JPS59173245A - Steel for oil well pipe excellent in corrosion resistance - Google Patents
Steel for oil well pipe excellent in corrosion resistanceInfo
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- JPS59173245A JPS59173245A JP4787383A JP4787383A JPS59173245A JP S59173245 A JPS59173245 A JP S59173245A JP 4787383 A JP4787383 A JP 4787383A JP 4787383 A JP4787383 A JP 4787383A JP S59173245 A JPS59173245 A JP S59173245A
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Abstract
Description
【発明の詳細な説明】
本発明は、油井管用鋼、特に油井、ガス弁用のケーノン
ク、チュービング、トリルパイプ、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
される鋼の構造（組成、組織）に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention provides steel for oil country tubular goods, particularly for use in oil well and gas valve pipes, tubing, trill pipes, and other oil and natural gas production pipes (hereinafter collectively referred to as oil country tubular goods). Concerning the structure (composition, structure) of steel.
石油または天然ガスを採取するための井戸の環境は近年
まずます苛酷なものとなっており、採掘深さの増大に加
えて湿潤な炭酸ガス（ＣＯ２）や硫化水素（Ｈ２Ｓ）、
塩素イオン（ＣＩ〜 ）などの腐食性の成分を含む井戸
も多くなっている。それにつれて材料の強度か要求され
る一方、」二連のような成分による腐食、そしてそれに
よる材料の脆化が大きな問題となっている。例えば、／
！ｉｉ！潤なＣＯ２を含む油ノ１、ガス井では炭酸ガス
腐食と呼はれる激しい腐食現象を生じ、また湿潤なＨ２
Ｓ、ＣＩ−を含む場合には硫化物割れ（ＳＳＣＣ１以下
耐硫化物割れ性を“耐５ｓｃｃ性”という）やピッチィ
ンクが生しることは良く知られている。The environment in wells used to extract oil or natural gas has become increasingly harsh in recent years, and in addition to increasing drilling depths, wet carbon dioxide (CO2), hydrogen sulfide (H2S),
The number of wells containing corrosive components such as chloride ions (CI~) is also increasing. As this progresses, the strength of the material is required, but corrosion due to components such as ``double'' and the resulting embrittlement of the material have become a major problem. for example,/
! ii! In oil and gas wells containing moist CO2, a severe corrosion phenomenon called carbon dioxide corrosion occurs;
It is well known that when S and CI- are contained, sulfide cracking (sulfide cracking resistance of SSCC 1 or less is referred to as "5 SCC resistance") and pitching occur.
こうした現象を防止するためにインヒヒターと呼ばれる
腐食抑制剤を油井管内に投入する方法が一般的方法とし
て用いられているが、ごの方法は実際にはそれ程十分な
効果も期待でき−Ｊ゛、また油井お３Ｌびガス井か海上
にある場合などには有効に活用できないことも多い。更
ムこ、油井管を保護皮膜で被覆する方法も提案され、一
部実施されているが、この場合も十分な防食成果は期待
できない。In order to prevent this phenomenon, a method of injecting a corrosion inhibitor called inhibitor into oil country tubular goods is commonly used, but this method is not expected to be very effective. In many cases, such as oil wells, gas wells, or offshore locations, it cannot be used effectively. A method of coating oil country tubular goods with a protective film has also been proposed and has been partially implemented, but in this case as well, sufficient corrosion prevention results cannot be expected.
ところで、経験的に、湿潤なＣＯ２を含む環境下ではＡ
ｌ５Ｉ ４１０鋼や４２０鋼といった１３Ｃｒ鋼が使わ
れる場合もあるが、しかし、微量のＨ２Ｓを同時に含む
環境ではこうした鋼は耐５ｓｃｃ性、耐ピノティング性
に問題があり、更に特ムこ４１０鋼は低Ｃ鋼であるため
δ−フェライトの生成をきたして高温での焼戻しでは高
強度を得ることが難しり、−力そのようなδ−フェライ
１−は焼付き（Ｇｏｌｆｉｎｇ 、ゴーリング）の要因
となるばかりでなく熱間加工性をも損なうといった問題
をも拘え一ζいる。例えばＳＯ３４２０，１１鋼では一
般にＳｉ ・０．４％、Ｍｎ：０．６％程度含有されて
いるため、本発明者らの実験結果によれば、耐５ｓｃｃ
性、耐ピッチインク性はほとんど期待できない。一方、
Ｈ２Ｓを含む環境下では、使用する油井管。鋼の強度を
規制することが５ｓｃｃ番、二対して自効であるごとが
ずでに経験的に知られており、例えば、ＡＰＩ規格５Ａ
Ｃの中のＬ−８０には最高硬度ＨＲＣ２３か規定されて
いる。また、鋼材の組織の面からは、完全な焼入れと高
温での焼戻しを施した焼戻しマルテンザイト組織がよい
とされている。By the way, empirically, in a humid environment containing CO2, A
13Cr steels such as l5I 410 steel and 420 steel are sometimes used, but in environments that also contain trace amounts of H2S, these steels have problems with 5scc resistance and pinoting resistance, and in addition, special 410 steel Since it is a low C steel, it is difficult to obtain high strength by tempering at high temperatures due to the formation of δ-ferrite, and such δ-ferrite is a cause of seizure (Golfing). However, there are also problems such as impairing hot workability. For example, SO3420.11 steel generally contains about 0.4% Si and 0.6% Mn, so according to the experimental results of the present inventors,
Almost no expectations can be expected for its properties and pitch ink resistance. on the other hand,
Oil country tubing used in environments containing H2S. It is empirically known that regulating the strength of steel is self-effective for 5scc, for example, API standard 5A.
L-80 in C has a maximum hardness of HRC23. In addition, from the viewpoint of the structure of the steel material, it is said that a tempered martenzite structure that has been completely quenched and tempered at a high temperature is good.
こうした経験から、従来、Ｈ２Ｓを含む環境下では、Ａ
ＩＳ＋ ４１３０系で組織と強度の」二限を調整した油
ブ１管が使用されることが多かった。Based on this experience, conventionally, in environments including H2S, A
Oil tubes of the IS+ 4130 series with adjusted limits for structure and strength were often used.
しかしながら、Ｈ２ＳがＣＯ２と共存する環境下では、
以上述へたような低合金鋼は前記の炭酸ガス腐食を生し
−ζしまう。そこで、こうした複合腐食環境下では、最
近、２相ステンレス鋼やオーステナイト系のインコロイ
やハステロイ （いずれも商品名）といった高級な材料
も使用されはしめたが、それらはいずれもかなり高価な
材料であるという問題を拘えている。However, in an environment where H2S coexists with CO2,
The low-alloy steels mentioned above suffer from the carbon dioxide corrosion described above. Therefore, in recent years, high-grade materials such as duplex stainless steel and austenitic Incoloy and Hastelloy (both trade names) have been used in such complex corrosive environments, but these are all quite expensive materials. fixing the problem.
よって、本発明の目的とするところは、以上のような従
来技術にのられた各種欠点を一挙に解決した油井管用鋼
を提供することである。Therefore, it is an object of the present invention to provide a steel for oil country tubular goods that solves all the various drawbacks of the prior art as described above.
さらに、本発明の目的とするところは、降伏強度（Ｙ、
Ｓ、）か５２．７ Ｊｆ／ｍｍ′（７５ＫＳｉ） ’Ｊ
上という高強度で、耐炭酸カス腐食性と耐５ｓｃｃ性お
よび耐ピノティング性を具備し、かつコーリングや？へ
間加工性の問題をも騎決した比較的廉価な油井管用鋼を
提供すること−である。Furthermore, it is an object of the present invention to obtain yield strength (Y,
) or 52.7 Jf/mm' (75KSi) 'J
It has high strength, carbon dioxide corrosion resistance, 5scc resistance, and pinoting resistance, and also has anti-coaling and corrosion resistance. An object of the present invention is to provide a relatively inexpensive steel for oil country tubular goods which also solves the problem of machinability.
ここに、本発明者らは永年の研究、開発の結果鋼自身の
化学組成を規定するとともにその鋼組織を規定する、つ
まり熱処理組織を規定することにより、それらの相乗的
作用効果の結果として上述のような目的か有利に達成さ
れることを見い出して本発明を完成したものである。As a result of many years of research and development, the present inventors have defined the chemical composition of the steel itself and defined its steel structure, that is, the heat-treated structure, and as a result of their synergistic effects, the above-mentioned results have been achieved. The present invention has been completed by discovering that the following objects can be advantageously achieved.
ずなわら、本発明は、Ｙ、Ｓか５２．７ｋｇｆ ／ ｍ
ｍ ２（７５ＫＳｉ ）以−ヒの高強度と、耐炭酸カス
腐食性と耐５ｓｃｃ性および耐ピノティング性を具備し
、更に耐ゴーリンク性をも有するタハ間加工性の良い比
較的廉価な高強度油井管用鋼であって、その要旨とする
とごろは、小量％で、Ｃ： ０．２２％以１・、Ｓｉ＋
Ｍｎ ： ０．２５％以下、Ｃｕ ： ０．０５％以下
、Ｎｉ：Ｏ，１０％以下、Ｃｒ ： １２．０−１４．
５％、へｌ：ｏ、ｌｏ％以下、Ｎ ： ０．００５０〜
０．１％を含み、更にｄ・要に応しこれにＭｏ ： ０
．０２〜０．１５％およびＮｂ二〇、００５〜００５０
％のうち少なくとも１種以上を加え、残部Ｆｅおよび不
可避的不純物から成り、不純物中のＰは０．０１５％以
下、Ｓば０．００５％以下とするとともに、式：
％式％）
を満足する組成を有し、かつ、９４０’ｃ以上、１０５
０’ｃ以下の温度に加熱後急冷し、屁１点以下の温度で
焼戻すことによって得た微細な焼戻しマルテンザイト組
識を有することを特徴とする耐食性のすくれた油井管用
鋼ｊ町。However, the present invention is based on Y, S or 52.7 kgf/m.
A relatively inexpensive high-performance steel with good strength between m2 (75KSi) and higher, carbon dioxide corrosion resistance, 5scc resistance, pinoting resistance, and go-link resistance. It is a steel for strength oil country tubular goods, and its gist is that in small percentages, C: 0.22% or more 1., Si+
Mn: 0.25% or less, Cu: 0.05% or less, Ni:O, 10% or less, Cr: 12.0-14.
5%, Hel: o, lo% or less, N: 0.0050~
Contains 0.1%, and if necessary, Mo: 0
．． 02-0.15% and Nb20, 005-0050
%, the balance consists of Fe and unavoidable impurities, P in the impurities is 0.015% or less, S is 0.005% or less, and the formula: % formula %) is satisfied. and has a composition of 940'c or more, 105
A corrosion-resistant steel for oil country tubular goods characterized by having a fine tempered martenzite structure obtained by heating to a temperature of 0'C or less, then rapidly cooling, and then tempering at a temperature of 1 point or less.
このようシこ、本発明にあっては、その組成上の特徴と
しては、Ｃｒ含有量を高くし、Ｃｕ含有量、Ｎｉ含有量
および不純物中のｐ、ｓの各含有量を低く抑え、且つＳ
ｉ＋Ｍｎ含有量を制限し、さらにＣ含有量の士ｉｌ、！
およびＮ含有量の下限をそれぞれ設りるごとによって鋼
に耐食性を付与するのである。さらに本発明にあっては
、鋼組織上からは、δ−フェライトの生成を極力抑えて
、高温焼戻しで耐食性と強度を確保するとともに耐コー
リング性をも付与し、さらに熱間加工性を改善するので
ある。このためにＣ，Ｎ、Ｃｒの各含有量を、式・
１００ＸＣ（％） ＋１００ｘＮ （％） −２ＸＣｒ
（％）→９≧０を満足すべく規制するとともに、微細
マルテンサイト絹穐を得るための急冷前の加熱温度およ
び焼戻し温度をそれぞれ制限するのである。In this way, the compositional characteristics of the present invention include increasing the Cr content, suppressing the Cu content, Ni content, and each content of p and s in impurities to a low level, and S
Limit the i+Mn content and further reduce the C content!
Corrosion resistance is imparted to steel by setting lower limits for both N content and N content. Furthermore, in the present invention, the formation of δ-ferrite is suppressed as much as possible from the steel structure, and high-temperature tempering ensures corrosion resistance and strength, as well as imparting anti-coaling properties, and further improves hot workability. It is. For this purpose, each content of C, N, and Cr is calculated using the formula: 100XC (%) +100xN (%) -2XCr
(%) → 9≧0, and also limit the heating temperature and tempering temperature before quenching to obtain fine martensitic silk.
次に、本発明に係る油井管用鋼において成分組成範囲並
びに熱処理組Ｉｔ（条件）を、−］−記の１ｌｌｌり限
定した理由を説明する。、以下において１％」は特にこ
とわりがない限り１重量％」である。Next, the reason why the composition range and heat treatment set It (conditions) of the steel for oil country tubular goods according to the present invention are limited to -]- will be explained. , hereinafter, "1%" means "1% by weight" unless otherwise specified.
（ａ）Ｃ・
Ｃは鋼の強度増加に対して、また、δ−フェライトの生
成を抑制するのに有すＪな作用を有するか、０．２２％
を紹えるとオーステナイト域への加タハ時にＭ ２３
ＣＢ型のＣｒ炭化物の残存量が多くなり、耐食性、低温
靭性の劣化をもたらすので、本発明にあってはＣ含有量
は０．２２％以下とする。(a) C. C has a J effect on increasing the strength of steel and suppressing the formation of δ-ferrite, or 0.22%
Introducing M23 when it is added to the austenite region.
In the present invention, the C content is set to 0.22% or less, since a large amount of CB-type Cr carbide remains, resulting in deterioration of corrosion resistance and low-temperature toughness.
（ｂ） Ｓｉ４Ｍｎ
Ｓｉ、Ｍｎはいずれも１３％稈度のＣｒを含む鋼におい
て００、−微量Ｈ２Ｓ−Ｃｌ−環境下での耐５ｓｃｃ性
、耐ピツテイング性を劣化さゼる作用があり、この作用
Ｌ：１両成分成分有量の和が０．２５％を超えると顕著
に現れる（ψ向にある。したがって、（Ｓｉ４Ｍｎ ）
含有量の」１限を０２５％と定めた。(b) Si4Mn Both Si and Mn have the effect of deteriorating the 5scc resistance and pitting resistance in a 00, -trace amount of H2S-Cl- environment in steel containing 13% Cr. L:1 It becomes noticeable when the sum of the abundances of both components exceeds 0.25% (in the ψ direction. Therefore, (Si4Mn)
The upper limit of the content was set at 0.025%.
（ｃ）Ｃｕ：
ＣｕはＣＯ３−微量＋１２５−ＣＩ−環境下で０．０５
％を超えると顕著にピッティンク発生に悪影響を与える
ため、その含有量は０．０５％以下に制限する。好まし
くは０．０２％以下とする。(c) Cu: Cu is 0.05 in CO3-trace+125-CI- environment
If the content exceeds 0.05%, the occurrence of pitting will be significantly adversely affected, so the content is limited to 0.05% or less. Preferably it is 0.02% or less.
（ｄ）Ｎｉ・
マルテンサイト系、フェライ１−系の各相においてＮ１
もＣｏ 、−′ｅ＠ Ｉｔ ２ Ｓ Ｃ１−１９境下
テ０．１０％を超えると顕著なピッティング発生および
５ｓｃｃ発生をもたらすためその上限を０．１０％とす
る。(d) Ni・N1 in each phase of martensitic system and ferrite 1- system
If Co exceeds 0.10%, significant pitting and 5scc occur, so the upper limit is set at 0.10%.
（ｅ）Ｃｒ：
ＣｒはＣＯ２−敬呈ＩＩ ２ Ｓ Ｃ１−環境下で腐
食速度を減少させるのに極めて有効であるが、１２，０
％未満ては高温域での効果が不十分になる。一方、１４
．５％を超えると、オーステナイト域への加熱時にＭ２
３ Ｃｎ型のＣｒ炭化物の残存量が多くなり耐食性、低
温靭性の劣化をもたらずのに加えて、δ−フェライトの
生成をきたして熱間加工性や耐コーリンク性を劣化さセ
る。したがって、本発明にあっては、その含有量を１２
．０〜１４．５％とした。(e) Cr: Cr is extremely effective in reducing the corrosion rate under CO2-Exercise II2S C1-environment, but 12,0
If it is less than %, the effect in high temperature range will be insufficient. On the other hand, 14
．． If it exceeds 5%, M2 will be reduced during heating to the austenite region.
The remaining amount of 3-Cn type Cr carbide is large and does not cause deterioration of corrosion resistance and low-temperature toughness, but also causes the formation of δ-ferrite, which deteriorates hot workability and coke resistance. Therefore, in the present invention, the content is reduced to 12
．． The content was set at 0 to 14.5%.
（ｆ） 八１ ：
屓は脱酸剤として添加されるか、０．１０％を超えると
そのりｌ果は飽和し、むしろ介在物の増大による疵が先
住し靭性も劣化するため、０．１０％以下とする。(f) 81: If the husks are added as a deoxidizing agent, or if the amount exceeds 0.10%, the husks will become saturated, and instead, defects will develop due to the increase in inclusions and the toughness will deteriorate. 10% or less.
（ｇ）Ｎ：
Ｎは１３％程度のＣｒを含む鋼においてＣＯ２−徹♀［
（２、Ｓ −ＣＩ−ＩＮＮ上下の耐ピツテイング性仁１
与のために０．００５０％以上かｄ・要であるか、０１
％を超えると熱間加工性か悪くなり好ましくない。した
がって、Ｎは０．００５０〜０１％に１−１ｉ１１ ＋
＋ｌｉ！する。好ま５くはｏ、ｏｏｓｏ〜０．０３％で
ある。(g) N: N is CO2-through♀ in steel containing about 13% Cr.
(2, S-CI-INN upper and lower pitting resistance
0.0050% or more or d/necessary for giving, 01
If it exceeds %, hot workability deteriorates, which is not preferable. Therefore, N is 1-1i11 + from 0.0050 to 01%
+li! do. Preferably it is o, ooso to 0.03%.
（ｈ）Ｐ、Ｓ ： −
不純物としてのＰ、Ｓは、靭性の向」−を図り、またＣ
Ｏ２−敬呈＋１２５−ＣＩ−環境「での良好なｎ１食性
を得るために、可及的に少なく場るのが望ましいが、コ
ス１−の面から上限をそれぞれ０．０１５％、０００５
％とする。(h) P, S: - P and S as impurities improve toughness, and C
In order to obtain good n1 eating habits in the O2 - respect + 125 - CI - environment, it is desirable to have as little as possible, but from the perspective of cost 1 - the upper limits are set at 0.015% and 0005 respectively.
%.
（ｉ）Ｍｏ、、Ｎｂ：
１０、Ｎｂはいずれも少量の添加で鋼の強度、耐食性を
向上させるかそれぞれ０．０２％、０．００５％未満て
はそれらの効果は得がたく、一方、それぞれ０．１５％
、００５０％を超えると、それらの効果は砲手１〕ある
いは減少−移る。したがって、Ｍｏ、 Ｎｂの含有量は
それぞれ０．０２〜０．１５％、０００５〜０．０５０
％とした。(i) Mo, Nb: Both 10 and Nb improve the strength and corrosion resistance of steel when added in small amounts, but it is difficult to obtain these effects if they are less than 0.02% and 0.005%, respectively. 0.15% each
, 0050%, their effectiveness is reduced to gunner 1] or reduced. Therefore, the content of Mo and Nb is 0.02~0.15% and 0005~0.050%, respectively.
%.
（））式：
％式％（９
Ｃ，Ｎ、およびＣｒの各含有量を代入した場合、１−記
式か負の４へとなるとき、δ−フェライトか生成してし
まい熱間加工性が損なわれ、また、最終的組織も焼戻し
マルテンサイトとδ−フェライトが〆昆合した不均一組
織となり、耐コーリング性が…なわわ、る。さらに上記
式の値か負の吉きには耐食性も劣化することが分かった
ので、したがって、本発明にあっては、１００ＸＣ（％
） ＋１００ｘ Ｎ （％） −２ＸＣｒ （％）＋９
≧０とする。()) formula: % formula % (9 When substituting the respective contents of C, N, and Cr, when it becomes 1-formula or negative 4, δ-ferrite is generated and hot workability In addition, the final structure becomes a heterogeneous structure in which tempered martensite and δ-ferrite are combined, resulting in poor corrosion resistance.Furthermore, when the value of the above formula is negative, corrosion resistance Therefore, in the present invention, 100XC (%
) +100x N (%) -2XCr (%) +9
≧0.
（ｋ、 ）熱処理組織（条件）。(k,) Heat treated structure (conditions).
本発明においては前記成分から成る鋼を９４０〜１０５
０°Ｃの温度に加熱後急冷してフルテンサイ１−組織る
こしたご、ＡＣ，点以下の温度で焼戻してｉ４た微細マ
ルテンサイト組織を利用するものである。すなワチ、９
４０〜■０５０°Ｃの温度でのオーステナイＩ・化によ
って、δ−フェライトの生成を抑えるとともに、Ｃｒ炭
化物を十分に基地に固溶させた細粒組織を得る。９４０
°Ｃ未満の温度ではオーステナイト化が十分でなく、一
方、１０５０°Ｃを超えた温度での加熱・保持は結晶粒
の粗大化を生して、得られる鋼の強度の低下、靭性の劣
化、さらには耐食性の劣化を招くことが分かった。かく
して、本発明によれば、９４０〜１０５０°Ｃの温度域
に加熱、保持した後、急冷してマルテンサイト組織とし
、次いでごれをＡＣ１点以下の温度で焼戻し処理するこ
とによって、均質微細な焼戻しマルテンサイト組織とな
り、高強度、高靭性とともに良好な耐炭酸ガス腐食性、
耐５ｓｃｃ性、耐ピノティング性も得られ、さらにコー
リンクや熱間加工性の問題をも解決することかできるの
である。In the present invention, the steel consisting of the above components is used in the range of 940 to 105.
It utilizes a fine martensitic structure which is heated to a temperature of 0° C., then rapidly cooled, and then tempered at a temperature below the full-tensile 1-structure. Sunawachi, 9
By austenizing I at a temperature of 40 to 050°C, the formation of δ-ferrite is suppressed, and a fine grain structure in which Cr carbide is sufficiently dissolved in the matrix is obtained. 940
At temperatures below 1050°C, austenitization is insufficient, while heating and holding at temperatures above 1050°C results in coarsening of crystal grains, resulting in a decrease in the strength and toughness of the resulting steel. Furthermore, it was found that corrosion resistance deteriorated. Thus, according to the present invention, after heating and holding in a temperature range of 940 to 1050°C, the dirt is rapidly cooled to form a martensitic structure, and then the dirt is tempered at a temperature below 1 point AC to form a homogeneous fine structure. It has a tempered martensitic structure with high strength and toughness, as well as good carbon dioxide corrosion resistance.
It also provides 5scc resistance and pinoting resistance, and can also solve the problems of coal linkage and hot workability.
なお、以上にあっては、本発明を油井管用鋼、つまり油
井管の鋼組成および鋼組織として限定、説明してきたが
、本発明の具体的実施の態様にあっては、以上の（ａ）
〜（ｊ）の各成分から構成された組成の鋼を／８製した
後、製管し、次いで（ｋ）の熱処理を施すことによって
目的とする油井管を得るのであるが、かくして得られる
油井管は、ｃ０２−微量１１２Ｓ−ＣＩ−環境下でも使
用可能であって、しかも比較的廉価であるにもかかわら
す、すくれた耐食性を有するのである。In the above, the present invention has been limited and explained as a steel for oil country tubular goods, that is, a steel composition and a steel structure of oil country tubular goods, but in a specific embodiment of the present invention, the above (a)
The target oil country tubular goods are obtained by making steel having a composition of 1/8 from each of the components in ~(j), forming a pipe, and then subjecting it to the heat treatment in (k). The tube can be used in a c02-trace 112S-CI environment, is relatively inexpensive, and has excellent corrosion resistance.
次に、実施例により本発明を更に説明するが、各実施例
は本発明を説明するためのものであって、それによって
本発明が何ら制限されるものではないことは理解されよ
う。Next, the present invention will be further explained with reference to examples, but it will be understood that each example is for illustrating the present invention, and the present invention is not limited thereto.
実Ｊ色利１
第１表に示す化学組成を有する各鋼種について加タハ圧
延後１０００°Ｃから鋼成分に応して水または油焼入れ
した後、Ｙ、Ｓ、（σｙ、降伏強度）が約７０．３ ｋ
ｇｆ／ｍｍ’ （１００Ｋｓｉ）になるようにＡＣ１
点以下の温度で焼戻しを行なった。ごれから厚２ｍｍ、
幅１０ｍｍ、長さ１１５ｍｍの試験片を切り出し、第１
図にその大略を示すように４点曲げ法でそれぞれｌσｙ
（ｔ！！伏強度）に相当する応力を付加した後、００２
四気圧）、およびＪＳ （０，１気圧）を含有させ
た３、５％ＮａＣｌ／８液（液温３０℃）中に１２０時
間浸漬して５ｓｃｃ特性を調査した。Real J Color 1 For each steel type having the chemical composition shown in Table 1, after tach rolling and water or oil quenching from 1000°C depending on the steel composition, Y, S, (σy, yield strength) is approximately 70.3k
AC1 so that gf/mm' (100Ksi)
Tempering was carried out at a temperature below the point. 2mm thick from dirt,
Cut out a test piece with a width of 10 mm and a length of 115 mm.
As shown schematically in the figure, each lσy is
After applying stress equivalent to (t!! yielding strength), 002
The specimen was immersed for 120 hours in a 3.5% NaCl/8 solution (liquid temperature: 30°C) containing JS (0.1 atm) and JS (0.1 atm) to investigate its 5scc characteristics.
なお、上記の４点曲げ法は第１図に概略示すように、試
験片ｌを治具２および１゛型ネジ押え３によって４つの
支持点４で支持固定するものであって、両端の支持点間
距離を１００ｍｍ 、内側の支持点間距離を４０ｍｍと
するものである。As schematically shown in Fig. 1, the above-mentioned four-point bending method involves supporting and fixing the test piece l at four support points 4 using a jig 2 and a 1-inch screw holder 3. The distance between the points is 100 mm, and the distance between the inner support points is 40 mm.
その試験結果を第２表にまとめて示す。The test results are summarized in Table 2.
第２図は、第１図に示す４点曲げ法にしたがって図示状
態にまで曲げたときの応力（σ）の計算法の説明図であ
る。FIG. 2 is an explanatory diagram of a method for calculating stress (σ) when the product is bent to the state shown in the figure according to the four-point bending method shown in FIG.
第２表において、○印は割れ発生のない場合、×印は割
れ発生のある場合を示すものである。この結果より、本
発明に係る油井管用鋼は比較鋼に比べて富１品・常圧で
の耐５ＳＣＣ性にＪくれ−でいることが明らかである。In Table 2, the ○ mark indicates the case where no cracking occurred, and the x mark indicates the case where the cracking occurred. From this result, it is clear that the steel for oil country tubular goods according to the present invention has better 5SCC resistance at normal pressure than the comparative steel.
第 ２ 表
第３表に示す化学組成を有する各ｌｌｉｌ種Ｇこつし−
て）ＪＩＪ熱１］二延後、鋼成分に応じて９００〜１０
００°Ｃの温度力・ら水または油焼入れした後、７００
°Ｃで焼戻し処理してｔｉ１ｉ試Ｎ４を得、これから厚
さ３ｍｍ、幅４０＋ｎｍ、長さ５０ｍｍの試験具を切り
出し、Ｃ０２（３０気圧）を含有さ一艮た５％Ｎａｃ＋
ｉ＠液（液温１２０℃）中に浸漬して腐食８代験を行っ
た。本発明鋼である調香１．３．４は第１表の組成に同
し。なお、この浸漬期間中、試料表面に約２．０ｍ／秒
の流速を与えるように攪拌を行った。試験後は付着物を
除いて試験前後のＮ量差求めた。Table 2 Each type of G-kotsushi with the chemical composition shown in Table 3.
After rolling JIJ heat 1] 900 to 10 depending on the steel composition
After quenching at a temperature of 00°C, water or oil, 700°C
A ti1i test N4 was obtained by tempering at °C, and a test device with a thickness of 3 mm, a width of 40+ nm, and a length of 50 mm was cut out from it and 5% Nac+ containing CO2 (30 atm) was obtained.
Eight generations of corrosion tests were conducted by immersing the sample in i@ solution (liquid temperature: 120°C). Perfume 1.3.4, which is the steel of the present invention, has the same composition as shown in Table 1. During this immersion period, stirring was performed to give a flow rate of about 2.0 m/sec to the sample surface. After the test, the deposits were removed and the difference in N amount before and after the test was determined.
試験結果を第４表にまとめて示す、腐食特性値としては
、比較鋼である調香１１の試験片の腐食量を１００とし
た時の腐食率で表わした。これによれば、焼入れ加熱温
度を９８０°Ｃ〜１０００℃とした本発明に係わる鋼種
が嗣炭酸ガス腐食性能に優れていることが明らかである
。The test results are summarized in Table 4, and the corrosion characteristic values are expressed as corrosion rates when the amount of corrosion of the test piece of Comparative Steel No. 11 is set as 100. According to this, it is clear that the steel type according to the present invention in which the quenching heating temperature is 980°C to 1000°C has excellent carbon dioxide corrosion performance.
第４表
第５表に示す化学組成を有する各鋼種について加ｊハ圧
延後９８０°Ｃから油焼入れした後、Ｙ、Ｓ、（σｙ）
か約６３．３ ｋｇｆ／ｍｍ２（９０ＫＳｉ）になるよ
うにＡＯ，点以下の温度で焼戻しした。これから厚さ２
ｍｍ、幅１０ｍｍ、長さ１］、５ｍｍの試験片を切り出
し、第１図に示す前述の４点曲げ法−ζそれぞれ１σｙ
に相当する応力を付加した後、ｃｏ２ （３０気圧）、
および１−１２３ （０，１気圧）を含有させた５％Ｎ
ａＣｌ／８液（液温１００°Ｃ）中に１２０時間浸漬し
て耐５ｓｃｃ性、１１ｉｔピッチインク性をδ周査した
。After rolling and oil quenching at 980°C for each steel type having the chemical composition shown in Table 4 and Table 5, Y, S, (σy)
It was tempered at a temperature below the AO point to give a hardness of about 63.3 kgf/mm2 (90 KSi). From now on thickness 2
mm, width 10 mm, length 1], 5 mm specimens were cut out and subjected to the aforementioned four-point bending method - ζ each 1σy as shown in Figure 1.
After applying stress equivalent to CO2 (30 atm),
and 5% N containing 1-123 (0.1 atm)
It was immersed in aCl/8 liquid (liquid temperature 100°C) for 120 hours, and its 5scc resistance and 11it pitch ink resistance were checked over δ.
試験結果を第６表にまとめて示す。なお、第６表におい
て○印ば割れおよびピッティングの発生のない場合、×
印は割れおよび／またはピノティングの発生のある場合
を示すものである。これらの結果より、本発明による油
井管用鋼は比較鋼に比へて高温高圧のＣＯ２−微１Ｈ２
Ｓ−ＣＩ−環境下テノ耐５ＳＣＣ性、耐ピッチインク性
にもずくれていることか明らかである。The test results are summarized in Table 6. In addition, if there is no occurrence of cracks or pitting marked with ○ in Table 6, ×
Marks indicate where cracking and/or pinoting has occurred. From these results, the steel for oil country tubular goods according to the present invention has a higher CO2-1H2 value at high temperature and high pressure than the comparative steel.
It is clear that the 5SCC resistance and pitch ink resistance under the S-CI environment have deteriorated.
第 ６ 表
第７表に示す本発明に係る婿を加熱圧延後、種々の加熱
温度から油焼入れしてδ−フェライトの有無を光学顕＠
、鏡にて判定した。その結果を第８表にまとめて示す。After heat-rolling the in-laws according to the present invention shown in Table 6 and Table 7, they were oil-quenched at various heating temperatures and examined for the presence or absence of δ-ferrite using an optical microscope.
, judged in the mirror. The results are summarized in Table 8.
これらの結果から、δ−フェフイ１〜の生成を抑えて組
織を均質化するためには９４０〜１０５０°Ｃからの急
冷が効果のあることが明らかである。From these results, it is clear that rapid cooling from 940 to 1050°C is effective in suppressing the production of δ-fefi1 and homogenizing the structure.
第 ７ 表
第９表に示す化学組成を有する各鋼種について加熱圧延
後９８０℃から油焼入れした後、Ｙ、Ｓ、か約５９．８
ｋｇｆ／ｍｍ２ｍｍ２（８５）になるようにへＣ５点
以下の温度で焼戻しして、得られた供試材につき衝撃実
施例
その試験結果を第１Ｏ表にまとめて示す。第１０表に示
す結果によれば本発明に係る鋼が強度−靭性のバランス
の面でもずくれたものであることが明らかである。Table 7 After hot rolling and oil quenching at 980°C for each steel type having the chemical composition shown in Table 9, Y, S, or approximately 59.8
kgf/mm2mm2 (85) and tempered at a temperature below the C5 point, and the test results of the test materials obtained are summarized in Table 1O. According to the results shown in Table 10, it is clear that the steel according to the present invention has a poor balance between strength and toughness.
天新Ｕ列玉
第１１表に示す化学組成を有する各鋼種について、加熱
圧延後、種々の加熱温度から油焼入れして硬度（ＨＲＣ
）測定を行った。その結果を第１２表に示す。For each steel type having the chemical composition shown in Table 11 of Tenshin U series balls, after hot rolling, oil quenching is performed at various heating temperatures to determine the hardness (HRC).
) measurements were taken. The results are shown in Table 12.
本発明に係る鋼組成では、本発明における加熱温度であ
る９４０〜１０５０°Ｃの温度範囲内でいずれも硬度が
安定しており、したがってＣｒ炭化物が充分基地に固溶
していることが明らかである。In the steel composition according to the present invention, the hardness is stable within the temperature range of 940 to 1050°C, which is the heating temperature in the present invention, and it is therefore clear that Cr carbide is sufficiently dissolved in the matrix. be.
「−丁＝「−−曹"-Ding="-Cao
Claims (2)
０．２５％以下、Ｃｕ：０．０５％以下、Ｎｉ：０．１
０％以下、Ｃｒ ： １２．Ｌ−１４，５％、ＡＩ＝０
．１０％以下、Ｎ：０．００５０〜０８１％、残部Ｆｅ
および不可避的不純物から成り、不純物中のＰは０．０
１５％以下、Ｓは０．００５％以下とするとともに、式
： ％式％ を満足する組成を有し、かつ、９４０”Ｃ以上、１０５
０’ｃ以下の温度に加熱後急冷し、続いてＡ（１点以下
の温度で焼戻して得た焼戻しマルテンサイトの微細組織
を有していることを特徴とする、耐食性のすくれた油井
管用鋼。(1) In weight%, C: 0.22% or less, Si+Mn:
0.25% or less, Cu: 0.05% or less, Ni: 0.1
0% or less, Cr: 12. L-14,5%, AI=0
．． 10% or less, N: 0.0050-081%, balance Fe
and unavoidable impurities, P in the impurities is 0.0
15% or less, S is 0.005% or less, and has a composition that satisfies the formula:
For use in oil country tubular goods with corrosion resistance, which is characterized by having a fine structure of tempered martensite obtained by heating to a temperature of 0'C or less, then rapidly cooling, and then tempering at a temperature of A (1 point or less). steel.
：０．２５％以下、Ｃ１１； ０．０５％以下、Ｎ１
・０．１０％以下、Ｃｒ ： １２．０−１４．５％、
ＡＩ：０．１０％以下、Ｎ：０．００５０〜Ｏ１％、並
びにＭ Ｏ： ０．０２〜０１５％およびＮｂ： ０．
００５〜０．０５０％のうち少なくとも１種以上を含有
し、残部Ｆｅおよび不可避的不純物から成り、不純物中
のＰは００１５％以下、Ｓば０．００５％以下とすると
ともに、式二 １００ＸＣ（％）喜、１００ＸＮ（％）−２Ｘにｒ（％
）［９≧０を満足する組成を有し、かつ、９４０°Ｃ以
上、１０５０°Ｃ辺下の温度に加熱ｌ＆急冷し、続いて
ＡＣ１点以下の温度で焼戻して得た焼戻しマルテンサイ
トの微細組織を有していることを特徴とする、耐食性の
すくれた油井管用鋼。(2) In weight%, C: 0.22% or less, S i +Mn
: 0.25% or less, C11; 0.05% or less, N1
・0.10% or less, Cr: 12.0-14.5%,
AI: 0.10% or less, N: 0.0050-1%, MO: 0.02-015%, and Nb: 0.
005 to 0.050%, and the remainder consists of Fe and unavoidable impurities, P in the impurities is 0.015% or less, S is 0.005% or less, and the formula 2 is 100XC (% ) joy, 100XN (%) - 2X to r (%
) [Fine tempered martensite having a composition that satisfies 9≧0 and obtained by heating to a temperature of 940°C or higher and below 1050°C, followed by tempering at a temperature of 1 AC or lower. A corrosion-resistant steel for oil country tubular goods, characterized by having a rough structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4787383A JPS59173245A (en) | 1983-03-24 | 1983-03-24 | Steel for oil well pipe excellent in corrosion resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4787383A JPS59173245A (en) | 1983-03-24 | 1983-03-24 | Steel for oil well pipe excellent in corrosion resistance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59173245A true JPS59173245A (en) | 1984-10-01 |
| JPH0348261B2 JPH0348261B2 (en) | 1991-07-23 |
Family
ID=12787494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4787383A Granted JPS59173245A (en) | 1983-03-24 | 1983-03-24 | Steel for oil well pipe excellent in corrosion resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59173245A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59208055A (en) * | 1983-05-13 | 1984-11-26 | Kawasaki Steel Corp | Martensitic stainless steel for seamless steel pipe |
| JPH02217444A (en) * | 1989-02-18 | 1990-08-30 | Nippon Steel Corp | High strength martensitic stainless steel having excellent corrosion resistance and stress corrosion cracking resistance and its manufacture |
| JPH02247360A (en) * | 1989-03-20 | 1990-10-03 | Nippon Steel Corp | Martensitic stainless steel having high strength and excellent corrosion resistance and stress corrosion cracking resistance and its manufacture |
| JPH05171361A (en) * | 1991-12-19 | 1993-07-09 | Sumitomo Metal Ind Ltd | Production of martensitic stainless steel |
| JPH05263138A (en) * | 1992-02-18 | 1993-10-12 | Nippon Steel Corp | Production of seamless tube of martensitic stainless steel excellent in corrosion resistance |
| JPH05263137A (en) * | 1992-02-18 | 1993-10-12 | Nippon Steel Corp | Production of seamless tube of martensitic stainless steel excellent in corrosion resistance |
| EP1099772A1 (en) * | 1999-05-18 | 2001-05-16 | Sumitomo Metal Industries, Ltd. | Martensite stainless steel for seamless steel tube |
| WO2001061064A1 (en) * | 2000-02-16 | 2001-08-23 | Sandvik Ab; (Publ) | Elongated element and steel for percussive rock drilling |
| KR100479922B1 (en) * | 2002-02-21 | 2005-03-30 | 최백남 | CASTED Fe-Cr-X ELBOW PIPE AND MANUFACTURING METHOD THEREOF |
-
1983
- 1983-03-24 JP JP4787383A patent/JPS59173245A/en active Granted
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59208055A (en) * | 1983-05-13 | 1984-11-26 | Kawasaki Steel Corp | Martensitic stainless steel for seamless steel pipe |
| JPH0360904B2 (en) * | 1983-05-13 | 1991-09-18 | Kawasaki Steel Co | |
| JPH02217444A (en) * | 1989-02-18 | 1990-08-30 | Nippon Steel Corp | High strength martensitic stainless steel having excellent corrosion resistance and stress corrosion cracking resistance and its manufacture |
| JPH02247360A (en) * | 1989-03-20 | 1990-10-03 | Nippon Steel Corp | Martensitic stainless steel having high strength and excellent corrosion resistance and stress corrosion cracking resistance and its manufacture |
| JPH05171361A (en) * | 1991-12-19 | 1993-07-09 | Sumitomo Metal Ind Ltd | Production of martensitic stainless steel |
| JPH05263137A (en) * | 1992-02-18 | 1993-10-12 | Nippon Steel Corp | Production of seamless tube of martensitic stainless steel excellent in corrosion resistance |
| JPH05263138A (en) * | 1992-02-18 | 1993-10-12 | Nippon Steel Corp | Production of seamless tube of martensitic stainless steel excellent in corrosion resistance |
| EP1099772A1 (en) * | 1999-05-18 | 2001-05-16 | Sumitomo Metal Industries, Ltd. | Martensite stainless steel for seamless steel tube |
| EP1099772A4 (en) * | 1999-05-18 | 2003-05-07 | Sumitomo Metal Ind | Martensite stainless steel for seamless steel tube |
| WO2001061064A1 (en) * | 2000-02-16 | 2001-08-23 | Sandvik Ab; (Publ) | Elongated element and steel for percussive rock drilling |
| US6547891B2 (en) | 2000-02-16 | 2003-04-15 | Sandvik Ab | Elongated percussive rock drilling element |
| JP2003522837A (en) * | 2000-02-16 | 2003-07-29 | サンドビック アクティエボラーグ | Long members and steel for impact vibration drilling |
| KR100479922B1 (en) * | 2002-02-21 | 2005-03-30 | 최백남 | CASTED Fe-Cr-X ELBOW PIPE AND MANUFACTURING METHOD THEREOF |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0348261B2 (en) | 1991-07-23 |
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