JPH03232946A - Steel for pressure vessel - Google Patents
Steel for pressure vesselInfo
- Publication number
- JPH03232946A JPH03232946A JP2631790A JP2631790A JPH03232946A JP H03232946 A JPH03232946 A JP H03232946A JP 2631790 A JP2631790 A JP 2631790A JP 2631790 A JP2631790 A JP 2631790A JP H03232946 A JPH03232946 A JP H03232946A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- content
- pressure vessel
- strength
- seawater
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 60
- 239000010959 steel Substances 0.000 title claims abstract description 60
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 5
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 5
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 4
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 3
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 3
- 229910001566 austenite Inorganic materials 0.000 claims abstract 2
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract 2
- 239000013535 sea water Substances 0.000 abstract description 21
- 230000003111 delayed effect Effects 0.000 abstract description 18
- 230000007797 corrosion Effects 0.000 abstract description 15
- 238000005260 corrosion Methods 0.000 abstract description 15
- 238000005242 forging Methods 0.000 abstract description 5
- 229910052799 carbon Inorganic materials 0.000 abstract description 2
- 229910052804 chromium Inorganic materials 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 abstract 4
- 230000000694 effects Effects 0.000 description 28
- 239000000463 material Substances 0.000 description 25
- 239000000203 mixture Substances 0.000 description 11
- 239000000126 substance Substances 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- 238000005496 tempering Methods 0.000 description 7
- 238000010791 quenching Methods 0.000 description 4
- 230000000171 quenching effect Effects 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000009931 harmful effect Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000002970 Calcium lactobionate Substances 0.000 description 1
- 229910000677 High-carbon steel Inorganic materials 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000007656 fracture toughness test Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000009863 impact test Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000012549 training Methods 0.000 description 1
- 239000013585 weight reducing agent Substances 0.000 description 1
Landscapes
- Pressure Vessels And Lids Thereof (AREA)
Abstract
Description
【発明の詳細な説明】 〈産業上の利用分野〉 この発明は、種々の環境中で優れた強度、靭性。[Detailed description of the invention] <Industrial application field> This invention has excellent strength and toughness in various environments.
耐食性等を発揮する圧力容器用鋼に関するものである。This relates to steel for pressure vessels that exhibits corrosion resistance.
〈従来の技術〉
近年、産業分野の多岐に亘る目覚ましい技術革新を背景
として、様々な環境下で非常に多くの種類の圧力容器が
使用されるようになってきた。そして、圧力容器の需要
増に伴ってその設計・製作には一段と厳しい注意が払わ
れるようになり、現在では日本工業規格（Ｊ Ｉ Ｓ）
や米国機械学会規格（ＡＳＭＥ）等においても圧力容器
に係る多くの規格が設けられるに至っている。<Prior Art> In recent years, against the background of remarkable technological innovations in a wide variety of industrial fields, a large number of types of pressure vessels have come to be used in various environments. As the demand for pressure vessels increased, even stricter attention was paid to their design and manufacture, and today the Japanese Industrial Standards (JIS)
Many standards related to pressure vessels have been established, such as the American Society of Mechanical Engineers (ASME) and the American Society of Mechanical Engineers (ASME).
しかしながら、上記各規格は何れも室温又は中・高温の
大気中での使用を想定したものであって、容器の内容物
が腐食性物質である場合にはそれを考慮してステンレス
鋼等の耐食性材料が適用されることは言うまでもないも
のの、基本的には圧力容器に適用される材料の規定も前
記想定条件に沿ったものに止まっていた。However, all of the above standards assume use in the atmosphere at room temperature or medium to high temperatures, and if the contents of the container are corrosive substances, the corrosion resistance of stainless steel etc. should be taken into consideration. Although it goes without saying that materials are applied, the regulations for materials applied to pressure vessels have basically remained in line with the above-mentioned assumed conditions.
もっとも、圧力容器の使用圧力増大や軽量化と言った最
近の要求に伴って容器材料にも高強度化の波が打ち寄せ
ており、現在では例えばＪＩＳのＧ３２０４に「圧力容
器用調質型合金鋼鍛鋼品」として規定された高強度鋼や
ＡＳＭＥのｒＢｏｉｌｅｒ＆ Ｐｒｅｓｓｕｒｅ Ｖｅ
ｓｓｅｌ Ｃｏｄｅ ５ｅｃｔｉｏｎＩ［Ｊに５Ａ−７
２３として規定された高強度鋼が圧力容器用材料の代表
的なものとなっている。なお、該圧力容器用高強度鋼の
特徴は基本的には何れも化学成分組成のみにあり、中炭
素マルテンサイト組織の強度を利用し、焼入性確保のた
め圧力容器の胴部肉厚に応じて合金元素を添加したもの
である。ただ、このとき十分な靭性を得るためＪＩＳで
は焼戻し温度が６１０℃以上に、またＡＳＭＢでは焼戻
し温度が５４０℃以上と規定され、更に熱処理時の保持
時間はＪＩＳ及びＡＳＭＢ共に厚さ１１に対して１．２
分以上と定められている。However, with the recent demands for increased working pressure and lighter weight for pressure vessels, there is a wave of higher strength for vessel materials. High-strength steel specified as "forged steel products" and ASME's rBoiler & Pressure Ve
ssel Code 5ectionI[J to 5A-7
High-strength steel specified as No. 23 is a typical material for pressure vessels. The characteristics of these high-strength steels for pressure vessels basically lie only in their chemical composition; they utilize the strength of the medium-carbon martensitic structure, and increase the thickness of the body of the pressure vessel to ensure hardenability. Alloying elements are added accordingly. However, in order to obtain sufficient toughness at this time, JIS specifies that the tempering temperature be 610°C or higher, and ASMB specifies that the tempering temperature must be 540°C or higher, and the holding time during heat treatment is set at a thickness of 11 for both JIS and ASMB. 1.2
It is defined as more than 1 minute.
一方、最近、潜水夫の酸素ボンベや潜水調査船のガス貯
・蔵容器等の如き海水中で使用される圧力容器の需要が
目立って増える傾向にあり、大気中とは異なった環境に
適用する圧力容器用材料に対する検討も盛んに行われて
いる。勿論、これまでも海水中にて比較的低圧の下で使
用される圧力容器の需要は多かったが、このような容器
材料にはＣ：０．２５〜０．３０％（以降、成分割合を
示ず％は重量％とする）
Ｓｉ ： ０．１０〜０．３５％、 Ｍｎ ： ０．
６５％以下。On the other hand, recently there has been a noticeable increase in demand for pressure vessels used in seawater, such as oxygen cylinders for divers and gas storage containers for research submersibles. Materials for pressure vessels are also being actively studied. Of course, there has been a great deal of demand for pressure vessels used under relatively low pressure in seawater, but the materials for such containers have a C content of 0.25 to 0.30% (hereinafter referred to as component percentage). (% not shown is weight %) Si: 0.10 to 0.35%, Mn: 0.
65% or less.
Ｐ：０．０５％以下、 ｓ：ｏ、ｏ５％以下Ｃｒ：
２．５〜３．５％、 Ｍｏ ： ０．３０〜０．
７０％Ｆｅ及び不可避不純物：残部
なる化学成分組成で、
降伏強さ： ７０ｋｇｆ／ｍｆｆｌ（６８６ＭＰａ）以
上引張強さ： ８５ｋｇｆ／ｎｉ（８３３ＭＰａ）以上
伸び＝１５％以上５ 絞り：２５％以−ト。P: 0.05% or less, s: o, o5% or less Cr:
2.5-3.5%, Mo: 0.30-0.
70% Fe and unavoidable impurities: The chemical composition of the remainder: Yield strength: 70 kgf/mffl (686 MPa) or more Tensile strength: 85 kgf/ni (833 MPa) or more Elongation = 15% or more 5 Reduction of area: 25% or more.
０°Ｃシャルピー衝撃値：６０Ｊ／ｃ己以上と言った機
械的性質を有する鋼材が一般に適用されてきた。Steel materials having mechanical properties such as 0°C Charpy impact value of 60 J/c or more have been generally used.
しかし、適用圧力増大や一層の軽量化を自損してこのよ
うな圧力容器用鋼の強度向上を図ろうとすると靭性が不
足し、靭性を満足させようとすると今度は強度不足を来
たすとの不都合を免れ得す、上記従来の圧力容器用高強
度鋼では最近の要求性能を満足できないとの結論を出さ
ざるを得なかった。However, if we try to improve the strength of steel for pressure vessels by increasing the applied pressure or reducing the weight further, the toughness will be insufficient, and if we try to satisfy the toughness, this will lead to the inconvenience of insufficient strength. We were forced to conclude that the conventional high-strength steel for pressure vessels described above cannot satisfy the recent performance requirements.
そこで、海水中での用途に更に強度の高い圧力容器用ａ
（例えば前記ＡＳＭＥ（７）ＳＡ−７２３材）の適用も
検討されたが、既述の如くこれらの材料は海水中での使
用が考慮されていないために高強度域（ａ、＞ １２５
ｋｇｆ／ｍｍ２（１ｍｍ２（１２２５では遅れ破壊を生
じる危険性があり、やはり海水中での用途に適しないこ
とが確認されたのみであった。Therefore, we developed a pressure vessel a that is even stronger for use in seawater.
(For example, the above-mentioned ASME (7) SA-723 material) was also considered, but as mentioned above, these materials are not considered for use in seawater, and therefore have a high strength range (a, > 125
kgf/mm2 (1 mm2) It was only confirmed that 1225 had a risk of delayed failure and was not suitable for use in seawater.
このように、海水中で使用する実用的な圧力容器用材料
を考えた場合、従来の圧力容器用鋼は使用圧力を高める
ために強度を上げると靭性劣化や遅れ破壊と言った不利
を招くので不適当であり、結局、最近の要望に十分応え
得る“海水中で用いられる高圧力容器”の材料として適
切な実用的圧力容器材料は無いと言わざるを得なかった
。In this way, when considering practical pressure vessel materials for use in seawater, conventional pressure vessel steels suffer from disadvantages such as toughness deterioration and delayed fracture when the strength is increased in order to increase the working pressure. It was unsuitable, and in the end, it had to be said that there was no practical pressure vessel material suitable as a material for a "high pressure vessel used in seawater" that could fully meet recent demands.
そこで、本発明の目的は、最近の高圧化・軽量化要求に
対処できる十分な強度と靭性を有することは勿論、海水
に対する優れた耐食性及び耐遅れ破壊性をも示し、海水
中での使用に十分満足できる実用的な圧力容器用鋼を提
供することに置かれた。Therefore, the object of the present invention is to not only have sufficient strength and toughness to meet the recent demands for higher pressure and lighter weight, but also to exhibit excellent corrosion resistance and delayed fracture resistance against seawater, and to be suitable for use in seawater. The aim was to provide a fully satisfactory and practical steel for pressure vessels.
く課題を解決するための手段〉
本発明者等は、上記目的を達成すべくなされた数多くの
実験結果を踏まえ、まず“海水中で用いられる圧力容器
”に対する最近の要望に応えるには、
ａ）強度：現行の圧力容器を１５％以上軽量化するのに
必要な強度
ｂ）靭性：現行圧力の１．４倍の圧力下でも脆性破壊し
ない靭性。Means for Solving the Problems> Based on the results of numerous experiments conducted to achieve the above objectives, the present inventors first determined that in order to meet recent demands for "pressure vessels used in seawater", a. ) Strength: The strength required to reduce the weight of current pressure vessels by 15% or more b) Toughness: Toughness that does not cause brittle fracture even under pressure 1.4 times the current pressure.
Ｃ）耐遅れ破壊性：海水中で遅れ破壊を生じることがな
い。C) Delayed fracture resistance: Delayed fracture does not occur in seawater.
ｄ）耐食性：海水中での耐食性が現行材を下回らない。d) Corrosion resistance: Corrosion resistance in seawater is no lower than current materials.
との特性を備えた圧力容器用鋼材の開発が欠かせないと
の結論に達した。そして、このような認識に立って研究
を続けた本発明者等は、海水中での使用に主眼を置いた
場合には、これまで定量的に把握されていなかった脆性
破壊を確実に防ぐための“破壊靭性値”の考え方を圧力
容器用鋼材に導入することが特に重要である点を明らか
にし、更に研究を重ねた結果、以下に示すような新しい
知見を得ることができた。It was concluded that it is essential to develop steel materials for pressure vessels with these characteristics. Based on this understanding, the inventors of the present invention continued their research, and when focusing on use in seawater, they found that in order to reliably prevent brittle fracture, which had not been quantitatively understood until now, As a result of further research, we were able to obtain the following new knowledge.
即ち、鋼の化学成分組成に工夫を凝らすと、その鍛練比
や熱処理条件（焼入れ・焼戻し条件）によって
降伏強さ： ９５ｋｇｆ／ｎｏ（（９３０ＭＰａ）以上
。That is, if the chemical composition of the steel is modified, the yield strength can be increased to 95 kgf/no ((930 MPa) or more) depending on the forging ratio and heat treatment conditions (quenching/tempering conditions).
引張強さ： １２５ｋｇｆ／ｒｎＩＡ（１２２５ＭＰａ
）以下。Tensile strength: 125kgf/rnIA (1225MPa
)below.
伸び：１５％以上。Elongation: 15% or more.
絞り＝４０％以上 ０°Ｃシャルビ衝撃値： ６０ Ｊ／ｃＪ以上。Aperture = 40% or more 0°C Charby impact value: 60 J/cJ or more.
０°Ｃ平面歪破壊靭性値： ３５５ ｋｇｆ／ｍｕ””（１１０ＭＰａ５）以上。0°C plane strain fracture toughness value: 355 kgf/mu"" (110MPa5) or more.
結晶粒度ニア以上
なる特性の確保が可能であり、しかも海水中での耐食性
も先に述べた従来鋼を上回るものが得られることを見出
したのである。They discovered that it is possible to secure properties with a grain size of near or higher, and that corrosion resistance in seawater also exceeds that of the conventional steel mentioned above.
本発明は、上記知見に基づいてなされたものであり、
７
［圧力容器用鋼を
ｃ ： ０．２５〜０．４０％、 Ｓｉ ： ０．１
０〜０．４０％Ｍｎ ： ０．３０〜１．２０％、
ｐ：ｏ、ｏ１ｏ％以下Ｓ ： ｏ、ｏｉｏ％以下、
Ｎｉ ： ２．０〜３．０％。The present invention has been made based on the above findings, and includes the following: 7 [C: 0.25 to 0.40%, Si: 0.1]
0-0.40%Mn: 0.30-1.20%,
p: o, oio% or less S: o, oio% or less,
Ni: 2.0-3.0%.
Ｃｒ ： ０．８０〜１．５０％、 Ｍｏ ： ０．
３０〜０．８０％Ｖ ： ０．０１５〜０．２０％、
ｓｏｌ、 Ａｊ！ ： ０．０１５〜０．０６０％。Cr: 0.80-1.50%, Mo: 0.
30~0.80%V: 0.015~0.20%,
Sol, Aj! : 0.015-0.060%.
Ｎ ： ０．００６〜０．０１５％
を含むと共に（但し、Ｎｉ＋Ｃｒ≦４．０％）、残部が
実質的にＦｅから成る成分組成に構成することによって
、降伏強さ： ９５ｋｇｆ／−以上
引張強さ： １２５ｋｇｆ／−以下。By containing N: 0.006 to 0.015% (however, Ni+Cr≦4.0%), and configuring the component composition with the remainder substantially consisting of Fe, yield strength: 95 kgf/- or more tensile strength S: 125kgf/- or less.
伸び：１５％以上、 絞り：４０％以上。Elongation: 15% or more, Aperture: 40% or more.
０℃シャルビ衝撃値：６０Ｊ／ｃＪ以上０℃平面歪破壊
靭性値： ３５５ｋｇｆ／ｍ””以上結晶粒度ニア以上
の機械的及び冶金的性質を示し、かつ優れた耐食性及び
耐遅れ破壊性を備え得るようにした点」に特徴を有する
ものである。0°C Charvy impact value: 60 J/cJ or more 0°C plane strain fracture toughness: 355 kgf/m or more Shows mechanical and metallurgical properties with grain size near or higher, and has excellent corrosion resistance and delayed fracture resistance It is characterized by the fact that it is made as follows.
次に、本発明において鋼の各成分含有割合を前記の如く
に限定した理由をその作用と共に説明する。Next, the reason why the content ratio of each component of the steel is limited as described above in the present invention will be explained together with its effect.
く作用〉
Ｃはマルテンサイト組織における主要強度支配元素であ
り、圧力容器用鋼としての所要強度を確保するには０．
２５％以上の添加が必要である。一方、Ｃ含有量が０．
４０％を超えると靭性を損なうようになることから、Ｃ
含有量は０．２５〜０．４０％と定めた。Effect> C is the main strength-controlling element in the martensitic structure, and in order to secure the required strength as steel for pressure vessels, it must be 0.
It is necessary to add 25% or more. On the other hand, the C content is 0.
If it exceeds 40%, the toughness will be impaired, so C
The content was determined to be 0.25-0.40%.
Ｎｉ
Ｓｉは鋼の脱酸と焼入性確保の観点から０．１０％以上
の添加が必要であるが、同時にＳｉは粒界及び母相の靭
性を低下させるので含有量の上限を０．４０％と定めた
。Ni Si needs to be added at 0.10% or more from the viewpoint of deoxidizing steel and ensuring hardenability, but at the same time, Si reduces the toughness of grain boundaries and matrix, so the upper limit of the content should be set at 0.40% or more. %.
Ｍｎ
Ｍｎには鋼の脱酸、脱硫及び焼入性を向上させる作用が
あるが、その含有量が０．３０％未満では前記作用によ
る所望の効果が得られず、一方、１．２０％を超えて含
有させると非金属介在物が残留する恐れが生じることか
ら、Ｍｎ含有量は０．３０〜１．２０％と定めた。Mn Mn has the effect of improving the deoxidation, desulfurization, and hardenability of steel, but if its content is less than 0.30%, the desired effects cannot be obtained by the above effects; If the Mn content exceeds the Mn content, there is a risk that nonmetallic inclusions may remain, so the Mn content was set at 0.30 to 1.20%.
Ｐ、及びＳ
Ｐ及びＳは何れも鋼の清浄度を下げる有害な不純物元素
であり、特に遅れ破壊の抵抗性を改善するためにもその
含有量を極力低く抑えることが望ましい。しかし、Ｐ及
びＳ含有量を余りに低く抑えることは経済的ではないの
で、この観点から何れの含有量も上限を０．０１０％と
定めた。P and S Both P and S are harmful impurity elements that reduce the cleanliness of steel, and it is desirable to keep their content as low as possible, especially in order to improve resistance to delayed fracture. However, it is not economical to keep the P and S contents too low, so from this point of view, the upper limit of both contents was set at 0.010%.
Ｎｉ
Ｎｉは鋼の靭性を損なうことなく焼入性を改善する作用
を有しているが、その含有量が２．０％未満では所望の
焼入れ性を確保することができず、方、経済性と添加効
果の点より上限を定め、Ｎｉ含有量は２．０〜３．０％
と限定した。Ni Ni has the effect of improving the hardenability of steel without impairing its toughness, but if its content is less than 2.0%, the desired hardenability cannot be secured, and on the other hand, it is not economical. The upper limit was set based on the addition effect, and the Ni content was 2.0 to 3.0%.
limited to.
Ｃｒ
Ｃｒは、Ｎｉと同様の作用に加えて耐食性の改善作用を
も有しているが、その含有量が０．８０％未満では前記
作用による効果が十分でなく、一方、経済性と添加効果
の点より上限を定め、Ｃｒ含有量については０．８０〜
１．５０％と限定した。Cr In addition to the same effect as Ni, Cr also has the effect of improving corrosion resistance, but if its content is less than 0.80%, the effect of the above effect is insufficient, and on the other hand, the economical efficiency and addition effect are The upper limit is set based on the point, and the Cr content is 0.80~
It was limited to 1.50%.
なお、この場合にＮｉ含有量とＣｒ含有量の総和が０
４．０％を超えると破壊靭性値が低下し始めることから
、ｒＮｉ＋ｃｒ≦４．０％」と限定した。In this case, if the sum of Ni content and Cr content exceeds 04.0%, the fracture toughness value begins to decrease, so it was limited to "rNi+cr≦4.0%".
Ｍ。M.
Ｍｏには鋼の焼入性及び靭性を改善する作用があり、特
にＰの有害性を抑えて耐遅れ破壊性を向上するのに有効
な元素である。しかし、その含有量が０．３０％未満で
は前記作用による所望の効果が期待できず、一方、経済
性と添加効果の観点より上限を定め、Ｍｏ含有量は０．
３０〜０．８０％と限定した。Mo has the effect of improving the hardenability and toughness of steel, and is an element that is particularly effective in suppressing the harmful effects of P and improving delayed fracture resistance. However, if the Mo content is less than 0.30%, the desired effect due to the above action cannot be expected.On the other hand, an upper limit was set from the viewpoint of economical efficiency and the effect of addition, and the Mo content was set to 0.30%.
It was limited to 30-0.80%.
■
■は鋼の降伏点を上昇させる作用を有するが、その含有
量が０．０１５％未満では前記作用による所望の効果が
得られず、一方、０．２０％を超えて含有させると靭性
低下を招くことから、■含有量については０．０１５〜
０．２０％と定めた。■■ has the effect of increasing the yield point of steel, but if its content is less than 0.015%, the desired effect cannot be obtained, while if it is contained more than 0.20%, the toughness decreases. ■The content is 0.015~
It was set at 0.20%.
ｓｏｆ、ＡＩ！
Ａｌは鋼の脱酸及び結晶粒微細化に効果を有し、耐遅れ
破壊性を改善する作用があるが、ｓｏｌ、Ａｌｌ含有量
が０．０１５％未満では前記作用による効果が十分でな
く、一方、０．０６０％を超えて含有させると非金属介
在物が残留する恐れがあるため、ｓｏｌ、Ａｌ含有量は
０．０１５〜０．０６０％と定めた。sof, AI! Al has the effect of deoxidizing steel and refining grains, and has the effect of improving delayed fracture resistance, but when the sol and All contents are less than 0.015%, the effects of the above effects are not sufficient, On the other hand, if the content exceeds 0.060%, nonmetallic inclusions may remain, so the sol and Al contents were determined to be 0.015 to 0.060%.
ＮにはＡｆｉと化合物を作って結晶粒を微細化する作用
があるが、その含有量が０．００６％未満であると前記
作用による所望の効果が得られず、一方、０．０１５％
を超えて含有させると粗大な八βＮが残留するようにな
って上記効果を減じることから、Ｎ含有量は０．００５
〜０．０１５％と定めた。N has the effect of forming a compound with Afi and refining the crystal grains, but if its content is less than 0.006%, the desired effect of the above effect cannot be obtained;
If the N content exceeds 0.005, coarse 8βN will remain and reduce the above effect.
It was set at ~0.015%.
なお、本発明に係る圧力容器用鋼は 降伏強さ： ９５ｋｇｆ／−以上。In addition, the steel for pressure vessels according to the present invention is Yield strength: 95 kgf/- or more.
引張強さ： １２５ｋｇｆ／−以下。Tensile strength: 125 kgf/- or less.
伸び：１５％以上、 絞り：４０％以上０℃シャルビ
衝撃値：５ＱＪ／ｃｍ以上。Elongation: 15% or more, Aperture: 40% or more, 0°C Charvi impact value: 5QJ/cm or more.
０℃平面歪破壊靭性値： ３５５ｋｇｆ／璽１３／２以
上結晶粒度ニア以上
なる機械的及び冶金的性質の確保を狙いとしたものであ
るが、その理由は次の通りである。The aim is to secure mechanical and metallurgical properties with a plane strain fracture toughness value of 0°C: 355 kgf/13/2 or more and a grain size of Nia or more, and the reason is as follows.
且獣１侭ニレｉ〕
圧力容器は、基本的には胴部での発生応力（σ）２
が材料の降伏強さ（σｙ）より十分低くなるよう設計さ
れる。また胴部板厚（１）は
であり、同じ使用圧力及び大きさの容器であれば高い降
伏強さを有する材料を用いることにより板厚を小さくし
、軽量化することができる。そして、材料の降伏強さが
９５ ｋｇｆ／ｍｍ”（９３０ＭＰａ）以上であれば、
現在の軽量化要求に十分対処することが可能である。Pressure vessels are basically designed so that the stress (σ)2 generated in the body is sufficiently lower than the yield strength (σy) of the material. Further, the body plate thickness (1) is, and if the container has the same working pressure and size, the plate thickness can be reduced and the weight can be reduced by using a material having a high yield strength. If the yield strength of the material is 95 kgf/mm" (930 MPa) or more,
It is possible to fully meet current demands for weight reduction.
■鷹１濾−りｊ〕
引張強さが１２５ ｋｇｆ／ｍｆｆｌ（１２２５ＭＰａ
）を超える鋼材を海水中で使用すると使用中に遅れ破壊
が発生する恐れがある。そのため、引張強さは１２５ｋ
ｇｆ／−以下に調整するのが良い。■Taka 1 filter j] Tensile strength is 125 kgf/mffl (1225 MPa
) If steel materials exceeding 100% are used in seawater, delayed fracture may occur during use. Therefore, the tensile strength is 125k
It is best to adjust it to below gf/-.
び、 、 びシャルビ
伸び、絞り及びシャルビ衝撃値については現行材の実績
値以上とすれば圧力容器として十分に満足できる性能が
確保できることから、その値である「伸び二１５％以上
」、「絞り２４０％以上」。, , Charby elongation, reduction of area, and Charvy impact value can be set to the actual values of current materials or higher to ensure sufficiently satisfactory performance as a pressure vessel. 240% or more.”
「０℃シャルビ衝撃値：６０Ｊ／ｃＪ以上」を基準値３ とした。Standard value 3: "0℃ Charby impact value: 60J/cJ or more" And so.
破壊靭性値
圧力容器において脆性破壊が発生しない条件は、如何な
る場合も
１（＜ｋｌｃ
が成立することである。なお、ｋは
で表わされ、応力或いは欠陥が大きくなるほど大きくな
る。Ｋが最大となるのはａ（欠陥の大きさ）が板厚を貫
通する時であり、この場合においても、脆性破壊さえし
なければ内容物が漏洩して内圧が低下するので破局的な
破壊に至らない。そして、本発明では海水中で使用する
圧力容器の要望条件をσ＝ ４３ｋｇｆ／−（４２０Ｍ
Ｐａ）、 ｔ＝ ２０ ｖｎｒと把握したことからｋ
ｍｍｘ＝ ３５５ ｋｇｆ／ｎ＋””（１１０ＭＰａＦ
石）となり、そのためこれを材料の必要破壊靭性値の下
限とした。Fracture toughness valueThe condition that brittle fracture does not occur in a pressure vessel is that 1 (<klc) holds in all cases.K is expressed as and increases as the stress or defect increases.K is the maximum This happens when a (the size of the defect) penetrates the plate thickness, and even in this case, catastrophic failure will not occur as long as there is no brittle failure as the contents will leak and the internal pressure will drop. In the present invention, the required conditions for a pressure vessel used in seawater are σ=43kgf/-(420M
Pa), t = 20 vnr, so k
mmx=355 kgf/n+””(110MPaF
Therefore, this was taken as the lower limit of the required fracture toughness value of the material.
４
詰ＪＨｄ友度
遅れ破壊に対する感受性は同一の引張強さを有する鋼で
も異なり、その要因の一つに結晶粒度がある。そして、
一般に同一化学成分組成の鋼であれば結晶粒が微細にな
るほど遅れ破壊に対する抵抗力は増す。ただ、引張強さ
が１２５ｋｇｆ／−以下の鋼については結晶粒度が７以
上であれば十分な耐遅れ割れ性を示すため、これを基準
値とした。4. Susceptibility to delayed fracture differs even among steels with the same tensile strength, and one of the factors is grain size. and,
Generally, if the steel has the same chemical composition, the finer the crystal grains, the higher the resistance to delayed fracture. However, since steel with a tensile strength of 125 kgf/- or less exhibits sufficient delayed cracking resistance if the grain size is 7 or more, this was used as the reference value.
ところで、次に示すものは、本発明鋼に上記機械的性質
の目標値を達成するための標準的な鍛練比並びに熱処理
条件である。By the way, the following are standard forging ratios and heat treatment conditions for achieving the above-mentioned target values of mechanical properties for the steel of the present invention.
鍛練比：３以上。Training ratio: 3 or more.
焼入れ：８２０〜９２０°Ｃの温度域に肉厚１■当り３
０分以上保持してから焼入
れする
焼戻し；５６０〜６３０°Ｃにて焼戻す。Quenching: 3 per wall thickness in the temperature range of 820 to 920°C
Tempering: Hold for 0 minutes or more and then harden; Temper at 560-630°C.
続いて、本発明の効果を実施例により更に具体的に説明
する。Next, the effects of the present invention will be explained in more detail with reference to Examples.
〈実施例〉
実施例 １
まず、第１表に示す化学成分組成の４種類の鋼塊を溶製
し、次いで鍛練比：９．３の熱間鍛造を施して供試材を
製作した。<Examples> Example 1 First, four types of steel ingots having the chemical composition shown in Table 1 were melted, and then hot forged at a forging ratio of 9.3 to produce test materials.
なお、第１表中、比較鋼Ｉとは低炭素鋼でＮｉ添加量の
多いもの、比較鋼■とは高炭素鋼でＮｉ添加量の少ない
もの、比較鋼■とは従来鋼である。In Table 1, Comparative Steel I is a low carbon steel with a large amount of Ni added, Comparative Steel (■) is a high carbon steel with a small amount of Ni added, and Comparative Steel (2) is a conventional steel.
次に、この供試材を９１０℃に加熱して２時間保持した
後、油焼入れした。そして、該供試材を５つの試験片に
切断し、各々５００〜６６０℃までの異なる温度で５時
間の焼戻し処理を施した。Next, this test material was heated to 910° C., held for 2 hours, and then oil quenched. The sample material was then cut into five test pieces, each of which was tempered at different temperatures from 500 to 660°C for 5 hours.
そして、上記処理終了後の各試験片について降伏強さ（
σｙ）＋ 引張強さ（σい及び破壊靭性値（＋＋＋ｃ）
を調査し、その結果を第１図に示した。ここで、引張試
験はＪＩＳＺ２２４１に、衝撃試験はＪＩＳ Ｚ２２４
２に、そして破壊靭性試験はＡＳＴＭのＥ３９９にそれ
ぞれ従って実施した。Then, the yield strength (
σy) + tensile strength (σy and fracture toughness value (+++c)
The results are shown in Figure 1. Here, the tensile test is based on JIS Z2241, and the impact test is based on JIS Z224.
2 and fracture toughness tests were conducted according to ASTM E399, respectively.
第１図に示される結果からも明らかなように、本発明に
係る圧力容器用鋼は十分に満足できる機械的性質を有す
るのに対して、化学成分組成が本発明の規定から外れて
いる比較鋼では、何れも圧力容器用としての最近の機械
的性質要求値を全てに亘って十分に示さないことが分か
る。As is clear from the results shown in FIG. 1, the steel for pressure vessels according to the present invention has sufficiently satisfactory mechanical properties, whereas the steel for pressure vessels according to the present invention has a chemical composition that deviates from the specifications of the present invention. It can be seen that none of the steels satisfactorily meet the recent mechanical property requirements for pressure vessels.
次に、前記本発明鋼と比較鋼■とを耐海水腐食試験（Ａ
ＳＴＭの０３１）に供し、その結果を第２表に示した。Next, the above-mentioned steel of the present invention and comparative steel (2) were subjected to a seawater corrosion resistance test (A
STM 031) and the results are shown in Table 2.
第２表に示される結果から明らかなように、実際上問題
となり、しかも腐食量の大きい乾湿繰り返し腐食は、本
発明鋼では腐食量が０．８５５ｇであったのに対して、
比較鋼■では２．１６３ｇと大きかったことが確認でき
る。As is clear from the results shown in Table 2, dry and wet repeated corrosion, which is a practical problem and causes a large amount of corrosion, was 0.855 g for the steel of the present invention, whereas the amount of corrosion was 0.855 g for the steel of the present invention.
It can be confirmed that comparative steel ■ had a large weight of 2.163 g.
更に、本発明鋼をｋ ＋ ＝ ３００ ｋｇｆ／ｍｍ”
２にて４０００時間の遅れ破壊試験に供したが、この条
件では遅れ破壊が発生せず、十分良好な耐遅れ破壊性能
を有することが分かった。Furthermore, the steel of the present invention is k + = 300 kgf/mm"
2, it was subjected to a delayed fracture test for 4000 hours, and it was found that delayed fracture did not occur under these conditions, and it had sufficiently good delayed fracture resistance.
実施例 ２
この例では、化学成分組成のバラツキによる影響を調査
するため、“本発明にて規定する範囲内で化学成分組成
の異なる数種の鋼塊”及び“比較鋼の鋼塊”をそれぞれ
２種類溶製し、供試材を製作した。なお、これら鋼塊の
化学成分組成は第３表に示される通りであった。Example 2 In this example, in order to investigate the influence of variations in chemical composition, "several types of steel ingots with different chemical compositions within the range specified by the present invention" and "steel ingots of comparative steel" were each used. Two types were melted to produce test materials. The chemical compositions of these steel ingots were as shown in Table 3.
次いで、これらの鋼塊を鍛練比：４．８で熱間鍛造し、
本発明鋼については９１０℃に加熱して２時間保持した
後“油焼入れ”及び“６１０℃で５時間の焼戻し処理”
を、比較網については９００℃に２時間加工後“油焼入
れ”及び“６２０℃で５時間の焼戻し処理”をそれぞれ
施した。Next, these steel ingots were hot forged at a forging ratio of 4.8,
The steel of the present invention is heated to 910°C and held for 2 hours, then subjected to "oil quenching" and "tempering treatment at 610°C for 5 hours".
The comparison mesh was processed at 900°C for 2 hours and then subjected to "oil quenching" and "tempering treatment at 620°C for 5 hours", respectively.
そして、上記各処理の後、各鋼材について機械的性質の
調査及び耐食性試験を行ったが、この結果を第４表に示
す。After each of the above-mentioned treatments, the mechanical properties of each steel material were investigated and a corrosion resistance test was conducted, and the results are shown in Table 4.
第４表に示される結果からも明らかなように、本発明鋼
では実施例１の場合と同様に十分満足できる機械的性質
及び耐食性能を有しているのに対して、化学成分組成が
本発明の規定から外れている比較鋼では何れも特性に劣
ることが分かる。As is clear from the results shown in Table 4, the steel of the present invention has sufficiently satisfactory mechanical properties and corrosion resistance as in Example 1, but the chemical composition is It can be seen that all comparative steels that deviate from the specifications of the invention have inferior properties.
上述の試験結果からも、本発明に従うと海水中において
も十分満足できる性能を発揮する圧力容器用網が実現さ
れることを確認できる。The above test results also confirm that according to the present invention, a pressure vessel net that exhibits sufficiently satisfactory performance even in seawater can be realized.
なお、本発明鋼は海水中で使用される圧力容器そのもの
だけではなく 容器の付帯設備（バルブ。The steel of the present invention can be used not only for the pressure vessels themselves used in seawater, but also for the vessel's ancillary equipment (valves).
配管類等）にも適用することができ、更に淡水中太気中
の類似機器にも利用できることは勿論である。Of course, it can also be applied to similar equipment in fresh water or air.
〈効果の総括〉
以上に説明した如く、本発明によれば、圧力容器製品の
使用圧力を一段と高めたり軽量化することが可能で、し
かも遅れ破壊等の懸念を一掃し得る圧力容器用鋼を提供
することができ、潜水夫向は酸素ボンベや潜水調査船用
空気容器等、海水中で使用される各種圧力容器の性能向
上にも大きく寄与し得るなど、産業上極めて有用な効果
がもたらされる。<Summary of Effects> As explained above, according to the present invention, a steel for pressure vessels has been developed which can further increase the working pressure of pressure vessel products and reduce their weight, and can eliminate concerns such as delayed fracture. This will bring about extremely useful effects industrially, such as greatly contributing to improving the performance of various pressure vessels used in seawater, such as oxygen cylinders for divers and air containers for underwater research vessels.
第１図は、実施例で得られた鋼材の焼戻し温度と機械的
性質との関係を、本発明対象鋼と比較鋼とで対比したグ
ラフである。FIG. 1 is a graph comparing the relationship between the tempering temperature and mechanical properties of the steel materials obtained in the examples, between the steels subject to the present invention and the comparative steels.
Claims (1)
％、Ｍｎ：０．３０〜１．２０％、Ｐ：０．０１０％以
下、Ｓ：０．０１０％以下、Ｎｉ：２．０〜３．０％、
Ｃｒ：０．８０〜１．５０％、Ｍｏ：０．３０〜０．８
０％、Ｖ：０．０１５〜０．２０％、ｓｏｌ．Ａｌ：０
．０１５〜０．０６０％、Ｎ：０．００６〜０．０１５
％ を含むと共に（但し、Ｎｉ＋Ｃｒ≦４．０％）、残部が
実質的にＦｅから成り、オーステナイト結晶粒度が７以
上の圧力容器用鋼。[Claims] Weight percentage: C: 0.25-0.40%, Si: 0.10-0.40
%, Mn: 0.30-1.20%, P: 0.010% or less, S: 0.010% or less, Ni: 2.0-3.0%,
Cr: 0.80-1.50%, Mo: 0.30-0.8
0%, V: 0.015-0.20%, sol. Al: 0
．． 015-0.060%, N: 0.006-0.015
% (however, Ni+Cr≦4.0%), the remainder substantially consists of Fe, and the austenite grain size is 7 or more. Steel for pressure vessels.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2631790A JP2712702B2 (en) | 1990-02-06 | 1990-02-06 | Steel for pressure vessels |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2631790A JP2712702B2 (en) | 1990-02-06 | 1990-02-06 | Steel for pressure vessels |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03232946A true JPH03232946A (en) | 1991-10-16 |
| JP2712702B2 JP2712702B2 (en) | 1998-02-16 |
Family
ID=12190013
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2631790A Expired - Lifetime JP2712702B2 (en) | 1990-02-06 | 1990-02-06 | Steel for pressure vessels |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2712702B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7662246B2 (en) * | 2003-11-07 | 2010-02-16 | Boehler Hochdrucktechnik Gmbh | Steel for components of chemical installations |
| CN103409699A (en) * | 2013-09-06 | 2013-11-27 | 陕西华威锻压有限公司 | Steel forging with ultra-high strength and ultra-high low-temperature impact on box body of fracturing pump valve and manufacturing method of steel forging |
| CN103470757A (en) * | 2013-10-11 | 2013-12-25 | 湖南师范大学 | Equal-strength self-enhancement pressure vessel with variable structure size |
| JP2023514864A (en) * | 2020-02-28 | 2023-04-11 | バオシャン アイアン アンド スティール カンパニー リミテッド | Controlled yield ratio steel and its manufacturing method |
-
1990
- 1990-02-06 JP JP2631790A patent/JP2712702B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7662246B2 (en) * | 2003-11-07 | 2010-02-16 | Boehler Hochdrucktechnik Gmbh | Steel for components of chemical installations |
| CN103409699A (en) * | 2013-09-06 | 2013-11-27 | 陕西华威锻压有限公司 | Steel forging with ultra-high strength and ultra-high low-temperature impact on box body of fracturing pump valve and manufacturing method of steel forging |
| CN103470757A (en) * | 2013-10-11 | 2013-12-25 | 湖南师范大学 | Equal-strength self-enhancement pressure vessel with variable structure size |
| JP2023514864A (en) * | 2020-02-28 | 2023-04-11 | バオシャン アイアン アンド スティール カンパニー リミテッド | Controlled yield ratio steel and its manufacturing method |
| EP4089198A4 (en) * | 2020-02-28 | 2024-06-19 | Baoshan Iron & Steel Co., Ltd. | Yield-ratio-controlled steel and manufacturing method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2712702B2 (en) | 1998-02-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS63230851A (en) | Low-alloy steel for oil well pipe excellent in corrosion resistance | |
| JPS63230847A (en) | Low-alloy steel for oil well pipe excellent in corrosion resistance | |
| JPH0545660B2 (en) | ||
| JPH03232946A (en) | Steel for pressure vessel | |
| JPH06271975A (en) | High strength steel excellent in hydrogen embrittlement resistance and its production | |
| JPH07188840A (en) | High strength steel excellent in hydrogen embrittlement resistance and its production | |
| JPH04214841A (en) | Stainless steel for engine gasket excellent in formability and its manufacture | |
| JPS625986B2 (en) | ||
| JPH09118919A (en) | Manufacture of steel product excellent in seawater corrosion resistance | |
| JPH05148581A (en) | Steel for high strength spring and production thereof | |
| JPH03173718A (en) | Production of extra thick high tensile steel excellent in toughness at low temperature and reduced in welding hardenability | |
| US5643532A (en) | Corrosion-resistant spring steel | |
| JPH0532461B2 (en) | ||
| JP3223543B2 (en) | High corrosion resistance and high strength steel for bolts | |
| JPH0653895B2 (en) | Method for manufacturing pressure vessel used in seawater | |
| JPH033727B2 (en) | ||
| JPS63266022A (en) | Manufacture of highly corrosion resistant ferrous precipitation hardening-type alloy | |
| JPH0593244A (en) | Carburized and case-hardened steel having delayed fracture resistance | |
| JPS63241145A (en) | High-strength cr-mo steel excellent in weldability | |
| JPS6133049B2 (en) | ||
| JPS6169947A (en) | Martensitic stainless steel superior in sulfide stress cracking resistance | |
| JP2002115023A (en) | High strength spring steel having excellent hydrogen fatigue cracking resistance and its production method | |
| JPS5945753B2 (en) | Steel for line pipes with excellent hydrogen sulfide cracking resistance and its manufacturing method | |
| JPS6339660B2 (en) | ||
| RU2528606C2 (en) | Heat-resistant austenite steel with resistance to cracking at stress relief |