JPH11147196A - Shielded metal arc welding method for high tensile strength steel - Google Patents
Shielded metal arc welding method for high tensile strength steelInfo
- Publication number
- JPH11147196A JPH11147196A JP9308277A JP30827797A JPH11147196A JP H11147196 A JPH11147196 A JP H11147196A JP 9308277 A JP9308277 A JP 9308277A JP 30827797 A JP30827797 A JP 30827797A JP H11147196 A JPH11147196 A JP H11147196A
- Authority
- JP
- Japan
- Prior art keywords
- tensile strength
- weight
- steel
- ceq
- low
- 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
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、引張強度が880 〜
1180 MPaの高張力鋼材（鋼板など）の被覆アーク溶接方
法に関し、特に耐低温割れ性に優れるとともに、引張強
度および靱性にも優れる被覆アーク溶接方法に関するも
のである。BACKGROUND OF THE INVENTION The present invention relates to a tensile strength of 880 to 880.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated arc welding method for a high-strength steel material (such as a steel plate) having a pressure of 1180 MPa, and more particularly to a coated arc welding method having excellent low-temperature cracking resistance and excellent tensile strength and toughness.
【０００２】[0002]
【従来の技術】最近の溶接鋼構造物の大型化に伴い、構
造物に使用される鋼材の厚みが増大し、強度はより高強
度へと変化してきている。この高張力鋼材の被覆アーク
溶接においては、従来より、溶接部に低温割れが発生し
易いことが知られており、溶接施工にあたっては低温割
れ対策が必要とされている。溶接部の拡散性水素量は、
低温割れの発生に及ぼす影響が大きいとされており、こ
のため、溶接部の拡散性水素量を低減させて低温割れを
防止する方法がよく適用されている。このうち最も一般
的に用いられるのは、溶接部の予熱あるいは後熱であ
る。しかし、この方法では高張力の程度が高まるととも
に、より高い予熱温度あるいは後熱温度を必要とするよ
うになるため、溶接作業環境の悪化や溶接施工コストの
上昇などを招くことになり、その解決が求められてい
る。2. Description of the Related Art With the recent increase in the size of welded steel structures, the thickness of steel materials used for the structures has increased, and the strength has been changing to higher strength. It has been known that low-temperature cracking is likely to occur in a welded portion in covered arc welding of a high-tensile steel material, and measures for low-temperature cracking are required in welding. The amount of diffusible hydrogen in the weld is
It is said that the influence on the occurrence of low-temperature cracking is large. Therefore, a method of reducing the amount of diffusible hydrogen in the welded portion to prevent low-temperature cracking is often applied. Of these, the most commonly used is preheating or afterheating of the weld. However, this method increases the degree of high tension and requires a higher preheating temperature or post-heating temperature, which leads to a deterioration in the welding work environment and an increase in welding work costs. Is required.
【０００３】こうした中で、引張強度が880 MPa 未満の
高張力鋼の被覆アーク溶接においては、低温割れが溶接
熱影響部に発生することから、鋼板の化学成分、拡散性
水素量、拘束度に基づいた低温割れ感受性指数が提案さ
れ、この低温割れ感受性指数を減少させた耐低温割れ性
に優れた高張力鋼板が開発された。すなわち、圧延によ
り鋼板を製造する際に、圧延温度, 圧下率, 圧下スケジ
ュール等の圧延条件や冷却条件をコントロールして結晶
組織や析出物の析出形態を制御する、いわゆる制御圧
延、制御冷却の技術を適用することにより、炭素当量を
低くしつつも高い強度レベルを維持した低温割れ感受性
指数の低い鋼板が製造できるようになり、溶接熱影響部
に発生する低温割れの防止技術は大きく改善された。こ
れにともない、予熱温度が低減され、予熱などによる溶
接作業環境の悪化、溶接施工コストの増加は大きく改善
されてきたといえる。[0003] Under such circumstances, in covered arc welding of high-tensile steel having a tensile strength of less than 880 MPa, low-temperature cracking occurs in the heat-affected zone of the welding. A low-temperature cracking susceptibility index based on the low-temperature cracking susceptibility index was proposed, and a high-strength steel sheet excellent in low-temperature cracking resistance and having a reduced low-temperature cracking sensitivity index was developed. In other words, when producing steel sheets by rolling, the so-called controlled rolling, controlled cooling technology that controls the crystal structure and the precipitation form of precipitates by controlling rolling conditions and cooling conditions such as rolling temperature, rolling reduction, rolling schedule, etc. By applying, it is possible to manufacture steel sheets with low cold cracking susceptibility index while maintaining a high strength level while lowering the carbon equivalent, and the technology for preventing cold cracking occurring in the weld heat affected zone has been greatly improved. . Accordingly, it can be said that the preheating temperature has been reduced, and the deterioration of the welding work environment due to the preheating and the like, and the increase in welding construction costs have been greatly improved.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上述し
たような、鋼板の炭素当量を低下させて、低温割れの防
止方法によっても、引張強度が880 MPa 以上の高張力鋼
板になると低温割れの発生を抑制することができなくな
る。その理由は、鋼板の高強度化が進むにつれて低温割
れの発生場所が溶接熱影響部から溶接金属へと移行し、
引張強度が880MPa以上の高張力鋼では、低温割れのほと
んどは溶接金属で発生するようになるからである。した
がって、引張強度が880MPa以上の高張力鋼の低温割れを
改善するためには、鋼板の改善よりもむしろ溶接棒の改
善が必要となる。例えば、溶接施工時の予熱温度を格段
に低減することができる低水素系被覆アーク溶接棒が求
められる。However, even with the above-described method for preventing the low-temperature cracking by lowering the carbon equivalent of the steel sheet, low-temperature cracking occurs when a high-tensile steel sheet having a tensile strength of 880 MPa or more is formed, as described above. It cannot be suppressed. The reason is that as the strength of the steel sheet increases, the location of low temperature cracking shifts from the weld heat affected zone to the weld metal,
This is because in a high-tensile steel having a tensile strength of 880 MPa or more, most of the low-temperature cracks occur in the weld metal. Therefore, in order to improve low-temperature cracking of high-tensile steel having a tensile strength of 880 MPa or more, it is necessary to improve a welding rod rather than a steel plate. For example, a low-hydrogen-based coated arc welding rod that can significantly reduce the preheating temperature during welding is required.
【０００５】ところで、高張力鋼板用の低水素系被覆ア
ーク溶接棒については、従来より多くの研究が行われて
いるが、そのほとんどは溶接金属の靱性を改善すること
を目的としたものである。というのは、一般的に、溶接
金属が高強度になればなるほどその靱性は低下していく
傾向にあるからである。この靱性を改善するための従来
方法として、例えば、特公平８−29431 号公報に、Ｃ％
およびNi％を規制した鋼心線の周囲に、金属炭酸塩、金
属弗化物、Mgを含有する被覆剤を塗装した低水素系被覆
アーク溶接棒により、破壊靱性を改善する技術が開示さ
れている。また、特公平８−25059 号公報には、低水素
系被覆アーク溶接棒の被覆剤に添加する金属Mgの平均粒
径を制限することにより、溶接金属の靱性を改善する技
術が開示されている。これらの方法は、いずれも溶接金
属中の酸素の低減による靱性改善効果を利用するもの
で、被覆剤中に強脱酸剤であるMgを多量に添加する点で
共通している。By the way, much research has been conducted on low-hydrogen-based coated arc welding rods for high-tensile steel sheets, but most of them are aimed at improving the toughness of the weld metal. . This is because generally, the higher the strength of a weld metal, the lower its toughness tends to be. As a conventional method for improving this toughness, for example, Japanese Patent Publication No.
Disclosed is a technique for improving fracture toughness by using a low hydrogen coated arc welding rod coated with a coating containing a metal carbonate, a metal fluoride, and Mg around a steel core wire whose Ni% is regulated. . Japanese Patent Publication No. 8-25059 discloses a technique for improving the toughness of a weld metal by limiting the average particle size of metal Mg added to a coating agent for a low hydrogen-based coated arc welding rod. . These methods all utilize the effect of improving the toughness by reducing the oxygen in the weld metal, and are common in that a large amount of Mg, which is a strong deoxidizer, is added to the coating material.
【０００６】しかしながら、このように多量のMgを含有
する低水素系被覆アーク溶接棒では、溶接棒中の拡散性
水素量を低減させるための一般的に採用されている高温
乾燥をおこなうと、被覆剤中の金属Mgが酸化してしま
い、目的とする酸素低減の機能を十分に発揮できなくな
り、低温割れを防止することが難しいという問題があ
る。また、仮に高温乾燥による金属Mgの酸化が靱性劣化
を引き起こさない程度の場合であっても、高温乾燥を施
すことにより生じる酸化Mgは水分を吸着し易いという性
質を有しているため、安定した拡散性水素量低減の達成
は難しいと考えられる。このようなことから、Mgを多量
に含有する低水素系被覆アーク溶接棒を用いても、耐低
温割れ性の改善と溶接金属の靱性確保の両立を図るのは
難しいのが現状である。[0006] However, in the case of such a low hydrogen-coated arc welding rod containing a large amount of Mg, if a commonly employed high-temperature drying is performed to reduce the amount of diffusible hydrogen in the welding rod, the coating becomes poor. There is a problem in that the metal Mg in the agent is oxidized and the intended oxygen reduction function cannot be sufficiently exhibited, and it is difficult to prevent low-temperature cracking. Also, even if the oxidation of metal Mg by high-temperature drying does not cause deterioration of toughness, oxidized Mg generated by performing high-temperature drying has a property of easily adsorbing moisture, so it is stable. It is considered difficult to achieve a reduction in the amount of diffusible hydrogen. For these reasons, it is difficult at present to achieve both improvement of low-temperature cracking resistance and securing of toughness of the weld metal even when a low hydrogen-based coated arc welding rod containing a large amount of Mg is used.
【０００７】そこで、本発明は、従来技術が抱えている
上記問題点を解決するためになされたものであり、引張
強度 880〜1180 MPaの高張力鋼材の被覆アーク溶接にお
いて、耐低温割れ性を改善するとともに、引張強度およ
び靱性にも優れた低水素系被覆アーク溶接方法を提供す
ることを目的とするものである。Accordingly, the present invention has been made to solve the above-mentioned problems of the prior art, and is intended to reduce the low-temperature cracking resistance in coated arc welding of a high-tensile steel having a tensile strength of 880 to 1180 MPa. It is an object of the present invention to provide a low hydrogen-based coated arc welding method which is improved and has excellent tensile strength and toughness.
【０００８】[0008]
【課題を解決するための手段】発明者らは、上掲の目的
を実現すべく、引張強度が880 〜1180 MPaの高張力鋼材
の被覆アーク溶接において溶接金属に生じる低温割れ、
特に、溶接継手作製時の初層溶接において生じる低温割
れに影響を及ぼす要因について鋭意検討した。その結
果、溶接継手作製時の耐低温割れ性を改善するために
は、溶接金属中の拡散性水素量を低下させ、溶接金属の
硬さを適正範囲に調整することが必要であるとの知見を
得て、本発明を完成するに至った。SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present inventors have developed low-temperature cracking that occurs in weld metal in covered arc welding of high-tensile steel having a tensile strength of 880 to 1180 MPa.
In particular, the factors that affect the low-temperature cracking that occurs during initial layer welding during the production of welded joints were studied diligently. As a result, in order to improve low-temperature crack resistance during the production of welded joints, it is necessary to reduce the amount of diffusible hydrogen in the weld metal and adjust the hardness of the weld metal to an appropriate range. To complete the present invention.
【０００９】すなわち、本発明は、鋼中のＣ：0.16重量
％以下、かつ下記(1) 式で表されるＣeqが0.50〜0.70重
量％であり、引張強度が 880〜1180 MPaである高張力鋼
材を被覆アーク溶接するにあたり、 Ｃ：0.02重量％以下の鋼心線の周囲に、Mgの含有量を0.
5 重量％未満に制限した被覆剤を塗装した溶接棒であっ
て、この溶接棒全体の成分がＣ：0.35重量％以下、Si：
0.5 〜2.5 重量％、Mn：0.5 〜2.5 重量％、Ni：1.0 〜
3.0 重量％、Cr：0.2 〜1.2 重量％およびMo：0.2 〜1.
0 重量％であり、しかも鋼材の引張強さＴＳと、入熱量
10〜40kJ／cmの溶接により得られる溶着金属についての
前記Ｃeqとで表される下記(2) 式のＹ値を−0.1 〜0.1
の範囲に入るように調整した、低水素系被覆アーク溶接
棒を用いて溶接することを特徴とする高張力鋼材の被覆
アーク溶接方法を要旨とするものである。 記 Ｃeq＝Ｃ＋Mn／６＋（Cr＋Mo＋Ｖ）＋（Ni＋Cu）／15 …… (1) Ｙ＝Ｃeq−ＴＳ／1300 …… (2) ここでＴＳ：鋼材の引張強さ(MPa）That is, the present invention provides a high tensile strength steel having a C content of 0.16% by weight or less, a Ceq represented by the following formula (1) of 0.50 to 0.70% by weight, and a tensile strength of 880 to 1180 MPa. In covering arc welding of steel, C: 0.02 wt%
A welding rod coated with a coating agent limited to less than 5% by weight, wherein the composition of the entire welding rod is C: 0.35% by weight or less, Si:
0.5-2.5 wt%, Mn: 0.5-2.5 wt%, Ni: 1.0-
3.0% by weight, Cr: 0.2-1.2% by weight and Mo: 0.2-1.
0% by weight, and the tensile strength TS of the steel material and the heat input
The Y value of the following formula (2) expressed by the above Ceq for the deposited metal obtained by welding at 10 to 40 kJ / cm is -0.1 to 0.1.
The invention is directed to a method for covering arc welding of a high-tensile steel material, characterized in that welding is performed using a low hydrogen-based covering arc welding rod adjusted to fall within the range of (1). Ceq = C + Mn / 6 + (Cr + Mo + V) + (Ni + Cu) / 15 (1) Y = Ceq-TS / 1300 (2) where TS: tensile strength of steel (MPa)
【００１０】[0010]
【発明の実施の形態】以下に、本発明における限定理由
の詳細を説明する。まず、使用する鋼材について述べ
る。使用する鋼材の引張強度が、880 MPa 未満では低温
割れが溶接熱影響部で発生するため本発明の適用すると
ころとはならない。一方、1180 MPaを超えると、低水素
系被覆アーク溶接棒によって得られる溶接金属において
引張強度と靱性の両方を満足することが難しくなる。し
たがって、引張強度は880 〜1180 MPaの範囲とする。次
に、鋼材の化学成分について述べる。高張力鋼材を低水
素系被覆アーク溶接棒で溶接継手を作製する場合には、
溶接金属中には鋼材も溶け込むため、溶接金属の化学成
分は鋼材の成分によっても変化する。特に、最も低温割
れの発生が懸念される初層溶接では希釈率 (溶接金属中
の鋼材の溶融率) が20〜30％程度となり、溶接金属に及
ぼす鋼材の化学成分の影響は大きい。したがって、溶接
金属の耐低温割れ性、引張強度および靱性を改善するた
めには鋼材の化学成分について考慮する必要がある。DESCRIPTION OF THE PREFERRED EMBODIMENTS The reasons for limitation in the present invention will be described below in detail. First, the steel used will be described. If the tensile strength of the steel material used is less than 880 MPa, the present invention cannot be applied because low-temperature cracking occurs in the heat affected zone. On the other hand, when it exceeds 1180 MPa, it becomes difficult to satisfy both the tensile strength and the toughness in the weld metal obtained by the low hydrogen-based coated arc welding rod. Therefore, the tensile strength is in the range of 880 to 1180 MPa. Next, the chemical composition of the steel material will be described. When making a welded joint of high-tensile steel with a low hydrogen-based coated arc welding rod,
Since steel material also dissolves into the weld metal, the chemical composition of the weld metal changes depending on the composition of the steel material. In particular, the dilution rate (melting rate of the steel material in the weld metal) is about 20 to 30% in the first-layer welding where the occurrence of low-temperature cracking is most concerned, and the chemical composition of the steel material on the weld metal has a large effect. Therefore, in order to improve the low-temperature crack resistance, tensile strength and toughness of the weld metal, it is necessary to consider the chemical composition of the steel material.
【００１１】低温割れを防止するためには、溶接金属の
Ｃ含有量が非常に重要となる。溶接継手作製時の初層溶
接では溶接部は急冷されるため、溶接金属はマルテンサ
イト主体の組織となり、その硬さはＣ％に左右されるか
らである。したがって、後述するように、Ｃ％を制限し
た低水素系被覆アーク溶接棒を使用する場合であって
も、鋼材中のＣ％が増加するにしたがい、溶接金属のＣ
％が増加し、溶接金属硬さが増大するため、溶接金属に
低温割れが発生しやすくなる。また、Ｃの過度の添加は
焼入れ性を増加させるため靱性も劣化させる。これら両
方の影響を勘案して鋼材中のＣは0.16重量％以下とす
る。In order to prevent low temperature cracking, the C content of the weld metal is very important. This is because, in the initial layer welding at the time of producing a welded joint, the welded portion is rapidly cooled, so that the weld metal has a structure mainly composed of martensite, and its hardness depends on C%. Therefore, as described later, even when a low hydrogen-based coated arc welding rod with a limited C% is used, as the C% in the steel increases, the C of the weld metal increases.
% And the hardness of the weld metal increases, so that low-temperature cracking is likely to occur in the weld metal. Excessive addition of C also increases the quenchability, thereby deteriorating the toughness. In consideration of both of these effects, C in the steel material is set to 0.16% by weight or less.
【００１２】また、鋼材中のMn、Cr、Moなど他の化学成
分は、溶接金属の引張強度および靱性に影響を及ぼすも
のの、Ｃ％が溶接金属の低温割れに及ぼす影響ほど大き
くはなく、 Ｃeq＝Ｃ＋Mn／６＋（Cr＋Mo＋Ｖ）＋（Ni＋Cu）／15 …… (1) で示されるＣeqが、一定の範囲内にあれば良好な特性を
示す。ただし、鋼材の引張強度を880 〜1180 MPaの範囲
とすることを考慮して、上記Ｃeqを0.50〜0.70重量％の
範囲とする。Although other chemical components such as Mn, Cr and Mo in the steel material affect the tensile strength and toughness of the weld metal, C% is not as large as the effect on the low-temperature cracking of the weld metal. = C + Mn / 6 + (Cr + Mo + V) + (Ni + Cu) / 15 (1) If Ceq is within a certain range, good characteristics are exhibited. However, considering that the tensile strength of the steel material is in the range of 880 to 1180 MPa, the above Ceq is in the range of 0.50 to 0.70% by weight.
【００１３】次に、鋼心線の成分については特にＣ量が
重要である。溶接金属の靱性を確保すると同時に、低温
割れの発生を十分に低減させるためには、Ｃ量を0.02重
量％以下とする必要がある。鋼心線中のＣが0.02重量％
を超えると、鋼材中に含まれるＣを0.16重量％以下とし
ても、溶接金属の機械的特性を確保するために被覆剤中
に添加する合金剤などに不可避的に含まれるＣ量と合算
されることにより、得られる溶接金属中のＣ量が増加す
るため溶接金属硬さが増加し、低温割れを防止できなく
なる。さらに、機械的特性を向上させるための鋼心線と
して、Ｐ：0.01重量％以下、Ｓ：0.01重量％以下、Ｎ：
0.005 重量％以下、Ｏ：0.001 〜0.01重量％の範囲にす
ることが望ましい。Next, as for the components of the steel core wire, the C content is particularly important. In order to ensure the toughness of the weld metal and to sufficiently reduce the occurrence of low-temperature cracking, the C content must be 0.02% by weight or less. C in steel core wire is 0.02% by weight
Is exceeded, even if the content of C in the steel material is 0.16% by weight or less, it is added to the amount of C inevitably contained in the alloying agent added to the coating material to secure the mechanical properties of the weld metal. Accordingly, the C content in the obtained weld metal increases, so that the hardness of the weld metal increases, and low-temperature cracking cannot be prevented. Further, as steel core wires for improving mechanical properties, P: 0.01% by weight or less, S: 0.01% by weight or less, N:
It is desirable that the content be 0.005% by weight or less and O: in the range of 0.001 to 0.01% by weight.
【００１４】次に、被覆剤は、金属炭酸塩、金属弗化
物、アーク安定剤、スラグ形成剤、脱酸剤、合金剤、固
着剤からなるものであるが、この被覆剤中のMgは、拡散
性水素起因による低温割れを防止するために、0.5 重量
％未満とする必要がある。図１に、被覆剤中のMg％と水
素試験による拡散性水素量との関係を示す。Mg量が0.5
重量％以上になると拡散性水素量が著しく増大している
ことがわかる。このような現象を招いたのは、Mgを0.5
重量％以上含有すると、溶接棒中の拡散性水素量低減の
ために通常採用される高温乾燥を行う際に、水分を吸着
し易い特性を持つ酸化Mgが生じ易くなり、結果的に、拡
散性水素量を安定して低減させることが困難になったた
めであると考えられる。Next, the coating agent is composed of a metal carbonate, a metal fluoride, an arc stabilizer, a slag forming agent, a deoxidizing agent, an alloying agent, and a fixing agent. In order to prevent low-temperature cracking due to diffusible hydrogen, the content needs to be less than 0.5% by weight. FIG. 1 shows the relationship between Mg% in the coating agent and the amount of diffusible hydrogen by a hydrogen test. Mg content 0.5
It can be seen that the amount of diffusible hydrogen is remarkably increased when the content is not less than% by weight. This phenomenon was caused by Mg of 0.5
When the content is more than 10% by weight, Mg oxide having a property of easily adsorbing moisture is likely to be generated during high-temperature drying, which is generally adopted for reducing the amount of diffusible hydrogen in a welding rod, and as a result, the diffusivity is increased. This is probably because it became difficult to stably reduce the amount of hydrogen.
【００１５】被覆剤中の金属炭酸塩は、アーク中で分解
し、ＣＯ2 ガスを発生して溶融メタルを大気から遮断
し、アーク雰囲気中の水素、窒素のガス分圧を下げると
ともに塩基性のスラグを生成する効果を有している。こ
のような効果を発揮させるためには、被覆剤全量に対し
て30〜60重量％の範囲で含有させることが望ましい。な
お、金属炭酸塩の具体例としては、炭酸カルシウム、炭
酸バリウム、炭酸マンガンなどが挙げられる。The metal carbonate in the coating material is decomposed in the arc, generates CO 2 gas, shuts off the molten metal from the atmosphere, lowers the partial pressures of hydrogen and nitrogen in the arc atmosphere, It has the effect of generating slag. In order to exert such an effect, it is desirable to contain the coating agent in the range of 30 to 60% by weight based on the total amount of the coating agent. Note that specific examples of the metal carbonate include calcium carbonate, barium carbonate, and manganese carbonate.
【００１６】金属弗化物は、スラグの融点を下げて流動
性を向上させ、また、アーク中で分解したフッ素は溶融
メタルや溶融スラグの中の水素と反応し、溶融メタルの
水素分圧を下げて耐割れ性の良好な溶接金属をつくる作
用を有する。このような効果を発揮させるためには、金
属弗化物の含有量は被覆剤全量に対して10〜30重量％の
範囲であることが望ましい。具体的な金属弗化物として
は、弗化カルシウム、弗化バリウム、弗化マンガンなど
が挙げられる。The metal fluoride lowers the melting point of the slag to improve the fluidity, and the fluorine decomposed in the arc reacts with the hydrogen in the molten metal or the molten slag to lower the hydrogen partial pressure of the molten metal. And has the effect of producing a weld metal having good crack resistance. In order to exert such an effect, the content of the metal fluoride is desirably in the range of 10 to 30% by weight based on the total amount of the coating agent. Specific examples of metal fluorides include calcium fluoride, barium fluoride, and manganese fluoride.
【００１７】このほか、被覆剤にはアーク安定剤および
スラグ安定剤としてルチール、アルカリ金属、鉄粉など
を添加でき、脱酸剤および合金剤としてSi、Mn、Ni、C
r、Mo、Ti、Alなどを添加できる。In addition, rutile, alkali metal, iron powder, and the like can be added to the coating agent as an arc stabilizer and a slag stabilizer, and Si, Mn, Ni, and C can be added as deoxidizing agents and alloying agents.
r, Mo, Ti, Al, etc. can be added.
【００１８】固着剤としては、アルカリ成分に対するSi
O2濃度が10〜30重量％の珪酸リチウム水溶液10〜35重量
％と、同じく20〜30重量％の珪酸ナトリウム水溶液20〜
60重量％と、同じく20〜30重量％の珪酸カリウム水溶液
20〜60重量％の混合液を添加することが望ましい。As the fixing agent, Si is used for the alkali component.
O 2 concentration and 10 to 35 wt% of 10 to 30 wt% of lithium silicate solution, also 20 to 30 wt% aqueous solution of sodium silicate 20
60% by weight and 20-30% by weight aqueous potassium silicate solution
It is desirable to add a mixture of 20 to 60% by weight.
【００１９】さらに、上述した鋼心線および被覆剤から
なる被覆アーク溶接棒全体にしめる各成分含有量の限定
理由について述べる。Ｃの含有量が増加すると、被覆ア
ーク溶接によって得られる溶接金属は高炭素マルテンサ
イトとなり硬さが増加し、溶接継手作製時の初層溶接に
おける低温割れ発生を防止できなくなる。したがって、
溶接棒中のＣは0.35重量％以下とする。Further, the reasons for limiting the content of each component in the entire coated arc welding rod comprising the above-mentioned steel core wire and the coating agent will be described. When the content of C increases, the weld metal obtained by the covered arc welding becomes high carbon martensite, the hardness increases, and it becomes impossible to prevent the occurrence of low-temperature cracking in the first layer welding at the time of producing a welded joint. Therefore,
C in the welding rod is 0.35% by weight or less.
【００２０】Siは、0.5 重量％未満の含有量では、溶接
メタルへのスラグのかぶりが大きくなり、溶接作業性が
劣化するとともに、継手の溶接金属の脱酸が不十分とな
り靱性も劣化する。一方、2.5 重量％を超えると、溶接
メタルの粘性が過度に上昇して作業性が劣化するととも
に、溶接金属中のSi量を増加させて靱性を劣化させる。
したがって、溶接棒中のSiは0.5 〜2.5 重量％の範囲と
する。When the content of Si is less than 0.5% by weight, the slag of the slag on the weld metal becomes large, and the welding workability is deteriorated. In addition, the deoxidation of the weld metal of the joint is insufficient and the toughness is also deteriorated. On the other hand, if the content exceeds 2.5% by weight, the viscosity of the weld metal excessively increases and the workability is deteriorated, and the Si content in the weld metal is increased to deteriorate the toughness.
Therefore, the content of Si in the welding rod is in the range of 0.5 to 2.5% by weight.
【００２１】Mnは、0.5 重量％未満の含有量では、溶接
継手の溶接金属中の酸素量が増加し、靱性が劣化すると
ともに、溶接金属強度を880MPa以上に確保することが困
難になる。一方、2.5 重量％を超えて含有すると、溶接
金属が上部ベイナイトなど低靱性組織となるため靱性確
保の観点から好ましくない。したがって、溶接棒中のMn
含有量は、0.5 〜2.5 重量％の範囲とする。If the content of Mn is less than 0.5% by weight, the amount of oxygen in the weld metal of the welded joint increases, and the toughness deteriorates, and it becomes difficult to secure the weld metal strength to 880 MPa or more. On the other hand, if the content exceeds 2.5% by weight, the weld metal has a low toughness structure such as upper bainite, which is not preferable from the viewpoint of securing toughness. Therefore, Mn in the welding rod
The content ranges from 0.5 to 2.5% by weight.
【００２２】Niは、1.0 重量％未満の含有量では、高張
力鋼の溶接継手で高靱性の溶接金属を得ることができな
い。一方、3.0 重量％を超えて添加しても、さらなる靱
性向上の効果は得られない。したがって、過剰な添加は
生産コストを上昇させることを考慮して、溶接棒中のNi
含有量は1.0 〜3.0 重量％の範囲とする。If the content of Ni is less than 1.0% by weight, a high toughness weld metal cannot be obtained from a high-strength steel welded joint. On the other hand, if it is added in excess of 3.0% by weight, the effect of further improving toughness cannot be obtained. Therefore, considering that excessive addition increases the production cost, Ni
The content is in the range of 1.0 to 3.0% by weight.
【００２３】Crは、0.2 重量％未満では、継手の溶接金
属の強度を確保することが難しい。一方、1.2 重量％を
超えて添加すると、溶接金属の靱性が劣化する。したが
って、溶接棒中のCr含有量は、0.2 〜1.2 重量％の範囲
とする。If Cr is less than 0.2% by weight, it is difficult to secure the strength of the weld metal of the joint. On the other hand, if added in excess of 1.2% by weight, the toughness of the weld metal deteriorates. Therefore, the Cr content in the welding rod is in the range of 0.2 to 1.2% by weight.
【００２４】Moは、0.2 重量％未満の含有量では、継手
の溶接金属強度を確保することが難しい。一方、1.0 重
量％を超えて添加すると、溶接金属の靱性が劣化する。
したがって、溶接棒中のMoは、0.2 〜1.0 重量％の範囲
とする。If the content of Mo is less than 0.2% by weight, it is difficult to secure the weld metal strength of the joint. On the other hand, if added in excess of 1.0% by weight, the toughness of the weld metal deteriorates.
Therefore, the content of Mo in the welding rod is in the range of 0.2 to 1.0% by weight.
【００２５】以上、鋼心線、被覆剤および被覆アーク溶
接棒について説明したが、これらの条件のみでは、引張
強度880 〜1180MPa の高張力鋼材の被覆アーク溶接に対
応することができない。すなわち、溶接しようとする鋼
材強度レベルに応じて、所定の引張強度および靱性を安
定して得られる溶接金属を形成する必要がある。そし
て、引張強度が880MPa以上の高強度を必要とする溶接金
属において、引張強度と靱性の両方を満足する化学成分
の範囲は、かなり狭くなると考えられる。しかし、鋼心
線および被覆剤を上記限定範囲内に調整した低水素系被
覆アーク溶接棒を用いて、入熱量10〜40kJ／cmの溶接を
することにより得られる溶着金属（JIS Z3111 による）
では、引張強度および靱性は (1)式で示されるＣeqと一
次関係を示し、Ｃeqが小さいほど引張強度は低下し、Ｃ
eqが大きいほど靱性は低下する傾向を示した。このた
め、Ｃeqを指標にすることで、溶接に供する鋼材強度に
適した溶着金属強度を限定することか可能といえる。The steel core wire, the coating agent and the coated arc welding rod have been described above. However, these conditions alone cannot cope with the coated arc welding of a high-tensile steel material having a tensile strength of 880 to 1180 MPa. That is, it is necessary to form a weld metal capable of stably obtaining a predetermined tensile strength and toughness in accordance with a steel material strength level to be welded. Then, in a weld metal requiring a high tensile strength of 880 MPa or more, the range of chemical components satisfying both the tensile strength and the toughness is considered to be considerably narrow. However, the deposited metal (according to JIS Z3111) obtained by welding with a heat input of 10 to 40 kJ / cm using a low hydrogen coated arc welding rod whose steel core wire and coating agent are adjusted within the above-mentioned limited range.
In, the tensile strength and toughness show a linear relationship with Ceq shown in equation (1), and the smaller the Ceq, the lower the tensile strength,
The toughness tended to decrease as eq increased. For this reason, it can be said that by using Ceq as an index, it is possible to limit the strength of the weld metal suitable for the strength of the steel material used for welding.
【００２６】そこで、発明者らは、溶接継手に供する鋼
材強度と溶接金属のＣeqの関係について、種々の実験を
行った結果、鋼材の引張強さと溶着金属（JIS Z3111 に
よる）の化学成分から (2)式： Ｙ＝Ｃeq−ＴＳ／1300 …… (2) ここでＴＳ：鋼材の引張強さ(MPa） によって得られるＹ値が−0.1 〜0.1 の範囲であると、
溶接継手の溶接金属の引張強度は鋼材強度の0.97倍以
上、1.03倍以下となり、かつ、靱性も十分満足されると
の知見を得た。Ｙ値が−0.1 よりも低下すると溶接金属
強度が鋼材強度の0.97倍の値よりも低くなり、強度不足
となる。一方、Ｙ値が0.1 よりも増加すると溶接金属の
靱性が劣化し、耐低温割れ性も低下する。したがって、
(2)式によって得られるＹ値が−0.1 〜0.1 の範囲とな
るように限定する。The inventors conducted various experiments on the relationship between the strength of the steel material used for the welded joint and the Ceq of the weld metal. 2) Formula: Y = Ceq−TS / 1300 (2) Here, TS: If the Y value obtained by the tensile strength (MPa) of the steel material is in the range of −0.1 to 0.1,
It has been found that the tensile strength of the weld metal of the welded joint is 0.97 times or more and 1.03 times or less the steel strength, and that the toughness is sufficiently satisfied. If the Y value is lower than -0.1, the weld metal strength becomes lower than the value of 0.97 times the steel material strength, resulting in insufficient strength. On the other hand, when the Y value exceeds 0.1, the toughness of the weld metal deteriorates, and the low-temperature cracking resistance also decreases. Therefore,
The Y value obtained by the equation (2) is limited so as to be in the range of -0.1 to 0.1.
【００２７】[0027]
【実施例】以下、実施例により、本発明の効果を具体的
に説明する。表１に示す、鋼心線と被覆剤（金属炭酸
塩：45重量％、金属弗化物：25重量％を含有し、残部が
アーク安定剤, スラグ形成剤, 脱酸剤, 合金剤および固
着剤からなる）よりなる各種の被覆アーク溶接棒を製造
した。溶接棒の心線径は4.O mmとし、通常の溶接棒塗装
機により被覆、乾燥した。その後、水分を除去するため
に 350〜550 ℃で乾燥し、さらに、溶接前には、400 〜
500 ℃で再乾燥した。これらの溶接棒を用い、入熱量10
〜40kJ／cmの溶接により、JIS 3111に従い溶着金属を作
製し、そのＣeqおよびＹ値を求めた。また、耐低温割れ
性試験を行うとともに、溶接継手についての引張強度お
よび靱性を調査した。耐低温割れ性は、予熱温度75℃、
溶接電流170A、溶接入熱17kJ／cm、下向き姿勢で、板厚
50mmの鋼板を使用してｙ形溶接割れ試験（JIS Z3158 ）
を実施し、ルート割れ率が20％未満のものを良好とし○
印で、20％以上のものを不良とし×印で示した。溶接金
属の引張強度は、予熱温度 100℃、溶接入熱10〜40kJ／
cmで溶接したＸ開先の溶接継手より加工した丸棒引張試
験片で評価し、鋼板の引張強度の0.97倍以上となるもの
を良好とし○印で示した。靱性は、同じく溶接継手より
加工したＶノッチシャルピー衝撃試験片で評価し、−40
℃での吸収エネルギが47Ｊ以上のものを良好とし○印で
示した。EXAMPLES Hereinafter, the effects of the present invention will be specifically described with reference to examples. As shown in Table 1, contains steel core wire and coating agent (metal carbonate: 45% by weight, metal fluoride: 25% by weight, the balance being arc stabilizer, slag forming agent, deoxidizing agent, alloying agent and fixing agent) ) Were produced. The core diameter of the welding rod was set to 4.0 mm, and the coating was dried with a usual welding rod coating machine and dried. After that, it is dried at 350-550 ° C to remove the moisture.
It was dried again at 500 ° C. Using these welding rods, heat input 10
A weld metal was prepared according to JIS 3111 by welding at に 従 い 40 kJ / cm, and its Ceq and Y values were determined. In addition, a low-temperature cracking resistance test was performed, and the tensile strength and toughness of the welded joint were investigated. Low temperature cracking resistance, preheating temperature 75 ℃,
Welding current 170A, welding heat input 17kJ / cm, downward position, plate thickness
Y-shaped weld cracking test using 50mm steel plate (JIS Z3158)
And if the crack rate of the root is less than 20%,
20% or more of the samples were judged to be defective, and indicated by X. The tensile strength of the weld metal is as follows: preheating temperature 100 ℃, welding heat input 10-40kJ /
Evaluation was made with a round bar tensile test piece processed from a welded joint with an X-groove welded in cm. The toughness was evaluated using a V-notch Charpy impact test specimen also processed from a welded joint.
Those having an absorption energy at 47 ° C. of 47 J or more were evaluated as good and indicated by a circle.
【００２８】[0028]
【表１】 [Table 1]
【００２９】得られた結果を、表１に合わせて示す。表
１から明らかなように、本発明の条件を満足するNo. １
〜15の発明例では、溶接金属の耐低温割れ性、引張強度
および靱性ともに良好な結果を示した。これに対して、
No. 16〜19では、それぞれ、Si、Mn、Cr、Moの添加が少
なく、さらにNo.17 〜19では、Ｙ値も−0.1 より小さい
ため、引張強度が低下し不良となった。特に、No.16 、
17は、Si、Mnが少ないため靱性も劣化している。No. 2
0、22では心線あるいは溶接棒全体のＣが多く、Ｙ値も
0.1 より大きいため、耐低温割れ性および靱性ともに不
良となった。No. 21、24では被覆剤中のMgが増加してい
るため、耐低温割れ性が不良となった。No. 23では、Ni
が少なすぎるため靱性が確保できず不良となった。No.2
5 では、Ｙ値が−0.1 より小さくなり、引張強度不足と
なった。No. 26〜29では、それぞれSi、Mn、Cr、Moの添
加量が多いため、いずれも靱性不足となり、特に、No.
27、29では、Mg添加量が多いため耐低温割れ性も劣化し
た。また、No. 30では、Ｙ値が−0.1 より小さくなり、
引張強度が不足し不良となった。The results obtained are shown in Table 1. As is clear from Table 1, No. 1 satisfying the conditions of the present invention.
In the invention examples Nos. To 15, good results were shown in the low-temperature cracking resistance, tensile strength and toughness of the weld metal. On the contrary,
In Nos. 16 to 19, the addition of Si, Mn, Cr, and Mo was small, and in Nos. 17 to 19, the Y value was smaller than -0.1, so that the tensile strength was lowered and the samples were poor. In particular, No. 16,
In No. 17, the toughness is also deteriorated due to the small amount of Si and Mn. No. 2
At 0 and 22, the C of the core wire or the entire welding rod is large, and the Y value is also
Since it was larger than 0.1, both low temperature cracking resistance and toughness were poor. In Nos. 21 and 24, the Mg content in the coating material increased, resulting in poor low-temperature cracking resistance. In No. 23, Ni
Was too small, the toughness could not be secured, and it was defective. No.2
In the case of 5, the Y value was smaller than -0.1, and the tensile strength was insufficient. In Nos. 26 to 29, the added amounts of Si, Mn, Cr, and Mo were large, and all of them became insufficient in toughness.
In 27 and 29, the low-temperature cracking resistance was also deteriorated due to the large amount of Mg added. In No. 30, the Y value is smaller than -0.1,
Insufficient tensile strength resulted in failure.
【００３０】[0030]
【発明の効果】以上説明したように、本発明によれば、
引張強度が880 〜1180MPa の高張力鋼材の被覆アーク溶
接において、耐低温割れ性を著しく改善することができ
るとともに、溶接金属の引張強度および靱性をも改善す
る溶接方法を提供することができる。したがって、高張
力鋼を使用した構造物の品質向上、歩留り向上、コスト
ダウン等をはかることが可能となり、産業の発展に寄与
するところ大である。As described above, according to the present invention,
It is possible to provide a welding method capable of remarkably improving low-temperature cracking resistance and also improving the tensile strength and toughness of a weld metal in covered arc welding of a high-tensile steel material having a tensile strength of 880 to 1180 MPa. Therefore, it is possible to improve the quality of the structure using the high-tensile steel, improve the yield, reduce the cost, and the like, and greatly contribute to industrial development.
【図１】被覆剤中のMg量が拡散性水素量に及ぼす影響を
示すグラフである。FIG. 1 is a graph showing the effect of the amount of Mg in a coating agent on the amount of diffusible hydrogen.
Claims (1)
表されるＣeqが0.50〜0.70重量％であり、引張強度が 8
80〜1180 MPaである高張力鋼材を被覆アーク溶接するに
あたり、 Ｃ：0.02重量％以下の鋼心線の周囲に、Mgの含有量を0.
5 重量％未満に制限した被覆剤を塗装した溶接棒であっ
て、この溶接棒全体の成分がＣ：0.35重量％以下、Si：
0.5 〜2.5 重量％、Mn：0.5 〜2.5 重量％、Ni：1.0 〜
3.0 重量％、Cr：0.2 〜1.2 重量％およびMo：0.2 〜1.
0 重量％であり、しかも鋼材の引張強さＴＳと、入熱量
10〜40kJ／cmの溶接により得られる溶着金属についての
前記Ｃeqとで表される下記(2) 式のＹ値を−0.1 〜0.1
の範囲に入るように調整した、低水素系被覆アーク溶接
棒を用いて溶接することを特徴とする高張力鋼材の被覆
アーク溶接方法。 記 Ｃeq＝Ｃ＋Mn／６＋（Cr＋Mo＋Ｖ）＋（Ni＋Cu）／15 …… (1) Ｙ＝Ｃeq−ＴＳ／1300 …… (2) ここでＴＳ：鋼材の引張強さ(MPa）C: 0.16% by weight or less, Ceq represented by the following formula (1) is 0.50 to 0.70% by weight, and tensile strength is 8%.
In covering arc welding of high-tensile steel material of 80 to 1180 MPa, C: 0.02% by weight or less of the Mg content around the steel core wire.
A welding rod coated with a coating agent limited to less than 5% by weight, wherein the composition of the entire welding rod is C: 0.35% by weight or less, Si:
0.5-2.5 wt%, Mn: 0.5-2.5 wt%, Ni: 1.0-
3.0% by weight, Cr: 0.2-1.2% by weight and Mo: 0.2-1.
0% by weight, and the tensile strength TS of the steel material and the heat input
The Y value of the following formula (2) expressed by the above Ceq for the deposited metal obtained by welding at 10 to 40 kJ / cm is -0.1 to 0.1.
The method of claim 1, wherein the welding is performed using a low-hydrogen-based coated arc welding rod adjusted to fall within the range of. Ceq = C + Mn / 6 + (Cr + Mo + V) + (Ni + Cu) / 15 (1) Y = Ceq-TS / 1300 (2) where TS: tensile strength of steel (MPa)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30827797A JP3354460B2 (en) | 1997-11-11 | 1997-11-11 | Covered arc welding method for high strength steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP30827797A JP3354460B2 (en) | 1997-11-11 | 1997-11-11 | Covered arc welding method for high strength steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11147196A true JPH11147196A (en) | 1999-06-02 |
| JP3354460B2 JP3354460B2 (en) | 2002-12-09 |
Family
ID=17979101
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP30827797A Expired - Fee Related JP3354460B2 (en) | 1997-11-11 | 1997-11-11 | Covered arc welding method for high strength steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3354460B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001335879A (en) * | 2000-05-29 | 2001-12-04 | Kobe Steel Ltd | Weld metal |
| SG131885A1 (en) * | 2005-11-07 | 2007-05-28 | Kobe Steel Ltd | Flux cored wire for gas-shielded arc welding of high tensile steel |
| CN101844282A (en) * | 2009-03-27 | 2010-09-29 | 株式会社神户制钢所 | Low-hydrogen coated electric arc welding bar |
| WO2012105617A1 (en) | 2011-02-02 | 2012-08-09 | 株式会社神戸製鋼所 | Weld metal having excellent sensitivity to hydrogen embrittlement resistance |
| WO2012137957A1 (en) | 2011-04-08 | 2012-10-11 | 株式会社神戸製鋼所 | Weld metal having excellent resistance to hydrogen embrittlement |
| WO2013129284A1 (en) | 2012-02-27 | 2013-09-06 | 株式会社神戸製鋼所 | Weld metal having excellent resistance to hydrogen embrittlement |
| WO2014109402A1 (en) | 2013-01-11 | 2014-07-17 | 株式会社神戸製鋼所 | Welded metal with excellent resistance to hydrogen embrittlement, and solid wire for submerged arc welding |
| KR20150136551A (en) | 2013-11-08 | 2015-12-07 | 신닛테츠스미킨 카부시키카이샤 | Method for producing weld joint |
| KR20180108730A (en) | 2016-03-08 | 2018-10-04 | 신닛테츠스미킨 카부시키카이샤 | Flux cored wire, manufacturing method of weld joint, and weld joint |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5633179A (en) * | 1979-08-27 | 1981-04-03 | Hitachi Zosen Corp | Welding method for nonrefining steel sheet or normalizing steel sheet |
| JPH04339593A (en) * | 1991-05-14 | 1992-11-26 | Nippon Steel Corp | Low hydrogen type coated electrode |
| JPH06285683A (en) * | 1993-04-07 | 1994-10-11 | Nippon Steel Corp | Low hydrogen coated electrode |
| JPH07195193A (en) * | 1993-12-29 | 1995-08-01 | Kobe Steel Ltd | Solid wire for thin sheet of high tension steel |
| JPH09192878A (en) * | 1996-01-11 | 1997-07-29 | Nippon Steel Corp | Gas shielded arc butt welding method for sheet |
-
1997
- 1997-11-11 JP JP30827797A patent/JP3354460B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5633179A (en) * | 1979-08-27 | 1981-04-03 | Hitachi Zosen Corp | Welding method for nonrefining steel sheet or normalizing steel sheet |
| JPH04339593A (en) * | 1991-05-14 | 1992-11-26 | Nippon Steel Corp | Low hydrogen type coated electrode |
| JPH06285683A (en) * | 1993-04-07 | 1994-10-11 | Nippon Steel Corp | Low hydrogen coated electrode |
| JPH07195193A (en) * | 1993-12-29 | 1995-08-01 | Kobe Steel Ltd | Solid wire for thin sheet of high tension steel |
| JPH09192878A (en) * | 1996-01-11 | 1997-07-29 | Nippon Steel Corp | Gas shielded arc butt welding method for sheet |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001335879A (en) * | 2000-05-29 | 2001-12-04 | Kobe Steel Ltd | Weld metal |
| SG131885A1 (en) * | 2005-11-07 | 2007-05-28 | Kobe Steel Ltd | Flux cored wire for gas-shielded arc welding of high tensile steel |
| CN101844282A (en) * | 2009-03-27 | 2010-09-29 | 株式会社神户制钢所 | Low-hydrogen coated electric arc welding bar |
| WO2012105617A1 (en) | 2011-02-02 | 2012-08-09 | 株式会社神戸製鋼所 | Weld metal having excellent sensitivity to hydrogen embrittlement resistance |
| US9718150B2 (en) | 2011-02-02 | 2017-08-01 | Kobe Steel, Ltd. | Weld metal excellent in hydrogen embrittlement resistance |
| US9592575B2 (en) | 2011-04-08 | 2017-03-14 | Kobe Steel, Ltd. | Weld metal having excellent resistance to hydrogen embrittlement susceptibility |
| WO2012137957A1 (en) | 2011-04-08 | 2012-10-11 | 株式会社神戸製鋼所 | Weld metal having excellent resistance to hydrogen embrittlement |
| KR20140114893A (en) | 2012-02-27 | 2014-09-29 | 가부시키가이샤 고베 세이코쇼 | Weld metal having excellent resistance to hydrogen embrittlement |
| WO2013129284A1 (en) | 2012-02-27 | 2013-09-06 | 株式会社神戸製鋼所 | Weld metal having excellent resistance to hydrogen embrittlement |
| US9956650B2 (en) | 2012-02-27 | 2018-05-01 | Kobe Steel, Ltd. | Weld metal having excellent resistance to hydrogen embrittlement |
| WO2014109402A1 (en) | 2013-01-11 | 2014-07-17 | 株式会社神戸製鋼所 | Welded metal with excellent resistance to hydrogen embrittlement, and solid wire for submerged arc welding |
| KR20150136551A (en) | 2013-11-08 | 2015-12-07 | 신닛테츠스미킨 카부시키카이샤 | Method for producing weld joint |
| KR20180108730A (en) | 2016-03-08 | 2018-10-04 | 신닛테츠스미킨 카부시키카이샤 | Flux cored wire, manufacturing method of weld joint, and weld joint |
| US10946486B2 (en) | 2016-03-08 | 2021-03-16 | Nippon Steel Corporation | Flux-cored wire, manufacturing method of welded joint, and welded joint |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3354460B2 (en) | 2002-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3476125B2 (en) | Flux-cored wire for duplex stainless steel welding | |
| JP5387168B2 (en) | Welding wire for high strength steel with flux and manufacturing method thereof | |
| JP4558780B2 (en) | Flux-cored wire for submerged arc welding of low-temperature steel | |
| EP2374571B1 (en) | Flux-cored wire for gas-shielding arc welding | |
| JP2009248175A (en) | Tig welding method of high-strength steel using flux-containing wire | |
| JP2010125509A (en) | Flux-cored wire for submerged arc welding of low-temperature steel, and welding method using the same | |
| JP3251505B2 (en) | Low hydrogen coated arc welding rod for high strength Cr-Mo steel | |
| JP3354460B2 (en) | Covered arc welding method for high strength steel | |
| WO1997024203A1 (en) | Method of manufacturing large diameter welded steel pipe having high strength and toughness | |
| JP5064928B2 (en) | Flux-cored wire for submerged arc welding for high-strength steel. | |
| JP3170165B2 (en) | Covered arc welding rod for Ni-based high Cr alloy | |
| JPH11347790A (en) | Coated electrode for ni group high cr alloy | |
| JPH08257789A (en) | Submerged arc welding | |
| JP2711071B2 (en) | Bond flux for submerged arc welding | |
| JP3718323B2 (en) | Flux-cored wire for multi-electrode vertical electrogas arc welding for extra heavy steel | |
| JP2011206828A (en) | Flux-cored welding wire for fine diameter wire multiple electrode submerged arc welding | |
| JP3547282B2 (en) | Low hydrogen coated arc welding rod | |
| JP3115484B2 (en) | Low hydrogen coated arc welding rod and welding method | |
| JP4522042B2 (en) | Steel with excellent high-pass temperature weldability and its welded joint | |
| JPH10180488A (en) | Flux cored wire for electro gas arc welding | |
| JPH11123589A (en) | Low hydrogen type covered electrode | |
| JP3163838B2 (en) | Bond flux for submerged arc welding | |
| JPH03294096A (en) | Combined wire for electrogas arc welding | |
| JPH04305396A (en) | Low hydrogen type coated arc welding rod | |
| JPH0542390A (en) | Low hydrogen type coated electrode for welding 9cr steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |