JPH0645822B2 - Method of manufacturing martensitic stainless steel pipe - Google Patents
Method of manufacturing martensitic stainless steel pipeInfo
- Publication number
- JPH0645822B2 JPH0645822B2 JP2102338A JP10233890A JPH0645822B2 JP H0645822 B2 JPH0645822 B2 JP H0645822B2 JP 2102338 A JP2102338 A JP 2102338A JP 10233890 A JP10233890 A JP 10233890A JP H0645822 B2 JPH0645822 B2 JP H0645822B2
- Authority
- JP
- Japan
- Prior art keywords
- steel pipe
- temperature
- stainless steel
- cutting
- martensitic stainless
- 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.)
- Expired - Fee Related
Links
- 229910001105 martensitic stainless steel Inorganic materials 0.000 title claims description 26
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 238000005520 cutting process Methods 0.000 claims description 40
- 238000001816 cooling Methods 0.000 claims description 37
- 229910000734 martensite Inorganic materials 0.000 claims description 18
- 230000009466 transformation Effects 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 229910001220 stainless steel Inorganic materials 0.000 claims description 2
- 239000010935 stainless steel Substances 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 description 38
- 239000010959 steel Substances 0.000 description 38
- 238000005336 cracking Methods 0.000 description 6
- 230000003111 delayed effect Effects 0.000 description 6
- 238000010791 quenching Methods 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 238000000137 annealing Methods 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 238000005098 hot rolling Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
Landscapes
- Sawing (AREA)
- Accessories And Tools For Shearing Machines (AREA)
- Heat Treatment Of Steel (AREA)
Description
【産業上の利用分野】 本発明は、切断加工後のマルテンサイト系ステンレス鋼
管に、その切断面を起点に低温割れが発生することを防
止でき、しかも生産性を向上できるマルテンサイト系ス
テンレス鋼管の製造方法に関する。TECHNICAL FIELD The present invention relates to a martensitic stainless steel pipe after cutting, which can prevent cold cracking from occurring at the cut surface of the martensitic stainless steel pipe and can improve productivity. It relates to a manufacturing method.
１３Ｃｒ鋼等からなるマルテンサイト系ステンレス継目
無鋼管を熱間圧延で製造する場合は、通常、該鋼管に対
する圧延工程が９００℃前後の温度で終了し、その後、
管サイズ等によって異なるが約４０℃／minの冷却速度
で上記鋼管を急冷して焼入れ組織とし、然る後に所定の
長さに、例えばフリクション・ソーで切断する加工を行
っている。 上記マルテンサイト系ステンレス鋼管は、マルテンサイ
ト変態終了温度（Ｍｆ）以下になれば、それ以上マルテ
ンサイト変態が進行しなくなるため切断加工が可能があ
る。しかし、通常、マルテンサイト系ステンレス鋼はＭ
ｆ点と、マルテンサイト変態開始温度（Ｍｓ）とが近接
しており、Ｍｆ点に近い温度で切断加工を行うと、その
加工に伴う発熱によりマルテンサイト系ステンレス鋼管
がＭｓ点を超える事態が生じる。これを１３Ｃｒ鋼の場
合を例に具体的に説明すると、Ｍｆ＝２０４℃、ＭＳ＝
３０２℃であり、切断加工時の発熱による鋼管の上昇温
度は約１００〜１８０℃である。従って、１３Ｃｒ鋼か
らなるマルテンサイト系ステンレス鋼管を、Ｍｆ点より
低い、例えば１８０℃で切断加工を開始しても、加工発
熱により該鋼管の温度がＭｓ点を超えることが起こる。
このように、一度Ｍｆ点以下に冷却された鋼管が再度Ｍ
ｓ点以上に昇温されると、マルテンサイト組織が生長す
る。 上記の如くマルテンサイト組織が生長すると焼入硬化に
よる焼入歪と加工歪が発生し、その結果切断後の鋼管の
端部（管端）には、切断面に生じた加工による微細な応
力割れを起点にして、切断直後（切断から２〜３分後）
に５〜１０mm程度の焼割れや、切断から１週間程度経過
した後に、時には１ｍ位の長さにまで達する遅れ破壊が
発生する（以下、焼割れ及び遅れ破壊を低温割れともい
う）。 そこで、上記低温割れの発生を防止するため、圧延後の
鋼管をＭｆ点以下まで空却した後、切断加工に伴う発熱
による温度上昇によってもＭｓ点を超えない温度まで、
例えば１３Ｃｒ鋼であれば１３０℃まで空却により冷却
し、その後該鋼管の切断加工を行っていた。 又、遅れ破壊を防止するために、切断加工の後、例えば
３〜５日以内に軟化焼鈍のための熱処理を行っていた。When a martensitic stainless seamless steel pipe made of 13Cr steel or the like is manufactured by hot rolling, the rolling process for the steel pipe is usually completed at a temperature of about 900 ° C., and then,
Although it depends on the pipe size and the like, the steel pipe is quenched at a cooling rate of about 40 ° C./min to obtain a quenched structure, and then cut into a predetermined length, for example, with a friction saw. When the martensitic transformation temperature (Mf) is lower than the martensitic transformation end temperature (Mf), the martensitic stainless steel tube can be cut because martensitic transformation does not proceed any further. However, martensitic stainless steel is usually M
The point f and the martensitic transformation start temperature (Ms) are close to each other, and when cutting is performed at a temperature close to the point Mf, the heat generated by the processing causes the martensitic stainless steel pipe to exceed the point Ms. . This will be specifically described by taking the case of 13Cr steel as an example. Mf = 204 ° C., MS =
The temperature is 302 ° C., and the temperature rise of the steel pipe due to the heat generated during cutting is about 100 to 180 ° C. Therefore, even if the martensitic stainless steel pipe made of 13Cr steel is cut at a temperature lower than the Mf point, for example, 180 ° C., the temperature of the steel pipe may exceed the Ms point due to the heat generated during processing.
In this way, the steel pipe once cooled to below the Mf point is re-exposed to M
When the temperature is raised above the s point, the martensite structure grows. As described above, when the martensite structure grows, quenching strain and work strain occur due to quench hardening, and as a result, fine stress cracks caused by working on the cut surface occur at the end (pipe end) of the steel pipe after cutting. Immediately after cutting (2 to 3 minutes after cutting)
In addition, a quench crack of about 5 to 10 mm or a delayed fracture that reaches a length of about 1 m sometimes occurs about one week after cutting (hereinafter, quench crack and delayed fracture are also referred to as low temperature crack). Therefore, in order to prevent the occurrence of the above-mentioned low temperature cracking, after the rolled steel pipe is evacuated to the Mf point or lower, the temperature does not exceed the Ms point even if the temperature rises due to the heat generated by the cutting process
For example, in the case of 13Cr steel, the steel pipe was cooled to 130 ° C by cooling, and then the steel pipe was cut. Further, in order to prevent delayed fracture, heat treatment for softening annealing is performed, for example, within 3 to 5 days after cutting.
しかしながら、上述のように、低温割れを防止するた
め、Ｍｆ点に空冷した後も更に空冷により、例えば１３
０℃まで冷却するには、非常に長時間を要し、生産性を
阻害するという問題がある。又、遅れ破壊を防止するた
めに別個に行う熱処理も、同様に生産性を阻害するとい
う問題がある。 本発明は、熱間加工により製管したマルテンサイト系ス
テンレス鋼管について、切断加工後に切断面を起点に発
生する低温割れを有効に防止でき、しかも生産性を向上
することができるマルテンサイト系ステンレス鋼管の管
端割れ防止方法を提供することを課題とする。However, as described above, in order to prevent cold cracking, even after air cooling to the Mf point, further air cooling is performed, for example, 13
It takes a very long time to cool to 0 ° C., and there is a problem that productivity is hindered. Further, the heat treatment separately performed to prevent delayed fracture also has a problem of impairing productivity. The present invention is a martensitic stainless steel pipe manufactured by hot working, which can effectively prevent cold cracking that occurs from the cut surface after cutting and can improve the productivity. An object of the present invention is to provide a method for preventing pipe end cracking.
本発明は、前記従来の問題点を解決するべくなされたも
ので、熱間加工により製管したマルテンサイト系ステン
レス鋼管を、切断加工に伴う温度上昇によってもマルテ
ンサイト変態開始温度（Ｍｓ）を超えない切断開始可能
温度まで冷却した後、該マルテンサイト系ステンレス鋼
管の切断加工を開始して所定長さのマルテンサイト系ス
テンレス鋼管を製造するマルテンサイト系ステンレス鋼
管の製造方法において、熱間加工後のマルテンサイト系
ステンレス鋼管をマルテンサイト変態終了温度（Ｍｆ）
以下に空冷し、次いで、該マルテンサイト系ステンレス
鋼管を、前記切断開始可能温度まで水冷により強制冷却
することにより、前記課題を達成したものである。The present invention has been made to solve the above-mentioned conventional problems. A martensitic stainless steel pipe manufactured by hot working exceeds a martensitic transformation start temperature (Ms) even when the temperature rises due to cutting. After cooling to a temperature at which cutting is not possible, in the method for producing a martensitic stainless steel pipe, in which the martensitic stainless steel pipe is started to be cut to produce a martensitic stainless steel pipe having a predetermined length, after hot working, Martensitic transformation temperature (Mf) of martensitic stainless steel pipe
The above problem is achieved by air cooling below and then forcibly cooling the martensitic stainless steel pipe to the cutting startable temperature by water cooling.
本発明者は、種々検討した結果、空冷によりマルテンサ
イト系ステンレス鋼管をマルテンサイト変態終了温度
（Ｍｆ）以下に冷却した後、該鋼管を水冷による強制冷
却を行っても、硬さに大きな変化が生じないことを知見
し、該知見に基づいてＭｆ点以下まで空冷した後の強制
冷却を可能としたものである。 本発明においては、マルテンサイト系ステンレス鋼管を
Ｍｆ点以下に空冷した後、水冷による強制冷却を行うこ
とができるため、該鋼管を熱間加工終了時点から極めて
短時間で、フリクション・ソー等による切断加工に伴う
発熱によってもマルテンサイト変態開始温度（Ｍｓ）を
超えない安全な温度、即ち切断開始可能温度まで冷却す
ることができる。このように、鋼管を短時間で且つ確実
に切断開始可能温度まで冷却した後の該鋼管を切断する
ため、迅速に切断加工を開始できると共に、切断加工に
伴う発熱によっても該鋼管がＭｓ点を超えることを確実
に防止できる。従って、上記鋼管の切断面を起点にして
発生する焼割れや遅れ破壊等の低温割れを有効に防止で
きると同時に、切断加工を迅速に行うことができ、しか
も切断後の熱処理も不要であるため、生産性を大幅に向
上することができる。As a result of various studies, the present inventor has found that even if the martensite stainless steel pipe is cooled to a temperature below the martensite transformation end temperature (Mf) by air cooling and then the steel pipe is forcedly cooled by water cooling, a large change in hardness occurs. It has been found that it does not occur, and based on this finding, forced cooling is possible after air cooling to the Mf point or lower. In the present invention, since the martensitic stainless steel pipe can be air-cooled below the Mf point and then forcedly cooled by water cooling, the steel pipe is cut with a friction saw or the like in an extremely short time from the end of hot working. It is possible to cool to a safe temperature that does not exceed the martensitic transformation start temperature (Ms), that is, a temperature at which cutting can be started, even by heat generated during processing. In this way, since the steel pipe is cut after the steel pipe is cooled to the cutting startable temperature in a short time and reliably, the cutting process can be started quickly, and the Ms point of the steel pipe also increases due to the heat generated by the cutting process. It can be reliably prevented from exceeding. Therefore, it is possible to effectively prevent low temperature cracks such as quench cracks and delayed fractures that occur from the cut surface of the steel pipe as a starting point, and at the same time, it is possible to perform cutting work promptly, and there is no need for heat treatment after cutting. , The productivity can be greatly improved.
以下、図面を参照して、本発明の実施例を詳細に説明す
る。 第１図は、マルテンサイト系ステンレス鋼管が、１３Ｃ
ｒ鋼管（８８．９φ×１２．０９ｔ）である場合の第１
実施例の冷却曲線を示し、縦軸はパイプ（鋼管）温度、
横軸は熱間加工終了時点からの時間を表わす、熱間圧延
等の熱間加工により１３Ｃｒ鋼からなる継目無鋼管を常
法により製造する。その際、上記熱間加工は、例えば９
００℃で終了し、その後空冷により上記鋼管を空冷終了
温度Ｔ１まで冷却し、次いで水冷により該鋼管を、強制
冷却する。上記空冷終了温度、換言すれば強制冷却開始
温度Ｔ１は、本実施例では約１８０℃である。なお、全
体の温度曲線は後述の第２実施例の場合と略同様であ
る。 上記強制冷却は、パイプ（鋼管）の内表面の温度が１０
０℃になるまで行い、その後、フリクション・ソーによ
る切断を開始した。図示はしないが、このフリクション
切断によって、鋼管を、切断加工に伴う発熱によっても
Ｍｓ点（３０２℃）を超えさせることなく、所定の長さ
に切断することができた。又、それ故に切断後の上記鋼
管に、低温割れの発生が認められなかった。 又、パイプの内表面の温度を１８０℃から１００℃まで
の冷却を、従来の方法（空冷）では１１４０秒かかった
ものを、本実施例では８秒で行うことが可能であり、し
かも、本実施例では、確実に十分に低い温度まで冷却す
ることができるため、切断後の熱処理（軟化焼鈍）も不
要であった。 上述の如く、本実施例によれば、切断後のマルテンサイ
ト系ステンレス鋼管に焼割れや遅れ破壊等の低温割れの
発生を防止できると共に、該切断鋼管の生産性を大幅に
向上することが可能となる。 第２図は、本発明の第２実施例の冷却曲線を示すグラフ
である。 本実施例は、前記第１実施例の場合と同じ１３Ｃｒ鋼管
であるが、管径が８９．１mm、厚さ６．４５mmのマルテ
ンサイト系ステンレス鋼管に係るものである。 図中、Ｐ１は従来方法による場合の切断開始温度を、Ｐ
２は本発明による場合の切断開始温度を、Ｐ３は本発明
の強制冷却開始温度を、Ｐ４は測定開始点を、それぞれ
示している。 従来方法によれば、鋼管温度は破線で示したようになだ
らかな曲線に沿って約４０分で切断開始温度Ｐ１に到達
する。 一方、本実施例の場合は、従来方法と同様にＭｆ点以下
の強制冷却開始温度Ｐ３まで冷却した後、水冷による強
制冷却により切断開始温度Ｐ２まで実線に従って冷却す
ることにより、約２２分で切断開始状態にすることがで
きた。その後、鋼管を切断すると、切断面における鋼管
温度は、一点鎖線で示すような上昇を示し、切断完了ま
でに到達する最高温度はＭｓ点以下であった。 従って、本実施例の場合も、前記第１実施例と同様、低
温割れの発生防止、生産性の向上等が可能である。 以上、本発明を具体的に説明したが、本発明は前記実施
例に限定されるものでないことはいうまでもない。 例えば、強制冷却開始温度Ｔ１（℃）は、下記(1)式に
示すように、マルテンサイト変態終了温度（Ｍｆ）以下
であればよい。 Ｔ１≦Ｍｆ ……(1) 従って、１３Ｃｒ鋼の場合は、Ｍｆ＝２０４℃であるた
め、Ｔ１≦２０４℃であればよい。 一方、パイプ切断開始温度Ｔｃ（℃）は、下記(2)式で
表わすことができる。 Ｔｃ＝Ｍｆ−Ａ …… (2) ここで、Ａは切断加工に伴う発熱によっても、パイプ温
度がマルテンサイト変態開始温度（Ｍｓ）を超えない温
度にＴｃを設定できる温度である。上記Ａは、特に限定
されるものでなく、マルテンサイト系ステンレス鋼の種
類、管系φ、肉厚ｔ等を考慮し、切断加工に伴う発熱量
を勘案して決定される。 上記Ａの具体的な値としては、前記１３Ｃｒ鋼の場合の
例を示せば、Ａ＝８０〜１２０℃を挙げることができ
る。Ａ＝８０℃は肉厚が小さい場合であり、Ａ＝１２０
℃は肉厚が大きい場合の値である。 又、前記実施例では、１３Ｃｒ鋼管の場合について説明
したが、本発明は種々のマルテンサイト系ステンレス鋼
管に適用できるものである。 また、本発明における強制冷却の方法としては、鋼管全
体を水冷する方法であってもよいことはいうまでもない
が、例えば、切断時に使用するブレード冷却水により切
断箇所を局所的に冷却してもよい。このように、ブレー
ド冷却水により強制冷却を行う場合は、特別な設備を用
いることなく本発明を実施できる利点もある。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 shows that the martensitic stainless steel pipe is 13C
1st in case of r steel pipe (88.9φ × 12.09t)
The cooling curve of the example is shown, the vertical axis is the pipe (steel pipe) temperature,
The horizontal axis represents the time from the end of hot working. A seamless steel pipe made of 13Cr steel is manufactured by a conventional method by hot working such as hot rolling. At that time, the hot working is, for example, 9
After finishing at 00 ° C., the steel pipe is cooled to the end temperature T 1 of air cooling by air cooling, and then the steel pipe is forcibly cooled by water cooling. The air cooling end temperature, in other words, the forced cooling start temperature T 1 is about 180 ° C. in this embodiment. The entire temperature curve is substantially the same as in the case of the second embodiment described later. In the forced cooling, the temperature of the inner surface of the pipe (steel pipe) is 10
The process was carried out until the temperature reached 0 ° C., after which cutting with a friction saw was started. Although not shown, this friction cutting enabled the steel pipe to be cut into a predetermined length without exceeding the Ms point (302 ° C.) even by the heat generated by the cutting process. Further, therefore, no occurrence of cold crack was observed in the steel pipe after cutting. Further, it is possible to cool the inner surface of the pipe from 180 ° C. to 100 ° C. in 8 seconds in this embodiment, which takes 1140 seconds in the conventional method (air cooling). In the example, since it was possible to surely cool to a sufficiently low temperature, heat treatment (softening annealing) after cutting was not necessary. As described above, according to the present embodiment, it is possible to prevent the occurrence of low temperature cracks such as quench cracks and delayed fractures in the martensitic stainless steel pipe after cutting, and it is possible to significantly improve the productivity of the cut steel pipe. Becomes FIG. 2 is a graph showing the cooling curve of the second embodiment of the present invention. This example is the same 13Cr steel pipe as in the first example, but relates to a martensitic stainless steel pipe having a tube diameter of 89.1 mm and a thickness of 6.45 mm. In the figure, P 1 is the cutting start temperature in the case of the conventional method,
2 shows the cutting start temperature in the case of the present invention, P 3 shows the forced cooling start temperature of the present invention, and P 4 shows the measurement start point. According to the conventional method, the temperature of the steel pipe reaches the cutting start temperature P 1 in about 40 minutes along the gentle curve as shown by the broken line. On the other hand, in the case of the present embodiment, as in the conventional method, after cooling to the forced cooling start temperature P 3 below the Mf point, and then cooling to the cutting start temperature P 2 by forced cooling with water, it takes about 22 minutes. I was able to start cutting with. Thereafter, when the steel pipe was cut, the temperature of the steel pipe at the cut surface showed an increase as indicated by the alternate long and short dash line, and the maximum temperature reached by the completion of cutting was the Ms point or lower. Therefore, also in the case of the present embodiment, it is possible to prevent the occurrence of cold cracking, improve productivity, etc., as in the first embodiment. The present invention has been specifically described above, but it goes without saying that the present invention is not limited to the above-mentioned embodiments. For example, the forced cooling start temperature T 1 (° C.) may be equal to or lower than the martensite transformation end temperature (Mf) as shown in the following formula (1). T 1 ≦ Mf (1) Therefore, in the case of 13Cr steel, since Mf = 204 ° C., it is sufficient that T 1 ≦ 204 ° C. On the other hand, the pipe cutting start temperature Tc (° C.) can be expressed by the following equation (2). Tc = Mf-A (2) Here, A is a temperature at which Tc can be set to a temperature at which the pipe temperature does not exceed the martensitic transformation start temperature (Ms) even by the heat generated by the cutting process. The above-mentioned A is not particularly limited, and is determined in consideration of the type of martensitic stainless steel, the pipe system φ, the wall thickness t, etc., and the heat generation amount due to the cutting process. As a specific value of A, A = 80 to 120 ° C. can be cited as an example in the case of the 13Cr steel. A = 80 ° C. is when the wall thickness is small, and A = 120
C is the value when the wall thickness is large. Further, in the above embodiment, the case of the 13Cr steel pipe has been described, but the present invention can be applied to various martensitic stainless steel pipes. Further, as the method of forced cooling in the present invention, it goes without saying that it may be a method of water cooling the entire steel pipe, for example, by locally cooling the cutting site by blade cooling water used at the time of cutting Good. As described above, when the forced cooling is performed with the blade cooling water, there is also an advantage that the present invention can be carried out without using special equipment.
第１図は、本発明の第１実施例の冷却曲線を示すグラ
フ、 第２図は、本発明の第２実施例の冷却曲線を示すグラフ
である。FIG. 1 is a graph showing a cooling curve of the first embodiment of the present invention, and FIG. 2 is a graph showing a cooling curve of the second embodiment of the present invention.
Claims (1)
ステンレス鋼管を、切断加工に伴う温度上昇によっても
マルテンサイト変態開始温度（Ｍｓ）を超えない切断開
始可能温度まで冷却した後、該マルテンサイト系ステン
レス鋼管の切断加工を開始して所定長さのマルテンサイ
ト系ステンレス鋼管を製造するマルテンサイト系ステン
レス鋼管の製造方法において、 熱間加工後のマルテンサイト系ステンレス鋼管をマルテ
ンサイト変態終了温度（Ｍｆ）以下に空冷し、 次いで、該マルテンサイト系ステンレス鋼管を、前記切
断開始可能温度まで水冷により強制冷却することを特徴
とするマルテンサイト系ステンレス鋼管の製造方法。1. A martensite stainless steel pipe produced by hot working is cooled to a temperature at which cutting can be started without exceeding the martensite transformation start temperature (Ms) even if the temperature rises due to cutting, and then the martensite is cooled. In the method for producing a martensitic stainless steel pipe, which starts the cutting of the martensitic stainless steel pipe to produce a martensitic stainless steel pipe of a predetermined length, in the martensitic stainless steel pipe after hot working, the martensite transformation end temperature (Mf ) A method for producing a martensitic stainless steel pipe, which comprises air-cooling to the following and then forcibly cooling the martensitic stainless steel pipe to a temperature at which cutting can be started by water cooling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2102338A JPH0645822B2 (en) | 1990-04-18 | 1990-04-18 | Method of manufacturing martensitic stainless steel pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2102338A JPH0645822B2 (en) | 1990-04-18 | 1990-04-18 | Method of manufacturing martensitic stainless steel pipe |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH042409A JPH042409A (en) | 1992-01-07 |
| JPH0645822B2 true JPH0645822B2 (en) | 1994-06-15 |
Family
ID=14324723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2102338A Expired - Fee Related JPH0645822B2 (en) | 1990-04-18 | 1990-04-18 | Method of manufacturing martensitic stainless steel pipe |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0645822B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007270191A (en) * | 2006-03-30 | 2007-10-18 | Sumitomo Metal Ind Ltd | Method for producing martensitic stainless steel pipe |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07109008B2 (en) * | 1987-05-26 | 1995-11-22 | 住友金属工業株式会社 | Martensitic stainless steel seamless pipe manufacturing method |
| FR2617187B1 (en) * | 1987-06-24 | 1989-10-20 | Cezus Co Europ Zirconium | METHOD FOR IMPROVING THE DUCTILITY OF A MARTENSITICALLY TRANSFORMED ALLOY PRODUCT AND THE USE THEREOF |
-
1990
- 1990-04-18 JP JP2102338A patent/JPH0645822B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH042409A (en) | 1992-01-07 |
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