JP2005329461A - Welded steel structure having excellent brittle crack propagation stop characteristic, and method for manufacturing the same - Google Patents

Welded steel structure having excellent brittle crack propagation stop characteristic, and method for manufacturing the same Download PDF

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JP2005329461A
JP2005329461A JP2005108556A JP2005108556A JP2005329461A JP 2005329461 A JP2005329461 A JP 2005329461A JP 2005108556 A JP2005108556 A JP 2005108556A JP 2005108556 A JP2005108556 A JP 2005108556A JP 2005329461 A JP2005329461 A JP 2005329461A
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steel
brittle crack
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JP4505368B2 (en
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Hiroshi Shimanuki
広志 島貫
Takehiro Inoue
健裕 井上
Tadashi Koseki
正 小関
Tadashi Ishikawa
忠 石川
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Nippon Steel Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a welded steel structure having excellent brittle crack propagation stop characteristic capable of stopping a brittle crack propagating along a weld bead and stopping the brittle fracture, and a method for manufacturing the same. <P>SOLUTION: In the welded structure which is manufactured by assembling steel plates of the thickness t of ≥10 mm to each other by welding while occurrence and propagation of brittle fracture crack are expected in a vicinity of a weld melting line which is the Charpy fracture transition temperature higher than that of a stock steel plate, at least one pair of compression pre-strain parts in which the compression strain in the thickness direction of the steel plates is ≥ 0.5% and < 5%, and the area A occupied on the steel plate surface is 0.75t<SP>2</SP>-3.15t<SP>2</SP>are arranged substantially at the line-symmetrical positions on both sides of the weld bead, the minimum distance a from the weld melting line is separate by at least 5 mm at the position within the plane of the steel plate separate from each end of the steel plates by at least three times the thickness t, and the minimum distance b from the center line of the weld metal is at the position within the distance t equivalent to the thickness. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、造船分野でも特に大形船舶、タンク圧力容器分野でも特に石油やLNG貯蔵タンクなどの溶接大形鋼構造物の脆性き裂伝播停止特性に優れた溶接鋼構造物およびその製造方法に関するものである。   The present invention relates to a welded steel structure excellent in brittle crack propagation stopping characteristics of a welded large steel structure such as oil and LNG storage tanks, particularly in the field of shipbuilding, particularly large ships and tank pressure vessels, and a method for producing the same. Is.

大形船や大形貯蔵タンクなどは構造物自体が多数の鋼板の付き合わせ溶接により製作されている。このような構造物では脆性破壊が溶接接合部の溶接欠陥から発生することが懸念されているが、脆性き裂が発生すると、溶接残留応力によって母材側へ逸れるのが一般的であり、母材側での脆性き裂伝播停止特性が十分に高い場合には伝播停止が期待できる。しかし、万が一溶接ビードに沿って脆性き裂が大きく伝播すること危険性を考慮し、例えば円筒型タンクでは鋼板の溶接線が負荷方向と直角方向に一列に並ばないよう、脆性き裂が溶接部をもし伝播してもできるだけ速やかに比較的脆性き裂伝播停止特性の高い母材に突入するように施工するのが一般的である。 Large ships, large storage tanks, and the like are manufactured by butt welding a large number of steel plates. In such a structure, there is a concern that brittle fracture may occur due to weld defects in the welded joint, but when a brittle crack occurs, it is common for it to shift to the base metal side due to welding residual stress. Propagation stop can be expected when the brittle crack propagation stop property on the material side is sufficiently high. However, considering the danger that a brittle crack will propagate greatly along the weld bead, for example, in a cylindrical tank, the brittle crack is not welded in a line perpendicular to the load direction so that the weld line of the steel plate is not aligned in a line. In general, it is constructed so as to enter a base material having a relatively high brittle crack stoppage property as soon as possible even if it propagates.

造船分野でも甲板やデッキで生じた脆性き裂が船体を大きく伝播しないよう、脆性き裂伝播停止性能の高い鋼材が要所に用いられることがある。脆性き裂伝播停止性能の高い鋼材としては例えば、合金成分としてNi含有する鋼材や結晶粒径が小さい鋼材(特許文献1、特許文献2、特許文献3)などがある。
その他、脆性き裂の伝播を停止させる方法としては金沢らがクラックアレスターの一連の研究で種々の方法を検討しており、1:き裂伝播経路の両側に穴をあける方法(非特許文献1)、2:鋼板を貼り付ける方法(非特許文献2)、3:リベットスチフナーを取り付けたもの(非特許文献3)、4:スチフナーを溶接接合したもの(非特許文献1)などが考えられている。
特開平10−088281号公報 特開平10−102183号公報 特開平11−140584号公報 金沢ら:クラックアレスターに関する基礎的研究(第1報),造船協会論文集,第115,pp78−88,1964. 金沢ら:クラックアレスターに関する基礎的研究(第2報)−Patch型アレスターモデルについての基礎的考察−,造船協会論文集,第116,pp124−135,1964. 吉識ら:クラックアレスターに関する基礎的研究(第3報)−実験的検討−,造船協会論文集,第118,pp192−203,1965. 金沢ら:クラックアレスターに関する基礎的研究(第6報)−スチフナ型アレスタの有効性について,日本造船学会論文集,第124,pp321−330,1968.
In the shipbuilding field, steel materials with high brittle crack propagation stopping performance are sometimes used in key areas so that brittle cracks generated on decks and decks do not propagate through the hull. Examples of steel materials having high brittle crack propagation stopping performance include steel materials containing Ni as an alloy component and steel materials having a small crystal grain size (Patent Document 1, Patent Document 2, and Patent Document 3).
In addition, as a method for stopping the propagation of a brittle crack, Kanazawa et al. Have studied various methods in a series of researches on crack arresters. 1: A method of drilling holes on both sides of a crack propagation path (Non-Patent Document 1) ) 2: A method of attaching a steel plate (Non-patent document 2), 3: A rivet stiffener attached (Non-patent document 3), 4: A stiffener welded (Non-patent document 1), etc. Yes.
Japanese Patent Laid-Open No. 10-088281 JP-A-10-102183 JP-A-11-140584 Kanazawa et al .: Basic research on crack arresters (1st report), Shipbuilding Association papers, 115, pp 78-88, 1964. Kanazawa et al .: Fundamental study on crack arresters (2nd report) -Fundamental study on Patch type arrester model-, Shipbuilding Association papers, No. 116, pp124-135, 1964. Yoshinori et al .: Basic research on crack arresters (3rd report) -Experimental examination-, Shipbuilding Association papers, 118, pp 192-203, 1965. Kanazawa et al .: Fundamental study on crack arresters (6th report)-Effectiveness of stiffener type arresters, Proceedings of the Japan Institute of Shipbuilding, 124, pp321-330, 1968.

従来の技術では、溶接部で生じた脆性き裂は溶接残留応力により母材側に逸れることが多いため、母材の伝播停止特性を確保することで安全性を確保してきたが、工期の短縮や溶接効率のために行われる大入熱溶接などでは溶接部の破壊靭性が著しく低下する場合や溶接熱影響部が軟化する場合があるため、熱影響を受けていない素材では十分な脆性破壊伝播阻止特性を持っていたとしても、母材側に逸れず、溶接ビードに沿って溶接熱影響部付近をき裂が伝播し、大規模破壊に至る危険性が高い。
溶接構造物の施工では溶接ビードが一列に並んだ方が溶接しやすく、工期を短く、施工費用を安くすることが可能であるため、例えば大型船では大きなブロックごとに組み立てられ、そのブロック同士を溶接接合することで製作されている。特にブロックごとの溶接に大入熱溶接を利用することは溶接効率や工期の点で優れているが、溶接ビードに沿う脆性き裂伝播の危険性が高いため採用できないことが多い。
前記の部材の主応力方向に対して直角に近い方向に大入熱溶接ビードを一列に連続させた場合には、脆性き裂伝播停止特性の高い鋼材を脆性き裂の進行すると考えられる方向に配置することで大規模脆性破壊を防止する方法を用いたとしても、素材のままでは脆性き裂伝播停止特性の高い鋼材であっても溶接によって熱影響部の脆性き裂伝播停止特性が低下し、溶接ビードに沿う溶接熱影響部での脆性き裂の伝播が起こりやすくなるため、脆性き裂伝播停止特性の高い鋼材を用いた効果がなくなってしまう場合がある。このため、特許文献1、特許文献2、特許文献3にある脆性き裂伝播停止特性の高い鋼材でも溶接ビードの溶融線に沿う脆性破壊は停止させることができない場合がある。
In the conventional technology, brittle cracks generated in the weld zone often deviate to the base metal side due to welding residual stress, so safety has been ensured by ensuring the propagation stop characteristics of the base material. In case of high heat input welding for welding efficiency or the like, the fracture toughness of the welded part may be significantly reduced or the heat affected zone may be softened. Even if it has a blocking characteristic, it does not deviate to the base metal side, but a crack propagates along the weld bead in the vicinity of the heat affected zone of the weld, and there is a high risk of large-scale fracture.
In the construction of welded structures, it is easier to weld the weld beads arranged in a row, the construction period can be shortened, and the construction cost can be reduced. It is manufactured by welding. In particular, the use of high heat input welding for each block is excellent in terms of welding efficiency and construction period, but is often not adopted because of the high risk of brittle crack propagation along the weld bead.
When a high heat input weld bead is continued in a line in a direction close to a right angle with respect to the principal stress direction of the member, a steel material having a high brittle crack propagation stopping characteristic is assumed to progress in a brittle crack. Even if a method to prevent large-scale brittle fracture is used, the brittle crack propagation stop property of the heat-affected zone is reduced by welding, even if the steel material has high brittle crack propagation stop property. In addition, since the propagation of a brittle crack is likely to occur in the weld heat affected zone along the weld bead, the effect of using a steel material having a high brittle crack propagation stopping property may be lost. For this reason, even the steel materials having high brittle crack propagation stopping characteristics described in Patent Literature 1, Patent Literature 2, and Patent Literature 3 may not be able to stop brittle fracture along the weld bead melting line.

以上のことから、脆性き裂伝播停止特性の低い溶接ビードに沿う溶接熱影響部から脆性き裂を速やかに母材側へ逸らし脆性き裂伝播停止特性の高い部位へ誘導することおよび、溶接部で脆性き裂の伝播を阻止する方法が望まれている。
前記非特許文献の技術を溶接部を伝播する脆性き裂の停止のために利用することを考えると、非特許文献1では鋼板に穴をあけてしまうため船やタンクなどの外板には適用できない。非特許文献2、非特許文献3、非特許文献4は鋼板に付加物を取り付けることになり、重量の増加や取り付け溶接部からの疲労き裂発生や形状による腐食の懸念など、脆性き裂伝播以外の問題が生じるため適用できないことが多い。
そこで、本発明は、溶接鋼構造物の溶接部に添って伝播する脆性き裂を脆性き裂伝播停止性能の高い母材側に逸らし脆性き裂の伝播を停止させることと溶接部に沿う脆性き裂の伝播を停止させることの二つの効果をもつ脆性き裂伝播停止特性に優れた溶接鋼構造物およびその製造方法を提供することを目的とするものである。
Based on the above, it is possible to quickly guide the brittle crack from the weld heat-affected zone along the weld bead with low brittle crack propagation stopping property to the base metal side to the site with high brittle crack propagation stopping property, Therefore, a method for preventing the propagation of a brittle crack is desired.
Considering that the technology of the non-patent literature is used for stopping a brittle crack propagating through a welded portion, the non-patent literature 1 applies a hole to a steel plate, so that it can be applied to an outer plate such as a ship or a tank. Can not. In Non-Patent Document 2, Non-Patent Document 3, and Non-Patent Document 4, an appendage is attached to a steel sheet, and a brittle crack propagation such as an increase in weight, fatigue crack generation from a welded part, and corrosion due to shape. It is often not applicable because of problems other than
Therefore, the present invention shifts the brittle crack propagating along the welded portion of the welded steel structure to the base material side having a high brittle crack propagation stopping performance to stop the propagation of the brittle crack and the brittleness along the welded portion. It is an object of the present invention to provide a welded steel structure excellent in brittle crack propagation stopping characteristics having two effects of stopping crack propagation and a method for manufacturing the same.

上記課題を解決するための本発明の要旨は以下のとおりである。
(1)厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製され、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定される溶接鋼構造物において、 前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部が、前記き裂の初期伝播方向に沿った溶接ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設されており、該圧縮予ひずみ部は、各々、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ溶接金属中央線からの最短距離bが板厚相当距離t以内の位置となる位置関係を有することを特徴とする脆性き裂伝播停止特性に優れた溶接鋼構造物。
(2)厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製される鋼構造物であって、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定され、該脆性き裂の初期伝播方向に沿った溶接ビード(脆性き裂初期伝播ビード)方向には、溶接溶融線付近に脆性き裂の発生が想定される鋼板(脆性き裂発生鋼板)、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板が順に配設されるとともに、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビードまたは該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれシャルピー破面遷移温度の異なる異種鋼板同士は、前記脆性き裂初期伝播ビードまたは該ビードの延長ビードにほぼ直交する突き合わせ溶接またはT継手溶接(これらを総称して直交溶接という。)により接合されてなる溶接鋼構造物において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部が、前記脆性き裂発生鋼板の前記脆性き裂初期伝播ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設されており、各圧縮予ひずみ部は、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、前記脆性き裂初期伝播ビードの溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ前記脆性き裂初期伝播ビードの溶接金属中央線からの最短距離bが板厚相当距離t以内の位置であり、前記直交ビードの高靱性鋼板側の溶接溶融線からの最短距離cが2√(A/3)以内となる位置関係を有することを特徴とする脆性き裂伝播停止特性に優れた溶接鋼構造物。
(3)前記脆性き裂発生鋼板と前記高靱性鋼板との接合部のなす角度dが20°〜180°であることを特徴とする(2)に記載の脆性き裂伝播停止特性に優れた溶接鋼構造物。
The gist of the present invention for solving the above problems is as follows.
(1) Made by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, and is brittle near the weld melting line that is a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel sheet material. In a welded steel structure in which crack generation and propagation are assumed, the sheet thickness direction compressive strain of the steel sheet is 0.5% or more and less than 5%, and the area A occupying on the steel sheet surface is 0.75 t 2 to A pair of compression prestrained portions of 3.15t 2 are disposed along the weld bead along the initial propagation direction of the crack at substantially line symmetrical positions on both sides of the weld bead. Each part is a position in the steel plate surface that is 3 times or more the plate thickness t away from the edge of the steel plate, the shortest distance a from the weld melt line is 5 mm or more, and the shortest distance from the weld metal center line b is equivalent to the plate thickness Excellent welding steel structure brittle crack arrest properties and having a positional relation of position within away t.
(2) A steel structure produced by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, at a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel plate material. It is assumed that a brittle crack is generated and propagated in the vicinity of a weld melt line. In the direction of the weld bead (brittle crack initial propagation bead) along the initial propagation direction of the brittle crack, a brittle crack is formed near the weld melt line. A steel plate (brittle crack-initiating steel plate) that is assumed to generate cracks, and a high toughness steel plate having a material Charpy fracture surface transition temperature lower than that of the steel plate by 20 ° K or more are sequentially disposed. Dissimilar steel plates that are joined by butt welding, which is an initial propagation bead of the crack or an extended bead of the bead, each having a different Charpy fracture surface transition temperature, In joined comprising welded steel structure by butt substantially perpendicular to the extension beads seeding bead or the bead welding or T joint weld (. Orthogonality welding these are collectively),
A compressive pre-strained portion in which the sheet thickness direction compressive strain of the steel sheet is 0.5% or more and less than 5% and the area A on the steel sheet surface is 0.75 t 2 to 3.15 t 2 is the brittle crack. A pair or more are arranged along the brittle crack initial propagation bead of the generated steel plate at substantially line symmetrical positions on both sides of the weld bead, and each compression pre-strained portion is at least three times the plate thickness t from the steel plate end. The shortest distance from the weld metal center line of the brittle crack initial propagation bead is a position where the shortest distance a from the weld melt line of the brittle crack initial propagation bead is 5 mm or more at a position in the plane of the separated steel plate. b is a position within a plate thickness equivalent distance t, and the shortest distance c from the weld fusion line on the high toughness steel plate side of the orthogonal bead has a positional relationship within 2√ (A / 3). A welded steel structure with excellent brittle crack propagation stopping characteristics.
(3) The brittle crack propagation stopping property described in (2) is excellent, in which an angle d formed by a joint between the brittle crack generating steel plate and the high toughness steel plate is 20 ° to 180 °. Welded steel structure.

(4)厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製され、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定される溶接鋼構造物の製造方法において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部を、前記き裂の初期伝播方向に沿った溶接を行った後に、該溶接ビードに沿って、該溶接ビードの両側のほぼ線対称位置に、一対以上配設する溶接鋼構造物の製造方法であって、
該圧縮予ひずみ部は、各々、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ溶接金属中央線からの最短距離bが板厚相当距離t以内の位置となる位置関係を有することを特徴とする、脆性き裂伝播停止特性に優れた溶接鋼構造物の製造方法。
(5)厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製される鋼構造物であって、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定され、該脆性き裂の初期伝播方向に沿った溶接ビード(脆性き裂初期伝播ビード)方向には、溶接溶融線付近に脆性き裂の発生が想定される鋼板(脆性き裂発生鋼板)、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板が順に配設されるとともに、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビードまたは該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれシャルピー破面遷移温度の異なる異種鋼板同士は、前記脆性き裂初期伝播ビードまたは該ビードの延長ビードにほぼ直交する突き合わせ溶接またはT継手溶接(これらを総称して直交溶接という。)により接合されてなる溶接鋼構造物の製造方法において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部を、前記脆性き裂発生鋼板の前記脆性き裂初期伝播ビードを溶接した後に、該溶接ビードの沿いであって、該溶接ビードの両側のほぼ線対称位置に、一対以上配設する溶接鋼構造物の製造方法であって、
各圧縮予ひずみ部は、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、前記脆性き裂初期伝播ビードの溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ前記脆性き裂初期伝播ビードの溶接金属中央線からの最短距離bが板厚相当距離t以内の位置であり、前記直交ビードの高靱性鋼板側の溶接溶融線からの最短距離cが2√(A/3)以内となる位置関係を有することを特徴とする、脆性き裂伝播停止特性に優れた溶接鋼構造物の製造方法。
(4) Made by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, and is brittle near the weld melting line that is a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel sheet material. In the manufacturing method of welded steel structure where crack generation and propagation are assumed,
A compression pre-strained portion in which the plate thickness direction compressive strain of the steel plate is 0.5% or more and less than 5%, and the area A occupying the steel plate surface is 0.75 t 2 to 3.15 t 2 , A method of manufacturing a welded steel structure in which a pair of welded steel structures are disposed along the weld bead at substantially line symmetrical positions on both sides of the weld bead after performing welding along the initial propagation direction,
Each of the compression pre-strained portions is a position in the steel plate surface that is 3 times or more the plate thickness t from the steel plate end, a position where the shortest distance a from the weld melt line is 5 mm or more, and a weld metal center line The manufacturing method of the welded steel structure excellent in the brittle crack propagation stop characteristic characterized by having the positional relationship in which the shortest distance b from the position is within the plate thickness equivalent distance t.
(5) A steel structure produced by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, at a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel plate material. It is assumed that a brittle crack is generated and propagated in the vicinity of a weld melt line. In the direction of the weld bead (brittle crack initial propagation bead) along the initial propagation direction of the brittle crack, a brittle crack is formed near the weld melt line. A steel plate (brittle crack-initiating steel plate) that is assumed to generate cracks, and a high toughness steel plate having a material Charpy fracture surface transition temperature lower than that of the steel plate by 20 ° K or more are sequentially disposed. Dissimilar steel plates that are joined by butt welding, which is an initial propagation bead of the crack or an extended bead of the bead, each having a different Charpy fracture surface transition temperature, In butt weld or T joint welding method for manufacturing welded steel structures formed by joining by (these referred to collectively orthogonal welding.) Substantially perpendicular to the extension beads seeding bead or the bead,
The plate thickness strain direction compression of the steel sheet is less than 5% 0.5% or more, a compression pre-strain portion area A is 0.75t 2 ~3.15t 2 occupying the steel sheet surface, the brittle crack After welding the brittle crack initial propagation bead of the generated steel plate, there is a method for producing a welded steel structure in which a pair or more are disposed along the weld bead and at substantially line symmetrical positions on both sides of the weld bead. And
Each compression pre-strained portion is a position in the steel plate surface that is 3 times or more the plate thickness t away from the steel plate end, and a position where the shortest distance a from the weld melting line of the brittle crack initial propagation bead is 5 mm or more. And the shortest distance b from the weld metal center line of the brittle crack initial propagation bead is a position within the plate thickness equivalent distance t, and the shortest distance c from the weld fusion line on the high toughness steel plate side of the orthogonal bead is 2 A method for producing a welded steel structure excellent in brittle crack propagation stopping characteristics, characterized by having a positional relationship within √ (A / 3).

本発明は脆性き裂伝播停止特性の高い鋼材をあわせて使うことで、溶接鋼構造物の溶接部に沿って伝播する脆性き裂を、脆性き裂伝播停止特性の高い鋼材側へ逸らすことによって、溶接構造物の脆性破壊を小規模に食い止めることができる。
また、脆性き裂が脆性き裂伝播停止特性の高い鋼材側に逸れなくても、き裂伝播方向の応力を低下させ、脆性き裂の伝播を妨げることに効果がある。
さらに、溶接後の穴あけや溶接を行うことが無いため、従来の方法より手数がかからず、簡易に脆性き裂伝播停止特性を向上させることができる。
In the present invention, by using a steel material having a high brittle crack propagation stopping property, the brittle crack propagating along the welded portion of the welded steel structure is diverted to the steel material side having a high brittle crack propagation stopping property. The brittle fracture of the welded structure can be stopped on a small scale.
Moreover, even if the brittle crack does not deviate to the steel material side having high brittle crack propagation stopping characteristics, it is effective in reducing the stress in the crack propagation direction and preventing the propagation of the brittle crack.
Furthermore, since no drilling or welding is performed after welding, it is less labor-intensive than the conventional method, and the brittle crack propagation stopping characteristics can be easily improved.

本発明は、大形船やタンクなど溶接鋼構造物の溶接継手部の両側に圧縮負荷を与えることにより脆性き裂の経路となりやすい溶接部の一部に圧縮残留応力を与え、脆性き裂の伝播を阻止することと、同時に溶接部から離れた位置に引張応力を発生させることで鋼板の脆性き裂を脆性き裂伝播停止特性の高い部位に導き、脆性き裂を停止させることを特徴とするものである。
具体的には、請求項1の発明は、厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製され、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定される溶接鋼構造物において、前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部が、前記き裂の初期伝播方向に沿った溶接ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設されており、該圧縮予ひずみ部は、各々、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ溶接金属中央線からの最短距離bが板厚相当距離t以内の位置となる位置関係を有することを特徴とする。
The present invention gives compressive residual stress to a part of a weld that tends to be a path of a brittle crack by applying a compressive load to both sides of a welded joint of a welded steel structure such as a large ship or a tank. It is characterized by stopping the brittle crack by guiding the brittle crack of the steel plate to the part with high brittle crack propagation stop property by preventing the propagation and at the same time generating the tensile stress at the position away from the weld zone. To do.
Specifically, the invention of claim 1 is produced by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, and has a Charpy fracture surface transition higher than the Charpy fracture surface transition temperature of the steel plate material. In a welded steel structure where brittle cracks are generated and propagated in the vicinity of the weld melting line, which is the temperature, the plate thickness direction compressive strain of the steel plate is 0.5% or more and less than 5%, on the steel plate surface distribution area a is 0.75 T 2 ~3.15T compression prestrain portions is 2, substantially in line symmetry on either side of the weld bead in along the weld bead along the initial direction of propagation of the crack, one or more pairs occupying Each of the compression pre-strained portions is a position in the steel plate surface at a distance of 3 times or more of the plate thickness t from the steel plate end, and a position where the shortest distance a from the weld melt line is 5 mm or more, And the weld metal center line The shortest distance b is characterized by having a positional relation of a position within the thickness corresponding distance t.

本発明の対象を、厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製され、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定される溶接鋼構造物とするのは、厚みtが10mm以下では脆性破壊が極めて起こりにくいためであり、また、脆性き裂の発生伝播は溶接により破壊靭性の低下している部位で起こる危険性が高いからである。
また、前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部を、前記き裂の初期伝播方向に沿った溶接ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設するのは、圧縮予ひずみ部の周りに圧縮残留応力を発生させるためからである。
さらに、該圧縮予ひずみ部は、各々、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ溶接金属中央線からの最短距離bが板厚相当距離t以内の位置となる位置関係を有するのは、aが5mmより小さい場合には圧縮予ひずみ付加部の変形により溶接ビードのトウ部も変形してしまう可能性があり、き裂を誘発する可能性があるためであり、また、bがtより大きい場合には圧縮予ひずみ付加による溶接ビードの熱影響部付近の残留圧縮応力が低下するため、本発明の効果が減少するからである。
The weld melt line which is produced by assembling the objects of the present invention mainly by butt welding and / or T-joint welding of steel plates having a thickness t of 10 mm or more, and has a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel plate material. The reason why a welded steel structure is assumed that brittle cracks are generated and propagated in the vicinity is that brittle fracture is extremely difficult to occur when the thickness t is 10 mm or less. This is because there is a high risk of occurring at a site where the toughness is reduced.
In addition, a compression pre-strain portion in which the sheet thickness direction compressive strain of the steel sheet is 0.5% or more and less than 5% and the area A occupying on the steel sheet surface is 0.75 t 2 to 3.15 t 2 , The reason why a pair or more are disposed along the weld bead along the initial propagation direction of the cracks at substantially line-symmetrical positions on both sides of the weld bead is to generate a compressive residual stress around the compression prestrained portion.
Further, each of the compression pre-strained portions is a position in the steel plate surface that is 3 times or more the plate thickness t away from the end of the steel plate, a position where the shortest distance a from the weld melt line is 5 mm or more, and a weld metal. The position where the shortest distance b from the center line is within the thickness equivalent distance t is that when the a is smaller than 5 mm, the toe portion of the weld bead is also deformed by the deformation of the compression pre-strained portion. This is because there is a possibility of inducing a crack, and when b is larger than t, the residual compressive stress in the vicinity of the heat-affected zone of the weld bead due to the compression pre-strain is reduced. This is because the effect of the present invention is reduced.

図1は、 請求項1に記載の本発明の一実施例を示す図である。
図1において、1は鋼板、2は圧縮予ひずみ部、3は溶接ビード、4は脆性き裂を示す。
図1のaは、圧縮予ひずみ部の溶接溶融線からの最短距離を示す。
図1のbは、圧縮予ひずみ部の溶接金属中央線からの最短距離を示す。
請求項2の発明は、厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製される鋼構造物であって、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定され、該脆性き裂の初期伝播方向に沿った溶接ビード(脆性き裂初期伝播ビード)方向には、溶接溶融線付近に脆性き裂の発生が想定される鋼板(脆性き裂発生鋼板)、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板が順に配設されるとともに、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビードまたは該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれシャルピー破面遷移温度の異なる異種鋼板同士は、前記脆性き裂初期伝播ビードまたは該ビードの延長ビードにほぼ直交する突き合わせ溶接またはT継手溶接(これらを総称して直交溶接という。)により接合されてなる溶接鋼構造物において、 前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部が、前記脆性き裂発生鋼板の前記脆性き裂初期伝播ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設されており、各圧縮予ひずみ部は、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、前記脆性き裂初期伝播ビードの溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ前記脆性き裂初期伝播ビードの溶接金属中央線からの最短距離bが板厚相当距離t以内の位置であり、前記直交ビードの高靱性鋼板側の溶接溶融線からの最短距離cが2√(A/3)以内となる位置関係を有することを特徴とする。
FIG. 1 is a view showing an embodiment of the present invention as set forth in claim 1.
In FIG. 1, 1 is a steel plate, 2 is a compression pre-strained part, 3 is a weld bead, 4 is a brittle crack.
FIG. 1a shows the shortest distance from the weld melt line of the compression pre-strained portion.
1b of FIG. 1 shows the shortest distance from the weld metal center line of a compression pre-strain part.
The invention of claim 2 is a steel structure produced by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T joint welding, and has a Charpy fracture higher than the Charpy fracture surface transition temperature of the steel plate material. It is assumed that a brittle crack is generated and propagated near the weld melting line, which is the surface transition temperature, and in the direction of the weld bead (brittle crack initial propagation bead) along the initial propagation direction of the brittle crack, Steel plates in which brittle cracks are expected to occur (brittle crack-occurring steel plates), and high toughness steel plates having a material Charpy fracture surface transition temperature of 20 ° K or more lower than the steel plates are disposed in order, and the same type of steel plates. Are joined by butt welding that becomes the brittle crack initial propagation bead or an extended bead of the bead, and different steel plates having different Charpy fracture surface transition temperatures, In a welded steel structure joined by butt welding or T-joint welding (these are collectively referred to as orthogonal welding) that are substantially orthogonal to the initial crack propagation bead or an extended bead of the bead, the thickness direction of the steel plate A compression prestrained portion having a compressive strain of 0.5% or more and less than 5% and an area A occupying on the surface of the steel plate of 0.75 t 2 to 3.15 t 2 is the brittle crack of the brittle crack generating steel plate. One or more pairs are disposed along the crack initial propagation bead at substantially line-symmetrical positions on both sides of the weld bead, and each compression pre-strained part is located within the steel sheet plane at a distance of three times or more the sheet thickness t from the steel sheet end. The shortest distance a from the weld melting line of the brittle crack initial propagation bead is 5 mm or more, and the shortest distance b from the weld metal center line of the brittle crack initial propagation bead is a plate thickness equivalent distance. is within t The shortest distance c from the weld fusion line on the high toughness steel plate side of the orthogonal bead has a positional relationship that is within 2√ (A / 3).

本発明の対象を、請求項1の条件に加えて、該脆性き裂の初期伝播方向に沿った溶接ビード(脆性き裂初期伝播ビード)方向には、溶接溶融線付近に脆性き裂の発生が想定される鋼板(脆性き裂発生鋼板)、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板が順に配設され溶接鋼構造物とするのは、脆性き裂を高靭性鋼板に誘導することにより停止させることができるからである。
また、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビードまたは該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれシャルピー破面遷移温度の異なる異種鋼板同士は、前記脆性き裂初期伝播ビードまたは該ビードの延長ビードにほぼ直交する突き合わせ溶接またはT継手溶接(これらを総称して直交溶接という。)により接合されてなる溶接鋼構造物とするのは、鋼板の溶接組み立ての場合、溶接効率の面から溶接線が直線であることが望ましく、鋼板の形状については長方形であることが切断による端材の発生が少なく鋼板を無駄なく用いることが出来るため溶接組み立ては直交溶接が望まれるからである。
さらに、各圧縮予ひずみ部、請求項1の条件に加えて、前記直交ビードの高靱性鋼板側の溶接溶融線からの最短距離cが2√(A/3)以内となる位置関係を有するのは、脆性き裂の伝播を停止させるためには、脆性き裂が溶接ビードから逸れ圧縮予ひずみ部の周りを伝播して直交ビードに突入し、破断した後に高靭性鋼板に突入することが必要であるが、cが大きい場合には、脆性き裂が直交ビードを破断する以前に初めに伝播してきた溶接ビードに戻ってしまい、高靭性鋼板の溶接ビードに沿って伝播してしまう可能性が高まるからである。
In addition to the conditions of claim 1, the subject of the present invention is the occurrence of a brittle crack in the vicinity of the weld melting line in the weld bead (brittle crack initial propagation bead) direction along the initial propagation direction of the brittle crack. Steel plates (brittle crack-initiating steel plates), and high-toughness steel plates having a Charpy fracture surface transition temperature lower than that of the steel plate by 20 ° K or more in sequence are used to form a welded steel structure. It is because it can be stopped by guiding to a high toughness steel plate.
In addition, steel plates of the same type are joined by butt welding that becomes the brittle crack initial propagation bead or an extension bead of the bead, and different steel plates having different Charpy fracture surface transition temperatures are the brittle crack initial propagation bead. Alternatively, a welded steel structure joined by butt welding or T-joint welding (collectively referred to as orthogonal welding) that is substantially orthogonal to the extended bead of the bead is a welding efficiency in the case of steel plate welding assembly. It is desirable that the welding line is a straight line from the surface of the steel sheet, and because the shape of the steel plate is rectangular, the generation of end material due to cutting is small and the steel plate can be used without waste, so welding assembly is desired to be orthogonal welding. is there.
Furthermore, in addition to the conditions of each compression pre-strained part and claim 1, the orthogonal bead has a positional relationship in which the shortest distance c from the weld melt line on the high-toughness steel plate side is within 2√ (A / 3). In order to stop the propagation of brittle cracks, it is necessary that the brittle cracks deviate from the weld bead and propagate around the compression pre-strained part and enter the orthogonal bead, and then enter the high toughness steel plate after breaking. However, if c is large, the brittle crack may return to the weld bead originally propagated before breaking the orthogonal bead, and may propagate along the weld bead of the high toughness steel plate. Because it increases.

図2は、 請求項2に記載の本発明の一実施例を示す図である。
図2において、5は脆性き裂発生鋼板、6は脆性き裂、7は脆性き裂初期伝播溶接ビード、8は高靭性鋼板、9は直交溶接ビード、10は圧縮予ひずみ部を示す。
図2のaは、圧縮予ひずみ部の溶接溶融線からの最短距離を示す。
図2のbは、圧縮予ひずみ部の溶接金属中央線からの最短距離を示す。
図2のCは、圧縮予ひずみ部の直交ビードの高靱性鋼板側の溶接溶融線からの最短距離を示す。
請求項3の発明は、請求項2において、前記脆性き裂発生鋼板と前記高靱性鋼板との接合部のなす角度dが20°〜180°であることを特徴とする。これは、鋼板同士の突き合わせ溶接においてdが180°以上の角度となることはありえなく、またdが20°より小さい場合には圧縮負荷を行う装置を鋼板の間に挿入することが困難であるため所定の圧縮負荷を行うことが出来ないからである。
FIG. 2 is a view showing an embodiment of the present invention as set forth in claim 2.
In FIG. 2, 5 is a brittle crack generating steel plate, 6 is a brittle crack, 7 is a brittle crack initial propagation weld bead, 8 is a high toughness steel plate, 9 is an orthogonal weld bead, and 10 is a compression prestrained portion.
FIG. 2a shows the shortest distance from the weld melt line of the compression pre-strained portion.
FIG. 2b shows the shortest distance from the weld metal center line of the compression prestrained portion.
C in FIG. 2 shows the shortest distance from the weld fusion line on the high toughness steel plate side of the orthogonal bead of the compression pre-strained portion.
The invention of claim 3 is characterized in that, in claim 2, an angle d formed by a joint portion between the brittle crack generating steel plate and the high toughness steel plate is 20 ° to 180 °. This is because d cannot be an angle of 180 ° or more in butt welding between steel plates, and when d is smaller than 20 °, it is difficult to insert a device for applying a compression load between the steel plates. This is because a predetermined compression load cannot be performed.

図3は、 請求項3に記載の本発明の一実施例を示す図である。
図3において、5は脆性き裂発生鋼板、6は脆性き裂、7は脆性き裂初期伝播溶接ビード、8は高靭性鋼板、9は直交溶接ビード、10は圧縮予ひずみ部、11は溶接ビードに続く溶接ビード、12は溶接交差部を示す。
図3のdは脆性き裂発生鋼板5と高靱性鋼板8との接合部のなす角度を示す。
本発明の溶接鋼構造物における圧縮予ひずみ部近傍の応力状態を確認するために、図6に示す直径40mmの円形の圧縮面を持つポンチで板厚40mmの鋼板15に2.5%の圧縮塑性歪を与えた後に、鋼板の降伏応力の半分(165MPa)の引張負荷を与えた場合について有限要素法解析を行い、図4に示す鋼板内部の最大主応力分布を試算した。圧縮予ひずみ部13の上下部に最大主応力の最大が現れ、圧縮予ひずみ部の間の応力は遠方の応力より低くなっている。脆性き裂は主応力の高い部位を伝播する特性があるため、本発明は圧縮予ひずみの残留応力と構造物に作用する応力とを合成した場合の最大主応力が大きい位置を脆性き裂の伝播を防止したい溶接ビード14に沿った溶接熱影響部から離すことによって脆性き裂の経路を溶接熱影響部から鋼板の素材側へ誘導する効果がある。さらに、脆性き裂が溶接ビード14から遠ざかることにより、経路16で溶接熱影響部より脆性き裂伝播停止特性の高い素材部で伝播を停止させることが可能である。また圧縮予ひずみ部の間に発生する圧縮応力による溶接部を伝播する脆性き裂先端に作用する応力を低下させる効果があり、万一脆性き裂が溶接溶融線付近から逸れない場合でも、脆性き裂の伝播を阻止することができる。
FIG. 3 is a view showing an embodiment of the present invention as set forth in claim 3.
In FIG. 3, 5 is a brittle crack generating steel plate, 6 is a brittle crack, 7 is a brittle crack initial propagation weld bead, 8 is a high toughness steel plate, 9 is an orthogonal weld bead, 10 is a compression prestrained portion, and 11 is a weld. A weld bead 12 following the bead indicates a weld intersection.
FIG. 3 d shows the angle formed by the joint between the brittle crack generating steel plate 5 and the high toughness steel plate 8.
In order to confirm the stress state in the vicinity of the compression prestrained portion in the welded steel structure of the present invention, the punch having a circular compression surface with a diameter of 40 mm shown in FIG. After applying the plastic strain, the finite element method analysis was performed for a case where a tensile load that was half the yield stress (165 MPa) of the steel sheet was applied, and the maximum principal stress distribution inside the steel sheet shown in FIG. 4 was estimated. The maximum principal stress appears at the upper and lower portions of the compression pre-strained portion 13, and the stress between the compression pre-strained portions is lower than the stress in the distance. Since a brittle crack has the property of propagating through a site with a high principal stress, the present invention determines the position of the brittle crack where the maximum principal stress is large when the residual stress of compressive prestrain and the stress acting on the structure are combined. There is an effect of guiding the path of the brittle crack from the weld heat affected zone to the material side of the steel sheet by separating from the weld heat affected zone along the weld bead 14 to prevent propagation. Furthermore, since the brittle crack moves away from the weld bead 14, the propagation can be stopped at the material portion having a brittle crack propagation stop property higher than the weld heat affected zone in the path 16. It also has the effect of reducing the stress acting on the brittle crack tip propagating through the weld due to the compressive stress generated between the compression pre-strained parts. Even if the brittle crack does not deviate from the vicinity of the weld melting line, it is brittle. Crack propagation can be prevented.

また、前記有限要素法解析結果に基づく図5を用いて請求項2について説明する。鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製される鋼構造物であって、脆性き裂初期伝播ビード方向には、脆性き裂発生鋼板20、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板21が順に配設されるとともに、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビード18または該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれ脆性き裂発生鋼板20と高靱性鋼板21は、直交溶接ビード19により接合されてなる溶接鋼構造物に本発明の請求項2を適用した場合には、脆性き裂発生鋼板の溶接ビード18に沿って伝播したき裂は前記のき裂誘導効果により溶接ビード18から脆性き裂発生鋼板側20へ逸れる。その後、さらに脆性き裂は直行溶接19へ伝播し、高靱性鋼板21へ突入するという経路22をたどることになり、脆性き裂伝播停止性能の高い高靱性鋼板21で伝播を停止することになり、溶接構造物の大規模な脆性き裂伝播を防止することができる。   Claim 2 will be described with reference to FIG. 5 based on the finite element method analysis result. A steel structure produced by assembling steel plates together mainly by butt welding and / or T-joint welding, and in the brittle crack initial propagation bead direction, the brittle crack generating steel plate 20 and further the material Charpy fracture surface from the steel plate High-toughness steel plates 21 having a transition temperature of 20 ° K or lower are sequentially disposed, and the same type of steel plates are joined by butt welding as the brittle crack initial propagation bead 18 or an extension bead of the beads, respectively. When the second aspect of the present invention is applied to a welded steel structure in which the brittle crack generating steel plate 20 and the high toughness steel plate 21 are joined by the orthogonal weld bead 19, the weld bead 18 of the brittle crack generating steel plate is used. The crack propagating along the axis deviates from the weld bead 18 to the brittle crack generating steel plate side 20 due to the crack induction effect. Thereafter, the brittle crack further propagates to the direct weld 19 and follows a path 22 where it enters the high toughness steel plate 21, and the propagation stops at the high toughness steel plate 21 having a high brittle crack propagation stopping performance. In addition, large-scale brittle crack propagation in the welded structure can be prevented.

前記圧縮予ひずみを与える方法としては、図6に示すように円形や矩形の平面の断面を持つ押しポンチ23をプレス装置等を用いて鋼板24に押し当てる方法が考えられるが、同様の圧縮負荷を与えられる装置であれば他の装置でも可能である。なお、押しポンチ23で圧縮予ひずみを与えた場合、押しポンチ23の角部が鋼板24に段差を作ることになるが、この段差は応力集中を発生させるためできるだけ滑らかになるよう、面取りや曲面加工しておくことが望ましい。
ポンチの断面形状については円形や矩形以外にも適用が可能であり、効果には大きな差は出ないと考えられるため、自由にデザインできるが、ポンチの寿命や圧縮荷重をできるだけ低くするためには外に凸の中実断面が合理的である。
ポンチの大きさについては鋼材の内部にまで十分に塑性歪を与えることが重要であるためポンチの寸法は板厚と比例させる必要がある。また、面積に比例して大きな圧縮荷重が必要となり、負荷が困難となることがあるため注意が必要である。圧縮予ひずみ付与面積Aは板厚tに対して0.75t2〜3.15t2と定めたが、大きい方が広い領域に渡って圧縮残留応力残すことができるため、可能であればより大きいポンチを使うことも同様の効果がある。しかし、予ひずみを付与するために必要な荷重が面積に比例して大きくなるため実施する設備が大きくなるため困難である。
As a method of applying the compression prestrain, a method of pressing a pressing punch 23 having a circular or rectangular cross section against a steel plate 24 using a pressing device or the like as shown in FIG. Other devices are possible as long as the device can be given. When compressive prestrain is applied by the push punch 23, the corner of the push punch 23 creates a step in the steel plate 24. This step is chamfered or curved so as to be as smooth as possible to generate stress concentration. It is desirable to process.
As for the cross-sectional shape of the punch, it can be applied to other than circular and rectangular shapes, and it is thought that there will be no big difference in effect, so it can be designed freely, but in order to make the punch life and compression load as low as possible An outwardly convex solid section is reasonable.
As for the size of the punch, it is important to give sufficient plastic strain to the inside of the steel material, so the size of the punch needs to be proportional to the plate thickness. Also, care must be taken because a large compressive load is required in proportion to the area, and the load may be difficult. The compression prestraining area A is determined to be 0.75 t 2 to 3.15 t 2 with respect to the plate thickness t, but a larger one can leave a compressive residual stress over a wide region, and is larger if possible. Using punches has the same effect. However, since the load required for applying the pre-strain increases in proportion to the area, it is difficult because the equipment to be implemented becomes large.

圧縮負荷の回数は所定のひずみの範囲になるまで複数回押してよく、ポンチの大きさと鋼材の強度の関係から圧縮負荷装置の負荷荷重が十分に取れない場合には、ポンチの位置をずらしながら、面積が0.75t2以上3.15t2以下の領域を面積が0.5t2以上のポンチを用いて複数回圧縮負荷を与えることにより、0.5%以上かつ5%未満のひずみを圧縮負荷により与えることで同様の効果が得られる。
また、予ひずみの付与は脆性き裂の伝播を想定する溶接部を溶接した後に行わなければ脆性き裂をそらす効果が期待できない。予ひずみの付与が溶接前である可能性がある場合には磁歪法などにより予ひずみ部の周辺の溶接部の残留応力分布を測定することで、予ひずみ付与と溶接の前後関係を確認することができる。たとえば、溶接後の予ひずみ付与であれば、圧縮予ひずみ部付近の溶接金属部の引張残留応力分布が乱れるが、溶接前の予ひずみ付与であれば、圧縮予ひずみ部付近での溶接方向の引張残留応力には前記の残留応力分布は見られず、単調な応力勾配となっていることで溶接と圧縮予ひずみの順番が確認できる。
The number of compression loads may be pushed several times until the predetermined strain range is reached.If the load of the compression load device cannot be taken sufficiently due to the relationship between the size of the punch and the strength of the steel material, the position of the punch is shifted, by area area of 0.75 T 2 or 3.15T 2 following areas providing a plurality of times the compression load with 0.5 t 2 or more punches, the compression load distortion less than 0.5% or more and 5% The same effect can be obtained by giving
Moreover, the effect of deflecting the brittle crack cannot be expected unless the pre-strain is applied after the welded portion assuming the propagation of the brittle crack is welded. If there is a possibility that pre-strain is applied before welding, the residual stress distribution around the pre-strained part should be measured by the magnetostrictive method, etc., to confirm the relationship between pre-strain and welding. Can do. For example, if prestraining is applied after welding, the distribution of tensile residual stress in the weld metal part near the compression prestrained part is disturbed, but if prestraining before welding is applied, the welding direction in the vicinity of the compression prestrained part The residual stress distribution is not seen in the tensile residual stress, and the order of welding and compression pre-strain can be confirmed by a monotonic stress gradient.

溶接熱影響を受けない素材部の場合、−40℃のシャルピー衝撃吸収エネルギーが約200Jであって、脆性き裂伝播停止性能も6000N/mm1.5と高い特性を有した、板厚50mmの2枚のJIS G3106のSM490Bに相当する鋼板26を1層大入熱溶接と多層盛溶接の二種類の溶接法により突合せ溶接28し、図7のESSO試験体を作製した。鋼板26は1層大入熱溶接では熱影響部の約15mmの幅において鋼材の結晶粒径が粗大化するため、−40℃のシャルピー衝撃試験で10J程度であり、脆性き裂伝播停止性能も大きく低下している鋼材である。一方、鋼板26は多層盛溶接の場合、溶接入熱が低く、母材と溶接金属の境界の3mm程度の幅の位置に粗大化した結晶粒が確認できる程度であるため、−40℃のシャルピー衝撃試験で100J程度であり、脆性き裂伝播停止性能の低下も少ない。
前記2種の溶接を行った鋼板26を用いて作製したESSO試験体に本発明を適用した。圧縮予ひずみ処理は該鋼板の溶接前および後に400トン万能試験機により直径が50mmの円形断面を持つポンチを用いて行った。ポンチ間の距離eは板厚tに対して1.5tとし、また、残留の圧縮ひずみは2.5%とした。
試験は−40℃で、応力を降伏応力の2/3レベルと1/2レベルの二段階で付与し、表1に示すそれぞれの条件でESSO試験を行った。表1の結果に欄に示すように本発明である圧縮予ひずみ処理を溶接後に行ったものについてはいずれも脆性き裂の伝播を停止させることができた。
なお、試験体1−5は溶接熱影響部の靭性があまり低下していないことと、負荷応力が低いため溶接残留応力の影響により母材側へき裂が逸れたものと考えられる。
また、圧縮予ひずみを溶接前に行った場合には、表1の結果の欄に示すようにき裂を母材側にそらす効果はみられなかった。

Figure 2005329461
In the case of a material part that is not affected by welding heat, two sheets with a plate thickness of 50 mm having a high charpy impact absorption energy at −40 ° C. of about 200 J and a high brittle crack propagation stopping performance of 6000 N / mm 1.5. A steel plate 26 corresponding to SM490B of JIS G3106 was butt welded 28 by two types of welding methods, one-layer large heat input welding and multi-layer welding, to prepare an ESSO specimen shown in FIG. The steel plate 26 has a grain size of about 10 mm in a heat affected zone of about 15 mm in single layer large heat input welding, so it is about 10 J in a Charpy impact test at −40 ° C., and also has a brittle crack propagation stopping performance. It is a steel material that is greatly reduced. On the other hand, in the case of the multi-layer welding, the steel plate 26 has a low welding heat input, and a coarse crystal grain can be confirmed at a position with a width of about 3 mm at the boundary between the base metal and the weld metal. It is about 100 J in the impact test, and there is little decrease in brittle crack propagation stopping performance.
The present invention was applied to an ESSO specimen prepared using the steel plate 26 subjected to the two types of welding. The compression pre-strain treatment was performed using a punch having a circular cross section having a diameter of 50 mm by a 400 ton universal testing machine before and after welding of the steel sheet. The distance e between punches was 1.5 t with respect to the plate thickness t, and the residual compressive strain was 2.5%.
The test was performed at −40 ° C., and stress was applied in two stages of 2/3 level and 1/2 level of yield stress, and the ESSO test was performed under each condition shown in Table 1. As shown in the column of the results in Table 1, in all cases where the compression pre-strain treatment according to the present invention was performed after welding, propagation of brittle cracks could be stopped.
In addition, it is thought that the test body 1-5 has a crack to the base material side by the influence of the welding residual stress because the toughness of the welding heat affected zone is not so much lowered and the load stress is low.
Moreover, when compression pre-strain was performed before welding, as shown in the result column of Table 1, the effect of deflecting the crack toward the base metal was not observed.
Figure 2005329461

本発明の効果の範囲を明らかにする目的でポンチの大きさと距離を変化させた実験を行った。使用した鋼材は実施例1と同様の板厚50mmおよびJIS G3106 SM490Bであって板厚15mm鋼材である。これらの鋼材を用いて1層大入熱溶接による突合せ溶接を行い、図7のESSO試験体を作製した。溶接後本発明の圧縮負荷処理を表2に示す種々の条件で行い、ポンチの位置eと寸法の効果を確認した。なお、ポンチの断面形状は円形とした。
実験は−40℃で試験応力は降伏応力の1/2である。実験の結果、ポンチの距離が大きく、ポンチの大きさが小さくなると効果が小さくなることを確認し、板厚が変わっても同様の傾向があることを確認した。この結果を元に必要断面面積とポンチ距離を定めた。

Figure 2005329461
In order to clarify the range of the effect of the present invention, an experiment was conducted in which the size and distance of the punch were changed. The steel material used is a steel material having a plate thickness of 50 mm and JIS G3106 SM490B as in Example 1 and having a plate thickness of 15 mm. These steel materials were used for butt welding by one-layer large heat input welding to produce an ESSO specimen shown in FIG. After welding, the compression load treatment of the present invention was performed under various conditions shown in Table 2, and the effect of the position e and the size of the punch was confirmed. The punch had a circular cross-sectional shape.
The experiment is −40 ° C. and the test stress is ½ of the yield stress. As a result of the experiment, it was confirmed that the effect was reduced when the punch distance was large and the punch size was small, and it was confirmed that the same tendency was observed even if the plate thickness was changed. Based on this result, the required cross-sectional area and punch distance were determined.
Figure 2005329461

シャルピー破面遷移温度が−40℃であって、板厚が15mmのJIS G3106 SM490A鋼33とほぼ同強度であってシャルピー破面遷移温度が−62℃であって板厚が15mmのJIS G3106 SM490B鋼34をCO2溶接により付き合わせ溶接36により接合して作製した鋼板2枚を同鋼種同士が隣り合い、溶接部が十字になるよう、大入熱1層溶接35によりつき合わせ溶接を行った。こうして4枚の鋼板を溶接して作成した鋼板から試験体記号3−4に相当する図8のESSO試験片を作製し、続いて試験片中央部に直径20mmの円形断面を持つポンチを用いて請求項1および請求項2の圧縮予ひずみ負荷を行なった。この試験体に対して−40℃で試験応力を100MPaとしてESSO試験を行ない、溶接ビード29付近の初期切欠部から伝播してきた脆性き裂を停止できることを確認した。発明の有効性を確認するため、請求項1および請求項2の圧縮ひずみを与えない場合と破壊靭性の高いSM490B鋼を用いずにすべてSM490A鋼を用いた場合について、表3に示す試験体3−1、試験体3−2、試験体3−3を作成し、−40℃でESSO試験を行なった。
この結果、表3に示すように本発明の圧縮負荷処理を施さなかった試験体3−1と試験体3−2の場合、試験体上部から生じ、溶接ビード35の溶接溶融線付近を伝播した脆性き裂は溶接熱影響部を通り試験体を貫通した。特に脆性き裂伝播停止特性が高い鋼材を用いた試験体3−2でも、大入熱溶接の熱影響部は著しく脆化したためSM490B鋼素材の本来の特性を発揮できなかったものと考えられる。
一方、試験体3−3では本発明の請求項1のき裂を溶接部から逸らす効果により脆性き裂は溶接部35の熱影響部の外へ逸れるものの、伝播停止には至らなかった。以上のことから本発明の有効性を確認した。

Figure 2005329461
JIS G3106 SM490B with Charpy fracture surface transition temperature of −40 ° C., approximately the same strength as JIS G3106 SM490A steel 33 with a plate thickness of 15 mm, Charpy fracture surface transition temperature of −62 ° C. and plate thickness of 15 mm Two steel plates produced by joining steel 34 by butt welding 36 by CO 2 welding were subjected to butt welding by large heat input one-layer welding 35 so that the same steel type was adjacent to each other and the welded portion was a cross. . The ESSO test piece shown in FIG. 8 corresponding to the specimen symbol 3-4 is produced from the steel sheet prepared by welding the four steel plates in this manner, and subsequently using a punch having a circular cross section with a diameter of 20 mm at the center of the test piece. The compression pre-strain load of claim 1 and claim 2 was performed. An ESSO test was performed on the specimen at −40 ° C. with a test stress of 100 MPa, and it was confirmed that a brittle crack propagating from the initial notch in the vicinity of the weld bead 29 could be stopped. In order to confirm the effectiveness of the invention, the specimens 3 and 3 shown in Table 3 in the case of not applying the compressive strain of claims 1 and 2 and the case of using all SM490A steel without using SM490B steel having high fracture toughness. -1, specimen 3-2 and specimen 3-3 were prepared, and an ESSO test was performed at -40 ° C.
As a result, as shown in Table 3, in the case of the test body 3-1 and the test body 3-2 that were not subjected to the compression load treatment of the present invention, it occurred from the upper part of the test body and propagated in the vicinity of the weld melt line of the weld bead 35. The brittle crack penetrated the specimen through the weld heat affected zone. In particular, even in the specimen 3-2 using a steel material having high brittle crack propagation stopping characteristics, the heat-affected zone of the high heat input welding was remarkably embrittled, so it is considered that the original characteristics of the SM490B steel material could not be exhibited.
On the other hand, in the test body 3-3, the brittle crack escaped out of the heat affected zone of the welded portion 35 due to the effect of deflecting the crack of claim 1 of the present invention from the welded portion, but the propagation was not stopped. From the above, the effectiveness of the present invention was confirmed.
Figure 2005329461

請求項1に記載の本発明の一実施例を示す図である。It is a figure which shows one Example of this invention of Claim 1. 請求項2に記載の本発明の一実施例を示す図である。It is a figure which shows one Example of this invention of Claim 2. 請求項3に記載の本発明の一実施例を示す図である。It is a figure which shows one Example of this invention of Claim 3. 図1の実施例の場合の鋼板の応力分布を説明する図である。It is a figure explaining the stress distribution of the steel plate in the case of the Example of FIG. 図2の実施例の場合の鋼板の応力分布を説明する図である。It is a figure explaining the stress distribution of the steel plate in the case of the Example of FIG. 本発明の圧縮負荷方法の一つの例を概略的に説明する図である。It is a figure which illustrates roughly one example of the compression load method of this invention. 実施例1および実施例2で用いたESSO試験片を説明する図である。It is a figure explaining the ESSO test piece used in Example 1 and Example 2. FIG. 実施例3で用いたESSO試験片を説明する図である。FIG. 5 is a diagram illustrating an ESSO test piece used in Example 3.

符号の説明Explanation of symbols

1: 鋼板、2:圧縮予ひずみ部、3:溶接ビード、4:脆性き裂、5:脆性き裂発生鋼板、6:脆性き裂、7:脆性き裂初期伝播溶接ビード、8:高靭性鋼板、9:直交溶接ビード、10:圧縮予ひずみ部、11:溶接ビードに続く溶接ビード 、12:溶接交差部、13:圧縮予ひずみ部、14:溶接ビード、15:鋼板、16:脆性き裂伝播経路、17:圧縮予ひずみ部、18:溶接ビード、19:直交溶接ビード、20:脆性き裂発生鋼板、21:高靭性鋼板 、22:脆性き裂伝播経路、23:ポンチ、24:鋼板、25:溶接ビード、26:鋼板、27:圧縮予ひずみ部、28:溶接ビード、29:荷重負荷方向、30:衝撃負荷方向、31:初期切欠 、32:タブ板、33:脆性き裂発生鋼板、34:試験鋼板、35:溶接ビード、36:直交溶接ビード、37:圧縮予ひずみ部、38:衝撃負荷方向、39:初期切欠、40:荷重負荷方向、41:タブ板

1: Steel plate, 2: Compression pre-strained part, 3: Weld bead, 4: Brittle crack, 5: Brittle crack generating steel plate, 6: Brittle crack, 7: Brittle crack initial propagation weld bead, 8: High toughness Steel plate, 9: orthogonal weld bead, 10: compression pre-strained part, 11: weld bead following weld bead, 12: weld crossing part, 13: compression pre-strained part, 14: weld bead, 15: steel plate, 16: brittle Crack propagation path, 17: compression pre-strained part, 18: weld bead, 19: orthogonal weld bead, 20: brittle crack generating steel sheet, 21: high toughness steel sheet, 22: brittle crack propagation path, 23: punch, 24: Steel plate, 25: Weld bead, 26: Steel plate, 27: Compression pre-strained part, 28: Weld bead, 29: Load loading direction, 30: Impact loading direction, 31: Initial notch, 32: Tab plate, 33: Brittle crack Generation steel plate, 34: Test steel plate, 35: Weld bead , 36: orthogonal weld bead, 37: compression pre-strained part, 38: impact load direction, 39: initial notch, 40: load load direction, 41: tab plate

Claims (5)

厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製され、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定される溶接鋼構造物において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部が、前記き裂の初期伝播方向に沿った溶接ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設されており、該圧縮予ひずみ部は、各々、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ溶接金属中央線からの最短距離bが板厚相当距離t以内の位置となる位置関係を有することを特徴とする、脆性き裂伝播停止特性に優れた溶接鋼構造物。
A steel sheet having a thickness t of 10 mm or more is mainly assembled by butt welding and / or T-joint welding, and a brittle crack is formed in the vicinity of the weld melting line having a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel sheet material. In welded steel structures where generation and propagation are assumed,
A compression pre-strained portion having a sheet thickness direction compressive strain of the steel sheet of 0.5% or more and less than 5% and an area A occupying on the steel sheet surface of 0.75 t 2 to 3.15 t 2 is A pair or more are disposed along the weld bead along the initial propagation direction at substantially line-symmetrical positions on both sides of the weld bead, and the compression pre-strained portions are each three times or more the plate thickness t from the end of the steel plate. A position in which the shortest distance a from the weld melt line is 5 mm or more at a position in the surface of the separated steel plate, and the shortest distance b from the weld metal center line is a position within the plate thickness equivalent distance t. A welded steel structure with excellent brittle crack propagation stopping characteristics.
厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製される鋼構造物であって、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定され、該脆性き裂の初期伝播方向に沿った溶接ビード(脆性き裂初期伝播ビード)方向には、溶接溶融線付近に脆性き裂の発生が想定される鋼板(脆性き裂発生鋼板)、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板が順に配設されるとともに、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビードまたは該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれシャルピー破面遷移温度の異なる異種鋼板同士は、前記脆性き裂初期伝播ビードまたは該ビードの延長ビードにほぼ直交する突き合わせ溶接またはT継手溶接(これらを総称して直交溶接という。)により接合されてなる溶接鋼構造物において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部が、前記脆性き裂発生鋼板の前記脆性き裂初期伝播ビード沿いで該溶接ビードの両側のほぼ線対称位置に、一対以上配設されており、各圧縮予ひずみ部は、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、前記脆性き裂初期伝播ビードの溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ前記脆性き裂初期伝播ビードの溶接金属中央線からの最短距離bが板厚相当距離t以内の位置であり、前記直交ビードの高靱性鋼板側の溶接溶融線からの最短距離cが2√(A/3)以内となる位置関係を有することを特徴とする、脆性き裂伝播停止特性に優れた溶接鋼構造物。
A steel structure manufactured by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, and having a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel plate material It is assumed that a brittle crack is generated and propagated in the vicinity of the wire, and in the direction of the weld bead (brittle crack initial propagation bead) along the initial propagation direction of the brittle crack, a brittle crack is generated near the weld melting line. An assumed steel sheet (brittle crack-initiating steel sheet) and a high toughness steel sheet having a material Charpy fracture surface transition temperature lower than the steel sheet by 20 ° K or more are disposed in order, and the same kind of steel sheets are in the initial stage of the brittle crack. Dissimilar steel plates that are joined by butt welding, which is a propagation bead or an extension bead of the bead, and have different Charpy fracture surface transition temperatures, respectively, In de or said substantially orthogonal to butt weld or T joint weld extension bead bead welding steel structures formed by joining the (. Orthogonality welding these are collectively),
A compressive pre-strained portion in which the sheet thickness direction compressive strain of the steel sheet is 0.5% or more and less than 5% and the area A on the steel sheet surface is 0.75 t 2 to 3.15 t 2 is the brittle crack. A pair or more are arranged along the brittle crack initial propagation bead of the generated steel plate at substantially line symmetrical positions on both sides of the weld bead, and each compression pre-strained portion is at least three times the plate thickness t from the steel plate end. The shortest distance from the weld metal center line of the brittle crack initial propagation bead is a position where the shortest distance a from the weld melt line of the brittle crack initial propagation bead is 5 mm or more at a position in the plane of the separated steel plate. b is a position within a plate thickness equivalent distance t, and the shortest distance c from the weld fusion line on the high toughness steel plate side of the orthogonal bead has a positional relationship within 2√ (A / 3). , Welded steel structures with excellent brittle crack propagation stopping properties.
前記脆性き裂発生鋼板と前記高靱性鋼板との接合部のなす角度dが20°〜180°であることを特徴とする、請求項2に記載の脆性き裂伝播停止特性に優れた溶接鋼構造物。   The weld steel having excellent brittle crack propagation stop characteristics according to claim 2, wherein an angle d formed by a joint portion between the brittle crack generating steel plate and the high toughness steel plate is 20 ° to 180 °. Structure. 厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製され、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定される溶接鋼構造物の製造方法において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部を、前記き裂の初期伝播方向に沿った溶接を行った後に、該溶接ビードに沿って、該溶接ビードの両側のほぼ線対称位置に、一対以上配設する溶接鋼構造物の製造方法であって、
該圧縮予ひずみ部は、各々、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ溶接金属中央線からの最短距離bが板厚相当距離t以内の位置となる位置関係を有することを特徴とする、脆性き裂伝播停止特性に優れた溶接鋼構造物の製造方法。
A steel sheet having a thickness t of 10 mm or more is mainly assembled by butt welding and / or T-joint welding, and a brittle crack is formed in the vicinity of the weld melting line having a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel sheet material. In the method of manufacturing a welded steel structure that is expected to generate and propagate,
A compression pre-strained portion in which the plate thickness direction compressive strain of the steel plate is 0.5% or more and less than 5%, and the area A occupying the steel plate surface is 0.75 t 2 to 3.15 t 2 , A method of manufacturing a welded steel structure in which a pair of welded steel structures are disposed along the weld bead at substantially line symmetrical positions on both sides of the weld bead after performing welding along the initial propagation direction,
Each of the compression pre-strained portions is a position in the steel plate surface that is 3 times or more the plate thickness t from the steel plate end, a position where the shortest distance a from the weld melt line is 5 mm or more, and a weld metal center line The manufacturing method of the welded steel structure excellent in the brittle crack propagation stop characteristic characterized by having the positional relationship in which the shortest distance b from the position is within the plate thickness equivalent distance t.
厚みtが10mm以上の鋼板同士を主として突き合わせ溶接および/またはT継手溶接により組み立てて作製される鋼構造物であって、鋼板素材のシャルピー破面遷移温度より高いシャルピー破面遷移温度である溶接溶融線付近に脆性き裂の発生、伝播が想定され、該脆性き裂の初期伝播方向に沿った溶接ビード(脆性き裂初期伝播ビード)方向には、溶接溶融線付近に脆性き裂の発生が想定される鋼板(脆性き裂発生鋼板)、さらに該鋼板より素材シャルピー破面遷移温度が20°K以上低い高靱性鋼板が順に配設されるとともに、それぞれ同種の鋼板同士は前記脆性き裂初期伝播ビードまたは該ビードの延長ビードとなる突き合わせ溶接にて接合され、それぞれシャルピー破面遷移温度の異なる異種鋼板同士は、前記脆性き裂初期伝播ビードまたは該ビードの延長ビードにほぼ直交する突き合わせ溶接またはT継手溶接(これらを総称して直交溶接という。)により接合されてなる溶接鋼構造物の製造方法において、
前記鋼板の板厚方向圧縮ひずみが0.5%以上5%未満であり、該鋼板面上に占める面積Aが0.75t2〜3.15t2である圧縮予ひずみ部を、前記脆性き裂発生鋼板の前記脆性き裂初期伝播ビードを溶接した後に、該溶接ビードの沿いであって、該溶接ビードの両側のほぼ線対称位置に、一対以上配設する溶接鋼構造物の製造方法であって、
各圧縮予ひずみ部は、鋼板端部から板厚tの3倍以上離れた鋼板面内位置で、前記脆性き裂初期伝播ビードの溶接溶融線からの最短距離aが5mm以上離れた位置であり、かつ前記脆性き裂初期伝播ビードの溶接金属中央線からの最短距離bが板厚相当距離t以内の位置であり、前記直交ビードの高靱性鋼板側の溶接溶融線からの最短距離cが2√(A/3)以内となる位置関係を有することを特徴とする、脆性き裂伝播停止特性に優れた溶接鋼構造物の製造方法。


A steel structure manufactured by assembling mainly steel plates having a thickness t of 10 mm or more by butt welding and / or T-joint welding, and having a Charpy fracture surface transition temperature higher than the Charpy fracture surface transition temperature of the steel plate material It is assumed that a brittle crack is generated and propagated in the vicinity of the wire, and in the direction of the weld bead (brittle crack initial propagation bead) along the initial propagation direction of the brittle crack, a brittle crack is generated near the weld melting line. An assumed steel sheet (brittle crack-initiating steel sheet) and a high toughness steel sheet having a material Charpy fracture surface transition temperature lower than the steel sheet by 20 ° K or more are disposed in order, and the same kind of steel sheets are in the initial stage of the brittle crack. Dissimilar steel plates that are joined by butt welding, which is a propagation bead or an extension bead of the bead, and have different Charpy fracture surface transition temperatures, respectively, In de or substantially orthogonal to butt weld or T joint welding method for manufacturing welded steel structures formed by joining by (these referred to collectively orthogonal welded.) Extension bead of said bead,
The plate thickness strain direction compression of the steel sheet is less than 5% 0.5% or more, a compression pre-strain portion area A is 0.75t 2 ~3.15t 2 occupying the steel sheet surface, the brittle crack After welding the brittle crack initial propagation bead of the generated steel plate, there is a method for producing a welded steel structure in which a pair or more are disposed along the weld bead and at substantially line symmetrical positions on both sides of the weld bead. And
Each compression pre-strained portion is a position in the steel plate surface that is 3 times or more the plate thickness t away from the steel plate end, and a position where the shortest distance a from the weld melting line of the brittle crack initial propagation bead is 5 mm or more. And the shortest distance b from the weld metal center line of the brittle crack initial propagation bead is a position within the plate thickness equivalent distance t, and the shortest distance c from the weld fusion line on the high toughness steel plate side of the orthogonal bead is 2 A method for producing a welded steel structure excellent in brittle crack propagation stopping characteristics, characterized by having a positional relationship within √ (A / 3).


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CN111433585B (en) * 2017-11-22 2022-10-28 杰富意钢铁株式会社 Method for evaluating brittle crack propagation stopping performance of thick steel plate

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