carbide mainly composed of 23 C 6 , a nitride mainly composed of Cr 2 N and AIN have been found to play an important role. As a result, by controlling the amount of Al, N and the balance of Al and N, and controlling the normalizing temperature,
It has been found that the toughness of AISI 420 type 13% Cr steel can be enhanced.
【０００８】すなわち、本発明はこのような知見に基づ
くものであり、その要旨とするところは、重量％で、Ｃ
：０．１５〜０．２２％、 Ｓｉ：１．０％以下、
Ｍｎ：０．２５〜１．０％、 Ｃｒ：１２．０〜１
４．０％、Ｐ ：０．０２０％以下、 Ｓ ：
０．０１０％以下を含有し、さらに、Ａｌ：０．０３％
以下、 Ｎ ：０．０１５〜０．０３０％を含
有してかつ、ΔＮ＝Total Ｎ％−（１４／２７）Ａｌ％
で表されるΔＮが、０．００５０以上を満足し、その他
不可避的不純物よりなる鋼を、９６０℃以上１０００℃
以下に加熱後室温まで空冷し、当該鋼のＡｃ1 点以下の
温度で焼戻すことを特徴とする、靭性に優れた油井管用
マルテンサイト系ステンレス鋼である。That is, the present invention is based on such knowledge, and the gist of the present invention is C in% by weight.
: 0.15 to 0.22%, Si: 1.0% or less,
Mn: 0.25 to 1.0%, Cr: 12.0 to 1
4.0%, P: 0.020% or less, S:
Contains 0.010% or less, and further Al: 0.03%
Hereinafter, N: 0.015 to 0.030% is contained and ΔN = Total N% − (14/27) Al%
ΔN represented by is satisfied with 0.0050 or more, and steel containing other unavoidable impurities is 960 ° C or more and 1000 ° C or more.
A martensitic stainless steel for oil country tubular goods having excellent toughness, which is characterized by being heated to room temperature and then cooled to room temperature and tempered at a temperature of Ac 1 point or lower of the steel.
【０００９】[0009]
【作用】以下、本発明について詳細に説明する。まず、
成分の限定理由について述べる。Ｃは、熱間加工温度
域、及び焼きならしの加熱温度域でオーステナイト単相
組織を得るために添加する。熱間加工温度域でδフェラ
イトが存在すると、継目無鋼管の製管時に割れや疵が発
生しやすく、生産性や歩留の低下を招くので熱間加工温
度域ではオーステナイト単相組織であることが必要であ
る。また、焼きならしの加熱温度域でδフェライトが存
在すると、焼きならし後にマルテンサイトとδフェライ
トとの混合組織となるために所望の強度が得られなかっ
たり、靭性が低下したりする。以上の理由からＣは少な
くとも０．１５％以上添加する。しかし、過剰に添加す
ると、焼きならし焼戻し後の組織においてＣｒ23Ｃ6 を
主体とする炭化物が多量に生成し、耐食性及び靭性を低
下させるので、上限を０．２２％とする。The present invention will be described in detail below. First,
The reasons for limiting the components will be described. C is added to obtain an austenite single phase structure in the hot working temperature range and the normalizing heating temperature range. If δ-ferrite is present in the hot working temperature range, cracks and flaws are likely to occur during the production of seamless steel pipes, leading to reduced productivity and yield.Therefore, austenite single-phase structure should be used in the hot working temperature range. is necessary. Further, if δ-ferrite exists in the heating temperature range of normalizing, the desired strength cannot be obtained or the toughness deteriorates because a mixed structure of martensite and δ-ferrite is formed after normalizing. For the above reason, at least 0.15% or more of C is added. However, if added excessively, a large amount of carbides mainly composed of Cr 23 C 6 is generated in the structure after normalizing and tempering, and the corrosion resistance and toughness are reduced, so the upper limit is made 0.22%.
【００１０】Ｓｉは製鋼時の脱酸剤が残存したものであ
るが、多量に含有すると炭酸ガス環境中での耐応力腐食
割れ性を低下するので上限を１．０％とする。Ｍｎは製
鋼時の脱酸剤として及びＣと同じく熱間におけるオース
テナイト安定化を目的として０．２５％以上含有させ
る。しかし、多量に含有すると炭酸ガス環境中での耐応
力腐食割れ性を低下するので上限を１．０％をする。Si is a deoxidizing agent remaining during steel making, but if it is contained in a large amount, the resistance to stress corrosion cracking in a carbon dioxide environment is deteriorated, so the upper limit is made 1.0%. Mn is contained as a deoxidizing agent at the time of steel making and, like C, for containing 0.25% or more for the purpose of stabilizing austenite during hot working. However, if contained in a large amount, the stress corrosion cracking resistance in a carbon dioxide gas environment is lowered, so the upper limit is made 1.0%.
【００１１】Ｃｒは炭酸ガス環境で腐食速度を減少させ
るのに極めて有効であるが、１２．０％未満では高温域
での効果が不十分になる。一方１４．０％を超えると、
オーステナイト域への加熱時にＣｒ23Ｃ6 を主体とする
炭化物が多量に生成し、耐食性、靭性の劣化をもたらす
のに加えて、δフェライトの生成をきたして熱間加工性
を劣化させる。従って、本発明でのＣｒは１２．０〜１
４．０％とする。Cr is extremely effective in reducing the corrosion rate in a carbon dioxide environment, but if it is less than 12.0%, the effect in the high temperature range becomes insufficient. On the other hand, if it exceeds 14.0%,
When heated to the austenite region, a large amount of carbides mainly composed of Cr 23 C 6 is generated, which causes deterioration of corrosion resistance and toughness, and also causes formation of δ ferrite to deteriorate hot workability. Therefore, Cr in the present invention is 12.0 to 1
It is set to 4.0%.
【００１２】Ｐ，Ｓはいわゆる不純物元素である。靭性
の向上を図り、炭酸ガス環境での耐食性を得るために
Ｐ、Ｓはできるだけ低いことが好ましいが、製造コスト
の面からそれぞれ、上限をＰは０．０２０％、Ｓは０．
０１０％とする。また、Ｓは熱間加工性を劣化する元素
である。継目無鋼管の製管時における割れ、疵の発生を
防止するためには０．００２５％以下とすることが望ま
しい。P and S are so-called impurity elements. In order to improve toughness and obtain corrosion resistance in a carbon dioxide gas environment, it is preferable that P and S are as low as possible, but from the viewpoint of manufacturing cost, the upper limit is 0.020% for P and S.
010%. Further, S is an element that deteriorates hot workability. In order to prevent the occurrence of cracks and flaws during the production of seamless steel pipe, it is desirable that the content be 0.0025% or less.
【００１３】本発明では、Ａｌ，ＮをそれぞれＡｌ：
０．０３％以下、Ｎ：０．０１５〜０．０３０％の範囲
で添加し、かつ、ΔＮ＝Total Ｎ％−（１４／２７）Ａ
ｌ％≧０．００５０（ここで、Ｎ，Ａｌは重量％を表わ
す。以下同じ）を満たす範囲に両元素量を制御する。以
下に、その理由を述べる。本発明者らは、表１の本発明
１〜本発明６及び比較例１〜比較例６の成分を有する１
３％Ｃｒ鋼を実験室で溶解し、板厚１２mmまで熱間圧延
した後、それぞれ表１に示した焼きならし温度で焼きな
らしを行った後、降伏強度がＡＰＩ規格８０ｋｓｉグレ
ード（５５２ＭＰａ）となるように焼戻しを行い、ＪＩ
Ｓ４号相似引張試験、ＪＩＳ４号衝撃試験（シャルピー
試験）を行って、強度、靭性に及ぼすＡＩ、Ｎ添加量の
影響を調べた。結果を図１に示す。In the present invention, Al and N are Al:
0.03% or less, N: added in the range of 0.015 to 0.030%, and ΔN = Total N%-(14/27) A
The amounts of both elements are controlled in a range satisfying 1% ≧ 0.0050 (where N and Al represent weight%, the same applies hereinafter). The reason will be described below. The present inventors have 1 having the components of the present invention 1 to the present invention 6 and the comparative example 1 to the comparative example 6 in Table 1.
After melting 3% Cr steel in a laboratory and hot rolling to a plate thickness of 12 mm, after normalizing at the normalizing temperature shown in Table 1, the yield strength is API standard 80 ksi grade (552 MPa). And temper it to JI
The S4 similarity tensile test and the JIS4 impact test (Charpy test) were conducted to examine the effects of the amounts of AI and N added on the strength and toughness. The results are shown in Fig. 1.
【００１４】まず、強度靭性にＮは大きな影響を及ぼ
す。Ｎ量が少なく０．０１５％未満の場合、vTrsが−２
０℃以下の靭性を確保した上で油井管として必要な８０
ｋｓｉの強度を得ることが難しい。また、Ｎを０．０１
５％以上添加しても、Ａｌ添加量との関係でΔＮ＝Tota
l Ｎ％−（１４／２７）Ａｌ％≧０．００５０となるよ
うにＮを添加しなければ同様に８０ｋｓｉの強度を得る
ことが難しい。これは、Ｎが、Ｃｒ2 Ｎとして析出する
ことにより強化に効果的に寄与しているためである。Ｎ
添加量が０．０１５％未満ではＣｒ2 Ｎの析出量が少な
く、強度が低下する。また、Ｎを０．０１５％以上添加
してもＡｌの添加量が多くなるとＮがＡＩＮとして析出
するため、Ｃｒ2 Ｎの析出量が少なくなり、強度が低下
する。一方、Ｎを０．０３０％を超えて多量に添加する
と今度はＣｒ2 Ｎが多量に析出するために、かえって靭
性が低下する。First, N has a great influence on the strength and toughness. When the N content is less than 0.015%, vTrs is -2
80 required for oil country tubular goods after ensuring toughness below 0 ℃
It is difficult to obtain the strength of ksi. In addition, N is 0.01
Even if added more than 5%, ΔN = Tota
Similarly, it is difficult to obtain a strength of 80 ksi unless N is added so that N% − (14/27) Al% ≧ 0.0050. This is because N is effectively contributing to strengthening by precipitating as Cr 2 N. N
If the amount added is less than 0.015%, the amount of Cr 2 N precipitated will be small and the strength will decrease. Further, even if N is added in an amount of 0.015% or more, if the amount of Al added increases, N will precipitate as AIN, so the amount of Cr 2 N precipitated will decrease and the strength will decrease. On the other hand, when N is added in a large amount exceeding 0.030%, a large amount of Cr 2 N is precipitated this time, which rather reduces the toughness.
【００１５】Ａｌは製鋼時の脱酸剤が残存したもので、
多量に含有させると図１に示すように靭性を劣化させ
る。これは、ＡＩＮの析出量が増大するためである。以
上の理由で、本発明では、Ａｌ，ＮをそれぞれＡｌ：
０．０３％以下、Ｎ：０．０１５〜０．０３０％の範囲
で添加し、かつ、ΔＮ＝Total Ｎ％−（１４／２７）Ａ
ｌ％≧０．００５０を満たす範囲に両元素量を制御す
る。Al is a deoxidizing agent remaining during steel making.
If contained in a large amount, the toughness deteriorates as shown in FIG. This is because the amount of AIN deposited increases. For the above reason, in the present invention, Al and N are respectively Al:
0.03% or less, N: added in the range of 0.015 to 0.030%, and ΔN = Total N%-(14/27) A
The amounts of both elements are controlled within the range that satisfies 1% ≧ 0.0050.
【００１６】次に、本発明における熱処理条件について
述べる。本発明では、油井管の熱処理として９６０℃以
上１０００℃以下に加熱後室温まで空冷するいわゆる焼
きならし処理を行い、しかる後当該鋼のＡｃ1 点以下の
温度で焼き戻しを行う。焼きならしの加熱においては、
Ｃｒ23Ｃ6 等の析出物を十分に固溶して耐食性と靭性を
確保する必要がある。このために加熱は９６０℃以上で
行う。しかし、焼きならしの加熱が１０００℃を超える
と加熱時のオーステナイト粒径が大きくなり、靭性を劣
化させるので、上限を１０００℃とする。ＡＩＳＩ４２
０タイプの１３％Ｃｒ鋼は十分な焼き入れ性を有してい
るので、油井管に使用される鋼管の肉厚では、加熱後の
冷却速度は空冷で十分である。焼きならし後は強度調整
のために焼き戻しを行うが、焼戻し温度が当該鋼のＡｃ
1 点を超えると新たにマルテンサイトが形成され、靭性
を劣化するので焼戻し温度の上限を当該鋼のＡｃ1点と
する。Next, the heat treatment conditions in the present invention will be described. In the present invention, as a heat treatment of the oil country tubular good, a so-called normalizing treatment of heating to 960 ° C. or more and 1000 ° C. or less and then air cooling to room temperature is performed, and then tempering is performed at a temperature of Ac 1 point or less of the steel. In the heating of normalizing,
It is necessary to sufficiently form a solid solution of precipitates such as Cr 23 C 6 to secure corrosion resistance and toughness. For this reason, heating is performed at 960 ° C or higher. However, if the normalizing heating exceeds 1000 ° C., the austenite grain size at the time of heating becomes large and the toughness deteriorates, so the upper limit is made 1000 ° C. AISI42
Since 0 type 13% Cr steel has sufficient hardenability, air cooling is sufficient as the cooling rate after heating for the wall thickness of the steel pipe used for the oil country tubular goods. After normalizing, tempering is performed to adjust the strength, but the tempering temperature is
If it exceeds 1 point, martensite is newly formed and the toughness deteriorates, so the upper limit of the tempering temperature is set to Ac 1 point of the steel.
【００１７】[0017]
【実施例】表１に化学成分を示す１３％Ｃｒ鋼（マルテ
ンサイト系ステンレス鋼）を実験室で溶解し、板厚１２
mmまで熱間圧延した後、それぞれ表１に示した焼きなら
し温度で焼きならしを行った後、本発明７、比較例７，
８を除く各鋼は降伏強度がＡＰＩ規格８０ｋｓｉグレー
ド（５５２ＭＰａ）となるように、本発明７では降伏強
度がＡＰＩ規格９５ｋｓｉグレード（６５５ＭＰａ）と
なるように、比較例７，８ではvTrsが−２０℃以下とな
るように焼戻しを行い、ＪＩＳ４号相似引張試験、ＪＩ
Ｓ４号衝撃試験（シャルピー試験）を行った。表１から
明らかなように、本発明法による組成を有し、熱処理を
施した鋼は８０ｋｓｉグレード、９５ｋｓｉグレードの
いずれにおいても、比較例に比べて強度、靭性に優れる
ことがわかる。EXAMPLE 13% Cr steel (martensitic stainless steel) whose chemical composition is shown in Table 1 was melted in a laboratory to obtain a plate thickness of 12
After hot rolling to mm, after normalizing at the normalizing temperature shown in Table 1, the present invention 7, Comparative Example 7,
Each of the steels except 8 had a yield strength of API standard 80 ksi grade (552 MPa), and a yield strength of the present invention 7 was API standard 95 ksi grade (655 MPa). In Comparative Examples 7 and 8, vTrs was −20. Tempered to below ℃, JIS No. 4 similar tensile test, JI
An S4 impact test (Charpy test) was performed. As is clear from Table 1, it is understood that the heat-treated steel having the composition according to the method of the present invention is superior in strength and toughness to both the 80 ksi grade and the 95 ksi grade as compared with the comparative example.
【００１８】[0018]
【表１】 [Table 1]
【００１９】[0019]
【発明の効果】本発明によれば、油井管に使用される、
降伏強度が５５２ＭＰａ（８０ｋｓｉ）以上の高強度で
かつ靭性に優れた１３％Ｃｒ鋼が安価に得られるため、
その工業的意義は極めて大きい。According to the present invention, it is used for oil country tubular goods,
Since 13% Cr steel having a high yield strength of 552 MPa (80 ksi) or more and excellent toughness can be obtained at low cost,
Its industrial significance is extremely large.
【図１】ＡＩＳＩ４２０タイプの１３％Ｃｒ鋼の強度、
靭性に及ぼすＡｌ，Ｎ量、及びＡｌとＮのバランスの影
響を示したもので、Ａｌ，ＮをそれぞれＡｌ：０．０３
％以下、Ｎ：０．０１５〜０．０３０％以下の範囲で添
加し、かつ、ΔＮ＝Total Ｎ％−（１４／２７）Ａｌ％
≧０．００５０を満たす範囲に両元素量を制御すること
により、高強度でかつ靭性に優れたマルテンサイト系ス
テンレス鋼が得られることを示す。FIG. 1 Strength of AISI 420 type 13% Cr steel,
It shows the effect of Al and N contents and the balance of Al and N on toughness. Al and N are Al: 0.03, respectively.
% Or less, N: added in the range of 0.015 to 0.030% or less, and ΔN = Total N% − (14/27) Al%
It is shown that by controlling the amounts of both elements within the range of ≧ 0.0050, martensitic stainless steel having high strength and excellent toughness can be obtained.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 佐藤 直治 福岡県北九州市戸畑区飛幡町１番１号 新 日本製鐵株式会社八幡製鐵所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoji Sato 1-1-1, Toibata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka New Nippon Steel Corporation Yawata Works
Claims (1)
Ｎが０．００５０以上を満足し、その他不可避的不純物
よりなる鋼を、９６０℃以上１０００℃以下に加熱後室
温まで空冷し、当該鋼のＡｃ1 点以下の温度で焼戻すこ
とを特徴とする、靭性に優れた油井管用マルテンサイト
系ステンレス鋼。1. By weight%, C: 0.15 to 0.22%, Si: 1.0% or less, Mn: 0.25 to 1.0%, Cr: 12.0 to 14.0%, P: 0.020% or less, S: 0.010% or less, Al: 0.03% or less, N: 0.015 to 0.030%, and ΔN = Total N% -(14/27) Al% represented by Al%
A steel having N of 0.0050 or more and other unavoidable impurities is heated to 960 ° C. or more and 1000 ° C. or less, air-cooled to room temperature, and tempered at a temperature of Ac 1 point or less of the steel. , Martensitic stainless steel for oil country tubular goods with excellent toughness.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25526394A JP3538915B2 (en) | 1994-10-20 | 1994-10-20 | Martensitic stainless steel for oil country tubular goods with excellent toughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25526394A JP3538915B2 (en) | 1994-10-20 | 1994-10-20 | Martensitic stainless steel for oil country tubular goods with excellent toughness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08120415A true JPH08120415A (en) | 1996-05-14 |
| JP3538915B2 JP3538915B2 (en) | 2004-06-14 |
Family
ID=17276326
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25526394A Expired - Lifetime JP3538915B2 (en) | 1994-10-20 | 1994-10-20 | Martensitic stainless steel for oil country tubular goods with excellent toughness |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3538915B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004007780A1 (en) * | 2002-07-15 | 2004-01-22 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel seamless pipe and a manufacturing method thereof |
| US7662244B2 (en) | 2001-10-19 | 2010-02-16 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel and method for manufacturing same |
| US7686897B2 (en) | 2002-07-15 | 2010-03-30 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel seamless pipe and a manufacturing method thereof |
| CN104988403A (en) * | 2015-07-09 | 2015-10-21 | 山西太钢不锈钢股份有限公司 | Martensitic stainless steel seamless steel tube for oil and gas exploitation and manufacturing method thereof |
-
1994
- 1994-10-20 JP JP25526394A patent/JP3538915B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7662244B2 (en) | 2001-10-19 | 2010-02-16 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel and method for manufacturing same |
| WO2004007780A1 (en) * | 2002-07-15 | 2004-01-22 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel seamless pipe and a manufacturing method thereof |
| US7686897B2 (en) | 2002-07-15 | 2010-03-30 | Sumitomo Metal Industries, Ltd. | Martensitic stainless steel seamless pipe and a manufacturing method thereof |
| CN104988403A (en) * | 2015-07-09 | 2015-10-21 | 山西太钢不锈钢股份有限公司 | Martensitic stainless steel seamless steel tube for oil and gas exploitation and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3538915B2 (en) | 2004-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4390081B2 (en) | Seamless steel pipe for oil well with excellent resistance to sulfide stress cracking and method for producing the same | |
| JP4305681B2 (en) | Seamless steel pipe manufacturing method | |
| US8021502B2 (en) | Method for producing martensitic stainless steel pipe | |
| JP2001271134A (en) | Low-alloy steel excellent in sulfide stress cracking resistance and toughness | |
| JPH06220536A (en) | Production of high strength steel pipe excellent in sulfide stress corrosion cracking resistance | |
| JP2003129190A (en) | Martensitic stainless steel and manufacturing method therefor | |
| JPH07197125A (en) | Production of high strength steel pipe having excellent sulfide stress corrosion crack resistance | |
| JP2003013138A (en) | Method for manufacturing steel sheet for high-strength line pipe | |
| JPH0741856A (en) | Production of high strength steel pipe excellent in sulfide stress corrosion cracking resistance | |
| EP3395998B1 (en) | Thick steel plate having excellent low-temperature toughness and hydrogen-induced cracking resistance, and method for manufacturing same | |
| JP2000017389A (en) | Cr-Mo SERIES LOW ALLOY SEAMLESS STEEL PIPE EXCELLENT IN TOUGHNESS AND ITS Cr-Mo SERIES LOW ALLOY STEEL | |
| JPH07109545A (en) | Non-heat treated steel for hot forging excellent in tensile strength, fatigue strength and machinability | |
| JP2001073086A (en) | Seamless steel tube with high toughness and high corrosion resistance | |
| JP3538915B2 (en) | Martensitic stainless steel for oil country tubular goods with excellent toughness | |
| JPH05271772A (en) | Manufacture of steel pipe for oil well excellent in sulfide stress cracking resistance | |
| JP2000160300A (en) | 655 Nmm-2 CLASS LOW-C HIGH-Cr ALLOY OIL WELL PIPE WITH HIGH CORROSION RESISTANCE, AND ITS MANUFACTURE | |
| JP4123597B2 (en) | Manufacturing method of steel with excellent strength and toughness | |
| JP2002275576A (en) | Low yield ratio steel for low temperature use and production method therefor | |
| JP3218447B2 (en) | Method of producing sour resistant thin high strength steel sheet with excellent low temperature toughness | |
| JP3009558B2 (en) | Manufacturing method of thin high-strength steel sheet with excellent sour resistance | |
| JPH0953142A (en) | Non-tempered steel material excellent in fatigue resistance and its production | |
| KR100328051B1 (en) | A Method of manufacturing high strength steel sheet | |
| JPH11310823A (en) | Manufacture of martensitic stainless steel tube excellent in toughness at low temperature | |
| JPH08109444A (en) | Production of seamless martensitic stainless steel tube for oil well use, excellent in crushing pressure | |
| CN112143965B (en) | Non-quenched and tempered oil casing pipe and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20040302 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20040315 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080402 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090402 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100402 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110402 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120402 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120402 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130402 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130402 Year of fee payment: 9 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130402 Year of fee payment: 9 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140402 Year of fee payment: 10 |
|
| EXPY | Cancellation because of completion of term |