JPH07150287A - Production of tube stock for steel tube joint coupling and iron powder used therefor - Google Patents
Production of tube stock for steel tube joint coupling and iron powder used thereforInfo
- Publication number
- JPH07150287A JPH07150287A JP5301632A JP30163293A JPH07150287A JP H07150287 A JPH07150287 A JP H07150287A JP 5301632 A JP5301632 A JP 5301632A JP 30163293 A JP30163293 A JP 30163293A JP H07150287 A JPH07150287 A JP H07150287A
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- JP
- Japan
- Prior art keywords
- steel
- steel tube
- iron powder
- coupling
- joint coupling
- 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.)
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- Powder Metallurgy (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、油井管の継手カップリ
ング素管の製造方法及びそれに用いる鉄粉に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a coupling / coupling element pipe for an oil country tubular good and an iron powder used therefor.
【０００２】[0002]
【従来の技術】従来、油井管の継手カップリングの素管
には、シームレスパイプが用いられており、切削加工、
ネジ切りプロセスを経てカップリング形状に仕上げられ
ている。しかしながら、高耐蝕性材料である高Ｃｒ鋼の
切削性は低いため、上記切削加工及びネジ切り加工のコ
ストは極めて高いものとなっている。2. Description of the Related Art Conventionally, a seamless pipe has been used as a base pipe for a joint coupling of an oil well pipe.
Finished into a coupling shape through a thread cutting process. However, since the high-Cr steel, which is a highly corrosion-resistant material, has low machinability, the cost of the cutting and threading is extremely high.
【０００３】一方、高Ｃｒ鋼管をシームレスプロセスで
製造する場合、熱間加工性の点からＳ量を０．００３ｗ
ｔ％以下に低減している（特公平3- 60904号公報）。し
たがって、シームレスパイプをカップリングの素管とす
る場合には、切削性向上元素であるＳを添加することが
困難である。On the other hand, when a high Cr steel pipe is manufactured by a seamless process, the S content is 0.003 w from the viewpoint of hot workability.
It is reduced to t% or less (Japanese Patent Publication No. 3-60904). Therefore, when a seamless pipe is used as a coupling pipe, it is difficult to add S which is a machinability improving element.
【０００４】[0004]
【発明が解決しようとする課題】前記したように、従来
のシームレスパイプを高Ｃｒ鋼のカップリング素管とし
て用いる方法では、切削性の改善が極めて困難であり、
コスト的に不利であった。さらに、カップリングの概念
断面図を図１に示すが（２−７／８インチサイズの
例）、円周上に突起物があり、従来法では切削代が大き
くなり、この点でもコスト的に不利であった。As described above, it is extremely difficult to improve machinability in the conventional method of using a seamless pipe as a coupling element pipe of high Cr steel,
It was a cost disadvantage. Furthermore, a conceptual cross-sectional view of the coupling is shown in FIG. 1 (example of 2-7 / 8 inch size), but there are protrusions on the circumference, and the cutting allowance is large in the conventional method, and in this respect also in terms of cost. It was a disadvantage.
【０００５】本発明の目的は、前記問題点を解決するた
めに、鉄粉の焼結鍛造材を用いる鋼管継手カップリング
素管の製造方法及びそれに用いる鉄粉を提案することで
ある。An object of the present invention is to propose a method for producing a steel pipe coupling coupling element pipe using a sintered forged material of iron powder and an iron powder used for the same, in order to solve the above problems.
【０００６】[0006]
【課題を解決するための手段】本発明は、Ｃｒ：５〜２
０ｗｔ％、Ｓ：０．００５〜０．０５ｗｔ％を含む鉄粉
に、必要に応じて０．４ｗｔ％以下の黒鉛を添加し、該
粉末を圧粉体に成形し、さらに１１００℃以上１３００
℃以下の不活性ガスあるいは還元ガス中で焼結し、その
後、空冷し９００℃以上１３００℃以下に不活性ガスあ
るいは還元ガス中で再加熱し鍛造するか、もしくは焼結
後直ちに９００℃以上１３００℃以下の温度で鍛造し、
さらに熱処理することを特徴とする鋼管継手カップリン
グ素管の製造方法であり、また本発明は、Ｃｒ：５〜２
０ｗｔ％、Ｓ：０．００５〜０．０５ｗｔ％を含む鋼管
継手カップリング素管用鉄粉である。The present invention provides Cr: 5 to 2
If necessary, 0.4 wt% or less of graphite is added to an iron powder containing 0 wt% and S: 0.005 to 0.05 wt%, the powder is molded into a green compact, and further 1100 ° C or higher and 1300 ° C.
Sintering in an inert gas or reducing gas below ℃, then air-cooling and reheating to 900 ° C to 1300 ° C in an inert gas or reducing gas forging, or immediately after sintering 900 ° C to 1300 Forged at a temperature below ℃,
Further, the present invention is a method for producing a steel pipe coupling coupling element pipe characterized by further heat treatment, and the present invention provides Cr: 5 to 2
It is an iron powder for a steel pipe joint coupling element pipe containing 0 wt% and S: 0.005 to 0.05 wt%.
【０００７】[0007]
【作 用】本発明のカップリング素管は、粉末を原料と
して成形→焼結→熱間鍛造→熱処理のプロセスで製造す
るため、シームレスパイプ製造において必要となる熱間
加工性は、大きな問題とはならず、したがって、切削性
改善元素であるＳを添加することができる。[Operation] Since the coupling tube of the present invention is manufactured by a process of molding → sintering → hot forging → heat treatment using powder as a raw material, the hot workability required for seamless pipe production is a major problem. Therefore, S, which is a machinability improving element, can be added.
【０００８】さらに、焼結鍛造法では、図１に示した突
起物を形成することが容易で、したがって、より素管に
近いニアネットシェープのカップリング素管が製造でき
る。また、焼結鍛造法であれば、ほぼ真密度に近い材料
が得られ、強度、靭性ともに十分な特性が得られる。次
に、まず鉄粉組成の限定理由について説明する。Further, in the sintering forging method, the projection shown in FIG. 1 can be easily formed, and therefore, a near net shape coupling element pipe closer to the element pipe can be manufactured. In addition, if the sintering forging method is used, a material close to the true density can be obtained, and sufficient strength and toughness characteristics can be obtained. Next, the reasons for limiting the iron powder composition will be described first.
【０００９】Ｃｒ：５〜２０ｗｔ％ Ｃｒは耐蝕性とくにＣＯ2 環境下での全面腐食性を向上
させる。そのためにはＣｒは５ｗｔ％以上、好ましくは
９ｗｔ％以上必要である。一方、２０ｗｔ％を超えると
コスト的に不利となるのでＣｒは５〜２０ｗｔ％に限定
される。 Ｓ：０．００５〜０．０５ｗｔ％ Ｓは本発明の大きな特徴の一つである。Ｓは０．００５
ｗｔ％未満であると切削性向上効果はなく、一方、０．
０５ｗｔ％を超えると靭性が低下するので、Ｓは０．０
０５〜０．０５ｗｔ％に限定される。Cr: 5 to 20 wt% Cr improves the corrosion resistance, especially the general corrosion resistance in a CO 2 environment. For that purpose, Cr needs to be 5 wt% or more, preferably 9 wt% or more. On the other hand, if it exceeds 20 wt%, there is a cost disadvantage, so Cr is limited to 5 to 20 wt%. S: 0.005-0.05 wt% S is one of the major characteristics of the present invention. S is 0.005
If it is less than wt%, there is no machinability improving effect, while on the other hand,
If it exceeds 05 wt%, the toughness decreases, so S is 0.0
It is limited to 05 to 0.05 wt%.
【００１０】本発明で用いる鉄粉の基本的組成は上記の
通りであるが、Ｍｎは1.0 ｗｔ％以下、Ｓｉは2.0 ｗｔ
％以下、Ｎｉは10ｗｔ％以下、Ｍｏは10ｗｔ％以下含有
できる。また、不可避的不純物としてＣは0.01ｗｔ％以
下、Ｐは0.030 ｗｔ％以下含有できる。以上のような組
成の鉄粉を用いて成形する際、必要に応じて黒鉛を０．
４ｗｔ％以下添加することができる。その理由は、黒鉛
を添加することで高強度化が図れるためである。しか
し、0.4 ｗｔ％を超えると靱性が低下する。The basic composition of the iron powder used in the present invention is as described above, but Mn is 1.0 wt% or less and Si is 2.0 wt%.
%, Ni can be contained in an amount of 10 wt% or less, and Mo can be included in an amount of 10 wt% or less. Further, as unavoidable impurities, C can be contained in an amount of 0.01 wt% or less and P can be included in an amount of 0.030 wt% or less. When the iron powder having the above composition is used for molding, graphite may be added in an amount of 0.
4 wt% or less can be added. The reason is that the addition of graphite can increase the strength. However, if the content exceeds 0.4 wt%, the toughness decreases.
【００１１】次に、成形・焼結・鍛造・熱処理条件につ
いて説明する。前記粉末から成形体を製造するが、これ
は従来の成形条件を用いればよく特に問題はない。その
際、ハンドリング時での割れを考慮して密度６．６ｇ／
ｃｍ3以上の成形体を製造することが望ましい。成形体
を焼結するプロセスにおいては、温度を１１００℃以上
１３００℃以下とする必要がある。１１００℃未満であ
ると緻密化が進行せず、次の鍛造プロセスで内部まで酸
化し強度、靭性を損なう。一方、１３００℃超の加熱で
は経済的に不利となる。Next, the conditions of molding, sintering, forging and heat treatment will be described. A molded body is manufactured from the above powder, and there is no particular problem as long as conventional molding conditions are used. At that time, considering the cracking during handling, the density is 6.6 g /
It is desirable to produce a molded body having a size of 3 cm 3 or more. In the process of sintering the compact, the temperature needs to be 1100 ° C or higher and 1300 ° C or lower. If the temperature is lower than 1100 ° C, the densification does not proceed and the interior is oxidized in the next forging process, and the strength and toughness are impaired. On the other hand, heating above 1300 ° C is economically disadvantageous.
【００１２】また、焼結雰囲気ガスは窒素ガスのような
不活性ガスあるいは水素ガス、ＡＸガスのような還元ガ
スとする必要がある。高Ｃｒ鋼焼結材料は酸化しやす
く、ＲＸガスのような酸化雰囲気ガスであると酸化が進
行し、強度、靭性が低下する。焼結後空冷し再加熱する
か、あるいは焼結後空冷せずに直ちに鍛造するが、鍛造
温度は９００℃以上１３００℃以下とする。９００℃未
満であると高密度材が得られない。なお、上限は経済性
から決定した。Further, the sintering atmosphere gas needs to be an inert gas such as nitrogen gas, a hydrogen gas, or a reducing gas such as AX gas. The high Cr steel sintered material is easily oxidized, and if it is an oxidizing atmosphere gas such as RX gas, the oxidation progresses and the strength and toughness deteriorate. It is air-cooled after sintering and reheated, or forged immediately without air-cooling after sintering, but the forging temperature is 900 ° C. or more and 1300 ° C. or less. If it is lower than 900 ° C, a high-density material cannot be obtained. The upper limit was determined from economics.
【００１３】鍛造材は強度、靭性を確保するために熱処
理が施される。この熱処理は通常実施されている焼入れ
・焼戻し処理などでよい。The forged material is heat-treated to secure its strength and toughness. This heat treatment may be a quenching / tempering treatment that is usually performed.
【００１４】[0014]
（実施例１）表１に示す化学組成の鉄粉に０．２ｗｔ％
の黒鉛及び潤滑材として１ｗｔ％のステアリン酸亜鉛を
添加、混合し密度６．８ｇ／ｃｍ3 に成形した。その後
１２００℃で６０ｍｉｎ窒素ガス中で焼結し空冷した
後、１１００℃で１０ｍｉｎ窒素ガス中で再加熱し、鍛
造した。その後９８０℃で焼入れ、７２０℃で焼戻し処
理し、切削性および機械的特性を調べた。また、比較材
として表１に示す化学組成の従来のパイプ材についても
切削性を調べた。なお、切削性はＪＩＳ Ｋ０１工具を
用いて旋削加工した時の工具寿命を、従来材を１として
比較した（切削性指数）。その結果を図２に示すが、本
発明法で製造したＳ量０．００５ｗｔ％以上の試料はす
ぐれた切削性を示していることが分かる。(Example 1) 0.2 wt% of iron powder having the chemical composition shown in Table 1
Of graphite and 1 wt% of zinc stearate as a lubricant were added and mixed to form a density of 6.8 g / cm 3 . After that, it was sintered at 1200 ° C. for 60 min in nitrogen gas, air-cooled, and then reheated at 1100 ° C. for 10 min in nitrogen gas for forging. Then, quenching was performed at 980 ° C. and tempering treatment was performed at 720 ° C., and machinability and mechanical properties were examined. The machinability of the conventional pipe material having the chemical composition shown in Table 1 was also examined as a comparative material. As for the machinability, the tool life when lathe turning was performed using JIS K01 tool, and the conventional material was compared as 1 (machinability index). The results are shown in FIG. 2, and it can be seen that the samples having an S content of 0.005 wt% or more produced by the method of the present invention exhibit excellent machinability.
【００１５】一方、図３には−２０℃でのシャルピー吸
収エネルギーを示すが、Ｓ量０．０５ｗｔ％を超えると
靭性は低下する。On the other hand, FIG. 3 shows the Charpy absorbed energy at −20 ° C., but if the S content exceeds 0.05 wt%, the toughness decreases.
【００１６】[0016]
【表１】 [Table 1]
【００１７】（実施例２）表１に示す記号Ｄの化学組成
の鉄粉に０．２ｗｔ％の黒鉛及び潤滑材として１ｗｔ％
のステアリン酸亜鉛を添加、混合し密度６．８ｇ／ｃｍ
3 に成形した。その後１０００〜１３００℃の範囲でＡ
Ｘガス中で焼結し、空冷した後、１１００℃で１０ｍｉ
ｎ窒素ガス中で再加熱し、鍛造した。その後９８０℃で
焼入れ、７２０℃で焼戻し処理した材料について降伏強
さ（０．２％耐力）及び−２０℃でのシャルピー吸収エ
ネルギーを調べた。その結果を図４及び図５に示すが、
焼結温度を１１００℃以上とすることで、高強度、高靭
性の材料が得られる。(Example 2) Iron powder having a chemical composition of D shown in Table 1 was added with 0.2 wt% graphite and 1 wt% as a lubricant.
Zinc stearate is added and mixed to obtain a density of 6.8 g / cm
Molded to 3 . After that, in the range of 1000 to 1300 ° C, A
Sintered in X gas, air-cooled, and then 10 mi at 1100 ° C
It was reheated in nitrogen gas and forged. Then, the yield strength (0.2% proof stress) and the Charpy absorbed energy at −20 ° C. of the material quenched at 980 ° C. and tempered at 720 ° C. were examined. The results are shown in FIGS. 4 and 5,
By setting the sintering temperature to 1100 ° C. or higher, a material having high strength and high toughness can be obtained.
【００１８】（実施例３）表１に示す記号Ｃの化学組成
の鉄粉に０．２ｗｔ％の黒鉛及び潤滑材として１ｗｔ％
のステアリン酸亜鉛を添加、混合し密度６．８ｇ／ｃｍ
3 に成形した。その後１２００℃でＡＸガス中で焼結
し、その後直ちに８００〜１３００℃にＮ2ガス中で加
熱し鍛造した。その後９８０℃で焼入れ、７２０℃で焼
戻し処理した材料について降伏強さ（０．２％耐力）及
び−２０℃でのシャルピー吸収エネルギーを調べた。そ
の結果を図６及び図７に示すが、鍛造温度を９００℃以
上とすることで、高強度、高靭性の材料が得られる。(Example 3) Iron powder having a chemical composition of symbol C shown in Table 1 was added with 0.2 wt% graphite and 1 wt% as a lubricant.
Zinc stearate is added and mixed to obtain a density of 6.8 g / cm
Molded to 3 . After that, it was sintered in AX gas at 1200 ° C., and immediately thereafter, it was heated to 800 to 1300 ° C. in N 2 gas and forged. Then, the yield strength (0.2% proof stress) and the Charpy absorbed energy at −20 ° C. of the material quenched at 980 ° C. and tempered at 720 ° C. were examined. The results are shown in FIGS. 6 and 7, and by setting the forging temperature to 900 ° C. or higher, a material having high strength and high toughness can be obtained.
【００１９】（実施例４）表２に示す化学組成の鉄粉に
黒鉛を無添加あるいは０．０５〜０．５ｗｔ％と変化さ
せて添加し、実施例１と同様に焼結鍛造材を作成した。
その材料の−２０℃でのシャルピー吸収エネルギーを調
べた。その結果を図８に示すが、鍛造温度を９００℃以
上とすることで、高強度、高靭性の材料が得られる。な
お、図８の横軸は焼結鍛造材中に結果的に含まれるＣ含
有量を示している。Example 4 Graphite was added to iron powder having the chemical composition shown in Table 2 without adding graphite or by changing it to 0.05 to 0.5 wt% to prepare a sintered forged material in the same manner as in Example 1. did.
The Charpy absorbed energy at −20 ° C. of the material was examined. The results are shown in FIG. 8. By setting the forging temperature to 900 ° C. or higher, a material having high strength and high toughness can be obtained. The horizontal axis of FIG. 8 shows the C content contained in the sintered forged material as a result.
【００２０】これより、必要に応じて０．４ｗｔ％以下
の黒鉛を添加しても靱性は低下しないことが分かる。From this, it is understood that the toughness does not decrease even if 0.4 wt% or less of graphite is added if necessary.
【００２１】[0021]
【表２】 [Table 2]
【００２２】[0022]
【発明の効果】本発明によれば、鋼管継手カップリング
素管の製造に鉄粉を用いた焼結鍛造法を適用することに
より、高強度、高靭性を維持した上での、高Ｃｒ含有鋼
の切削性向上が可能となり、大幅なコスト削減が可能と
なった。EFFECTS OF THE INVENTION According to the present invention, by applying the sintering forging method using iron powder to the production of the steel pipe coupling coupling element pipe, the high Cr content while maintaining the high strength and high toughness can be maintained. It has made it possible to improve the machinability of steel, and has made it possible to significantly reduce costs.
【図１】鋼管継手カップリング素管の概略断面図。FIG. 1 is a schematic sectional view of a steel pipe coupling coupling element pipe.
【図２】Ｓ含有量と切削性指数との関係を示すグラフ。FIG. 2 is a graph showing the relationship between the S content and the machinability index.
【図３】Ｓ含有量と靭性との関係を示すグラフ。FIG. 3 is a graph showing the relationship between S content and toughness.
【図４】焼結温度と強度との関係を示すグラフ。FIG. 4 is a graph showing the relationship between sintering temperature and strength.
【図５】焼結温度と靭性との関係を示すグラフ。FIG. 5 is a graph showing the relationship between sintering temperature and toughness.
【図６】鍛造温度と強度との関係を示すグラフ。FIG. 6 is a graph showing the relationship between forging temperature and strength.
【図７】鍛造温度と靭性との関係を示すグラフ。FIG. 7 is a graph showing the relationship between forging temperature and toughness.
【図８】Ｃ含有量と靭性との関係を示すグラフ。FIG. 8 is a graph showing the relationship between C content and toughness.
Claims (2)
〜０．０５ｗｔ％を含む鉄粉に、必要に応じて０．４ｗ
ｔ％以下の黒鉛を添加し、該粉末を圧粉体に成形し、さ
らに１１００℃以上１３００℃以下の不活性ガスあるい
は還元ガス中で焼結し、その後、空冷し９００℃以上１
３００℃以下に不活性ガスあるいは還元ガス中で再加熱
し鍛造するか、もしくは焼結後直ちに９００℃以上１３
００℃以下の温度で鍛造し、さらに熱処理することを特
徴とする鋼管継手カップリング素管の製造方法。1. Cr: 5 to 20 wt%, S: 0.005
Iron powder containing ~ 0.05wt%, 0.4w as required
Graphite of t% or less is added, the powder is molded into a green compact, and further sintered in an inert gas or a reducing gas of 1100 ° C. or higher and 1300 ° C. or lower, and then air-cooled to 900 ° C. or higher.
Reheat in inert gas or reducing gas to 300 ° C or less and forge it, or immediately after sintering, 900 ° C or more 13
A method for producing a steel pipe coupling coupling blank, comprising forging at a temperature of 00 ° C. or lower and further heat treating.
〜０．０５ｗｔ％を含む鋼管継手カップリング素管用鉄
粉。2. Cr: 5 to 20 wt%, S: 0.005
Iron powder for steel pipe coupling coupling element pipe containing ~ 0.05wt%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5301632A JPH07150287A (en) | 1993-12-01 | 1993-12-01 | Production of tube stock for steel tube joint coupling and iron powder used therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5301632A JPH07150287A (en) | 1993-12-01 | 1993-12-01 | Production of tube stock for steel tube joint coupling and iron powder used therefor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07150287A true JPH07150287A (en) | 1995-06-13 |
Family
ID=17899287
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5301632A Pending JPH07150287A (en) | 1993-12-01 | 1993-12-01 | Production of tube stock for steel tube joint coupling and iron powder used therefor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07150287A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004536967A (en) * | 2001-05-14 | 2004-12-09 | ハネウェル・インターナショナル・インコーポレーテッド | Sintering methods and tools used for metal injection molding of large parts |
| US7635405B2 (en) | 2001-05-14 | 2009-12-22 | Honeywell International Inc. | Sintering process and tools for use in metal injection molding of large parts |
| CN104862698A (en) * | 2015-06-02 | 2015-08-26 | 贵州大学 | Coating material and coating with high contact fatigue strength based on 304 stainless steel base material |
| WO2024070784A1 (en) * | 2022-09-29 | 2024-04-04 | Ｊｆｅスチール株式会社 | Stainless steel powder, stainless steel member, and stainless steel member manufacturing method |
-
1993
- 1993-12-01 JP JP5301632A patent/JPH07150287A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004536967A (en) * | 2001-05-14 | 2004-12-09 | ハネウェル・インターナショナル・インコーポレーテッド | Sintering methods and tools used for metal injection molding of large parts |
| US7635405B2 (en) | 2001-05-14 | 2009-12-22 | Honeywell International Inc. | Sintering process and tools for use in metal injection molding of large parts |
| CN104862698A (en) * | 2015-06-02 | 2015-08-26 | 贵州大学 | Coating material and coating with high contact fatigue strength based on 304 stainless steel base material |
| WO2024070784A1 (en) * | 2022-09-29 | 2024-04-04 | Ｊｆｅスチール株式会社 | Stainless steel powder, stainless steel member, and stainless steel member manufacturing method |
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