JPH10277777A - Ni base coated electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily obtain the weld metal having excellent welding workability preventing the deterioration of an arc condition and the phenomena of slab burning, capable of executing efficient welding and further having an excellent mechanical performance, porosity resistance and high temperature crack resistance by reducing the consumption quantity due to oxidation of alloy constituents as much as possible even though a coated electrode generates electrode burning phenomena due to welding under a severe executing condition. SOLUTION: In this electrode, metal powder or alloy powder selected from alloy constituents composing the core wire and metal powder of one kind or two kinds or above of Al, Si, Ti as the deoxidizer or alloy powder containing these metal constituents are granulated in 300-150 μm for the Ni-Cr base core wire containing alloy constituents of Mn, Nb, Mo, Cr. And granulated grains are mixed with the coating constituent agent of a metallic carbonate, metallic fluoride, silicate and silicate compound, potassium compound or the like to make the coating flux, and the Ni-Cr base core wire is coated with the coating flux.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、ＬＮＧ貯蔵タンク
用９％Ｎｉ鋼の溶接用に使用される高Ｎｉ合金の溶接材
料の改良に係わり、さらに詳しくは優れた溶接作業性を
有し、機械的性能、耐気孔性能及び耐高温割れ性能が良
好な溶接金属を容易に得ることができるＮｉ基被覆ア−
ク溶接棒に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a welding material of a high Ni alloy used for welding 9% Ni steel for an LNG storage tank, and more particularly, to an improved welding workability. Ni-based coating that can easily obtain a weld metal with good mechanical performance, porosity resistance and hot crack resistance.
It relates to a welding rod.

【０００２】[0002]

【従来の技術】石油に替わるクリーンエネルギーとして
天然ガスの消費量が急速に伸び、それに伴い天然ガスの
運搬・貯蔵タンクの建造量も増加している。天然ガスの
運搬、貯蔵を簡便にする目的で天然ガスを冷却（−１６
２℃）して液化したものが液化天然ガス（ＬＮＧ）であ
り、ＬＮＧの容器として９％Ｎｉ鋼が主に用いられてい
る。この鋼は低温じん性の優れたフェライト系合金鋼で
あり、強度が高く溶接性も優れており、溶接には極低温
じん性の良好なＮｉ−Ｃｒ系の溶接材料が多く使用され
ている。被覆アーク溶接棒としてはＮｉ、Ｃｒ以外にＭ
ｎ、Ｍｏ、Ｎｂ、Ｗ等の合金成分を適宜添加したものが
主に使用されており、例えば特開昭５３−３７５５５号
公報において本発明者等はＮｉ−Ｃｒ系心線を用い、心
線又は被覆剤の一方又は両方にＴａを含有し、被覆剤の
全水分量を制御することにより溶接金属の耐ミクロ割れ
性を改善した被覆ア−ク溶接棒を開示している。2. Description of the Related Art The consumption of natural gas is increasing rapidly as a clean energy alternative to petroleum, and the amount of natural gas transport / storage tanks is increasing accordingly. Cool natural gas for the purpose of simplifying transportation and storage of natural gas (-16
Liquefied natural gas (2 ° C.) is liquefied natural gas (LNG), and 9% Ni steel is mainly used as an LNG container. This steel is a ferritic alloy steel excellent in low-temperature toughness, has high strength and excellent weldability, and many Ni-Cr-based welding materials having excellent low-temperature toughness are used for welding. In addition to Ni and Cr, M
A material to which alloy components such as n, Mo, Nb, and W are appropriately added is mainly used. For example, in JP-A-53-37555, the present inventors used a Ni-Cr-based core wire and used a core wire. Also disclosed is a coated arc welding rod containing Ta in one or both of the coating agents and controlling the total water content of the coating agent to improve the micro crack resistance of the weld metal.

【０００３】Ｎｉ−Ｃｒ合金を心線に使用した被覆ア−
ク溶接棒は、溶接中に心線が電気抵抗熱により赤熱し、
被覆剤が変質し溶接作業性が劣化する棒焼け現象が起こ
りやすい。棒焼け現象を改善する技術として、本発明者
等は特公昭６２−５１７１６号公報にＮｉ−Ｃｒ系心線
に被覆剤中の石灰石の粒度を制御し、Ｌｉ化合物を含有
する被覆剤を被覆することで溶接中の保護筒を強化し、
耐棒焼け性を改善した被覆ア−ク溶接棒を開示してい
る。[0003] A coating arc using a Ni-Cr alloy for the core wire.
In the welding rod, the core wire glows red due to electric resistance heat during welding,
The burning of the stick, which deteriorates the coating agent and deteriorates the welding workability, is likely to occur. As a technique for improving the stick burning phenomenon, the present inventors disclosed in Japanese Patent Publication No. Sho 62-51716 a method of controlling the particle size of limestone in a coating material on a Ni-Cr type core wire and coating the coating material containing a Li compound. This strengthens the protection tube during welding,
A coated arc welding rod having improved bar burning resistance is disclosed.

【０００４】近年、作業効率を上げるため溶接電流を高
くする傾向があり、電流値の上昇とともに、耐棒焼け性
が従来技術では不十分となり、脱酸剤や酸化しやすい合
金成分の酸化消耗が著しく、脱酸不足で耐気孔性能が劣
化したり、ア−クの不安定化やスラグ剥離性などの溶接
作業性の劣化や、性能改善目的で被覆剤から添加した合
金成分が不足して、機械的性質や耐割れ性が劣化するな
どの問題が発生している。特に大入熱での立向溶接でス
ラグの焼き付現象が起こり易く、スラグの除去作業に多
大な工数が必要となるばかりでなく、すみ肉溶接部のカ
ラーチェック検査においてはビード表面に欠陥の疑似模
様が発生するためビード表面を整形する必要があり、さ
らに工数が増加して施工効率が低下するという問題も提
起されている。高電流での溶接で良好な溶接作業性を有
し、さらに溶接金属の耐気孔性能、耐割れ性能が良好で
目的の機械的性能が容易に得られるＮｉ基被覆ア−ク溶
接棒の開発が望まれている。In recent years, there has been a tendency to increase the welding current in order to increase the work efficiency, and as the current value increases, the bar burn resistance becomes insufficient with the prior art, and the oxidative consumption of deoxidizers and easily oxidizable alloy components increases. Insufficiently deoxidation deteriorates the pore resistance performance, destabilizes the arc, deteriorates welding workability such as slag peeling, and lacks the alloy component added from the coating agent for the purpose of improving performance. Problems such as deterioration of mechanical properties and crack resistance have occurred. In particular, slag seizure tends to occur during vertical welding with large heat input, which requires not only a large number of man-hours to remove the slag, but also a defect on the bead surface in color check inspection of fillet welds. Since a pseudo pattern is generated, it is necessary to shape the bead surface, and there is also a problem that the number of steps is increased and the construction efficiency is reduced. The development of a Ni-based coated arc welding rod that has good welding workability when welding at high current, and also has good porosity and cracking resistance of the weld metal and easily obtains the desired mechanical performance. Is desired.

【０００５】[0005]

【発明が解決しようとする課題】上述のようにＬＮＧ貯
蔵タンク用９％Ｎｉ鋼の溶接に用いられてきたＮｉ基被
覆ア−ク溶接棒は、高電流使用による被覆剤の棒焼け現
象に伴う合金成分の酸化消耗が原因となる溶接金属の耐
気孔性能、耐割れ性能、機械的性能の劣化や、ア−クの
不安定化、スラグ剥離性不良等の溶接作業性劣化による
施工能率の低下等の問題があった。As described above, the Ni-based coated arc welding rod used for welding 9% Ni steel for LNG storage tanks is accompanied by the burning of the coating agent due to the use of high current. Deterioration of welding efficiency due to deterioration of porosity, cracking resistance and mechanical performance of weld metal due to oxidative consumption of alloy components, deterioration of welding workability such as instability of arc and poor slag peeling property And so on.

【０００６】本発明はこれらの現状を鑑み、被覆ア−ク
溶接棒による９％Ｎｉ鋼の溶接に際し、苛酷な施工条件
での溶接で被覆ア−ク溶接棒が棒焼け現象をおこしても
合金成分の酸化消耗量を極力減少することにより、ア−
ク状態の劣化やスラグの焼き付き現象を防止して良好な
溶接作業性を有し、能率的な溶接施工が行え、さらに機
械的性能、耐気孔性能及び耐高温割れ性能が良好な溶接
金属が容易に得られるＮｉ基被覆ア−ク溶接棒を提供す
ることにある。[0006] In view of these circumstances, the present invention, when welding 9% Ni steel with a coated arc welding rod, the alloy does not burn even if the coated arc welding rod causes a rod burning phenomenon under severe working conditions. By reducing the oxidative consumption of components as much as possible,
It has good welding workability by preventing deterioration of the welding condition and seizure of slag, enables efficient welding, and facilitates welding metal with good mechanical performance, pore resistance and hot cracking resistance. An object of the present invention is to provide a Ni-based coated arc welding rod obtained as described above.

【０００７】[0007]

【課題を解決するための手段】本発明は、以上の様な問
題点を解決すべくＮｉ−Ｃｒ基心線に脱酸剤を含む合金
成分の種類、添加量及び添加方法を変化させた被覆剤を
被覆した、被覆ア−ク溶接棒を試作し、溶接作業性及び
溶接金属性能を調査した結果、金属成分の添加方法を造
粒工程を設けて予備処理して配合する事により、従来よ
り高電流で溶接することで溶接棒が赤熱し棒焼け現象を
おこしても合金成分の粒度を管理することにより合金成
分の酸化消耗量が減少し、歩留り率を改善できることを
見いだした。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a coating in which the type, amount and method of addition of an alloy component containing a deoxidizer in a Ni-Cr base wire are changed. As a result of trial production of coated arc welding rod coated with the agent and investigation of welding workability and weld metal performance, the method of adding metal components was preliminarily treated by providing a granulation process and compounded. It has been found that, even when the welding rod glows due to welding at a high current and the rod burns, the grain size of the alloy component is controlled to reduce the oxidative consumption of the alloy component and improve the yield.

【０００８】さらに詳しく述べると、被覆剤中に配合す
る金属成分の粉末を造粒し、特定の粒度に整粒する予備
処理を行い、この造粒合金成分を他の被覆剤と混合した
後、粘結剤を用いてＮｉ−Ｃｒ基心線に塗装してなる被
覆アーク溶接棒を試作し、溶接作業性能、溶接金属の機
械的性能、耐気孔性能及び耐割れ性能の調査を実施し
た。耐気孔性能は気孔が発生しやすい上向き溶接姿勢で
薄板の継手溶接を実施してＸ線透過試験で判定した。割
れ性能は耐高温割れ性を評価するＪＩＳＺ３１１５で規
定されているＣ型治具拘束溶接割れ試験では耐割れ性評
価が明確に判定できないため、本発明者等が、拘束状況
が過酷な補修溶接を想定して独自に考案した横向き姿勢
によるＵ溝内に１パス溶接を行い、その試験ビードを表
面から順次１ｍｍ程度毎に研削して割れの発生状況を数
回検査して判定した。[0008] More specifically, a powder of a metal component to be blended in a coating agent is granulated and subjected to a pretreatment for sizing to a specific particle size, and after mixing this granulated alloy component with another coating agent, A coated arc welding rod formed by coating a Ni-Cr core wire with a binder was prototyped, and welding performance, mechanical properties of the weld metal, pore resistance and crack resistance were investigated. The porosity resistance was determined by an X-ray transmission test by performing joint welding of a thin plate in an upward welding position where porosity is likely to occur. The cracking performance cannot be clearly determined in the C-type jig restrained welding crack test specified in JISZ3115, which evaluates hot cracking resistance. One-pass welding was performed in a U-groove in a lateral orientation that was originally devised, and the test bead was ground by about 1 mm sequentially from the surface, and the occurrence of cracks was inspected several times to determine.

【０００９】その結果、合金成分を未処理の粒度分布が
１８０〜４５μｍのままで添加したものに比べ、造粒、
乾燥して所定の粒度範囲に処理したものは棒焼けによる
合金類の酸化消耗が減少し、酸化消耗防止の改善により
合金類のスラグ化量が減少し、ア−ク状態の劣化やスラ
グの焼き付き現象が防止され溶接作業性が改善できると
いう知見が得られた。また、脱酸効果が向上するため従
来よりも脱酸剤の添加量を減少しても良好な溶接金属の
耐気孔性能が得られ、溶接金属の耐高温割れ感受性を高
めるＳｉ、Ａｌ、Ｔｉの添加量の減少が可能となり溶接
金属の耐高温割れ性能をも改善できるという知見も得ら
れた。さらに、歩留り率が改善され良好な機械的性能や
耐気孔性能を得るための合金添加量が減少でき経済的効
果も得られるという知見も得た。[0009] As a result, compared to the case where the alloy component was added while the untreated particle size distribution was maintained at 180 to 45 µm, granulation,
Drying and processing to a specified particle size range reduces the oxidative consumption of alloys due to burning, reduces the amount of slag of alloys by improving the prevention of oxidative consumption, degrades the arc state and burns in slag. It has been found that the phenomenon can be prevented and welding workability can be improved. In addition, since the deoxidizing effect is improved, even if the amount of the deoxidizing agent added is reduced as compared with the conventional case, good porosity resistance of the weld metal can be obtained, and Si, Al, Ti which enhances the hot metal cracking resistance of the weld metal can be obtained. It has also been found that the addition amount can be reduced and the hot crack resistance of the weld metal can be improved. In addition, it has been found that the yield can be improved, the amount of alloy addition for obtaining good mechanical performance and pore resistance can be reduced, and an economic effect can be obtained.

【００１０】すなわち金属成分粉末を所定の粒子に造粒
して添加することにより、数種の微細な粒子の金属成分
類を大きな一つの合金成分粒子に変換し、合金粒子を大
きくしたことにより溶接中に合金粒子が飛散して酸化、
消耗することを防止しつつ溶接ア−ク雰囲気中への移行
を容易にし、性能改善目的の合金類は歩留り率を向上
し、脱酸剤は脱酸効率が向上するという知見を得た。That is, the metal component powder is granulated into predetermined particles and added, thereby converting several types of fine particles of metal components into one large alloy component particle, and increasing the size of the alloy particles to thereby form a weld. Alloy particles scatter inside and oxidize,
It has been found that the transfer to the atmosphere of the welding arc is facilitated while preventing the wear, and that the alloys for the purpose of improving the performance improve the yield and the deoxidizing agent improves the deoxidizing efficiency.

【００１１】本発明は上記の知見によりなされたもので
あり、その要旨は、（１）Ｎｉ基被覆ア−ク溶接棒にお
いて、Ｍｎ、Ｎｂ、Ｍｏ、Ｃｒの合金成分を含むＮｉー
Ｃｒ基心線に、該心線を構成する合金成分から選択した
金属粉末或は合金粉末と、脱酸剤としてのＡｌ、Ｓｉ、
Ｔｉの１種又は２種以上の金属粉末或はこれらの金属成
分を含む合金粉末とを３００〜１５０μｍに造粒し、該
造粒粒子と金属炭酸塩、金属弗化物、硅酸塩及び硅酸塩
化合物、カリ化合物等の被覆成分剤とを混合して被覆剤
となし、前記Ｎｉ−Ｃｒ基心線に該被覆剤を被覆したこ
とを特徴とするＮｉ基被覆ア−ク溶接棒。（２）Ｎｉ−
Ｃｒ基心線が心線全重量に対して重量％でＮｉ；５５〜
７５％、Ｃｒ；１２〜２０％、Ｍｏ；０．５〜３．０
％、Ｍｎ；０．５〜３．０％、Ｎｂ；０．５〜２．５％
含有することを特徴とする（１）記載のＮｉ基被覆ア−
ク溶接棒。（３）被覆剤が被覆剤全重量に対して重量％
でＭｎ；０．５〜６．０％、Ｎｂ；０．５〜３．０
％、、Ｍｏ；０．５〜６．０％、更にＡｌ；１．５〜
４．０％、Ｓｉ；０．１〜２．０％、Ｔｉ；０．１〜
２．０％の１種又は２種以上を含むことを特徴とする
（１）、又は（２）記載のＮｉ基被覆ア−ク溶接棒にあ
る。The present invention has been made based on the above findings. The gist of the invention is as follows: (1) A Ni-Cr core containing an alloy component of Mn, Nb, Mo, Cr in a Ni-base coated arc welding rod. Wire, a metal powder or alloy powder selected from alloy components constituting the core wire, Al, Si as a deoxidizer,
One or more metal powders of Ti or an alloy powder containing these metal components is granulated to 300 to 150 μm, and the granulated particles are mixed with a metal carbonate, a metal fluoride, a silicate and a silicate. A Ni-base coated arc welding rod, wherein a coating component such as a salt compound or a potassium compound is mixed to form a coating, and the Ni-Cr base wire is coated with the coating. (2) Ni-
55 to 55% by weight of the Cr base wire with respect to the total weight of the core wire;
75%, Cr; 12 to 20%, Mo; 0.5 to 3.0
%, Mn: 0.5 to 3.0%, Nb: 0.5 to 2.5%
(1) The Ni-based coating alloy according to (1),
Welding rod. (3) The coating agent is weight% based on the total weight of the coating agent.
And Mn: 0.5 to 6.0%, Nb: 0.5 to 3.0
%, Mo; 0.5 to 6.0%, further Al: 1.5 to
4.0%, Si; 0.1 to 2.0%, Ti; 0.1 to
The Ni-based coated arc welding rod according to (1) or (2), wherein the Ni-based arc welding rod contains 2.0% or more of one or more types.

【００１２】[0012]

【発明の実施の形態】本発明は被覆に配合される合金類
に予備処理を施し被覆する事が最大の要件であり、金属
域は合金類を造粒し３００〜１５０μｍの粒度に整粒し
て配合・添加する事により、金属域は合金剤個々の粒度
で添加する場合に比べて歩留り率が改善されという知見
によりなされたものである。合金類を造粒することで添
加した合金剤が均一に撹拌され被覆剤での偏析が防止さ
れるとともに粒度を３００〜１５０μｍ以上に整粒する
ことで従来の微細な金属粉末での添加で顕著であった合
金類が溶接中に飛散し酸化、消耗する量が減少され性能
改善目的で添加する合金成分の歩留り率が向上し、脱酸
剤においては溶接金属の耐気孔性能を満足するための添
加量の減少が可能となり、耐気孔性を犠牲にすることな
く溶接金属の耐割れ性能が改善された。金属粒子の粒度
が１５０μｍ未満だと合金類を造粒した効果が殆どな
く、非造粒状態と同様に合金剤の酸化消耗量が増加し十
分な効果が得られず、ア−ク状態やスラグ剥離性及び溶
接金属の耐気孔性能も劣化する。また、粒度が３００μ
ｍを超えると被覆剤の塗装性が劣化し、被覆剤の均一性
が不充分で合金成分の偏析を起こす原因となることがあ
るため金属粒子の粒度を３００〜１５０μｍに制限す
る。なお、前記金属成分以外にＮｉ、Ｗ等の粉末等を添
加してもその効果に変わりなく、必要に応じて他の合金
剤を添加してもかまわない。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, it is the greatest requirement that the alloys to be blended into the coating be pretreated and coated, and the metal area is formed by granulating the alloys and sizing to a grain size of 300 to 150 μm. It has been made based on the finding that the yield rate is improved by mixing and adding the metal region as compared with the case where the metal region is added with the particle size of each alloying agent. The alloying agent added by granulating the alloys is uniformly stirred to prevent segregation in the coating agent, and the particle size is regulated to 300 to 150 μm or more, so that it is remarkable in addition to the conventional fine metal powder. The amount of alloys that were scattered during welding and oxidized during welding was reduced, the yield of alloy components added for the purpose of improving performance was improved, and the deoxidizing agent was used to satisfy the porosity resistance of the weld metal. The addition amount can be reduced, and the crack resistance of the weld metal is improved without sacrificing the porosity. When the particle size of the metal particles is less than 150 μm, there is almost no effect of granulating the alloys, and as in the non-granulated state, the amount of oxidative consumption of the alloying agent increases, and a sufficient effect cannot be obtained. The peelability and the porosity resistance of the weld metal also deteriorate. The particle size is 300μ
If it exceeds m, the coatability of the coating material will deteriorate, and the uniformity of the coating material will be insufficient, which may cause segregation of alloy components. Therefore, the particle size of the metal particles is limited to 300 to 150 μm. It should be noted that even if powders such as Ni and W are added in addition to the metal components, the effect is not changed, and other alloying agents may be added as needed.

【００１３】Ｎｉ−Ｃｒ基心線成分とその量の限定理由
について述べる。The Ni-Cr base line component and the reason for limiting the amount will be described.

【００１４】Ｎｉは、マトリックスを構成する主要元素
であり溶接金属の諸特性を得るために５５％以上必要で
あるが、必要に応じてＣｒ、Ｍｏ、Ｎｂ等の合金成分を
含有させるためには７５％が限度である。従って５５〜
７５％に制限する。Ni is a main element constituting the matrix and is required to be 55% or more in order to obtain various properties of the weld metal. However, in order to contain alloy components such as Cr, Mo, and Nb as necessary, 75% is the limit. Therefore 55-
Limit to 75%.

【００１５】Ｃｒは溶接金属強度特性等を保持するため
の主要元素であり、その効果を十分ならしめるために１
２％以上必要であるが、２０％を超えると靭性や延性が
劣化する。従って、１２〜２０％に制限する。Cr is a main element for maintaining the strength characteristics of the weld metal, etc.
2% or more is necessary, but if it exceeds 20%, toughness and ductility deteriorate. Therefore, it is limited to 12 to 20%.

【００１６】Ｍｏは溶接金属マトリックスに固溶して、
強度を向上させるのに効果があり、０．５％未満では効
果が少なく、３．０％を超えると心線製造工程の鍛造性
や伸線性が劣化する。従って０．５〜３．０％に制限す
る。Mo forms a solid solution in the weld metal matrix,
It is effective in improving the strength, and if it is less than 0.5%, the effect is small, and if it exceeds 3.0%, the forgeability and drawability in the core wire manufacturing process deteriorate. Therefore, it is limited to 0.5 to 3.0%.

【００１７】Ｍｎは、溶接金属の靭性を改善するのに有
効であるが０．５％未満では効果が少なく３．０％を超
えると心線製造工程の鍛造、圧延性が劣化する。従って
０．５〜３．０％に制限する。Mn is effective in improving the toughness of the weld metal, but if it is less than 0.5%, the effect is small, and if it exceeds 3.0%, the forgeability and rollability in the manufacturing process of the core wire deteriorate. Therefore, it is limited to 0.5 to 3.0%.

【００１８】Ｎｂは溶接金属の強度向上に有効であるが
０．５％未満では効果が少なく２．５％を超えると靭性
が劣化する。従って０．５〜２．５％に制限する。Nb is effective for improving the strength of the weld metal, but if it is less than 0.5%, the effect is small, and if it exceeds 2.5%, the toughness is deteriorated. Therefore, it is limited to 0.5 to 2.5%.

【００１９】次に被覆剤成分とその量の限定理由につい
て述べる 溶接金属に必要な合金である金属成分は心線から添加し
た方が被覆剤から添加するより歩留り率が良く、心線か
ら添加すべきであるが心線の鍛造性及び加工性の点で無
理な場合があり、溶接金属の要求性能を得るために心線
からのみでは添加できないので、被覆剤から添加する場
合があり、被覆剤からの合金剤の添加は避けられない。
先ず、被覆剤全重量に対する合金成分の配合量の制限理
由を述べる。Next, the reason for limiting the amount of the coating component and the amount thereof will be described. The metal component, which is an alloy necessary for the weld metal, has a better yield rate when added from the core wire than when added from the coating material, and is added from the core wire. Although it should be, there are cases where it is impossible in terms of the forgeability and workability of the core wire, and it can not be added only from the core wire to obtain the required performance of the weld metal, so it may be added from the coating agent, It is inevitable to add an alloying agent from steel.
First, the reasons for limiting the amount of the alloy component to the total weight of the coating agent will be described.

【００２０】Ｍｎは前述したように溶接金属の靭性を改
善し、耐気孔を改善するために有効であるが、０．５％
未満だと効果が少なく６．０％を超えると、ビード形状
が凸気味になり溶接作業性が劣化する傾向がある。従っ
て０．５％〜６．０％に制限する。好ましくは、１．０
〜６．０％の範囲である。As described above, Mn is effective in improving the toughness of the weld metal and improving the porosity resistance.
If it is less than 6.0%, the effect is small and if it exceeds 6.0%, the bead shape tends to be convex and the welding workability tends to deteriorate. Therefore, it is limited to 0.5% to 6.0%. Preferably, 1.0
６6.0%.

【００２１】Ｎｂはア−クを安定化し、溶接金属の強度
向上に有効であるが０．５％未満では効果が少なく３．
０％を超えると溶接金属の耐割れ性が劣化する傾向があ
る。従って０．５％〜３．０％に制限する。Nb stabilizes the arc and is effective in improving the strength of the weld metal, but less than 0.5% has little effect.
If it exceeds 0%, the crack resistance of the weld metal tends to deteriorate. Therefore, it is limited to 0.5% to 3.0%.

【００２２】Ｍｏはア−クの安定化と溶接金属の強度向
上に有効であるが０．５％未満では効果が少なく６．０
％を超えると溶接中の保護筒の形成性が劣化する。従っ
て０．５％〜６．０％に制限する。Mo is effective for stabilizing the arc and improving the strength of the weld metal.
%, The formability of the protective cylinder during welding deteriorates. Therefore, it is limited to 0.5% to 6.0%.

【００２３】Ａｌは溶接金属の耐気孔性能を改善するた
め非常に有効であり１．５％以上必要であるが４．０％
を超えると溶接金属の耐割れ性能が劣化する傾向があ
る。従って１．５％〜４．０％に制限する。Al is very effective for improving the porosity resistance of the weld metal and is required to be 1.5% or more, but 4.0%.
If it exceeds 300, the crack resistance of the weld metal tends to deteriorate. Therefore, it is limited to 1.5% to 4.0%.

【００２４】Ｓｉは溶接金属の耐気孔性能を改善し、ス
ラグの流動性を改善するために有効である。０．１％以
上必要であるが２．０％を超えると溶接金属の耐割れ性
能が劣化する。従って０．１％〜２．０％に制限する。[0024] Si is effective for improving the porosity resistance of the weld metal and improving the fluidity of the slag. 0.1% or more is necessary, but if it exceeds 2.0%, the crack resistance of the weld metal deteriorates. Therefore, it is limited to 0.1% to 2.0%.

【００２５】ＴｉはＳｉと同様に溶接金属の耐気孔性能
を改善し、スラグの流動性を改善するために有効であ
る。０．１％以上必要であるが２．０％を越えると溶接
金属の耐割れ性能が劣化する。従って０．１％〜２．０
％に制限する。Ti, like Si, is effective for improving the porosity resistance of the weld metal and improving the fluidity of the slag. 0.1% or more is required, but if it exceeds 2.0%, the crack resistance of the weld metal deteriorates. Therefore, 0.1% to 2.0
Limit to%.

【００２６】また、被覆成分剤としては、炭酸カルシウ
ム、炭酸バリウム、炭酸マグネシウム等の金属炭酸塩、
蛍石、弗化バリウム等の金属弗化物、硅石灰等の硅酸塩
や硅酸塩化物、およびカリガラス、Ｔｉ酸カリ等のカリ
化合物等の通常被覆成分として使用されているものを使
用することができる。Examples of the coating component include metal carbonates such as calcium carbonate, barium carbonate, and magnesium carbonate;
Metal fluorides such as fluorite and barium fluoride, silicates and silicates such as silica lime, and potash compounds such as potash glass and potash titanate, etc., must be used as coating components. Can be.

【００２７】以下に実施例により本発明の効果を具体的
に説明する。Hereinafter, the effects of the present invention will be specifically described with reference to examples.

【００２８】[0028]

【実施例】実験に供した心線は溶解後、鍛造、圧延、伸
線を行い４．０ｍｍφ×３５０ｍｍの寸法に作成した。
表１に心線組成を示す。EXAMPLE The core wire used in the experiment was melted and then forged, rolled and drawn to a size of 4.0 mmφ × 350 mm.
Table 1 shows the core composition.

【００２９】[0029]

【表１】 [Table 1]

【００３０】[0030]

【表２】 表２に表１の心線に被覆した被覆剤の組成を示すが、Ｆ
１〜Ｆ５は本発明に用いた被覆剤で、Ｆ１Ｎ、Ｆ１Ｂ、
Ｆ２Ｎ、Ｆ３Ｂは比較例に用いた被覆剤である。[Table 2] Table 2 shows the composition of the coating agent coated on the core wire of Table 1,
1 to F5 are coating agents used in the present invention, and include F1N, F1B,
F2N and F3B are coating agents used in Comparative Examples.

【００３１】被覆ア−ク溶接棒の製造方法について言及
すると、表２の被覆剤に硅酸カリ、硅酸ソーダ等の水ガ
ラスを被覆剤重量に対し約２０％前後添加し、湿式混合
した被覆剤を被覆率が３０％となるよう表１の心線に塗
装し、約４００℃で約６０分焼成して作成した。Referring to the method of manufacturing the coated arc welding rod, water glass such as potassium silicate, sodium silicate, etc. was added to the coatings shown in Table 2 in an amount of about 20% based on the weight of the coatings, and wet-coated. The coating agent was applied to the core wires shown in Table 1 so that the coating ratio became 30%, and baked at about 400 ° C. for about 60 minutes.

【００３２】表３に実験に供した９％Ｎｉ鋼の化学成分
を示す。表４及び表５に表１の心線と表２の被覆剤との
組み合わせた溶接棒で表３の９％Ｎｉ鋼（２０ｍｍｔ）
を用い下向姿勢で従来よりも高い電流値の１５５Ａにて
溶接した溶着金属の化学成分、溶着金属の機械的性能を
示す。Table 3 shows the chemical components of the 9% Ni steel used in the experiment. 9% Ni steel (20 mmt) shown in Table 3 was used as a welding rod obtained by combining the core wire shown in Table 1 and the coating agent shown in Table 2 in Tables 4 and 5.
5 shows the chemical composition of the weld metal welded at a current value of 155 A, which is higher than the conventional one, in a downward position, and the mechanical performance of the weld metal.

【００３３】[0033]

【表３】 [Table 3]

【００３４】[0034]

【表４】 表５には立向姿勢による継手溶接金属の機械的性能、溶
接作業性評価結果、上向姿勢による耐気孔性能評価結果
及び横向き姿勢による耐高温割れ性能評価結果を示す。
溶着金属性能試験はＪＩＳＺ３２２５に準拠して実施し
た。継手溶接金属性能は表３の９％Ｎｉ鋼（３０ｍｍ
ｔ）に図１に示す開先形状を形成し、立向姿勢で溶接電
流：１３０Ａ、速度：５０〜１００ｍｍ／ｍｉｎの溶接
条件で両面突き合わせ溶接を実施し短ゲージ引張試験
（継手引張試験片：ＪＩＳ Ｚ ３１２１、１号）、衝
撃試験（衝撃試験片：ＪＩＳ Ｚ ３１１１、４号）で
調査した。衝撃試験は−１９６℃にて試験し吸収エネル
ギーを求めた。溶接作業性は継手溶接で同時に判定し
た。[Table 4] Table 5 shows the mechanical performance of the welded metal in the upright position, the results of the evaluation of the welding workability, the results of the pore resistance evaluation in the upward position, and the results of the hot crack resistance evaluation in the horizontal position.
The weld metal performance test was performed according to JISZ3225. The weld metal performance of the joints was 9% Ni steel (30 mm
At t), the groove shape shown in FIG. 1 was formed, a double-sided butt welding was carried out in a vertical position under welding conditions of a welding current of 130 A and a speed of 50 to 100 mm / min, and a short gauge tensile test (joint tensile test piece: JIS Z 3121, No. 1) and an impact test (impact test piece: JIS Z 3111, No. 4). The impact test was performed at -196 ° C to determine the absorbed energy. Welding workability was determined simultaneously with joint welding.

【００３５】耐気孔性能評価は表３の９％Ｎｉ鋼（８ｍ
ｍｔ）に図４に示す開先形状を形成し、上向姿勢で溶接
電流：１２０Ａ、速度：６０〜１２０ｍｍ／ｍｉｎの溶
接条件で溶接長４００ｍｍの両面突き合わせ溶接を実施
し、Ｘ線透過試験（ＪＩＳＺ ３１０６）により判定し
た。The evaluation of the porosity resistance was performed using the 9% Ni steel (8 m
mt), the groove shape shown in FIG. 4 was formed, and a double-sided butt welding with a welding length of 400 mm was performed under the welding conditions of a welding current of 120 A and a speed of 60 to 120 mm / min in an upward posture, and an X-ray transmission test ( It was determined according to JISZ 3106).

【００３６】耐高温割れ性能は表３の９％Ｎｉ鋼（３０
ｍｍｔ）に図２の溝形状を形成し、図３の拘束を施し、
溶接電流：１５０Ａ、溶接速度：２０ｃｍ／ｍｉｎの条
件で試験ビードを横向き姿勢で５００ｍｍ溶接し、ビー
ド表面から約１ｍｍずつ３回研削してカラーチェック検
査を行い、割れの個数及び長さを測定し、３回の合計で
判定した。The hot cracking resistance is as shown in Table 3 for 9% Ni steel (30%).
mmt), the groove shape shown in FIG. 2 is formed, and the constraint shown in FIG.
The test bead was welded 500 mm in a horizontal position under the conditions of a welding current of 150 A and a welding speed of 20 cm / min, and the bead surface was ground three times for about 1 mm each to perform a color check test to measure the number and length of cracks. Judgment was made by a total of three times.

【００３７】本発明例のＮｏ．１〜Ｎｏ．６は、同じ配
合処方で合金類が非造粒であったり粒度が３００〜１５
０μｍを外れて心線に被覆されている比較例のＮｏ．７
〜Ｎｏ．１９に比べ良好な溶接作業性を有しており、フ
ラックスから性能改善目的で添加した合金成分含有量が
多く比較例よりも良好な機械的性能が得られている。ま
た、溶接金属の耐気孔性能、耐高温割れ性能も比較例に
比べ良好な性能が得られた。比較例のＮｏ．７〜Ｎｏ．
１９は合金類が非造粒であったり、粒度が３００〜１５
０μｍを外れて心線に被覆されているため高電流で試験
すると本発明例に比べ溶接作業性、溶接金属の機械的性
能、耐気孔性能及び耐割れ性能が劣る。In the example of the present invention, 1 to No. No. 6 is a non-granulated alloy or a particle size of 300 to 15
No. 0 of the comparative example in which the core wire was covered outside the range of 0 μm. 7
-No. The welding workability is better than that of No. 19, and the content of the alloy component added from the flux for the purpose of improving the performance is large, and a better mechanical performance than the comparative example is obtained. In addition, the porosity resistance and the hot crack resistance of the weld metal were better than those of the comparative example. No. of the comparative example. 7-No.
19 indicates that the alloys are non-granulated or have a particle size of 300 to 15
When the test is conducted at a high current, the welding workability, the mechanical performance of the weld metal, the porosity resistance, and the crack resistance are inferior to those of the examples of the present invention because the core is covered with a core wire having a length of 0 μm or less.

【００３８】[0038]

【表５】 注１）耐気孔性能の判定基準は溶接長４００ｍｍに認め
られる欠陥の大きさ、個数で下記の等級をつけ判定し
た。 Ａ；無欠陥 Ｂ；０．５ｍｍを超える欠陥が無く０．５ｍｍ未満の欠
陥が５個以下 Ｃ；０．５ｍｍを超える欠陥が２個以下、又は０．５ｍ
ｍ未満の欠陥が５〜１０個 Ｄ；０．５ｍｍを超える欠陥が３〜５個、又は０．５ｍ
ｍ未満の欠陥が１０〜２０個 Ｅ；０．５ｍｍを超える欠陥が５個以上、又は０．５ｍ
ｍ未満の欠陥が２０個以上 注２）アーク安定性の判定は溶接中にアークの吹き付け
強さなどのアーク状態が最後まで変化せず溶接できた場
合を良好、、溶接の途中からアークの吹き付け強さが弱
くなる、アークが切れるなど、最後まで同じアーク状態
で溶接できなかった場合を不良とした。スラグ剥離性の
判定は溶接直後にスラグを除去した時、ビード表面にス
ラグ焼付きが残らない場合を良好、スラグ焼付きが認め
られた場合を不良とした。[Table 5] Note 1) The criterion for the porosity resistance was determined according to the following grades based on the size and number of defects observed at a welding length of 400 mm. A; no defect B: no defect exceeding 0.5 mm and no defect less than 0.5 mm 5 or less C; defect exceeding 0.5 mm 2 or less or 0.5 m
5 to 10 defects less than m D; 3 to 5 defects greater than 0.5 mm, or 0.5 m
10 to 20 defects less than m E; 5 or more defects greater than 0.5 mm, or 0.5 m
20 or more defects less than m Note 2) Judgment of arc stability is good if welding can be performed without changing the arc state such as the spraying strength of the arc to the end during welding. A case where welding could not be performed in the same arc state until the end, such as a decrease in strength or a break in the arc, was regarded as defective. The slag peelability was evaluated as good when slag seizure did not remain on the bead surface when slag was removed immediately after welding, and as poor when slag seizure was observed.

【００３９】[0039]

【発明の効果】以上のように本発明は、Ｎｉ基合金の被
覆ア−ク溶接棒において高電流での溶接においてアーク
状態やスラグ剥離性が良好で、且つ、耐高温割れ性能や
耐気孔性能が良好で、溶接欠陥のない健全な溶接属を容
易に得られる被覆ア−ク溶接棒を提供するものであり、
９％Ｎｉ鋼の溶接を能率的かつ経済的に溶接施工するた
めに大きく貢献するものである。As described above, the present invention provides a coated arc welding rod made of a Ni-based alloy which has a good arc state and slag releasability when welding at a high current, and has a high temperature cracking resistance and a pore resistance. The present invention provides a coated arc welding rod that can easily obtain a healthy welding genus without welding defects.
This greatly contributes to efficient and economical welding of 9% Ni steel.

【図面の簡単な説明】[Brief description of the drawings]

【図１】実施例において用いた継手溶接用の開先形状を
示す断面図である。FIG. 1 is a sectional view showing a groove shape for joint welding used in Examples.

【図２】実施例において用いた割れ試験用の開先形状を
示す断面図である。FIG. 2 is a sectional view showing a groove shape for a crack test used in Examples.

【図３】実施例において用いた割れ試験用の拘束状態を
示す図である。FIG. 3 is a diagram showing a restrained state for a crack test used in an example.

【図４】実施例において用いた耐気孔性調査用の開先形
状を示す断面図である。FIG. 4 is a sectional view showing a groove shape for investigating porosity used in Examples.

Claims (3)

【特許請求の範囲】[Claims] 【請求項１】 Ｎｉ基被覆ア−ク溶接棒において、Ｍ
ｎ、Ｎｂ、Ｍｏ、Ｃｒの合金成分を含むＮｉーＣｒ基心
線に、該心線を構成する合金成分から選択した金属粉末
或は合金粉末と、脱酸剤としてのＡｌ、Ｓｉ、Ｔｉの１
種又は２種以上の金属粉末或はこれらの金属成分を含む
合金粉末とを３００〜１５０μｍに造粒し、該造粒粒子
と金属炭酸塩、金属弗化物、硅酸塩及び硅酸塩化合物、
カリ化合物等の被覆成分剤とを混合して被覆剤となし、
前記Ｎｉ−Ｃｒ基心線に該被覆剤を被覆したことを特徴
とするＮｉ基被覆ア−ク溶接棒。1. An Ni-coated arc welding rod comprising:
A Ni—Cr base wire containing alloy components of n, Nb, Mo, and Cr, a metal powder or an alloy powder selected from alloy components constituting the wire, and Al, Si, and Ti as deoxidizing agents. 1
A seed or two or more kinds of metal powder or an alloy powder containing these metal components is granulated to 300 to 150 μm, and the granulated particles are mixed with a metal carbonate, a metal fluoride, a silicate and a silicate compound,
By mixing with a coating component such as a potash compound and forming a coating,
A Ni-base coated arc welding rod, wherein the Ni-Cr base wire is coated with the coating agent. 【請求項２】 Ｎｉ−Ｃｒ基心線が心線全重量に対して
重量％でＮｉ；５５〜７５％、Ｃｒ；１２〜２０％、Ｍ
ｏ；０．５〜３．０％、Ｍｎ；０．５〜３．０％、Ｎ
ｂ；０．５〜２．５％含有することを特徴とする請求項
１記載のＮｉ基被覆ア−ク溶接棒。2. Ni-Cr base wire is 55% to 75% by weight of Ni relative to the total weight of the core wire; 12% to 20% of Cr;
o: 0.5 to 3.0%, Mn: 0.5 to 3.0%, N
b: The Ni-based coated arc welding rod according to claim 1, which contains 0.5 to 2.5%. 【請求項３】 被覆剤が被覆剤全重量に対して重量％で
Ｍｎ；０．５〜６．０％、Ｎｂ；０．５〜３．０％、、
Ｍｏ；０．５〜６．０％、更にＡｌ；１．５〜４．０
％、Ｓｉ；０．１〜２．０％、Ｔｉ；０．１〜２．０％
の１種又は２種以上を含むことを特徴とする請求項１ま
たは請求項２記載のＮｉ基被覆ア−ク溶接棒。3. The coating composition according to claim 1, wherein the Mn content is 0.5 to 6.0%, the Nb content is 0.5 to 3.0% by weight, based on the total weight of the coating material.
Mo: 0.5 to 6.0%, further Al: 1.5 to 4.0
%, Si; 0.1 to 2.0%, Ti; 0.1 to 2.0%
3. The Ni-based coated arc welding rod according to claim 1 or 2, comprising one or more of the following.