JP2000313941A - Seamless tube of martensitic stainless steel excellent in surface quality - Google Patents
Seamless tube of martensitic stainless steel excellent in surface qualityInfo
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- JP2000313941A JP2000313941A JP11119750A JP11975099A JP2000313941A JP 2000313941 A JP2000313941 A JP 2000313941A JP 11119750 A JP11119750 A JP 11119750A JP 11975099 A JP11975099 A JP 11975099A JP 2000313941 A JP2000313941 A JP 2000313941A
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- steel
- stainless steel
- surface quality
- martensitic stainless
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、熱間加工時に圧延
疵を生じない表面品質に優れたマルテンサイト系ステン
レス鋼継目無鋼管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 seamless steel pipe which does not cause rolling flaws during hot working and has excellent surface quality.
【０００２】[0002]
【従来の技術】マルテンサイト系ステンレス鋼は、ＡＩ
ＳＩ ４２０鋼に代表されるように、強度、耐ＣＯ2 腐
食性に優れ比較的安価であることから、１９８０年頃よ
り油井管として適用されてきたが、近年では、高温かつ
多量のＣＯ2 やそれに加えてＨ 2 Ｓを含む油井環境にも
適応しうるために、ＡＩＳＩ ４２０鋼より優れた耐食
性を有する鋼が開発されてきた。例えば、特公昭５９−
１５９７８号公報や特公平３−２２２７号公報などに見
られるような低Ｃ−Ｎｉ−Ｍｏ添加鋼、あるいは特開平
２−２１７４４４号公報などに見られるような低Ｃ−Ｃ
ｕ−Ｎｉ−Ｍｏ添加鋼といった鋼種（いわゆるModified
１３Ｃｒ鋼と称される鋼種）が提案されている。さら
に、溶接性を改善してラインパイプとしても適用されて
きている。2. Description of the Related Art Martensitic stainless steel has been developed using AI.
As represented by SI 420 steel, strength, CO resistanceTwoRot
It's around 1980 because it's good food and relatively cheap
Oil well pipes, but in recent years,
Large amount of COTwoAnd in addition to H TwoOil well environment including S
Better corrosion resistance than AISI 420 steel due to adaptability
Steels with properties have been developed. For example,
No. 159778 and Japanese Patent Publication No. 3-22727.
Low-C-Ni-Mo-added steel as disclosed in
Low CC as seen in JP-A-2-217444
Steel types such as u-Ni-Mo added steel (so-called Modified
13Cr steel). Further
In addition, it has been applied as a line pipe by improving weldability.
coming.
【０００３】一般に、合金量が多くなると、耐食性は向
上する反面、加工性が悪化する。上記鋼の油井管やライ
ンパイプはマンネスマン方式の圧延法によって継目無管
に製管されるのが通例である。従来マンネスマン圧延は
熱間加工方法の中でも最も苛酷な加工方法として知られ
ており、これらの鋼は，Ｃｒ，Ｎｉ，Ｍｏ，Ｃｕといっ
た合金元素を多量に含むため、マンネスマン方式の圧延
法によって製管する際圧延疵が発生することがあった。In general, when the amount of alloy is increased, corrosion resistance is improved, but workability is deteriorated. The above-mentioned steel oil country tubular goods and line pipes are generally produced seamlessly by the Mannesmann rolling method. Conventionally, Mannesmann rolling is known as the most severe working method among hot working methods. Since these steels contain a large amount of alloying elements such as Cr, Ni, Mo, and Cu, they are manufactured by the Mannesmann rolling method. In some cases, rolling flaws were generated.
【０００４】このような圧延疵の問題に対して、特開平
８−１２０３４５号公報などに見られるように熱間加工
温度域での組織をオーステナイト単相に制御するために
Ｃｒ，Ｎｉ，Ｍｏ，Ｃｕ，Ｃ，Ｎ等の主要合金元素添加
量バランスを調整する方法や、特公平３−６０９０４号
公報などに見られるように、ＰやＳに代表される熱間加
工性に有害な不純物の含有量を特に低く制限する技術が
提案されてきている。しかしながら、これらの策をとっ
てもなお、熱間加工に伴う疵の問題は解決できていない
のが現状である。特に、耐食性を向上させるためにＣｕ
を０．５重量％を超えて添加した鋼は、表層酸化層直下
に濃縮したＣｕの粒界偏析により粒界強度が低下し、表
層部の熱間加工性が低下するため、圧延疵を防止するこ
とが困難であった。In order to control the structure in the hot working temperature range to a single austenite phase as disclosed in Japanese Patent Application Laid-Open No. 8-120345, Cr, Ni, Mo, As disclosed in Japanese Patent Publication No. 3-60904, a method of adjusting the balance of the addition of main alloying elements such as Cu, C, and N, contains impurities harmful to hot workability such as P and S. Techniques for limiting the amount particularly low have been proposed. However, even with these measures, the problem of flaws associated with hot working has not been solved at present. In particular, in order to improve corrosion resistance, Cu
In steel containing more than 0.5% by weight of Cu, the grain boundary strength decreases due to the grain boundary segregation of Cu concentrated immediately below the surface oxide layer, and the hot workability of the surface layer decreases, thus preventing rolling flaws. It was difficult to do.
【０００５】このように、従来提案されてきた技術で
は、Ｃｕを０．５重量％を超えて含有するModified１３
Ｃｒ鋼を、マンネスマン方式の圧延法によって継目無管
に製管する時に発生する圧延疵の問題を解決することは
困難であった。[0005] As described above, according to the conventionally proposed technique, Modified 13 containing Cu exceeding 0.5% by weight is used.
It has been difficult to solve the problem of rolling flaws generated when a Cr steel is made into a seamless pipe by the Mannesmann rolling method.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、上記したよ
うな問題点を解決しようとするものであって、Ｃｕを
０．５重量％を超えて含有するModified１３Ｃｒ鋼を、
マンネスマン方式の圧延法によって継目無管に製管する
時の圧延疵を防止し、表面品質に優れたマルテンサイト
系ステンレス鋼継目無鋼管を提供することを目的とす
る。SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and it is an object of the present invention to provide a modified 13Cr steel containing Cu exceeding 0.5% by weight.
An object of the present invention is to provide a martensitic stainless steel seamless steel pipe having excellent surface quality by preventing rolling flaws when producing a seamless pipe by a Mannesmann rolling method.
【０００７】[0007]
【課題を解決するための手段】本発明者らは、成分の異
なる種々の素材に対して熱間加工性について研究を重ね
た結果、本鋼種においては、Ｃｕを０．５％超〜３重量
％以下に制限し、Ｓを０．００２重量％以下に制限し、
さらに、Ｂを０．０００５〜０．０２重量％添加すれ
ば、表層部の熱間加工性が著しく改善し、マンネスマン
方式の圧延法によって継目無管に製管する場合の圧延疵
を防止できること、を知見した。Means for Solving the Problems As a result of repeated studies on hot workability of various materials having different components, the present inventors have found that in the present steel type, Cu exceeds 0.5% to 3% by weight. %, S is limited to 0.002% by weight or less,
Furthermore, if B is added in an amount of 0.0005 to 0.02% by weight, the hot workability of the surface layer is remarkably improved, and it is possible to prevent rolling flaws when a seamless pipe is manufactured by a Mannesmann rolling method. Was found.
【０００８】本発明はこのような知見に基づいて構成し
たものであり、その要旨は以下の通りである。 （１） 重量％で、 Ｃ ：０．００１〜０．０５％、 Ｓｉ：０．５％以下、 Ｍｎ：０．１〜１．５％、 Ｐ ：０．０３％以下、 Ｓ ：０．００２％以下、 Ｃｒ：１０〜１４％、 Ｎｉ：２〜８％、 Ｍｏ：０．５〜３％、 Ｃｕ：０．５超〜３％、 Ａｌ：０．２％以下、 Ｎ ：０．００１〜０．０５％、 Ｂ ：０．０００５〜０．０２％、 Ｏ ：０．００５％以下 を含有し、残部がＦｅ及び不可避的不純物からなること
を特徴とする表面品質に優れたマルテンサイト系ステン
レス鋼継目無鋼管。 （２） 上記（１）記載の成分の鋼に、さらに重量％で、 Ｃａ：０．００１〜０．０１％、 Ｍｇ：０．０００５〜０．０１％、 ＲＥＭ：０．００１〜０．０５％、 Ｚｒ：０．０１〜０．０５％、 Ｔｉ：０．００５〜０．０５％の１種または２種以上 を含有することを特徴とする表面品質に優れたマルテン
サイト系ステンレス鋼継目無鋼管。 （３） 上記（１）又は（２）記載の成分の鋼に、さらに重量％で、 Ｎｂ：０．０５〜０．５％、 Ｖ ：０．０５〜０．５％、 Ｗ ：０．５〜３％の１種または２種以上 を含有することを特徴とする表面品質に優れたマルテン
サイト系ステンレス鋼継目無鋼管。The present invention has been made based on such knowledge, and the gist is as follows. (1) In weight%, C: 0.001 to 0.05%, Si: 0.5% or less, Mn: 0.1 to 1.5%, P: 0.03% or less, S: 0.002 %: Cr: 10 to 14%, Ni: 2 to 8%, Mo: 0.5 to 3%, Cu: more than 0.5 to 3%, Al: 0.2% or less, N: 0.001 to A martensitic stainless steel excellent in surface quality characterized by containing 0.05%, B: 0.0005 to 0.02%, and O: 0.005% or less, with the balance being Fe and unavoidable impurities. Steel seamless steel pipe. (2) In addition to the steel having the composition described in the above (1), Ca: 0.001 to 0.01%, Mg: 0.0005 to 0.01%, REM: 0.001 to 0.05 by weight%. %, Zr: 0.01 to 0.05%, and Ti: 0.005 to 0.05%. A martensitic stainless steel seamless having excellent surface quality, characterized in that it contains: Steel pipe. (3) In addition to the steel having the composition described in the above (1) or (2), Nb: 0.05 to 0.5%, V: 0.05 to 0.5%, W: 0.5 A martensitic stainless steel seamless steel pipe having excellent surface quality, characterized by containing one or more of 3% or more.
【０００９】[0009]
【発明の実施の形態】以下、本発明について詳細に説明
する。１．５重量％のＣｕを含有するModified１３Ｃｒ
鋼（０．０２Ｃ−０．０２Ｎ−１．５Ｃｕ−１２．２Ｃ
ｒ−５．８Ｎｉ−２．０Ｍｏ一０．００１８Ｓ）の熱間
加工性に及ぼすＢの影響を図１に示す。図１の縦軸と横
軸はそれぞれ、絞り値と変形温度Ｔ1 を示している。図
１に示す結果は図２に示した条件で熱間引張試験を行い
得られたものである。すなわち、１２５０℃に加熱し１
分保定後、変形温度（Ｔ1 ℃）まで１０℃/secで冷却
し、その温度で１分間保定後、３/secの歪み速度で引張
試験を行った。試験後の破断部の断面積を試験前の断面
積で割った値を絞り値と定義する。絞り値が高いほど熱
間加工性は良好である。これまでの知見から、絞り値が
７５％以上あればその温度で良好な熱間加工性を示すこ
とがわかっている。図１より、１．５重量％のＣｕを含
有するModified１３Ｃｒ鋼の熱間加工性は、Ｓ含有量が
低い場合にはＢ添加により大幅に改善することがわか
る。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Modified 13Cr containing 1.5% by weight of Cu
Steel (0.02C-0.02N-1.5Cu-12.2C
The effect of B on the hot workability of (r-5.8Ni-2.0Mo-0.0018S) is shown in FIG. Each vertical and horizontal axes of Figure 1 shows the aperture and deformation temperature T 1. The results shown in FIG. 1 were obtained by performing a hot tensile test under the conditions shown in FIG. That is, heating to 1250 ° C.
After the holding, the sample was cooled to a deformation temperature (T 1 ° C) at 10 ° C / sec, held at that temperature for 1 minute, and then subjected to a tensile test at a strain rate of 3 / sec. The value obtained by dividing the sectional area of the fractured part after the test by the sectional area before the test is defined as the aperture value. The higher the aperture value, the better the hot workability. From the findings so far, it has been found that if the aperture value is 75% or more, good hot workability is exhibited at that temperature. FIG. 1 shows that the hot workability of Modified 13Cr steel containing 1.5% by weight of Cu is significantly improved by the addition of B when the S content is low.
【００１０】さらに、べ一ス成分がほぼ同じ（０．０２
Ｃ−０．０２Ｎ−１２．２Ｃｒ−５．８Ｎｉ−２．０Ｍ
ｏ）でＣｕ，Ｓ及びＢ含有量のみ異なる組成の２１７mm
×２１７mm断面のブルームを、マンネスマン方式の熱間
圧延法によって外径１７８mm、肉厚１１．５mmの継目無
管に造管し、圧延終了後、パイプの表面疵の発生状況を
観察し、Ｃｕ，Ｓ及びＢ含有量と表面疵発生状況の関係
を詳細に調査した。その結果を図３に示す。図３より、
本鋼種においては、Ｃｕを３重量％以下に制限し、Ｓを
０．００２重量％以下に制限し、さらに、Ｂを０．００
０５〜０．０２重量％添加すれば、表層部の熱間加工性
が著しく改善し、マンネスマン方式の圧延法によって継
目無管に製管する場合の圧延疵を防止できることがわか
る。また、Ｃｕ含有量が３重量％を超えるとＳ含有量を
制限し、かつ適量のＢを添加しても圧延疵を防止するこ
とは困難であることがわかる。Furthermore, the base components are almost the same (0.02
C-0.02N-12.2Cr-5.8Ni-2.0M
o) 217 mm of composition that differs only in Cu, S and B contents
A bloom having a cross section of 217 mm was formed into a seamless pipe having an outer diameter of 178 mm and a wall thickness of 11.5 mm by the hot rolling method of the Mannesmann method. The relationship between the S and B contents and the occurrence of surface flaws was investigated in detail. The result is shown in FIG. From FIG.
In this steel type, Cu is limited to 3% by weight or less, S is limited to 0.002% by weight or less, and B is further limited to 0.00% by weight.
It can be seen that the addition of from 0.05 to 0.02% by weight significantly improves the hot workability of the surface layer portion and can prevent rolling flaws when a seamless pipe is manufactured by the Mannesmann rolling method. Further, it can be seen that if the Cu content exceeds 3% by weight, it is difficult to limit the S content, and to prevent rolling flaws even if an appropriate amount of B is added.
【００１１】本発明におけるマルテンサイト系ステンレ
ス鋼の成分限定理由は以下の通りである。成分の含有量
は重量％である。 Ｃ：ＣはＣｒ炭化物などを形成し耐食性を劣化させる元
素である。一方、強力なオーステナイト形成元素でもあ
り、高温加熱時にδフェライト相の生成を抑制する効果
がある。しかし、０．００１％未満ではその効果は発現
されず、０．０５％を超えて含有されると粒界にＣｒ炭
化物が多量に析出し、Ｃｒ欠乏層が形成されるために耐
ＣＯ2 腐食特性が低下し、また、粒界強度が低下するた
めに耐硫化物応力割れ性が劣化する。さらに溶接性も劣
化する。従って、Ｃ含有量は０．００１〜０．０５％と
した。The reasons for limiting the components of the martensitic stainless steel in the present invention are as follows. The content of the components is% by weight. C: C is an element that forms a Cr carbide or the like and deteriorates corrosion resistance. On the other hand, it is also a strong austenite-forming element and has the effect of suppressing the formation of a δ ferrite phase during high-temperature heating. However, if the content is less than 0.001%, the effect is not exhibited. If the content exceeds 0.05%, a large amount of Cr carbide precipitates at the grain boundary and a Cr-deficient layer is formed, so that CO 2 corrosion resistance is reduced. The properties are lowered, and the grain boundary strength is lowered, so that the sulfide stress cracking resistance is deteriorated. Further, the weldability also deteriorates. Therefore, the C content is set to 0.001 to 0.05%.
【００１２】Ｓｉ：Ｓｉは製鋼工程において脱酸剤とし
て添加され残存するものである。０．５％を超えて含有
すると靭性及び耐硫化物応力割れ性が劣化することか
ら、上限を０．５％とした。Si: Si is added as a deoxidizing agent in the steel making process and remains. If the content exceeds 0.5%, toughness and sulfide stress cracking resistance deteriorate, so the upper limit was made 0.5%.
【００１３】Ｍｎ：Ｍｎはオーステナイト安定化元素で
あり、高温加熱時にδフェライト相の生成を抑制する効
果がある。またＭｎＳを形成してＳの有害性を低減する
効果もある。しかし、０．１％未満ではそれらの効果は
発現されず、１．５％を超えて含有されると、粒界強度
が低下するために耐硫化物応力割れ性及び靭性が劣化す
る。従って、Ｍｎ含有量は０．１〜１．５％とした。Mn: Mn is an austenite stabilizing element and has an effect of suppressing the formation of a δ ferrite phase during high-temperature heating. It also has the effect of forming MnS to reduce the harmfulness of S. However, if the content is less than 0.1%, those effects are not exhibited, and if the content exceeds 1.5%, the sulfide stress cracking resistance and the toughness are deteriorated because the grain boundary strength is reduced. Therefore, the Mn content is set to 0.1 to 1.5%.
【００１４】Ｐ：Ｐは粒界に偏析して粒界強度を低下さ
せ、耐硫化物応力割れ性及び靭性を劣化させる不純物元
素であり、可及的低レベルが望ましいが、現状精錬技術
の到達可能レベルとコストを考慮して、上限を０．０３
％とした。P: P is an impurity element that segregates at the grain boundary to lower the grain boundary strength and deteriorates the sulfide stress cracking resistance and toughness. It is desirable that the level be as low as possible. Considering possible level and cost, the upper limit is 0.03
%.
【００１５】Ｓ：Ｓは熱間加工性を劣化させる不純物元
素である。０．００２％を超えて含有されると、Ｂによ
る熱間加工性改善効果が十分には得られず、製管時に表
面疵が発生するため、上限を０．００２％とした。S: S is an impurity element that deteriorates hot workability. If the content exceeds 0.002%, the effect of improving the hot workability by B cannot be sufficiently obtained, and surface flaws occur during pipe production. Therefore, the upper limit was made 0.002%.
【００１６】Ｃｒ：Ｃｒは耐食性を向上させる元素であ
り、ステンレス鋼として十分な耐食性を得るには１０％
以上含有されることが必要である。一方、フェライト安
定化元素でもあり、１４％を超えて含有されると、高温
加熱時にδフェライト相が生成して熱間加工性が劣化す
る。従って、Ｃｒ含有量は１０〜１４％とした。Cr: Cr is an element for improving corrosion resistance, and 10% is required to obtain sufficient corrosion resistance as stainless steel.
It is necessary that it be contained as described above. On the other hand, it is also a ferrite stabilizing element, and if it is contained in excess of 14%, a δ ferrite phase is formed at the time of high-temperature heating, and the hot workability deteriorates. Therefore, the Cr content was set to 10 to 14%.
【００１７】Ｎｉ：ＮｉはＣｒ含有鋼において耐食性を
向上させる元素である。また、強力なオーステナイト形
成元素であり、高温加熱時にδフェライト相の生成を抑
制する効果がある。しかし、２％未満ではそれらの効果
は発現されず、８％を超えて含有されると、Ａｃ1 変態
点が大幅に低下し強度調質が困難になる。従って、Ｎｉ
含有量は２〜８％とした。Ni: Ni is an element that improves the corrosion resistance of Cr-containing steel. Further, it is a strong austenite-forming element and has an effect of suppressing the formation of a δ ferrite phase during high-temperature heating. However, if the content is less than 2%, these effects are not exhibited, and if the content exceeds 8%, the Ac 1 transformation point is significantly reduced, and the tempering becomes difficult. Therefore, Ni
The content was 2 to 8%.
【００１８】Ｍｏ：Ｍｏは耐食性を向上させるのに有効
な元素である。しかし、０．５％未満ではその効果は発
現されないため、下限を１．０％とした。一方、Ｍｏは
強力なフェライト安定化元素でもあり、３％を超えて含
有されると、高温加熱時にδフェライト相が生成して熱
間加工性が劣化する。従って、Ｍｏ含有量は０．５〜３
％とした。Mo: Mo is an element effective for improving corrosion resistance. However, if the content is less than 0.5%, the effect is not exhibited, so the lower limit is set to 1.0%. On the other hand, Mo is also a strong ferrite-stabilizing element, and if it is contained in excess of 3%, a δ-ferrite phase is formed at the time of high-temperature heating, and the hot workability deteriorates. Therefore, the Mo content is 0.5 to 3
%.
【００１９】Ｃｕ：Ｃｕは耐食性を向上させるのに有効
な元素である。特に、Ｎｉと複合添加することにより腐
食皮膜の安定性を改善し、耐ＣＯ2 腐食特性を格段に向
上させることができる。また、オーステナイト安定化元
素であり高温加熱時にδフェライト相の生成を抑制する
効果がある。しかし、０．５％未満ではそれらの効果は
発現せず、また、３％を超えて添加すると、Ｃｕの粒界
偏析により粒界強度が低下し熱間加工性が著しく劣化す
るため、Ｓ含有量を制限し、かつ適量のＢを添加しても
圧延疵を防止することが困難である。従って、Ｃｕ含有
量は０．５％超〜３％以下とした。Cu: Cu is an element effective for improving corrosion resistance. In particular, by adding Ni in combination, the stability of the corrosion film can be improved, and the CO 2 corrosion resistance can be significantly improved. Further, it is an austenite stabilizing element and has an effect of suppressing the formation of a δ ferrite phase during high-temperature heating. However, if less than 0.5%, these effects are not exhibited, and if more than 3% is added, the grain boundary strength is reduced due to the grain boundary segregation of Cu, and the hot workability is significantly deteriorated. Even if the amount is limited and an appropriate amount of B is added, it is difficult to prevent rolling flaws. Therefore, the Cu content is set to more than 0.5% to 3% or less.
【００２０】Ａｌ：ＡｌはＳｉ同様に製鋼工程において
脱酸剤として添加され残存するものである。０．２％を
超えて含有されると、ＡｌＮが多量に形成されて熱間加
工性及び靭性が低下する。従って、上限を０．２％とし
た。Al: Like Al, Al is added as a deoxidizing agent in the steel making process and remains. If the content exceeds 0.2%, a large amount of AlN is formed, and the hot workability and toughness are reduced. Therefore, the upper limit is set to 0.2%.
【００２１】Ｎ：は強力なオーステナイト形成元素であ
り、高温加熱時にδフェライト相の生成を抑制する効果
がある。また、微細な窒化物は高温加熱時の結晶粒成長
を抑制し熱間加工性を向上させる効果がある。しかし、
０．００１％未満ではそれらの効果は発現されず、０．
０５％を超えて含有されると粗大な窒化物が析出して熱
間加工性及び靭性が劣化する。さらに溶接性も劣化す
る。従って、Ｎ含有量は０．００１〜０．０５％とし
た。N: is a strong austenite-forming element and has the effect of suppressing the formation of a δ-ferrite phase during high-temperature heating. Further, fine nitrides have the effect of suppressing crystal grain growth during high-temperature heating and improving hot workability. But,
If less than 0.001%, those effects are not exhibited, and
If the content exceeds 0.05%, coarse nitrides precipitate and the hot workability and toughness deteriorate. Further, the weldability also deteriorates. Therefore, the N content is set to 0.001 to 0.05%.
【００２２】Ｂ：Ｂは自ら粒界に偏析することにより粒
界結合力を向上させると共に、Ｓ及びＣｕの粒界偏析を
抑制し、粒界強度を高め、熱間加工性及び耐硫化物応力
割れ性を向上させるのに有効な元素である。しかし、
０．０００５％未満ではその効果は発現されず、０．０
２％を超えて含有すると溶融脆化温度が大幅に低下し、
熱間加工温度域が著しく制限されるとともに、粗大なホ
ウ化物を形成し熱間加工性、靭性及び溶接性が劣化す
る。従って、Ｂ含有量は０．０００５〜０．０２％とし
た。B: B segregates at the grain boundaries by itself, thereby improving the grain boundary bonding force, suppressing the grain boundary segregation of S and Cu, increasing the grain boundary strength, and improving hot workability and sulfide stress. It is an effective element for improving the cracking property. But,
If less than 0.0005%, the effect is not exhibited,
When the content exceeds 2%, the melt embrittlement temperature is greatly reduced,
The hot working temperature range is significantly restricted, and coarse borides are formed to deteriorate hot workability, toughness and weldability. Therefore, the B content is set to 0.0005 to 0.02%.
【００２３】Ｏ：製鋼工程での脱酸後に残存するＯは非
金属介在物として鋼中に残留して清浄度を害し、熱間加
工性、耐食性及び靭性を劣化させる不純物元素であり、
可及的低レベルが望ましいが、現状精錬技術の到達可能
レベルとコストを考慮して、上限を０．００５％とし
た。O: O remaining after deoxidation in the steelmaking process is an impurity element that remains in the steel as nonmetallic inclusions and impairs cleanliness and deteriorates hot workability, corrosion resistance and toughness;
The lowest possible level is desirable, but the upper limit is set to 0.005% in consideration of the achievable level and cost of the current refining technology.
【００２４】Ｃａ，Ｍｇ，ＲＥＭ，Ｚｒ，Ｔｉ：これら
の元素はＳによる熱間加工性劣化を抑制するものであ
り、必要に応じて添加するが、含有量が少なすぎるとそ
の効果は発現せず、多すぎると粗大な酸化物や窒化物を
形成して耐硫化物応力割れ性や靭性を劣化させるので、
Ｃａは０．００１〜０．０１％、Ｍｇは０．０００５〜
０．０１％、ＲＥＭは０．００１〜０．０５％、Ｚｒは
０．０１〜０．０５％、Ｔｉは０．００５〜０．０５％
とした。Ca, Mg, REM, Zr, Ti: These elements suppress the deterioration of hot workability due to S, and are added as necessary. However, if the content is too small, the effect is not exhibited. If too much, coarse oxides and nitrides are formed and sulfide stress cracking resistance and toughness deteriorate, so
Ca is 0.001 to 0.01%, Mg is 0.0005 to
0.01%, REM 0.001-0.05%, Zr 0.01-0.05%, Ti 0.005-0.05%
And
【００２５】Ｎｂ，Ｖ，Ｗ：これらの元素は耐食性を向
上させる元素であり、必要に応じて添加するが、含有量
が少なすぎるとその効果が発現せず、多すぎると靭性を
劣化させるので、Ｎｂは０．０５〜０．５％、Ｖは０．
０５〜０．５％、Ｗは０．５〜３％添加する。Nb, V, W: These elements are elements that improve the corrosion resistance and are added as necessary. However, if the content is too small, the effect is not exhibited, and if the content is too large, the toughness is deteriorated. , Nb is 0.05 to 0.5%, and V is 0.1 to 0.5%.
05 to 0.5%, and W is added to 0.5 to 3%.
【００２６】本発明鋼は、主にマンネスマン方式の熱間
圧延法によって継目無管に造管される。ここでいうマン
ネスマン方式の圧延法とは、通常の継目無鋼管製造のた
めの熱間圧延法で、矩形断面もしくは丸断面の製管用素
材（以下、管材と称す）を用い、プレスロール穿孔法あ
るいはマンネスマン穿孔法により穿孔した後、必要に応
じて傾斜圧延機（エロンゲータ）により延伸し、さらに
プラグミルあるいはマンドレルミルで肉厚を調整し、最
終仕上圧延機（サイザーミルあるいはストレッチレデュ
ーサー）で所定の外径に成形することにより造管してい
く一連のプロセスである。The steel of the present invention is formed into a seamless pipe mainly by the hot rolling method of the Mannesmann system. The rolling method of the Mannesmann method as used herein is a hot rolling method for producing a seamless steel pipe, using a material for forming a tube having a rectangular cross section or a round cross section (hereinafter, referred to as a pipe material), using a press roll drilling method, After drilling by the Mannesmann drilling method, it is stretched by an inclined rolling mill (elongator) if necessary, and the wall thickness is further adjusted by a plug mill or mandrel mill, and is adjusted to a predetermined outer diameter by a final finishing mill (sizer mill or stretch reducer). This is a series of processes for forming a tube by molding.
【００２７】[0027]
【実施例】表１に示す組成の２１７mm×２１７mm断面の
ブルームをマンネスマン方式の熱間圧延法によって外径
１７８mm、肉厚１１．５mmの継目無管に造管した。圧延
終了後、パイプの表面疵発生状況を調査した。結果を表
１に併せて示す。本発明例（Ｎｏ．１〜１０）では製管
時の表面疵は発生していない。一方、Ｃｕ，Ｓ，Ｂ含有
量のうち１つ以上が本発明の成分限定範囲を超えている
比較例（Ｎｏ．１１〜２０）では製管時に表面疵が発生
している。以上により、Ｃｕ，Ｓ，Ｂ含有量が本発明の
成分限定範囲内であれば、マンネスマン方式の熱間圧延
法によって継目無管に製管するときに圧延疵を防止でき
ることが明らかである。EXAMPLE A bloom having a composition shown in Table 1 and having a cross section of 217 mm × 217 mm was formed into a seamless tube having an outer diameter of 178 mm and a wall thickness of 11.5 mm by a Mannesmann hot rolling method. After the completion of the rolling, the occurrence of surface flaws on the pipe was examined. The results are shown in Table 1. In the present invention examples (Nos. 1 to 10), no surface flaw was generated during pipe production. On the other hand, in Comparative Examples (Nos. 11 to 20) in which at least one of the Cu, S, and B contents exceeds the component limitation range of the present invention, surface flaws occur during pipe production. From the above, it is apparent that when the Cu, S, and B contents are within the component limitation ranges of the present invention, rolling flaws can be prevented when a seamless pipe is manufactured by the Mannesmann hot rolling method.
【００２８】[0028]
【表１】 [Table 1]
【００２９】[0029]
【発明の効果】以上のように本発明によれば、Ｃｕを
０．５重量％を超えて含有し、かつ、マンネスマン方式
の圧延法によって継目無管に製管する時に圧延疵が発生
しない、表面品質に優れたマルテンサイト系ステンレス
鋼継目無鋼管が得られる。As described above, according to the present invention, Cu is contained in an amount of more than 0.5% by weight, and rolling flaws do not occur when a seamless pipe is formed by the Mannesmann rolling method. A seamless martensitic stainless steel pipe with excellent surface quality can be obtained.
【図１】Modified１３Ｃｒ鋼（０．０２Ｃ−０．０２Ｎ
−１．５Ｃｕ−１２．２Ｃｒ−５．８Ｎｉ−２．０Ｍｏ
−０．００１８Ｓ）の熱間加工性に及ぼすＢの影響を示
す図表である。FIG. 1 Modified 13Cr steel (0.02C-0.02N)
-1.5Cu-12.2Cr-5.8Ni-2.0Mo
4 is a chart showing the effect of B on hot workability of (−0.0018S).
【図２】熱間引張試験の条件を示す図表である。FIG. 2 is a table showing conditions of a hot tensile test.
【図３】Ｃｕ，Ｓ及びＢ含有量と表面疵発生状況の関係
を示す図表である。FIG. 3 is a chart showing a relationship between Cu, S, and B contents and a state of surface flaw occurrence.
フロントページの続き (72)発明者 山本 修治 北九州市戸畑区飛幡町１−１ 新日本製鐵 株式会社八幡製鐵所内 (72)発明者 能勢 幸一 富津市新富20−１ 新日本製鐵株式会社技 術開発本部内 (72)発明者 原 卓也 富津市新富20−１ 新日本製鐵株式会社技 術開発本部内Continued on the front page (72) Inventor Shuji Yamamoto 1-1 Niwahata-cho, Tobata-ku, Kitakyushu City Inside Nippon Steel Corporation Yawata Works (72) Inventor Koichi Nose 20-1 Shintomi, Futtsu City Nippon Steel Corporation (72) Inventor Takuya Hara 20-1 Shintomi, Futtsu-shi Nippon Steel Corporation Technology Development Division
Claims (3)
を特徴とする表面品質に優れたマルテンサイト系ステン
レス鋼継目無鋼管。C: 0.001 to 0.05%, Si: 0.5% or less, Mn: 0.1 to 1.5%, P: 0.03% or less, S: 0 0.002% or less, Cr: 10 to 14%, Ni: 2 to 8%, Mo: 0.5 to 3%, Cu: more than 0.5 to 3%, Al: 0.2% or less, N: 0. 001-0.05%, B: 0.0005-0.02%, O: 0.005% or less, the balance being Fe and unavoidable impurities, the balance being martensite having excellent surface quality. Stainless steel seamless steel pipe.
％で、 Ｃａ：０．００１〜０．０１％、 Ｍｇ：０．０００５〜０．０１％、 ＲＥＭ：０．００１〜０．０５％、 Ｚｒ：０．０１〜０．０５％、 Ｔｉ：０．００５〜０．０５％ の１種または２種以上を含有すことを特徴とする表面品
質に優れたマルテンサイト系ステンレス鋼継目無鋼管。2. The steel according to claim 1, further comprising: 0.001 to 0.01% of Ca, 0.0005 to 0.01% of Mg, 0.001 to 0.01% of REM by weight%. A martensitic stainless steel seam having excellent surface quality, characterized by containing one or more of 0.05%, Zr: 0.01 to 0.05%, and Ti: 0.005 to 0.05%. No steel pipe.
重量％で、 Ｎｂ：０．０５〜０．５％、 Ｖ ：０．０５〜０．５％、 Ｗ ：０．５〜３％ の１種または２種以上を含有することを特徴とする表面
品質に優れたマルテンサイト系ステンレス鋼継目無鋼
管。3. The steel according to claim 1 or 2, wherein Nb: 0.05-0.5%, V: 0.05-0.5%, W: 0.5-% by weight. A martensitic stainless steel seamless steel pipe excellent in surface quality, characterized by containing one or more kinds of 3%.
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|---|---|---|---|
| JP11975099A JP4035919B2 (en) | 1999-04-27 | 1999-04-27 | Martensitic stainless steel seamless steel pipe with excellent surface quality |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11975099A JP4035919B2 (en) | 1999-04-27 | 1999-04-27 | Martensitic stainless steel seamless steel pipe with excellent surface quality |
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| Publication Number | Publication Date |
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| JP2000313941A true JP2000313941A (en) | 2000-11-14 |
| JP4035919B2 JP4035919B2 (en) | 2008-01-23 |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1717328A1 (en) * | 2004-01-30 | 2006-11-02 | JFE Steel Corporation | Martensitic stainless steel tube |
| EP2692889A1 (en) * | 2011-03-29 | 2014-02-05 | Nippon Steel & Sumikin Stainless Steel Corporation | Ferritic stainless steel sheet having excellent heat resistance and processability, and method for producing same |
| CN105164294A (en) * | 2013-04-24 | 2015-12-16 | 新日铁住金株式会社 | Low-oxygen-purified steel and low-oxygen-purified steel product |
| CN114480952A (en) * | 2020-11-13 | 2022-05-13 | 中国科学院金属研究所 | High-strength high-toughness Cu-containing low-carbon martensitic stainless steel and heat treatment process thereof |
| EP4130317A4 (en) * | 2020-04-01 | 2023-05-17 | Nippon Steel Corporation | Steel material |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0762499A (en) * | 1993-08-26 | 1995-03-07 | Kawasaki Steel Corp | Martensitic stainless steel for oil well pipe |
| JPH0860238A (en) * | 1994-08-23 | 1996-03-05 | Nippon Steel Corp | Production of martensitic stainless steel excellent in hot workability and sulfide stress cracking resistance |
| JPH10503809A (en) * | 1994-07-21 | 1998-04-07 | 新日本製鐵株式会社 | Martensitic stainless steel with sulfide stress cracking resistance with excellent hot workability |
| JPH10130787A (en) * | 1996-10-29 | 1998-05-19 | Kawasaki Steel Corp | High strength martensitic stainless steel for oil well pipe, excellent in stress corrosion cracking resistance and high temperature tensile characteristic |
-
1999
- 1999-04-27 JP JP11975099A patent/JP4035919B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0762499A (en) * | 1993-08-26 | 1995-03-07 | Kawasaki Steel Corp | Martensitic stainless steel for oil well pipe |
| JPH10503809A (en) * | 1994-07-21 | 1998-04-07 | 新日本製鐵株式会社 | Martensitic stainless steel with sulfide stress cracking resistance with excellent hot workability |
| JPH0860238A (en) * | 1994-08-23 | 1996-03-05 | Nippon Steel Corp | Production of martensitic stainless steel excellent in hot workability and sulfide stress cracking resistance |
| JPH10130787A (en) * | 1996-10-29 | 1998-05-19 | Kawasaki Steel Corp | High strength martensitic stainless steel for oil well pipe, excellent in stress corrosion cracking resistance and high temperature tensile characteristic |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1717328A1 (en) * | 2004-01-30 | 2006-11-02 | JFE Steel Corporation | Martensitic stainless steel tube |
| EP1717328A4 (en) * | 2004-01-30 | 2012-03-28 | Jfe Steel Corp | Martensitic stainless steel tube |
| EP2692889A1 (en) * | 2011-03-29 | 2014-02-05 | Nippon Steel & Sumikin Stainless Steel Corporation | Ferritic stainless steel sheet having excellent heat resistance and processability, and method for producing same |
| EP2692889A4 (en) * | 2011-03-29 | 2014-11-26 | Nippon Steel & Sumikin Sst | Ferritic stainless steel sheet having excellent heat resistance and processability, and method for producing same |
| CN105164294A (en) * | 2013-04-24 | 2015-12-16 | 新日铁住金株式会社 | Low-oxygen-purified steel and low-oxygen-purified steel product |
| CN105164294B (en) * | 2013-04-24 | 2017-08-04 | 新日铁住金株式会社 | Hypoxemia clean steel and the pure product made from steel of hypoxemia |
| US10526686B2 (en) | 2013-04-24 | 2020-01-07 | Nippon Steel Corporation | Low-oxygen clean steel and low-oxygen clean steel product |
| EP4130317A4 (en) * | 2020-04-01 | 2023-05-17 | Nippon Steel Corporation | Steel material |
| CN114480952A (en) * | 2020-11-13 | 2022-05-13 | 中国科学院金属研究所 | High-strength high-toughness Cu-containing low-carbon martensitic stainless steel and heat treatment process thereof |
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|---|---|
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