JP2974846B2 - Low temperature structural steel - Google Patents
Low temperature structural steelInfo
- Publication number
- JP2974846B2 JP2974846B2 JP4083161A JP8316192A JP2974846B2 JP 2974846 B2 JP2974846 B2 JP 2974846B2 JP 4083161 A JP4083161 A JP 4083161A JP 8316192 A JP8316192 A JP 8316192A JP 2974846 B2 JP2974846 B2 JP 2974846B2
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- temperature
- steel
- test
- low
- weldability
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Description
【０００１】[0001]
【産業上の利用分野】この発明は、海上プラットフォー
ムや橋梁の支柱材に好適な、疲労特性および溶接性に優
れた低温用構造用鋼に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature structural steel suitable for offshore platforms and bridge supports, which is excellent in fatigue characteristics and weldability.
【０００２】[0002]
【従来の技術】石油掘削のために、北洋海上に設置され
る深海用海上プラットフォームや橋梁などの支柱材に
は、構造物として高い強度（例えば、耐力５００ＭＰａ
以上、引張強さ５６０ＭＰａ以上）が必要とされ、ま
た、低温環境下での使用に耐え得るように、低温靱性
（例えば、−４０℃でシャルピ−吸収エネルギ７０Ｊ以
上）に優れている必要がある。さらに、海水と接触した
状態で使用されるので、海水中の陰極防食下で優れた疲
労特性を有することも要求される。従来、低温環境下で
使用される低温用構造用鋼としては、Ｎi−Ｃr−Ｍo 系
の低合金鋼が開発されており、上記要求に応えられる材
料として提供されている。2. Description of the Related Art For drilling of oil, strut materials such as deep-sea offshore platforms and bridges installed on the North Sea are required to have high strength (for example, a yield strength of 500 MPa) as a structure.
As described above, a tensile strength of 560 MPa or more is required, and excellent low-temperature toughness (for example, Charpy absorption energy of 70 J or more at −40 ° C.) is required to withstand use in a low-temperature environment. . Furthermore, since it is used in contact with seawater, it is also required to have excellent fatigue properties under cathodic protection in seawater. Hitherto, as a low-temperature structural steel used in a low-temperature environment, a Ni-Cr-Mo-based low alloy steel has been developed and provided as a material meeting the above requirements.
【０００３】[0003]
【発明が解決しようとする課題】ところで、上記設備で
は大型化の要請も強く、その支柱材には、例えば肉厚が
１００〜４５０ｍｍに至るものや直径が１００〜１００
０ｍｍに至るような厚肉のものが使用されることも多
い。このように厚肉の材料では、質量効果のために肉厚
中心部にまで十分に焼入れすることは容易ではない。こ
れに対しては、焼入れ性を向上させることにより、均等
で高い強度を確保することができる。しかし、従来、焼
入れ性を向上させた材料では、溶接性が十分ではなく、
また、前記した低温靱性、疲労特性も上記用途の材料と
しては不十分である。In the above facilities, there is a strong demand for an increase in the size of the above-mentioned equipment. For example, the supporting members have a wall thickness of 100 to 450 mm or a diameter of 100 to 100 mm.
Thicknesses up to 0 mm are often used. With such a thick material, it is not easy to quench sufficiently to the center of the thickness due to the mass effect. On the other hand, by improving the hardenability, uniform and high strength can be secured. However, conventionally, materials with improved hardenability have insufficient weldability,
In addition, the low-temperature toughness and fatigue characteristics described above are insufficient as materials for the above-mentioned applications.
【０００４】したがって、従来、優れた焼入れ性、溶接
性、低温靱性、疲労特性を兼ね備えた材料は開発されて
おらず、前記した従来材を、厚肉の構造材に使用した場
合には、中心部にまで十分に焼入れをすることができ
ず、全体として満足できる性能を得ることができないと
いう問題点がある。この発明は、上記事情を背景として
なされたものであり、高い強度と優れた低温靱性、溶接
性、疲労特性を有するとともに、これらの優れた特性を
維持したままで、厚肉の構造材へ適用することを可能と
した低温用構造用鋼を提供することを目的とするもので
ある。Therefore, a material having excellent hardenability, weldability, low-temperature toughness, and fatigue properties has not been developed so far. There is a problem that it is not possible to sufficiently quench the part, and to obtain satisfactory performance as a whole. The present invention has been made in view of the above circumstances, and has high strength, excellent low-temperature toughness, weldability, and fatigue properties, and can be applied to thick structural materials while maintaining these excellent properties. It is an object of the present invention to provide a low-temperature structural steel capable of performing the above-mentioned steps.
【０００５】[0005]
【課題を解決するための手段】上記課題を解決するた
め、本願発明の低温用構造用鋼のうち、第１の発明は、
重量％で、Ｃ：０．０３〜０．１２％、Ｍｎ：０．５〜
１．２％、Ｎｉ：２〜３．５％、Ｃｒ：０．４０〜２
％、Ｍｏ：０．３〜０．６％、ＡｌＮ：０．０１〜０．
０６％（Ａｌ換算）を含有し、さらに、Ｖ：０．０１〜
０．０５％、Ｎｂ：０．０１〜０．０５％の１種または
２種を含有し、残部がＦｅおよび不可避的不純物からな
り、不可避的不純物のうち、Ｓｉ：０．１％以下を許容
含有量とすることを特徴とするものである。Means for Solving the Problems In order to solve the above problems, among the low-temperature structural steels of the present invention, the first invention is:
% By weight, C: 0.03 to 0.12%, Mn: 0.5 to
1.2%, Ni: 2-3.5%, Cr: 0.40-2
%, Mo: 0.3-0.6%, AlN: 0.01-0.
06% (in terms of Al) , and V: 0.01 to
One or two of 0.05% and Nb: 0.01 to 0.05% are contained, and the balance consists of Fe and unavoidable impurities. Of the unavoidable impurities, Si: 0.1% or less is allowed. It is characterized by the content.
【０００６】また、第２の発明は、第１の発明における
不可避的不純物のうち、重量％で、Ｓ：０．００３％以
下、Ｏ：０．００３％以下を許容含有量とすることを特
徴とするものである。The second invention is characterized in that, among the unavoidable impurities in the first invention, S: 0.003% or less and O: 0.003% or less are allowable contents by weight%. It is assumed that.
【０００７】[0007]
【作用】すなわち、本願発明によれば、高強度が確保さ
れるとともに、優れた低温靱性、溶接性が得られ、また
海中陰極防食下における疲労特性にも優れている。次
に、本願発明で各成分含有量を限定した理由を以下に述
べる。なお、以下に述べる含有量はいずれも重量％で示
す。According to the present invention, high strength is ensured, excellent low-temperature toughness and weldability are obtained, and fatigue properties under seawater cathodic protection are also excellent. Next, the reasons for limiting the content of each component in the present invention will be described below. In addition, the contents described below are all shown in% by weight.
【０００８】Ｃ ：０．０３〜０．１２％ Ｃ含有量が多いと溶接性、低温靱性を損なうので、これ
ら特性を損なわないように、Ｃ含有量の上限を０．１２
％に定めた。ただし、所望の引張強さ、耐力を確保し、
他の成分との間で炭化物を生成させるために、０．０３
％以上の含有が必要とされる。Ｍn ：０．５〜１．２％ Ｍn は、焼入れ性を改善して強度を向上させるために添
加する。肉厚中心部まで十分な強度を確保するため、
０．５％以上含有させる必要がある。また、１．２％を
超えると、切欠き靱性を損なうので上記範囲とした。 C: 0.03 to 0.12% When the C content is large, the weldability and low-temperature toughness are impaired. Therefore, the upper limit of the C content is set to 0.12 so as not to impair these properties.
%. However, ensure the desired tensile strength and proof stress,
0.03 to form carbides with other components
% Or more is required. Mn: 0.5 to 1.2% Mn is added to improve hardenability and improve strength. To ensure sufficient strength up to the center of the wall thickness,
It is necessary to contain 0.5% or more. On the other hand, if it exceeds 1.2%, the notch toughness is impaired.
【０００９】Ｎi ：２〜３．５％ Ｎi は、溶接性を損なうことなく、焼入れ性、強度を向
上させるために添加する。しかし、含有量が２％未満で
は、その作用は不十分であり、また、３．５％を超えて
添加しても、上記効果は飽和するので上記範囲とした。
Ｃr ：０．４〜２％、Ｍo ：０．３〜０．６％ Ｃr は、焼入れ性を改善して強度を向上させるために添
加される。ただし、０．３％未満のＭｏ含有では、その
作用は不十分であり、また、Ｃr は２％、Ｍoは０．６
％を超えて含有させると、切欠き靭性および溶接性に悪
影響を与えるので上記範囲とした。 Ni: 2 to 3.5% Ni is added to improve hardenability and strength without impairing weldability. However, if the content is less than 2%, the effect is insufficient, and if the content exceeds 3.5%, the effect is saturated, so that the content is set in the above range.
Cr: 0.4 to 2%, Mo: 0.3 to 0.6% Cr is added to improve hardenability and improve strength. However, if the content of Mo is less than 0.3%, the effect is insufficient, and Cr is 2% and Mo is 0.6%.
%, The notch toughness and weldability are adversely affected.
【００１０】Ａl ：０．０１〜０．０６％ ＡｌＮの生成により結晶粒を細粒化して、強度および低
温靱性を向上させる。ただし、０．０１％以下ではその
作用は不十分であり、０．０６％を超えると、非金属介
在物を形成して加工性を劣化させるため上記範囲とす
る。 Al: 0.01 to 0.06% AlN is used to refine crystal grains to improve strength and low-temperature toughness. However, if the content is less than 0.01%, the effect is insufficient, and if it exceeds 0.06%, non-metallic inclusions are formed and workability is deteriorated, so that the above range is set.
【００１１】次に、選択的に含有されるＶおよびＮb の
限定理由について説明する。Ｖ：０．０１〜０．０５％、Ｎb ：０．０１〜０．０５
％ Ｖ、Ｎb は炭化物を形成し、オーステナイト結晶粒を細
粒化して切欠き靱性を向上させる。さらに、微細分散に
より引張り強度を向上させるので、強度確保のためにＣ
を多く含有させる必要がなく、溶接割れ感受性に影響の
大きいＣの含有量を低減して溶接性を向上させることが
できる。ただし、含有量が、それぞれ０．０１％未満の
場合にはその作用は不十分であり、また、それぞれ０．
０５％を超えると、切欠き靱性および溶接性を害するた
め上記範囲とした。Next, the reasons for limiting V and Nb selectively contained will be described. V: 0.01-0.05%, Nb: 0.01-0.05
% V, Nb forms carbides and refines austenite grains to improve notch toughness. Furthermore, since tensile strength is improved by fine dispersion, C
Need not be contained in a large amount, and the weldability can be improved by reducing the content of C that has a large effect on weld cracking susceptibility. However, when the content is less than 0.01%, the action is insufficient, and the content is 0.1%.
If it exceeds 05%, the notch toughness and weldability are impaired, so the above range is set.
【００１２】また、不可避的不純物の限定理由を以下に
述べる。Ｓi ：０．１％以下 Ｓi は、通常、脱酸剤として使用され、その場合の含有
量は、通常０．３０〜０．５０％程度である。この程度
のＳi を含有すると、大型鋼塊においてはマクロ偏析を
発生する。また、Ｓi 含有量が高いと、切欠靭性が損な
われるので０．１％を上限とした。[0012] Also, describe the reasons for limiting the non-avoidable impurities below. Si: 0.1% or less Si is usually used as a deoxidizing agent, and its content is usually about 0.30 to 0.50%. When this level of Si is contained, macro segregation occurs in large steel ingots. If the Si content is high, the notch toughness is impaired, so the upper limit was set to 0.1%.
【００１３】Ｓ：０．００３％以下 Ｓは、厚肉鋼材においては、切欠き靱性を低下させると
ともに、溶接性を悪化させる。また、大型の鋼材では、
微量の含有でもＭnＳ等の非金属介在物を鋼中に形成
し、疲労限を著しく低下させるため、極力低減すること
が望ましく、現状の精錬技術レベルを考慮して、Ｓの許
容含有量を０．００３％以下に制限した。Ｏ：０．００３％以下 鋼中で非金属介在物を形成して切欠き靱性および疲労限
の低下を招くため極力低減するのが望ましいが、脱酸お
よび鋳込み条件の制約を考慮して上記上限を定めた。な
お、その他には、通常の製法によって不可避的に含まれ
る不純物が含有されるが、それらの含有量は特に限定さ
れるものではない。 S: 0.003% or less S reduces the notch toughness and deteriorates the weldability in a thick steel material. For large steel materials,
Even if the content is very small, non-metallic inclusions such as MnS are formed in the steel and the fatigue limit is remarkably reduced. Therefore, it is desirable to reduce the content as much as possible. 0.003% or less. O: 0.003% or less It is desirable to reduce non-metallic inclusions in steel to reduce notch toughness and fatigue limit, but it is desirable to reduce as much as possible. Was determined. In addition, other impurities that are unavoidably contained by a normal production method are contained, but their contents are not particularly limited.
【００１４】[0014]
【実施例】以下に、本発明の実施例（発明鋼）を、発明
の範囲外の比較鋼と比較して説明する。表１、２に示す
組成を有する供試鋼（発明鋼および比較鋼）を電炉で溶
解し、さらに、炉外精錬にて不純物を極力低減して清浄
度を高めて、８トンの鋼塊を得た。次に、この鋼塊に熱
間鍛造を行って、供試鋼Ｎｏ．１〜１０については、肉
厚３５０ｍｍの鍛造パイプを試作し、供試鋼Ｎｏ．１１
〜１９については、直径８００ｍｍの鍛造丸棒を試作し
た。その後、所定の熱処理（焼入れ、焼戻し）を行って
供試材を得た。各供試材から試験片を切り出して、鍛造
パイプについては、Ｔ／２部（Ｔ＝厚さ）、鍛造丸棒に
ついては、肉厚のＤ／４部（Ｄ＝直径）の機械的性質を
評価する試験を行い、その結果を表３、４に示した。Examples Examples of the present invention (inventive steels) will be described below in comparison with comparative steels outside the scope of the present invention. A test steel (inventive steel and comparative steel) having the composition shown in Tables 1 and 2 was melted in an electric furnace, and further, impurities were reduced as much as possible by out-of-pile smelting to increase the cleanliness. Obtained. Next, this steel ingot was subjected to hot forging, and the test steel no. For Nos. 1 to 10, forged pipes having a thickness of 350 mm were prototyped, and test steel Nos. 11
Regarding the samples No. to No. 19, forged round bars having a diameter of 800 mm were experimentally manufactured. Thereafter, a predetermined heat treatment (quenching, tempering) was performed to obtain a test material. A test piece was cut out from each test material, and the mechanical properties of a T / 2 part (T = thickness) for a forged pipe and a D / 4 part (D = diameter) of a thick forged round bar were measured. Tests for evaluation were performed, and the results are shown in Tables 3 and 4.
【００１５】前記試験は、引張試験、衝撃試験、海水疲
労試験、溶接性試験からなる。なお、衝撃試験では、Ｖ
ノッチ試験片を用い、破面遷移温度と−５０℃（供試鋼
Ｎｏ．１〜１０）または−４０℃（供試鋼Ｎｏ．１１〜
１９）における吸収エネルギーを測定した。また、疲労
試験は、陰極防食（−１１００ｍＶ／ＡgＣl）を行った
人工海水中において、繰り返し応力０．４Ｈｚ、繰り返
し数１０7 の条件下で行った。The above test includes a tensile test, an impact test, a seawater fatigue test, and a weldability test. In the impact test, V
Using a notch test piece, the fracture surface transition temperature and -50 ° C (test steel No. 1 to 10) or -40 ° C (test steel No. 11 to 11)
The absorption energy in 19) was measured. The fatigue test was performed in artificial seawater subjected to cathodic protection (-1100 mV / AgCl) under the conditions of a repetition stress of 0.4 Hz and a repetition number of 10 7 .
【００１６】さらに、溶接性試験では、斜めＹ形拘束割
れ試験を行った。具体的には、供試材から５０ｍｍ厚の
試験片を切出し、拘束溶接を行ったＹ開先部を有する試
験片に被覆アーク溶接により試験ビードを溶接し、溶接
母材（試験片）の予熱温度をパラメータとして、断面割
れを観察した。なお、この溶接では、溶接に先立つて溶
接棒を高温で短時間乾燥（３５０℃、１時間）した。溶
接後に、ＪＩＳ Ｚ３１１３に従って溶接金属から放
出される水素量を測定したところ、０．８または０．９
ｍｍｌ／１００ｇであった。Further, in the weldability test, an oblique Y-shaped restraint cracking test was performed. Specifically, a test piece having a thickness of 50 mm was cut out from the test material, and a test bead was welded to a test piece having a Y-groove portion subjected to constraint welding by covered arc welding to preheat the welding base material (test piece). Cross section cracks were observed using temperature as a parameter. In addition, in this welding, the welding rod was dried at a high temperature for a short time (350 ° C., 1 hour) prior to welding. After welding, the amount of hydrogen released from the weld metal was measured according to JIS Z3113, and was 0.8 or 0.9.
mml / 100 g.
【００１７】上記断面割れ観察では、予熱温度が一定の
温度以上になった場合には、割れの発生が停止してお
り、この温度を断面割れ停止温度としてを表５、６に示
した。表３、４から明らかなように、発明鋼は、引張り
性質、衝撃性質、疲労限度の全てにおいて優れた数値を
示しており、また、溶接性試験においても割れ停止温度
が低く、溶接性に優れている。これに対し、比較鋼は、
衝撃性質、疲労限度が劣っており、また割れ停止温度も
高く、溶接性も劣っていた。In the above-mentioned cross-sectional crack observation, when the preheating temperature became equal to or higher than a certain temperature, the generation of cracks was stopped. This temperature is shown in Tables 5 and 6 as the cross-sectional crack stop temperature. As is clear from Tables 3 and 4, the inventive steel shows excellent numerical values in all of the tensile properties, impact properties, and fatigue limits, and also has a low crack stop temperature and excellent weldability in a weldability test. ing. In contrast, the comparative steel
The impact properties and fatigue limit were inferior, the crack stopping temperature was high, and the weldability was also inferior.
【００１８】したがって、発明鋼は、厚肉材への適用に
おいても、高強度で、優れた低温靱性、疲労特性、溶接
性を兼ね備えている。なお、上記実施例では、比較的肉
厚な試験材に適用し、その優れた性質を示したが、本願
発明としては、必ずしも厚肉材への適用に限定されるも
のではなく、厚肉材に拘らず、上記の優れた性質が得ら
れるものである。ただし、厚肉材への適用に対し、特に
有用である。Therefore, the invention steel has high strength and excellent low-temperature toughness, fatigue characteristics, and weldability even when applied to a thick wall material. In the above-described embodiment, the present invention was applied to a relatively thick test material and exhibited excellent properties. However, the present invention is not necessarily limited to application to a thick material. Regardless, the above excellent properties can be obtained. However, it is particularly useful for application to thick materials.
【００１９】[0019]
【表１】 [Table 1]
【００２０】[0020]
【表２】 [Table 2]
【００２１】[0021]
【表３】 [Table 3]
【００２２】[0022]
【表４】 [Table 4]
【００２３】[0023]
【表５】 [Table 5]
【００２４】[0024]
【表６】 [Table 6]
【発明の効果】以上説明したように、本願発明の低温用
構造用鋼によれば、重量％で、Ｃ：０．０３〜０．１２
％、Ｍn ：０．５〜１．２％、Ｎi ：２〜３．５％、Ｃ
r ：２％以下、Ｍo ：０．３〜０．６％、Ａl ：０．０
１〜０．０６％を含有し、さらに、Ｖ：０．０１〜０．
０５％、Ｎb ：０．０１〜０．０５％の１種または２種
を含有し、残部がＦe および不可避的不純物からなるの
で、高強度で、しかも低温靱性、疲労特性、溶接性に優
れており、低温環境下で使用される構造物の材料として
好適である。さらに厚肉材への適用においても優れた特
性を得ることができ、厚肉な構造物の構築を促進できる
効果がある。さらに、不可避的不純物のうち、重量％
で、Ｓi ：０．１％以下、Ｓ：０．００３％以下、Ｏ：
０．００３％以下を許容含有量とすれば、低温の靱性が
さらに向上し、また経年劣化も抑制されるので、耐久性
が向上する効果がある。As described above, according to the low-temperature structural steel of the present invention, C: 0.03 to 0.12 by weight%.
%, Mn: 0.5 to 1.2%, Ni: 2 to 3.5%, C
r: 2% or less, Mo: 0.3 to 0.6%, Al: 0.0
1 to 0.06%, and V: 0.01 to 0.
It contains one or two types of Nb: 0.01% to 0.05% and the balance is Fe and unavoidable impurities, so it has high strength and excellent low-temperature toughness, fatigue properties and weldability. It is suitable as a material for a structure used under a low-temperature environment. Further, excellent properties can be obtained even when applied to a thick material, and there is an effect that the construction of a thick structure can be promoted. In addition, of the inevitable impurities,
And Si: 0.1% or less, S: 0.003% or less, O:
When the allowable content is 0.003% or less, the toughness at low temperature is further improved, and aging is suppressed, so that there is an effect that durability is improved.
フロントページの続き (72)発明者 深見 泰司 北海道室蘭市茶津町４番地 株式会社日 本製鋼所内 (56)参考文献 特開 昭61−23714（ＪＰ，Ａ) 特開 昭62−177120（ＪＰ，Ａ) 特開 昭55−41929（ＪＰ，Ａ) 特開 昭54−112369（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) C22C 38/00 - 38/60 Continuation of front page (72) Inventor Yasushi Fukami 4 Chazu-cho, Muroran-shi, Hokkaido Inside Nihon Steel Works (56) References JP-A-61-23714 (JP, A) JP-A-62-177120 (JP, A JP-A-55-41929 (JP, A) JP-A-54-112369 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) C22C 38/00-38/60
Claims (2)
Ｍｎ：０．５〜１．２％、Ｎｉ：２〜３．５％、Ｃｒ：
０．４０〜２％、Ｍｏ：０．３〜０．６％、ＡｌＮ：
０．０１〜０．０６％（Ａｌ換算）を含有し、さらに、
Ｖ：０．０１〜０．０５％、Ｎｂ：０．０１〜０．０５
％の１種または２種を含有し、残部がＦｅおよび不可避
的不純物からなり、不可避的不純物のうち、Ｓｉ：０．
１％以下を許容含有量とすることを特徴とする低温用構
造用鋼C .: 0.03 to 0.12% by weight,
Mn: 0.5 to 1.2%, Ni: 2 to 3.5%, Cr:
0.40 to 2%, Mo: 0.3 to 0.6%, AlN:
0.01 to 0.06% (in terms of Al)
V: 0.01-0.05%, Nb: 0.01-0.05
% Of one or two kinds, and the balance consists of Fe and inevitable impurities.
Low-temperature structural steel characterized by having an allowable content of 1% or less.
０．００３％以下、Ｏ：０．００３％以下を許容含有量
とする請求項１記載の低温用構造用鋼2. The amount of S:
The low-temperature structural steel according to claim 1, wherein the allowable content is 0.003% or less and O: 0.003% or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4083161A JP2974846B2 (en) | 1991-06-14 | 1992-03-05 | Low temperature structural steel |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16898491 | 1991-06-14 | ||
| JP3-168984 | 1991-06-14 | ||
| JP4083161A JP2974846B2 (en) | 1991-06-14 | 1992-03-05 | Low temperature structural steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0586438A JPH0586438A (en) | 1993-04-06 |
| JP2974846B2 true JP2974846B2 (en) | 1999-11-10 |
Family
ID=26424218
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4083161A Expired - Fee Related JP2974846B2 (en) | 1991-06-14 | 1992-03-05 | Low temperature structural steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2974846B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5229823B2 (en) * | 2009-09-25 | 2013-07-03 | 株式会社日本製鋼所 | High-strength, high-toughness cast steel and method for producing the same |
| CN105483542B (en) * | 2016-01-27 | 2017-04-19 | 南京工程学院 | Steel for deep sea oil extraction equipment and manufacturing method of steel forge piece for deep sea oil extraction equipment |
| CN105671431B (en) * | 2016-01-27 | 2017-04-19 | 南京工程学院 | Manufacturing method of steel and forge piece thereof for valve seat of deep sea oil extraction equipment |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54112369A (en) * | 1978-02-23 | 1979-09-03 | Nippon Steel Corp | Electric welded steel tube provided with high toughness electric welded zone |
| JPS5911658B2 (en) * | 1978-09-16 | 1984-03-16 | 株式会社神戸製鋼所 | High efficiency welding low temperature steel |
| JPS6123714A (en) * | 1984-07-12 | 1986-02-01 | Nippon Steel Corp | Manufacture of steel having superior toughness at low temperature in weld heat-affected zone |
| JPH062899B2 (en) * | 1986-01-30 | 1994-01-12 | 日本鋳鍛鋼株式会社 | Manufacturing method of cast steel with excellent low temperature toughness |
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1992
- 1992-03-05 JP JP4083161A patent/JP2974846B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0586438A (en) | 1993-04-06 |
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