JPH0688130A - Production of martensitic stainless steel seamless steel pipe excellent in corrosion resistance - Google Patents
Production of martensitic stainless steel seamless steel pipe excellent in corrosion resistanceInfo
- Publication number
- JPH0688130A JPH0688130A JP23869792A JP23869792A JPH0688130A JP H0688130 A JPH0688130 A JP H0688130A JP 23869792 A JP23869792 A JP 23869792A JP 23869792 A JP23869792 A JP 23869792A JP H0688130 A JPH0688130 A JP H0688130A
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- transformation point
- corrosion resistance
- temperature
- room temperature
- stainless steel
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Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は耐CO2 腐食特性に優
れ、耐硫化物応力割れ性を有する高靭性マルテンサイト
系ステンレス鋼継目無鋼管の製造法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high toughness martensitic stainless steel seamless steel pipe having excellent CO 2 corrosion resistance and sulfide stress cracking resistance.
【0002】[0002]
【従来の技術】近年、CO2 を多量に含むガスを生産す
るガス井の開発や2次回収のための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
では鋼管の腐食が激しいため耐CO2 腐食特性に優れた
マルテンサイト系ステンレス鋼管が多く使用されてい
る。特に、耐食性および熱間加工性に優れたマルテンサ
イト系ステンレス鋼として、特公昭59−15977号
公報が挙げられる。しかしながら、このマルテンサイト
系ステンレス鋼は耐食性を向上させるためにCならびに
Nの含有量を著しく低下させており、鋼塊加熱時にオー
ステナイト基地に熱間加工性を悪化させるδフェライト
相が形成されるという欠点をもつ。したがって、シーム
レス圧延のように苛酷な加工条件下では割れや疵を発生
し、歩留低下によるコストアップが避けられず、このよ
うな成分系で高耐食性を有する継目無鋼管の製造はこれ
まで非常に困難であった。2. Description of the Related Art In recent years, development of gas wells for producing gas containing a large amount of CO 2 and CO 2 injection for secondary recovery have been widely performed. In such an environment, since the steel pipe is severely corroded, a martensitic stainless steel pipe excellent in CO 2 corrosion resistance is often used. In particular, Japanese Patent Publication No. 59-15977 is cited as a martensitic stainless steel having excellent corrosion resistance and hot workability. However, in this martensitic stainless steel, the contents of C and N are remarkably reduced in order to improve the corrosion resistance, and a δ ferrite phase which deteriorates the hot workability is formed in the austenite matrix during heating of the ingot. It has drawbacks. Therefore, under severe processing conditions such as seamless rolling, cracks and flaws occur, cost increase due to yield reduction is inevitable, and the production of seamless steel pipes with high corrosion resistance with such a composition system has been extremely difficult until now. It was very difficult.
【0003】[0003]
【発明が解決しようとする課題】本発明は上記問題点を
解決するものであって、耐CO2 腐食特性に優れ、耐硫
化物応力割れ性を有する高靭性マルテンサイト系ステン
レス鋼継目無鋼管を、高い生産性のもとに製造する方法
を提供するものである。SUMMARY OF THE INVENTION The present invention solves the above problems and provides a high toughness martensitic stainless steel seamless steel pipe having excellent CO 2 corrosion resistance and sulfide stress cracking resistance. The present invention provides a method for manufacturing with high productivity.
【0004】[0004]
【課題を解決するための手段】本発明者らは多くの実験
結果から耐CO2 腐食性はCを低減化し、必要量のCr
およびMoさらにはCuを添加しておけば維持されるこ
と、耐硫化物応力割れ性は割れ抵抗性を示す組織制御を
行うことで向上することを知見した。また、熱間加工性
は、P,Sなどを低減化して介在物の形成を抑えること
と、C,Nの含有量を制御してさらにNiを添加するこ
とにより、変形抵抗の異なる異相の相分率および形状を
制御するような冶金的操作を行うことで維持されること
を知見した。From the results of many experiments, the inventors of the present invention have found that CO 2 corrosion resistance reduces C and reduces the required amount of Cr.
It was found that the addition of Mo, Cu, and Cu can maintain the sulfide stress cracking resistance, and that the sulfide stress cracking resistance can be improved by controlling the structure showing the cracking resistance. Further, the hot workability is obtained by reducing P, S, etc. to suppress the formation of inclusions, and by controlling the content of C, N, and further adding Ni, the phases of different phases having different deformation resistances can be obtained. It was found to be maintained by performing metallurgical operations such as controlling the fraction and shape.
【0005】特に、本発明者らはCならびにNの効果に
着目し次のような知見を得た。図1に、ベース成分を
1.5%Ni−12.5%Cr鋼としてCおよびN含有
量を変えた場合の耐CO2 腐食特性ならびに熱間加工時
の絞り値を示す。図1において、C.R.は40atm の
CO2 と平衡した180℃の人工海水中における年間の
腐食速度であり、C.R.<0.1mm/yであれば十分な
耐食性を有すると評価できる。また、R.A.は125
0℃に加熱した試料を900℃で歪速度3 sec-1の条件
にて単軸引張変形したときの絞り率であり、70%以上
となれば熱間変形能は良好であると言える。なお、CO
2 腐食試験には熱間加工後、焼入れ・焼きもどし処理を
行い、降伏強度が720MPa 程度を示すものを用いた。
図1より、耐CO2 腐食特性を満足するためにはC<
0.05%にする必要があり、また、十分な熱間加工性
を有するためには、C+0.8N>0.06にする必要
があるということが読み取れる(各元素記号の含有量の
単位はwt.%)。本発明は以上に述べた知見に基づいて
構成したものであって、その要旨は下記の通りである。
すなわち重量%で C ≦0.05、 Si≦0.50、 Mn≦1.0、 P ≦0.03、 S ≦0.01、 Cr:11〜17、 Ni:1.5〜5、 Cu:1〜4、 Al≦0.05、 N:0.02〜0.1で、かつC
+0.8N>0.06 を満足し、あるいはさらにMo:0.5〜2を含み、残
部が実質的にFeおよび不可避的不純物からなる鋼を熱
間加工し室温まで自然放冷した後、Ac3 変態点+10
℃〜Ac3 変態点+200℃の温度に加熱し室温まで空
冷以上の速度で冷却し、続いて、Ac1 変態点以下の温
度で焼きもどし処理するか、あるいは、上記成分の鋼を
熱間加工し室温まで自然放冷した後、Ac3 変態点+1
0℃〜Ac3 変態点+200℃の温度に加熱し室温まで
空冷以上の速度で冷却し、次いで、Ac1 変態点〜Ac
3 変態点の温度に加熱して室温まで空冷以上の速度で冷
却し、続いて、Ac1 変態点以下の温度にて焼きもどし
処理する耐食性に優れたマルテンサイト系ステンレス鋼
継目無鋼管の製造法である。In particular, the present inventors have paid attention to the effects of C and N and have obtained the following findings. FIG. 1 shows the CO 2 corrosion resistance characteristics and the drawing value during hot working when the C and N contents were changed with 1.5% Ni-12.5% Cr steel as the base component. In FIG. 1, C.I. R. Is the annual corrosion rate in artificial seawater at 180 ° C. equilibrated with 40 atm CO 2 . R. If it is <0.1 mm / y, it can be evaluated as having sufficient corrosion resistance. In addition, R. A. Is 125
It is the reduction ratio when the sample heated to 0 ° C. is uniaxially tensile deformed at 900 ° C. under a strain rate of 3 sec −1. If it is 70% or more, it can be said that the hot deformability is good. In addition, CO
(2) For the corrosion test, the one having a yield strength of about 720 MPa was used after quenching and tempering after hot working.
From FIG. 1, it was found that in order to satisfy the CO 2 corrosion resistance, C <
It can be read that it is necessary to set the content to 0.05%, and it is necessary to set C + 0.8N> 0.06 in order to have sufficient hot workability (the unit of the content of each element symbol is wt.%). The present invention is constructed on the basis of the above-mentioned findings, and its gist is as follows.
That is, in weight%, C ≦ 0.05, Si ≦ 0.50, Mn ≦ 1.0, P ≦ 0.03, S ≦ 0.01, Cr: 11 to 17, Ni: 1.5 to 5, Cu: 1-4, Al ≦ 0.05, N: 0.02-0.1, and C
Steel satisfying + 0.8N> 0.06 or further containing Mo: 0.5 to 2 and the balance being substantially Fe and unavoidable impurities is hot worked and naturally cooled to room temperature. 3 transformation points +10
℃ ~ Ac 3 transformation point + 200 ℃ temperature is cooled to room temperature at a rate of air cooling or more, followed by tempering treatment at a temperature of Ac 1 transformation point or less, or hot working of the steel of the above components After allowing to cool naturally to room temperature, Ac 3 transformation point +1
It is heated to a temperature of 0 ° C to Ac 3 transformation point + 200 ° C and cooled to room temperature at a rate of air cooling or higher, and then Ac 1 transformation point to Ac
3 Martensitic stainless steel seamless steel pipe with excellent corrosion resistance, which is heated to the temperature of 3 transformation points, cooled to room temperature at a rate of air cooling or higher, and then tempered at a temperature of the Ac 1 transformation point or lower Is.
【0006】以下に本発明について詳細に説明する。ま
ず、鋼成分の限定理由について述べる。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が、典型的
なオーステナイト形成元素であり、熱間加工温度域であ
る900〜1250℃でδフェライト相の発生を抑制す
る効果があるために含有させる。ただし、0.05%を
超える量を含有するとCr炭化物などの炭化物が多量に
析出してCr欠乏層を形成するために耐CO2 腐食特性
が低下し、また、粒界に炭化物が析出しやすくなるため
に耐硫化物応力割れ性が著しく低下する。したがってC
含有量は0.05%以下とした。The present invention will be described in detail below. First, the reasons for limiting the steel components will be described. C is an element that forms Cr carbide and deteriorates the corrosion resistance, but is a typical austenite forming element and has an effect of suppressing the occurrence of the δ ferrite phase in the hot working temperature range of 900 to 1250 ° C. Contained in. However, if the content exceeds 0.05%, a large amount of carbides such as Cr carbides precipitate to form a Cr-deficient layer, which deteriorates the CO 2 corrosion resistance and also causes carbides to easily precipitate at grain boundaries. Therefore, the sulfide stress cracking resistance is significantly reduced. Therefore C
The content was 0.05% or less.
【0007】Siは製鋼上脱酸材として添加され残有さ
れたもので、鋼の中に0.50%を超えて含有されると
靭性および耐硫化物応力割れ性を低下するために、0.
50%以下とした。Si is added as a deoxidizing agent in steelmaking and remains. When it is contained in the steel in an amount of more than 0.50%, toughness and sulfide stress cracking resistance are deteriorated. .
It was set to 50% or less.
【0008】Mnは介在物を形成し腐食環境下で割れ抵
抗性を損なう元素であるが、オーステナイト単相化する
ために有用な成分であるために添加する。ただし、1.
0%を超えて添加すると多量の介在物を形成するため
に、腐食環境下での割れ抵抗性と靭性が低下する。した
がって、Mnの含有量は1.0%以下とした。[0008] Mn is an element that forms inclusions and impairs crack resistance in a corrosive environment, but is added because it is a useful component for forming an austenite single phase. However, 1.
If added in excess of 0%, a large amount of inclusions are formed, so that the crack resistance and toughness in a corrosive environment deteriorate. Therefore, the Mn content is set to 1.0% or less.
【0009】Pは粒界に偏析して粒界強度を弱め、熱間
加工性および耐硫化物応力割れ性を低下させるので0.
03%以下とした。Sは硫化物として介在物を形成し熱
間加工性を低下させるため、その上限を0.01%とし
た。P segregates at the grain boundaries, weakens the grain boundary strength, and reduces hot workability and sulfide stress cracking resistance.
It was set to 03% or less. Since S forms inclusions as sulfides and deteriorates hot workability, the upper limit was made 0.01%.
【0010】Crは本発明の目的とする耐CO2 腐食性
を付与し、ステンレス鋼としての腐食性を有するために
は、11%以上の含有が必要である。しかし、17%を
超えて添加するとフェライト相が生成しやすくなるため
に、その限定範囲を11〜17%とした。In order to impart the CO 2 corrosion resistance, which is the object of the present invention, and to have the corrosion resistance as stainless steel, Cr must be contained in an amount of 11% or more. However, if it is added in excess of 17%, a ferrite phase is likely to be formed, so the limited range is set to 11 to 17%.
【0011】NiはCr含有鋼においては耐食性を向上
させる効果がある。しかも、強力なオーステナイト形成
元素であり、高温加熱時にδフェライト相の形成を抑制
するうえ、その形状を細く短くし熱間加工時にδフェラ
イト相内部に形成されるクラックの成長を抑える効果が
あることから、熱間加工性を向上させる効果も有する。
ただし、N:0.02%の場合にNi:1.5%以下の
添加ではそれらの効果を示さず、また、5%を超えて添
加するとAc1 点が非常に低くなり調質が困難になるこ
とと、残留オーステナイト相が形成されて強度・靭性を
損なうために、その限定範囲を1.5〜5%とした。Ni has the effect of improving the corrosion resistance of Cr-containing steel. Moreover, it is a strong austenite forming element, and it has the effect of suppressing the formation of the δ ferrite phase during high temperature heating, and also of suppressing the growth of cracks formed inside the δ ferrite phase during hot working by making the shape thin and short. Therefore, it also has an effect of improving hot workability.
However, when N: 0.02%, addition of Ni: 1.5% or less does not show these effects, and when it exceeds 5%, the Ac 1 point becomes extremely low and tempering becomes difficult. In addition, since the retained austenite phase is formed and the strength and toughness are impaired, the limiting range is set to 1.5 to 5%.
【0012】Cuは耐CO2 腐食特性を向上させる効果
がある。また、オーステナイト安定化元素であり、Ac
1 変態点を低下させないという利点も有する。ただし、
含有量が1%以下では耐食性向上効果が十分でないこ
と、4%を超える添加量では高温割れに敏感となり熱間
加工性が低下することから、添加量を1〜4%の範囲に
限定した。また、Cu単独の添加では上記効果が小さい
ことから、必ずNiと複合させて添加することとした。Cu has the effect of improving the CO 2 corrosion resistance. Further, it is an austenite stabilizing element, and Ac
1 It also has the advantage of not lowering the transformation point. However,
When the content is 1% or less, the effect of improving the corrosion resistance is not sufficient, and when the content is more than 4%, it is sensitive to hot cracking and the hot workability is deteriorated. Therefore, the content is limited to the range of 1 to 4%. Further, since the above effect is small when Cu alone is added, it is always added in combination with Ni.
【0013】AlはSiと同様に脱酸剤として添加され
残有されたもので、0.05%を超えて添加するとAl
Nが多数形成されて著しく靭性が低下する。したがっ
て、添加量の上限を0.05%とした。Al, like Si, was added as a deoxidizer and remained. If added in excess of 0.05%, Al
A large amount of N is formed and the toughness is significantly reduced. Therefore, the upper limit of the amount added is set to 0.05%.
【0014】Nは耐食性に対し無害であるうえに、Cと
同様に典型的なオーステナイト形成元素であり、熱間加
工温度域である900〜1250℃でフェライト相の形
成を抑える効果がある。その効果は、前述のように1.
5%Ni−12.5%Cr鋼をベース成分とする場合に
は、C+0.8N<0.06(C,Nはwt.%)を満た
す含有量の範囲において有効である。したがって、C<
0.05%の場合に熱間加工温度域にてフェライト相を
発生させず、良好な熱間加工性を得るためにはNを0.
02%以上添加する必要がある。また、通常の溶製工程
においては0.1%以上の添加は困難であるためにその
添加量の範囲を0.02〜0.1%とした。N is harmless to the corrosion resistance and is a typical austenite forming element like C, and has the effect of suppressing the formation of the ferrite phase in the hot working temperature range of 900 to 1250 ° C. The effect is 1.
When 5% Ni-12.5% Cr steel is used as the base component, it is effective in the range of the content satisfying C + 0.8N <0.06 (C and N are wt.%). Therefore, C <
In the case of 0.05%, in order to obtain a good hot workability without generating a ferrite phase in the hot working temperature range, N is set to 0.
It is necessary to add 02% or more. In addition, since it is difficult to add 0.1% or more in the usual melting process, the range of the addition amount is set to 0.02 to 0.1%.
【0015】Moは耐孔食性を向上させるのに有効な元
素であり、必要に応じてこれを添加する。ただし、0.
5%以下の添加ではその効果が小さい。また、強力なフ
ェライト安定化元素であり、2%を超えて添加するとδ
相を生成しやすくなることから、その限定範囲を0.5
〜2%とした。Mo is an element effective for improving the pitting corrosion resistance, and is added if necessary. However, 0.
The effect is small with the addition of 5% or less. It is also a strong ferrite stabilizing element, and if added in excess of 2%, δ
Since the phase is easily generated, the limited range is 0.5.
~ 2%.
【0016】次に熱処理条件の限定理由について述べ
る。オーステナイト化加熱温度は、Cr含有ステンレス
鋼のγループ内において、炭化物が完全に固溶せず結晶
粒の粗大化が生じない温度を上限とし、また、オーステ
ナイト相が安定となる最低の温度を下限とした。すなわ
ち、熱間加工して冷却された鋼管を、Ac3 変態点+2
00℃以上の温度に加熱すると炭化物が完全に固溶する
ために、冷却時にCr炭化物などが粒界に多量に析出し
耐食性が著しく低下し、さらに結晶粒の粗大化が生じる
ために、靭性が低下する。また、Ac3 変態点+10℃
以下の低い温度に加熱した場合には、オーステナイト相
が安定化せず、安定した強度を得ることが困難である。
したがって、加熱処理温度はAc3 変態点+10℃〜A
c3 変態点+200℃とした。この加熱後の冷却速度が
空冷よりも遅いと粒界に炭化物が板状に析出し、靭性が
著しく低下するために空冷以上の冷却速度に限定した。Next, the reasons for limiting the heat treatment conditions will be described. The upper limit of the austenitizing heating temperature is the temperature at which the carbide is not completely dissolved in the γ loop of the Cr-containing stainless steel and coarsening of the crystal grains does not occur, and the lower limit is the lowest temperature at which the austenite phase becomes stable. And That is, a steel pipe that has been hot worked and cooled has an Ac 3 transformation point of +2.
When heated to a temperature of 00 ° C. or higher, the carbide is completely dissolved, so that a large amount of Cr carbide or the like is precipitated at the grain boundary during cooling, the corrosion resistance is significantly lowered, and the coarseness of the crystal grain occurs, so that the toughness is improved. descend. Also, Ac 3 transformation point + 10 ° C
When heated to the low temperature below, the austenite phase is not stabilized and it is difficult to obtain stable strength.
Therefore, the heat treatment temperature is Ac 3 transformation point + 10 ° C to A
The c 3 transformation point was set to + 200 ° C. If the cooling rate after this heating is slower than that of air cooling, carbide precipitates in the grain boundary in the form of a plate and the toughness is significantly reduced, so the cooling rate was limited to air cooling or higher.
【0017】こうして室温まで冷却するとマルテンサイ
ト変態が生じて、マルテンサイト単相組織となる。この
マルテンサイト組織中の残留応力を回復により消滅さ
せ、過飽和炭素原子を炭化物として析出させることによ
って、靭性・延性を高め、所望の強度を得るために焼き
もどし処理を施す。このとき、Ac1 変態点以上の温度
に加熱すると逆変態が生じて靭性が著しく低下するため
に、焼きもどし処理はAc1 変態点以下の温度にて行
う。When cooled to room temperature in this way, martensitic transformation occurs to form a martensitic single-phase structure. The residual stress in the martensite structure is eliminated by recovery, and supersaturated carbon atoms are precipitated as carbides to enhance toughness and ductility, and a tempering treatment is performed to obtain desired strength. At this time, if the material is heated to a temperature above the Ac 1 transformation point, reverse transformation occurs and the toughness is significantly reduced, so the tempering treatment is performed at a temperature below the Ac 1 transformation point.
【0018】また、オーステナイト化処理後の焼きもど
し処理を行う前に、必要に応じてAc1 変態点〜Ac3
変態点の温度範囲に加熱することによる2相域加熱処理
を行う。これは、鋼を1回の焼きもどし処理では得られ
ない低い強度に調質することを目的としており、この処
理を用いて低い強度に調質することにより、鋼に十分な
耐硫化物応力割れ性を付与することが可能となる。以上
のような本発明法により製造された鋼管は、耐CO2 腐
食特性・耐硫化物応力割れ性だけでなく、靭性なども優
れている。Before the tempering treatment after the austenitizing treatment, if necessary, the Ac 1 transformation point to Ac 3
Two-phase heat treatment is performed by heating in the temperature range of the transformation point. This is aimed at tempering the steel to a low strength that cannot be obtained by a single tempering treatment. By tempering the steel to a low strength using this treatment, sufficient sulfide stress crack resistance of the steel can be obtained. It is possible to impart the sex. The steel pipe manufactured by the method of the present invention as described above is excellent not only in CO 2 corrosion resistance and sulfide stress cracking resistance but also in toughness.
【0019】[0019]
【実施例】まず、表1に示される化学成分の鋼を通常の
溶製工程にて鋳造した後、熱間圧延により鋼管を製造
し、加熱処理と焼きもどし処理を施したものを用いて、
強度、靭性、耐CO2 腐食性、耐硫化物応力割れ性を調
査した。そのときの熱処理温度と強度などの材質につい
ては表2に示す。耐CO2 腐食性は40気圧のCO2 と
平衡した150℃の人工海水中での腐食速度で評価し
た。腐食速度が0.1mm/y以下であれば耐食性を有する
と見なせる。耐硫化物応力割れ性は丸棒引張試験片を2
5℃の5%NaCl溶液中に1気圧の99%CO2 +1
%H2 Sガスを飽和した腐食環境中で単軸引張応力を加
え、720時間で破壊が生じない最大初期応力と降伏応
力の比(Rs値)を求めた。Rs≧0.8であれば優れ
た特性であるといえる。EXAMPLES First, after casting a steel having the chemical composition shown in Table 1 in a usual melting process, a steel pipe was manufactured by hot rolling and subjected to heat treatment and tempering treatment.
The strength, toughness, CO 2 corrosion resistance, and sulfide stress cracking resistance were investigated. Table 2 shows materials such as heat treatment temperature and strength at that time. The CO 2 corrosion resistance was evaluated by the corrosion rate in artificial seawater at 150 ° C. equilibrated with 40 atm of CO 2 . If the corrosion rate is 0.1 mm / y or less, it can be considered to have corrosion resistance. The resistance to sulfide stress cracking is 2 for round bar tensile test pieces.
99% CO 2 +1 at 1 atm in 5% NaCl solution at 5 ° C
A uniaxial tensile stress was applied in a corrosive environment saturated with% H 2 S gas, and the ratio (Rs value) of the maximum initial stress and yield stress at which breakage did not occur at 720 hours was determined. If Rs ≧ 0.8, it can be said that the characteristics are excellent.
【0020】[0020]
【表1】 [Table 1]
【0021】[0021]
【表2】 [Table 2]
【0022】表2の結果より、本発明法により製造され
た鋼管は良好な耐CO2 腐食性、耐硫化物応力割れ性な
らびに高靭性を示すのに対し、本発明の範囲から外れた
比較法ではいずれかの特性が劣っていることが明らかで
ある。From the results shown in Table 2, the steel pipes produced by the method of the present invention show good CO 2 corrosion resistance, sulfide stress cracking resistance and high toughness, while the comparative method out of the range of the present invention. It is clear that one of the characteristics is inferior.
【0023】[0023]
【発明の効果】以上のように本発明は含有成分を特定
し、かつ組織制御を行うことによって、耐CO2 腐食
性、耐硫化物応力割れ性にすぐれ、マルテンサイト系ス
テンレス鋼継目無鋼管を提供できる。INDUSTRIAL APPLICABILITY As described above, the present invention provides a martensitic stainless steel seamless steel pipe excellent in CO 2 corrosion resistance and sulfide stress cracking resistance by specifying the contained components and controlling the structure. Can be provided.
【図1】CO2 腐食環境での腐食速ならびに熱間変形時
の絞り率におよぼすC,Nの影響を示す図である。FIG. 1 is a diagram showing the influence of C and N on the corrosion rate in a CO 2 corrosive environment and the drawing rate during hot deformation.
Claims (4)
避的不純物からなる鋼を熱間加工し室温まで自然放冷し
た後、Ac3 変態点+10℃〜Ac3 変態点+200℃
の温度に加熱し室温まで空冷以上の速度で冷却し、続い
て、Ac1 変態点以下の温度で焼きもどし処理すること
を特徴とする耐食性に優れたマルテンサイト系ステンレ
ス鋼継目無鋼管の製造法。1. By weight%, C ≦ 0.05, Si ≦ 0.50, Mn ≦ 1.0, P ≦ 0.03, S ≦ 0.01, Cr: 11 to 17, Cu: 1 to 4 , Ni: 1.5 to 5, Al ≦ 0.05, N: 0.02 to 0.1, and C + 0.8N> 0.06, with the balance being substantially Fe and unavoidable. After hot working the steel made of impurities and allowing it to cool naturally to room temperature, the Ac 3 transformation point + 10 ° C to the Ac 3 transformation point + 200 ° C
Of the martensitic stainless steel with excellent corrosion resistance, which is characterized by heating to a temperature of room temperature, cooling to room temperature at a rate of air cooling or more, and subsequently tempering at a temperature of Ac 1 transformation point or less. .
避的不純物からなる鋼を熱間加工し室温まで自然放冷し
た後、Ac3 変態点+10℃〜Ac3 変態点+200℃
の温度に加熱し室温まで空冷以上の速度で冷却し、続い
て、Ac1 変態点以下の温度で焼きもどし処理すること
を特徴とする耐食性に優れたマルテンサイト系ステンレ
ス鋼継目無鋼管の製造法。2. In% by weight, C ≦ 0.05, Si ≦ 0.50, Mn ≦ 1.0, P ≦ 0.03, S ≦ 0.01, Cr: 11-17, Cu: 1-4 , Ni: 1.5 to 5, Mo: 0.5 to 2, Al ≦ 0.05, N: 0.02 to 0.1, and C + 0.8N> 0.06. Of steel substantially consisting of Fe and unavoidable impurities is hot-worked and naturally cooled to room temperature, and then Ac 3 transformation point + 10 ° C to Ac 3 transformation point + 200 ° C.
Of the martensitic stainless steel with excellent corrosion resistance, which is characterized by heating to a temperature of room temperature, cooling to room temperature at a rate of air cooling or more, and subsequently tempering at a temperature of Ac 1 transformation point or less. .
避的不純物からなる鋼を熱間加工し室温まで自然放冷し
た後、Ac3 変態点+10℃〜Ac3 変態点+200℃
の温度に加熱し室温まで空冷以上の速度で冷却し、次い
で、Ac1 変態点〜Ac3 変態点の温度に加熱して室温
まで空冷以上の速度で冷却し、続いて、Ac1 変態点以
下の温度で焼きもどし処理することを特徴とする耐食性
に優れたマルテンサイト系ステンレス鋼継目無鋼管の製
造法。3. By weight%, C ≦ 0.05, Si ≦ 0.50, Mn ≦ 1.0, P ≦ 0.03, S ≦ 0.01, Cr: 11 to 17, Cu: 1 to 4 , Ni: 1.5 to 5, Al ≦ 0.05, N: 0.02 to 0.1, and C + 0.8N> 0.06, with the balance being substantially Fe and unavoidable. After hot working the steel made of impurities and allowing it to cool naturally to room temperature, the Ac 3 transformation point + 10 ° C to the Ac 3 transformation point + 200 ° C
Temperature was heated to and cooled by air cooling or faster to room temperature, then, Ac 1 and heated to a temperature of transformation point to Ac 3 transformation point is cooled at a rate of more than air cooling to room temperature, followed by less Ac 1 transformation point A method for producing a seamless martensitic stainless steel pipe with excellent corrosion resistance, characterized by performing tempering treatment at
避的不純物からなる鋼を熱間加工し室温まで自然放冷し
た後、Ac3 変態点+10℃〜Ac3 変態点+200℃
の温度に加熱し室温まで空冷以上の速度で冷却し、次い
で、Ac1 変態点〜Ac3 変態点の温度に加熱して室温
まで空冷以上の速度で冷却し、続いて、Ac1 変態点以
下の温度で焼きもどし処理することを特徴とする耐食性
に優れたマルテンサイト系ステンレス鋼継目無鋼管の製
造法。4. By weight%, C ≦ 0.05, Si ≦ 0.50, Mn ≦ 1.0, P ≦ 0.03, S ≦ 0.01, Cr: 11-17, Cu: 1-4 , Ni: 1.5 to 5, Mo: 0.5 to 2, Al ≦ 0.05, N: 0.02 to 0.1, and C + 0.8N> 0.06. Of steel substantially consisting of Fe and unavoidable impurities is hot-worked and naturally cooled to room temperature, and then Ac 3 transformation point + 10 ° C to Ac 3 transformation point + 200 ° C.
Temperature was heated to and cooled by air cooling or faster to room temperature, then, Ac 1 and heated to a temperature of transformation point to Ac 3 transformation point is cooled at a rate of more than air cooling to room temperature, followed by less Ac 1 transformation point A method for producing a seamless martensitic stainless steel pipe with excellent corrosion resistance, characterized by performing tempering treatment at
Priority Applications (1)
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JP4238697A JP2672437B2 (en) | 1992-09-07 | 1992-09-07 | Manufacturing method of martensitic stainless steel seamless steel pipe with excellent corrosion resistance |
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Application Number | Priority Date | Filing Date | Title |
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JP4238697A JP2672437B2 (en) | 1992-09-07 | 1992-09-07 | Manufacturing method of martensitic stainless steel seamless steel pipe with excellent corrosion resistance |
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JPH0688130A true JPH0688130A (en) | 1994-03-29 |
JP2672437B2 JP2672437B2 (en) | 1997-11-05 |
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ID=17033958
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JP4238697A Expired - Fee Related JP2672437B2 (en) | 1992-09-07 | 1992-09-07 | Manufacturing method of martensitic stainless steel seamless steel pipe with excellent corrosion resistance |
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Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08246107A (en) * | 1995-03-10 | 1996-09-24 | Nippon Steel Corp | Martensitic stainless steel excellent in carbon dioxide corrosion resistance and sulfide stress corrosion cracking resistance |
EP0738784A1 (en) * | 1995-04-21 | 1996-10-23 | Kawasaki Steel Corporation | High chromium martensitic steel pipe having excellent pitting resistance and method of manufacturing |
JPH08295939A (en) * | 1995-04-21 | 1996-11-12 | Kawasaki Steel Corp | Production of high chromium martensitic steel pipe for line pipe |
EP2172573A1 (en) * | 2007-06-29 | 2010-04-07 | JFE Steel Corporation | Martensitic stainless-steel seamless pipe for oil well pipe and process for producing the same |
CN109689913A (en) * | 2016-05-19 | 2019-04-26 | 奥钢联百乐特殊钢有限两合公司 | The manufacturing method and steel of steel |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0499128A (en) * | 1990-08-03 | 1992-03-31 | Nippon Steel Corp | Production of martensitic stainless steel line pipe |
JPH04183816A (en) * | 1990-11-16 | 1992-06-30 | Nippon Steel Corp | Production of co2 corrosion resistant steel pipe having superior hot workability and weldability |
JPH04268019A (en) * | 1991-02-22 | 1992-09-24 | Nippon Steel Corp | Production of martensitic stainless steel line pipe |
JPH05263138A (en) * | 1992-02-18 | 1993-10-12 | Nippon Steel Corp | Production of seamless tube of martensitic stainless steel excellent in corrosion resistance |
-
1992
- 1992-09-07 JP JP4238697A patent/JP2672437B2/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0499128A (en) * | 1990-08-03 | 1992-03-31 | Nippon Steel Corp | Production of martensitic stainless steel line pipe |
JPH04183816A (en) * | 1990-11-16 | 1992-06-30 | Nippon Steel Corp | Production of co2 corrosion resistant steel pipe having superior hot workability and weldability |
JPH04268019A (en) * | 1991-02-22 | 1992-09-24 | Nippon Steel Corp | Production of martensitic stainless steel line pipe |
JPH05263138A (en) * | 1992-02-18 | 1993-10-12 | Nippon Steel Corp | Production of seamless tube of martensitic stainless steel excellent in corrosion resistance |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH08246107A (en) * | 1995-03-10 | 1996-09-24 | Nippon Steel Corp | Martensitic stainless steel excellent in carbon dioxide corrosion resistance and sulfide stress corrosion cracking resistance |
EP0738784A1 (en) * | 1995-04-21 | 1996-10-23 | Kawasaki Steel Corporation | High chromium martensitic steel pipe having excellent pitting resistance and method of manufacturing |
JPH08295939A (en) * | 1995-04-21 | 1996-11-12 | Kawasaki Steel Corp | Production of high chromium martensitic steel pipe for line pipe |
US5858128A (en) * | 1995-04-21 | 1999-01-12 | Kawasaki Steel Corporation | High chromium martensitic steel pipe having excellent pitting resistance and method of manufacturing |
US6136109A (en) * | 1995-04-21 | 2000-10-24 | Kawasaki Steel Corporation | Method of manufacturing high chromium martensite steel pipe having excellent pitting resistance |
EP2172573A1 (en) * | 2007-06-29 | 2010-04-07 | JFE Steel Corporation | Martensitic stainless-steel seamless pipe for oil well pipe and process for producing the same |
EP2172573A4 (en) * | 2007-06-29 | 2011-05-18 | Jfe Steel Corp | Martensitic stainless-steel seamless pipe for oil well pipe and process for producing the same |
CN109689913A (en) * | 2016-05-19 | 2019-04-26 | 奥钢联百乐特殊钢有限两合公司 | The manufacturing method and steel of steel |
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