JPH03173718A - Production of extra thick high tensile steel excellent in toughness at low temperature and reduced in welding hardenability - Google Patents
Production of extra thick high tensile steel excellent in toughness at low temperature and reduced in welding hardenabilityInfo
- Publication number
- JPH03173718A JPH03173718A JP31077789A JP31077789A JPH03173718A JP H03173718 A JPH03173718 A JP H03173718A JP 31077789 A JP31077789 A JP 31077789A JP 31077789 A JP31077789 A JP 31077789A JP H03173718 A JPH03173718 A JP H03173718A
- Authority
- JP
- Japan
- Prior art keywords
- less
- steel
- transformation point
- toughness
- welding
- 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 34
- 239000010959 steel Substances 0.000 title claims abstract description 34
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 11
- 238000003466 welding Methods 0.000 title abstract description 23
- 230000002829 reductive effect Effects 0.000 title abstract description 6
- 230000009466 transformation Effects 0.000 claims abstract description 16
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 7
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 6
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 4
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 4
- 229910052742 iron Inorganic materials 0.000 claims abstract description 3
- 238000010791 quenching Methods 0.000 claims description 4
- 230000000171 quenching effect Effects 0.000 claims description 3
- 238000003860 storage Methods 0.000 abstract description 10
- 239000000203 mixture Substances 0.000 abstract description 6
- 238000005496 tempering Methods 0.000 abstract description 6
- 238000000034 method Methods 0.000 abstract description 5
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 5
- 230000035945 sensitivity Effects 0.000 abstract description 5
- 229910052799 carbon Inorganic materials 0.000 abstract description 4
- 229910052804 chromium Inorganic materials 0.000 abstract description 4
- 229910052758 niobium Inorganic materials 0.000 abstract description 4
- 229910052720 vanadium Inorganic materials 0.000 abstract description 4
- 229910052796 boron Inorganic materials 0.000 abstract description 3
- 239000000463 material Substances 0.000 description 21
- 239000003915 liquefied petroleum gas Substances 0.000 description 12
- 238000000137 annealing Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000008439 repair process Effects 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007542 hardness measurement Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- JRKICGRDRMAZLK-UHFFFAOYSA-N peroxydisulfuric acid Chemical compound OS(=O)(=O)OOS(O)(=O)=O JRKICGRDRMAZLK-UHFFFAOYSA-N 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野ン
本発明は、石油工業等で使用する圧力容器用材料に用い
られる低溶接硬化性の極厚山高張力鋼の製造方法に関す
る。DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a method for producing extremely thick high tensile strength steel having low weld hardening properties and used as a material for pressure vessels used in the petroleum industry and the like.
〈従来の技術）
近年、液化石油ガス（Ｌ Ｐ Ｇ）等のプラント及び貯
槽設備、更には寒冷地向は溶接構造部材の需要が増加し
つつあり、それに使用される低温用構造材料が注目され
るようになってきた。しかも、最近では、ＬＰＧ等の使
用量の増大に伴い、これを貯槽する容器の大型化が図ら
れ、これに適合できる材料が要望されている。<Conventional technology> In recent years, there has been an increase in demand for welded structural members for liquefied petroleum gas (LPG) plants and storage tank equipment, as well as for cold regions, and the low-temperature structural materials used therein are attracting attention. It's starting to happen. Moreover, in recent years, as the amount of LPG and the like used has increased, containers for storing LPG have become larger, and there is a demand for materials that can accommodate this.
〈発明が解決しようとする課題〉
ＬＰＧ貯槽圧力容器を大型化するには、使用材料の板厚
を厚くする必要があるが、従来材料では断面内の均一性
、焼入れのむら等の問題があり、板厚は３０〜５０龍程
度が限度であった。従って、これ以上の板厚の容器を必
要と・する場合には、容器を複数設けるしかなかった。<Problem to be solved by the invention> In order to increase the size of the LPG storage pressure vessel, it is necessary to increase the thickness of the material used, but conventional materials have problems such as uniformity in the cross section and uneven quenching. The maximum plate thickness was about 30 to 50 mm. Therefore, if a container with a thickness greater than this is required, there is no choice but to provide a plurality of containers.
ところで、ＬＰＧ貯槽圧力容器では、従来からＬＰＧ中
に不純物として含有している硫化水素による応力腐食割
れ（Ｓｕｌｆｉｄｅ ５Ｌｒｅｓｓ Ｃｏｒｒｏｓｉｏ
ｎＣｒａｃｋ、以下５ｓｃｃとする）が発生することが
知られている。この５ｓｃｃに対する感受性を低下させ
るには、材料の溶接後の硬度を１−１ｎ≦２００に抑え
るのが効果的であり、材料の抗張力（引張強度）をある
程度低くすることも有効であることが知られている。ま
た、低温用構造材料で重要な低温靭性、特に−４６℃で
十分な低温靭性特性を得るには、通常Ｎｉを添加するこ
とが有効であることも知られている。By the way, in LPG storage pressure vessels, stress corrosion cracking (Sulfide 5Lress Corrosion) due to hydrogen sulfide, which is contained as an impurity in LPG, has conventionally occurred.
nCrack (hereinafter referred to as 5scc) is known to occur. In order to reduce this sensitivity to 5scc, it is effective to suppress the hardness of the material after welding to 1-1n≦200, and it is also known that it is also effective to lower the tensile strength of the material to some extent. It is being It is also known that it is usually effective to add Ni to obtain low-temperature toughness, which is important in low-temperature structural materials, particularly sufficient low-temperature toughness at -46°C.
しかし、従来材料において、板厚を厚くしてしかも低温
靭性を確保しようとするとＮｉ添加量の増大（例えば２
６５％ないし３．５％のＮｉ含有量）により５ｓｃｃの
抑制効果が低減するという問題を有している。However, in conventional materials, when trying to thicken the plate and ensure low-temperature toughness, the amount of Ni added (for example, 2
There is a problem in that the suppressing effect of 5scc is reduced by a Ni content of 65% to 3.5%.
さらに、低温靭性を有した従来材料では、５ＳＣＣに対
する感受性を低下させるために溶接後の硬度をＨ２Ｓ２
Ｏ８に抑える場合、溶接により材料硬度が大幅に増大す
るという溶接硬化性ため材料の硬度を低くせねばならな
い。硬度を下げると抗張力が必要以上に低下し従来以上
の大型容器を作る上で必要な強度が得られない止いう問
題を有している。Furthermore, in conventional materials with low-temperature toughness, the hardness after welding is reduced to H2S2 to reduce susceptibility to 5SCC.
When suppressing the temperature to O8, the hardness of the material must be lowered due to welding hardening, which significantly increases the hardness of the material due to welding. If the hardness is lowered, the tensile strength is lowered more than necessary, and there is a problem in that it is not possible to obtain the strength required to make larger containers than conventional ones.
また、ＬＰＧ貯槽圧力容器等の溶接構造物は、溶接後の
残留応力除去と硬度低下を目的に、焼きなましを行うこ
とがあるが、これにより、材料の強度低下を招き、その
ため、従来では前記焼きなましは通常１回しか行えなか
った。このため、運転中のメインテナンス時の溶接補修
等が制約される。Furthermore, welded structures such as LPG storage pressure vessels are sometimes annealed for the purpose of removing residual stress after welding and reducing hardness, but this leads to a decrease in the strength of the material. can usually only be done once. Therefore, welding repairs and the like during maintenance during operation are restricted.
本発明は上記の事情に鑑みなされたもので、従来より板
厚が厚く、低温靭性に優れしかも５ＳＣＣに対する感受
性が低く、大容量のＬＰＧ貯槽圧力容器の製造に好適な
低温靭性の優れ、溶接により硬度が増大することが少な
い極厚肉低溶接硬化性高張力鋼の製造方法を提供するこ
とを目的とする。The present invention was made in view of the above circumstances, and has a thicker plate than conventional ones, excellent low-temperature toughness, and low sensitivity to 5SCC, and has excellent low-temperature toughness suitable for manufacturing large-capacity LPG storage pressure vessels. It is an object of the present invention to provide a method for producing extremely thick wall, low weld hardening, high tensile strength steel with little increase in hardness.
く課題を解決するための手段及び作用〉このため本発明
の低温靭性の優れた極厚肉低溶接硬化性高張力鋼の製造
方法としては、重量比で、Ｃが０．０２〜０．１５％好
ましくは０．１θ％以下、Ｓｉが０．０５〜０．６％、
Ｍｎが０．５〜２．０％好ましくは１．４〜１．８％、
Ｎｉが０．３％以下好ましくは０．２５％以下、不純物
元素のＰ及びＳがそれぞれ０．０３５％以下、 ０．０
０５％以下であり、更に、０．０５％以下のＣｒ 、
０．０５％以下のＶ、 ０．０１％以下のＭｏ 。Means and Effects for Solving the Problems> Therefore, the method for manufacturing the ultra-thick wall, low weld hardening, high tensile strength steel with excellent low temperature toughness according to the present invention has a carbon content of 0.02 to 0.15 in terms of weight ratio. % preferably 0.1θ% or less, Si 0.05 to 0.6%,
Mn is 0.5 to 2.0%, preferably 1.4 to 1.8%,
Ni is 0.3% or less, preferably 0.25% or less, impurity elements P and S are each 0.035% or less, 0.0
0.05% or less, and further 0.05% or less of Cr,
V below 0.05%, Mo below 0.01%.
０．０１％以下のＢ及び０．０１％以下のＮｂのうちの
少なくとも１種を含有し、残部がＦｅと不可避不純物か
らなる組成の鋼を圧延し、その後Ａｃ３変態点＋３０℃
〜Ａｃ＋変態点＋２００℃の温度範囲で焼入れし、次い
でＡｃｌ変態点−４０℃〜Ａｃ１変態点−２００℃の温
度範囲で焼戻しを施したことを特徴とする。A steel containing at least one of 0.01% or less B and 0.01% or less Nb, with the balance consisting of Fe and unavoidable impurities is rolled, and then Ac3 transformation point + 30 ° C.
It is characterized by being quenched in a temperature range of ~Ac+transformation point +200°C, and then tempered in a temperature range of ACl transformation point -40°C to Ac1 transformation point -200°C.
かかる製造方法による鋼材によれば、板厚が厚く低温靭
性に優れ５ｓｃｃに対する感受性の低い従来より容量の
大きいＬＰＧ貯槽圧力容器等の製造が可能となる。また
、組立て溶接加工後に、焼戻し温度−２０℃〜焼戻し温
度−１００℃の範囲の温度で３回の焼きなましを施して
も十分な強度が得られる。According to the steel material manufactured by such a manufacturing method, it is possible to manufacture an LPG storage pressure vessel, etc., which has a large plate thickness, excellent low-temperature toughness, and low sensitivity to 5 SCC, and has a larger capacity than conventional ones. Moreover, sufficient strength can be obtained even if annealing is performed three times at a temperature in the range of tempering temperature -20°C to tempering temperature -100°C after assembly and welding.
この低温靭性の優れた極厚肉低溶接硬化性高張力鋼の各
元素の限定理由を以下に述べる。The reason for limiting each element in this ultra-thick wall, low weld hardening high tensile strength steel with excellent low temperature toughness will be described below.
Ｃ； Ｃの含有量と材料強度は比例関係にあり、強度を
確保するために０．０２％以上必要とし、高張力鋼はど
通常の鋼に比べＣ含有量を増加させなければならない。C: There is a proportional relationship between C content and material strength, and 0.02% or more is required to ensure strength, and high-strength steel must have an increased C content compared to ordinary steel.
また、同時に低温靭性と低溶接硬化性にはＣ′含有量は
低ければ低いほど良く、特に溶接後のＨ２Ｓ２Ｏ８の硬
度を得るにはＣ含有量は０．１５％ 以下好ましくは０
．１０以下とする必要がある。At the same time, the lower the C' content is, the better for low-temperature toughness and low weld hardenability. In particular, to obtain the hardness of H2S2O8 after welding, the C content is preferably 0.15% or less.
．． It must be 10 or less.
Ｓｉ： Ｓｉ は鋼中の脱酸に必要であり、０．０５
％以上必要であるが、低温靭性に悪影響を及ぼさぬ範囲
として０．６％を上限とする。Si: Si is necessary for deoxidation in steel, and 0.05
% or more, but the upper limit is set at 0.6% as long as it does not adversely affect low-temperature toughness.
Ｍｎ： Ｍｎは綱の強度増加にある程度まで必要であ
る。目的の強度を得るためには０．５％以上必要である
。また、含有量が多いと硬度が増し、低温靭性が劣化す
るので、好ましくは１．４〜１．８％とし２．０％を上
限とする。Mn: Mn is necessary to some extent for increasing the strength of the rope. In order to obtain the desired strength, 0.5% or more is required. Moreover, if the content is large, hardness increases and low temperature toughness deteriorates, so it is preferably 1.4 to 1.8% and the upper limit is 2.0%.
Ｎｉ： Ｎｉは低温靭性を改良することは広く知られ
ているが、一方で、５ｓｃｃには、多量な場合は害とな
ることから、０．３０％を上限とする。Ni: Although it is widely known that Ni improves low-temperature toughness, on the other hand, a large amount of Ni is harmful to 5scc, so the upper limit is set at 0.30%.
Ｐ、Ｓ：ＰとＳは高張力鋼においては、不可避不純物で
あるが、含有量がそれぞれ０．０３５％。P, S: P and S are unavoidable impurities in high-strength steel, but their content is 0.035% each.
０．００５％以下であれば影響が少ないのでこれを上限
とする。If it is 0.005% or less, the influence will be small, so this is set as the upper limit.
Ｃｒ、Ｍｏ： Ｃｒ、Ｍｏは粒子の微細化による靭性
の増強と、焼入性の改善に微量の添加で効果があるが、
それと共に硬度も増大させるので、Ｃｒは０．０５％、
Ｍｏは０．０１％を上限とする。Cr, Mo: Adding small amounts of Cr and Mo is effective in increasing toughness by making particles finer and improving hardenability.
At the same time, it also increases the hardness, so Cr is 0.05%,
The upper limit of Mo is 0.01%.
Ｖ、Ｎｂ： Ｖ、Ｎｂは微量の添加により強度の増強
に効果があるが、硬度増加も伴うので、■は０．０５％
、Ｎｂは０．０１％を上限とする。V, Nb: V and Nb are effective in increasing strength when added in small amounts, but they also increase hardness, so ■ is 0.05%.
, Nb has an upper limit of 0.01%.
Ｂ： Ｂは微量の添加により焼入性の改善に効果がある
が、一方、過量の添加は靭性の低下をもたらすので、０
．０１％を上限とする。B: B is effective in improving hardenability when added in a small amount, but on the other hand, addition of an excessive amount causes a decrease in toughness, so 0
．． The upper limit is 0.01%.
尚、上記組成に加えて、好ましくはＣｕを０．５％以下
に抑え、下記の式に示す炭素当量（Ｃｅｑ ）を０．４
５％以下とする。これにより、この発明の目的に沿った
より良い鋼を得ることができる。In addition to the above composition, it is preferable to suppress Cu to 0.5% or less, and to suppress the carbon equivalent (Ceq) shown in the following formula to 0.4.
5% or less. This makes it possible to obtain a better steel that meets the objectives of this invention.
このような化学成分を有する鋼材を通常の圧延方法にて
圧延を行い、Ａ、３変態点＋３０℃乃至ＡＣ３変態点＋
２００℃の温度範囲で焼入れを行い、Ａ（１変態点−４
０℃乃至ＡＣ１変態点−２００℃の温度範囲で焼戻しを
行うことにより、鋼板組織を微細化することで、引張強
度と靭性の増強に寄与することができる。A steel material having such a chemical composition is rolled using a normal rolling method, and the temperature ranges from A, 3 transformation point + 30°C to AC 3 transformation point +
Quenching is performed in a temperature range of 200℃, and A (1 transformation point -4
By performing tempering in the temperature range of 0° C. to AC1 transformation point −200° C., the steel plate structure is refined, which can contribute to enhancement of tensile strength and toughness.
通常、この状態で構造物として溶接加工を行うが、溶接
熱影響による残留応力と硬度上昇が発生する。このため
に、前記焼戻し温度−２０℃乃至前記焼戻し温度−１０
０℃の温度範囲で、最小保持時間を、板厚か５０龍以下
の場合には板厚２５關につき１時間の割合で算出した時
間、板厚が５０鰭を越える場合には板厚５０龍を越える
部分の板厚に対して２５鶴につき１５分の割合で算出し
た時間と２時間とを加えた時間とし、焼きなましを行う
。そして、本発明のものでは、３回繰返してもＨ，≦２
００の低溶接硬化性で、５Ｑ ｋｇ ／ ｗ ”級の高
張力鋼板を得ることができる。Normally, structures are welded in this state, but residual stress and hardness increase occur due to the effects of welding heat. For this purpose, the tempering temperature is -20°C to the tempering temperature -10°C.
In the temperature range of 0℃, the minimum holding time is calculated at the rate of 1 hour per 25 mm of plate thickness if the plate thickness is 50 mm or less, and 50 mm of plate thickness if the plate thickness exceeds 50 mm. Annealing is performed using the time calculated at a rate of 15 minutes per 25 cranes plus 2 hours for the plate thickness of the part exceeding . In the case of the present invention, even after repeating three times, H, ≦2
A high tensile strength steel plate of 5Q kg/w'' class can be obtained with a low weld hardenability of 0.00.
なお、上記の構造物として溶接加工を行う際の溶接棒と
しては下記に示す溶着金属成分の被覆ア一り溶接棒を使
用するのが好ましい。In addition, it is preferable to use a welding rod coated with the following weld metal components as a welding rod when welding the above-mentioned structure.
Ｃ： ０．０２〜０．１３％
Ｎｉ ： ０．０５〜０．６％
Ｍｎ ： ０．５〜２．０％
Ｐ ： ０．０３５％以下
Ｓ ； ０．０１％以下
Ｔｉ ： ０．００１〜０．０５％Ｂ ： ０
．００１〜０．０８％
Ｎｉ ： ０．１％以下
残部： 不可避不純物及びＦｅ
尚、成分比は重量％である。C: 0.02~0.13% Ni: 0.05~0.6% Mn: 0.5~2.0% P: 0.035% or less S: 0.01% or less Ti: 0.001~ 0.05%B: 0
．． 001 to 0.08% Ni: 0.1% or less Remainder: Unavoidable impurities and Fe Note that component ratios are in weight %.
〈実施例〉 以下に本発明の実施例について説明する。<Example> Examples of the present invention will be described below.
表１に示す化学成分の鋼板を通常の圧延方法により圧延
して圧延鋼材を得て、ローラクエンチ設備により８４０
℃で焼入れを行い、６４０℃で焼戻しを行い、厚さ７１
ｍｍの鋼板を得た。A steel plate having the chemical composition shown in Table 1 is rolled by a normal rolling method to obtain a rolled steel material, and then rolled using roller quench equipment to
Quenched at ℃, tempered at 640℃, thickness 71
A steel plate of mm was obtained.
この鋼板を低温靭性確保の／こめＮｉに代えてＴｉ。This steel plate was used in place of Ni to ensure low-temperature toughness.
Ｂを添加した表２に示す溶着金属成分の溶接棒にて、入
熱量４０．０００ジュール以下にてアーク溶接し、溶接
後、６１０℃で保持時間２時間１５分にて焼きなましを
３回繰返した。Arc welding was performed using a welding rod with the weld metal composition shown in Table 2 containing B, with a heat input of 40.000 joules or less, and after welding, annealing was repeated three times at 610°C for 2 hours and 15 minutes. .
このようにして得られた鋼板の機械的性質を表３に示す
。尚、５０ ｋｇ ／ ａｍ ２級高張力鋼は、米国Ａ
ＳＴＭ規格においては、Ａ ５１６ Ｇｒ７０（表中、
比較例１とする）がこれに類似し、ＪＩＳ規格において
は、ＪＩＳ Ｇ ３１０６ Ｓ？ｌ５０Ｂ （表中、比
較例２とする）が類似するので、これら規格値と比較し
た。Table 3 shows the mechanical properties of the steel plate thus obtained. In addition, 50 kg / am grade 2 high tensile strength steel is manufactured by U.S.A.
In the STM standard, A 516 Gr70 (in the table,
Comparative Example 1) is similar to this, and in the JIS standard, JIS G 3106 S? 150B (referred to as Comparative Example 2 in the table) is similar, so it was compared with these standard values.
また、本実施例により得られた鋼板の母材、熱影響部、
溶接金属部における硬度の測定結果を図面に示す。溶接
施工法試験は、ＡＳＭＥ Ｂｏｉｌｅｒ ＡｎｄＰｒｅ
ｓｓｕｒｅ Ｖｅｓｓｅｌ Ｃｏｄｅ ５ｅｃｔｉｏｎ
ｌＸ Ｗｅｌｄｉｎｇ ａｎｄ Ｂ−ｒａｚｉｎｇ Ｑ
ｕａｌｉｆｉｃａｔｉｏｎｓ ＰＡＲＴ ＱＷによる。In addition, the base material of the steel plate obtained in this example, the heat affected zone,
The drawing shows the measurement results of the hardness of the weld metal part. The welding method test is ASME Boiler AndPre.
ssure Vessel Code 5ection
lX Welding and B-razing Q
qualifications PART By QW.
尚、参考として、試験鋼材の硬度測定条件より悪条件で
ある現場における熱処理後の溶接部の硬度測定結果を表
４に示す。For reference, Table 4 shows the results of measuring the hardness of the welded part after heat treatment in the field, which was performed under conditions worse than the hardness measuring conditions of the test steel.
表１に示すように、本鋼材はＣの含有量が少なく、また
Ｃｅｑも低いので溶接性が良好であることが考えられ、
溶接構造物用として有効である。As shown in Table 1, this steel material has a low C content and low Ceq, so it is thought that it has good weldability.
Effective for welded structures.
また、図面に示す如く、溶接後の溶接熱影響部を含む鋼
板の硬度が、最高値でブリネル硬さＨ，ｔで２００（ビ
ッカース硬さＨｖで２２０）以下と低く、しかも、表４
に示すように、より悪条件下での測定結果も極めて良好
であり、更に、表１．３から明らかなように、引張強度
の上限を６０ ｋｇ ／ ｗ ”以下、Ｎｉ含有量も０
．２５％以下に抑えたことからも、ＬＰＧ等石消石油製
品純物として含有される硫化水素に起因して発生する５
ｓｃｃに対する感受性が低く、５ｓｃｃを抑制するのに
有効である。In addition, as shown in the drawing, the hardness of the steel plate including the weld heat affected zone after welding is as low as 200 or less in Brinell hardness H,t (220 in Vickers hardness Hv) at the maximum value, and Table 4
As shown in Table 1.3, the measurement results under more adverse conditions were also very good.Furthermore, as is clear from Table 1.3, the upper limit of the tensile strength was 60 kg/w'' or less, and the Ni content was 0.
．． 5%, which is generated due to hydrogen sulfide contained in pure petroleum products such as LPG, is suppressed to 25% or less.
It has low sensitivity to scc and is effective in suppressing 5scc.
また、−４６℃におけるシャルピー衝撃値が、２７、９
ｋｇ−＋ｗ （３個の平均値）、２５．８ｋｇ−ｍ
（最低値）であり、超厚肉にも拘らず、低温靭性に
優れており、例えば液化プロパンの球形タンク等の貯蔵
用容器に十分使用することができる。In addition, the Charpy impact value at -46°C is 27,9
kg-+w (average of 3 pieces), 25.8 kg-m
(lowest value), and despite its extremely thick wall, it has excellent low-temperature toughness, and can be used satisfactorily for storage containers such as spherical tanks for liquefied propane.
更に、通常は１回の焼きなまししか行えないが、これを
３回繰返した結果、表３のような機械的性質が得られた
ことは、運転中のメンテナンス時でも、溶接補修、再焼
きなましを可能として容器の寿命を延ばすことができる
。Furthermore, although normally only annealing can be performed once, after repeating this three times, the mechanical properties shown in Table 3 were obtained, which means that welding repairs and re-annealing can be performed even during maintenance during operation. This can extend the life of the container.
そして、肉厚が厚〈従来では不可能であった大容量の貯
蔵圧力容器を製造することが可能となる。Furthermore, it becomes possible to manufacture a large capacity storage pressure vessel with a thick wall, which was previously impossible.
〈発明の効果〉
以上説明したように本発明によれば、極厚肉で低温靭性
に優れ、溶接によって硬度の増大が少なく硫化水素に起
因する応力腐食割れに対する抑止効果が良好で、且つ、
運転中のメンテナンス性も良好で、ＬＰＧ等の貯蔵圧力
容器用材料に適した高張力鋼を製造することができる。<Effects of the Invention> As explained above, according to the present invention, the material has an extremely thick wall and excellent low-temperature toughness, has a small increase in hardness due to welding, has a good inhibiting effect on stress corrosion cracking caused by hydrogen sulfide, and
It is possible to manufacture high-strength steel that is easy to maintain during operation and is suitable as a material for storage pressure vessels such as LPG.
図面は本発明により製造した高張力鋼の一実施例の硬度
測定結果を示す図である。The drawing is a diagram showing the hardness measurement results of an example of high tensile strength steel manufactured according to the present invention.
Claims (1)
〜０．６％、Ｍｎが０．５〜２．０％、Ｎｉが０．３％
以下、不純物元素のＰ及びＳがそれぞれ０．０３５％以
下、０．００５％以下であり、更に、０．０５％以下の
Ｃｒ、０．０５％以下のＶ、０．０１％以下のＭｏ、０
．０１％以下のＢ及び０．０１％以下のＮｂのうちの少
なくとも１種を含有し、残部がＦｅと不可避不純物から
なる組成の鋼を圧延し、その後Ａｃ＿３変態点＋３０℃
〜Ａｃ＿３変態点＋２００℃の温度範囲で焼入れし、次
いでＡｃ＿１変態点−４０℃〜Ａｃ＿１変態点−２００
℃の温度範囲で焼戻しを施したことを特徴とする低温靭
性の優れた極厚肉低溶接硬化性高張力鋼の製造方法。In terms of weight ratio, C is 0.02 to 0.15%, Si is 0.05%
~0.6%, Mn 0.5-2.0%, Ni 0.3%
Hereinafter, the impurity elements P and S are 0.035% or less and 0.005% or less, respectively, and further, 0.05% or less Cr, 0.05% or less V, 0.01% or less Mo, 0
．． A steel containing at least one of 0.01% or less B and 0.01% or less Nb, with the balance consisting of Fe and unavoidable impurities is rolled, and then Ac_3 transformation point + 30 ° C.
~Ac_3 transformation point +200℃ quenching, then Ac_1 transformation point -40℃~Ac_1 transformation point -200
A method for producing ultra-thick walled, low weld-hardening high-strength steel with excellent low-temperature toughness, which is characterized by being tempered in the temperature range of °C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1310777A JPH06930B2 (en) | 1989-12-01 | 1989-12-01 | Manufacturing method of extra-thick, low-weldability high-strength steel with excellent resistance to hydrogen sulfide stress corrosion cracking and low temperature toughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1310777A JPH06930B2 (en) | 1989-12-01 | 1989-12-01 | Manufacturing method of extra-thick, low-weldability high-strength steel with excellent resistance to hydrogen sulfide stress corrosion cracking and low temperature toughness |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7003600A Division JP2842268B2 (en) | 1995-01-12 | 1995-01-12 | Method for producing welded structure excellent in hydrogen sulfide stress corrosion cracking resistance and low temperature toughness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03173718A true JPH03173718A (en) | 1991-07-29 |
| JPH06930B2 JPH06930B2 (en) | 1994-01-05 |
Family
ID=18009347
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1310777A Expired - Lifetime JPH06930B2 (en) | 1989-12-01 | 1989-12-01 | Manufacturing method of extra-thick, low-weldability high-strength steel with excellent resistance to hydrogen sulfide stress corrosion cracking and low temperature toughness |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06930B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010506804A (en) * | 2006-10-13 | 2010-03-04 | コロンビアナ ボイラー カンパニー，エルエルシー | Cargo container |
| KR20150122361A (en) * | 2014-04-23 | 2015-11-02 | 주영골프산업 주식회사 | Supply device of golf ball |
| CN107974612A (en) * | 2017-10-26 | 2018-05-01 | 江阴兴澄特种钢铁有限公司 | A kind of anti-SSCC spherical tanks high strength steel plate and its manufacture method |
| CN110184534A (en) * | 2018-07-27 | 2019-08-30 | 江阴兴澄特种钢铁有限公司 | One kind 100 ~ 150mm thickness has the super-thick steel plate and its production method of performance after the processing of excellent die welding |
| CN114231834A (en) * | 2021-10-15 | 2022-03-25 | 首钢集团有限公司 | Extra-thick structural steel with high strength and good low temperature toughness and its production method |
| CN114381662A (en) * | 2021-12-13 | 2022-04-22 | 首钢京唐钢铁联合有限责任公司 | Low-cost steel for pressure vessel and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63103021A (en) * | 1986-10-20 | 1988-05-07 | Nippon Steel Corp | Manufacture of steel plate having superior toughness at low temperature |
-
1989
- 1989-12-01 JP JP1310777A patent/JPH06930B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63103021A (en) * | 1986-10-20 | 1988-05-07 | Nippon Steel Corp | Manufacture of steel plate having superior toughness at low temperature |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010506804A (en) * | 2006-10-13 | 2010-03-04 | コロンビアナ ボイラー カンパニー，エルエルシー | Cargo container |
| KR20150122361A (en) * | 2014-04-23 | 2015-11-02 | 주영골프산업 주식회사 | Supply device of golf ball |
| CN107974612A (en) * | 2017-10-26 | 2018-05-01 | 江阴兴澄特种钢铁有限公司 | A kind of anti-SSCC spherical tanks high strength steel plate and its manufacture method |
| CN110184534A (en) * | 2018-07-27 | 2019-08-30 | 江阴兴澄特种钢铁有限公司 | One kind 100 ~ 150mm thickness has the super-thick steel plate and its production method of performance after the processing of excellent die welding |
| CN110184534B (en) * | 2018-07-27 | 2021-03-05 | 江阴兴澄特种钢铁有限公司 | 100-150 mm thick super-thick steel plate with excellent performance after die welding treatment and production method thereof |
| CN114231834A (en) * | 2021-10-15 | 2022-03-25 | 首钢集团有限公司 | Extra-thick structural steel with high strength and good low temperature toughness and its production method |
| CN114381662A (en) * | 2021-12-13 | 2022-04-22 | 首钢京唐钢铁联合有限责任公司 | Low-cost steel for pressure vessel and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06930B2 (en) | 1994-01-05 |
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