【発明の詳細な説明】[Detailed description of the invention]
本発明は溶接用複合ワイヤの製法に関し、殊に
金属外皮のシーム溶接部に溶接欠陥がない他、充
填物たるフラツクス成分偏析や充填率の不均一と
いつた問題も極めて少なく、良好な作業性のもと
で優れた品質の溶接継手を得ることのできる複合
ワイヤの製法に関するものである。
複合ワイヤとは、周知の通り軟鋼等の金属外皮
内へフラツクスを充填してなるものであり、管
状の金属外皮内へ粉粒状フラツクスを充填した後
所定の断面積まで伸線加工してなる複合ワイヤ
と、帯状の金属材を管状に湾曲加工しながら内
部へ粉粒状フラツクスを充填し、さらに、突き合
わせ部を接合した後、引続いて所定の断面積まで
伸線加工してなる複合ワイヤに分けられる。後者
の帯状外皮材を用いて得られる複合ワイヤにおけ
るシーム部を細かく検討してみると、シーム線に
沿つて微細な隙間が残されているが、前者の管状
外皮材を用いて得られる複合ワイヤには金属外皮
長手方向の隙間が全く存在しないので、(a)充填フ
ラツクスの吸湿が起こらず溶接金属中の拡散性水
素をソリツドワイヤ並に少なくすることができ
る、(b)銅めつきが行なえるので耐錆性、通電性、
送給性等が優れている、等の特徴を享受すること
ができる。ところがその製造手順を見ると、前述
の如く金属管内へ粉粒状フラツクスを充填した後
伸線加工するという方法によつて行なわれるもの
で、次の様な多くの問題がある。
() フラツクスの充填作業が極めて煩雑で長時
間を要し、又連続化が困難であるので生産性が
低い。
() 金属管の全長に亘つてフラツクスを均一に
充填することが困難である。
() フラツクスを充填した金属管同士のバツト
溶接が困難であり、伸線加工の連続化にも難点
がある。
() 金属管内・外面の脱脂・脱スケール処理等
が煩雑である。
即ち、管状外皮材を用いる複合ワイヤを現実の
生産ラインに乗せるまでには解決しておくべき課
題が多すぎ、実際問題としては後者の帯状外皮材
を用いる複合ワイヤの生産に頼らざるを得ない。
そこで後者の複合ワイヤにおけるシーム部の隙間
を解消する手段の確立が必要となつている。とこ
ろで現在汎用されているシーム溶接法としてはパ
ルスTIG溶接法、プラズマ溶接法、抵抗溶接法、
レーザー溶接法等が考えられるが、現在のところ
抵抗溶接法及びTIG溶接法が最も好ましい方法と
されている。
例えば第１〜３図は抵抗溶接によるシーム溶接
法を示すもので、まず第１図において基台１の上
面には、水平面内で回転し且つ帯鋼７を挟んで対
向するスクイズローラ６が帯鋼７の走行方向に沿
つて複数対配設されている。各スクイズローラ６
は帯鋼導入側（図の左下側）ほど裾開き形状とな
つており、又ワイヤ３を挟んで対設されるスクイ
ズローラ６同士の間隔はワイヤの進行方向前方へ
向かつて次第に狭くなつている。そして帯鋼７か
らワイヤ３を製造するに当たつては、帯鋼７をス
クイズローラ６の間へ矢印Ａ方向から連続的に導
入し、徐々に湾曲させながら長さ方向に腔部を形
成して該腔部にフラツクスＦを装入し、帯鋼７を
更に湾曲して管状とした後、制御装置４を介して
溶接電源５に接続された電極ローラ２を帯鋼７の
突合せ部７ａに当接させ、該突合せ部７ａを連続
的に抵抗溶接してワイヤ３を得る、尚電極ローラ
２は、例えば第２図の概念図（図中２ａ，２ｂは
通電ローラ、８は絶縁層、９は中空支軸、１０は
軸受を示す）に示す如く構成されている。そして
通電ローラ２ａ，２ｂを、帯鋼７の突合せ部７ａ
をまたぐ様にして該帯鋼の対向側縁（耳部）に夫
夫接触させ突合せ部７ａに溶接電流を流して抵抗
溶接を行なうものである。
ところで充填フラツクスには目的に応じた種々
の粉末原料が含まれており、鉄粉や酸化鉄の様な
強磁性原料が配合されることも多い。即ち鉄粉
は、溶着速度の向上、作業性の改善、フラツクス
率等の調整用として重要であり、酸化鉄は生成ス
ラグの物性改善、溶接作業性の改善、ビード形状
の改善等に有用であり、更にNiは定温靭性向上
の目的で添加されることがある。
一方上記の様な抵抗溶接に際して帯鋼突合せ部
に溶接電流を流すと、第２図（溶接点近傍を示す
断面説明図）の１点鎖線で示す如く給電点直下に
有効電流が流れると共に、溶接点のまわりには第
２図の２点鎖線で示す様な無効電流が流れ、これ
らによつて溶接部に磁界が発生する。そしてこの
磁界によつて上記強性磁成分及び帯鋼が磁化さ
れ、帯鋼突合せ部７ａの対向面に上記強磁性成分
が吸着されてブリツジF′を形成したり、溶接金属
中に強磁性成分が混入する。従つてこのままで抵
抗溶接を続けていくとワイヤ３のシーム溶接部に
融合不良が発生し、ワイヤ３の伸線加工時に断線
事故を引起こす原因となる他、抵抗溶接の際にス
パツタの多発、溶接不安定、電極焼損等のトラブ
ルが発生する。また強磁性体に付着している他の
原料も一部は引きずられて溶接点に持ち込まれ、
上記の問題を助長している。更に磁化された強磁
性成分の中には帯鋼突合せ部まで浮上しないまで
も湾曲した帯鋼内において移動するものがあり、
化学成分の偏析やフラツクス率の不均一といつた
問題の原因となつている。
また帯鋼突合せ部をTIG溶接する方法では、第
４図に略示する如く帯鋼突合せ部７ａの下流側直
後にTIG溶接トーチ１１を指向させて通電し溶接
を行なうが、この場合も抵抗溶接の場合と同様の
問題が発生する。
こうした問題に対処する為、
(1) 消磁コイルを電極ローラの下流側近接位置へ
設置する方法、
(2) 電極ローラの下流側近接位置に溶接線をまた
いで帯鋼の両端部に当接する通電体を配置し、
該通電体によつて電極ローラとは反対方向の電
流を帯鋼に流す方法、
(3) 充填フラツクスを、予め水ガラス等の固着剤
を用いて粗目の粒子に造粒・焼成する方法、
(4) 湾曲帯鋼内にフラツクスを充填するに当た
り、強磁性成分をフラツクス層のコア部分に集
中的に装入し、そのまわりに非磁性成分等を装
入して強磁性成分の周方向或は長手方向への移
動を防止する方法、
等が提案されているが、いずれも実施の為に大規
模な装置を必要としたり装置の制御や取扱いが煩
雑になる等の欠点があり、実用性に乏しいもので
あつた。その為、上記の方法は隙間のない複合ワ
イヤの効率的製法として極めて有効な方法である
にもかかわらず、殆んど実用化されていない。
本発明者等はこの様な事情に着目し、前述の様
な問題を解消し、優れた品質の複合ワイヤを高生
産性のもとに製造することのできる技術を確立し
ようとして種々研究を進めてきた。そして充填フ
ラツクスの原料として非磁性材料のみを選択使用
すれば、フラツクス成分の磁化に起因する前述の
様な問題を解消し得るという着想を得、この着想
を基に具体的な実用化研究を進めた結果本発明に
到達した。即ち本発明に係る溶接用複合ワイヤの
製法は、
30（重量％）≧Mn≧［18−14×Ｃ（重量％）］
Ｃ≦1.0（重量％）
の要件を満たすMn含有非磁性鉄粉５〜50重量％
を含み、比透磁率が1.10以下の粉末原料からなる
実質的に非磁性のフラツクスを、金属外皮内へ充
填した後、金属外皮をシーム溶接するところに要
旨が存在する。
本発明において、上記Mn含有非磁性鉄粉の全
フラツクス中に占める比率は、鉄粉系フラツクス
としての要求特性、即ち溶接速度、溶接作業性、
生成スラグの物性、ビード形状などの改善効果を
考慮して、５〜50重量％の範囲に定めた。
本発明においてフラツクス原料の比透磁率と
は、真空の透磁率に対するフラツクス原料の透磁
率の比をいうが、(A)フラツクス原料の比透磁率と
(B)シーム溶接部の欠陥発生率の間及び前記(A)と(C)
長さ方向のフラツクス率のばらつきとの間には
夫々一定の相関々係があることを確認した。即ち
第５図は、(A)フラツクス原料の比透磁率と、(B)抵
抗溶接法によるシーム溶接部の欠陥（融合不良及
び割れ）発生率〔（欠陥長さ）／（溶接長さ）〕の
関係を調べた実験結果を示すグラフである。但し
帯鋼としては軟鋼を使用し、またフラツクス原料
としては磁性体として鉄粉を用い、Mn及びＣを
添加することによつて比透磁率を調整した（フラ
ツクス中の鉄粉含有率は５〜50重量％とした）。
尚比透磁率は、試料の充填された環状チユーブに
磁化コイルを巻き、さぐりコイルを１か所に集中
させて巻きそれに磁束計を取付け、可変直流電源
により磁化電流を変化させてその都度磁束計の値
を読み取つて磁化曲線を作成し、その傾きから比
透磁率を求めた。
第５図からも明らかな様に、フラツクスの比透
磁率が1.1を超えると溶接欠陥が発生しはじめる
が、1.1以下であれば溶接欠陥は全く発生しない。
また第６図はフラツクスの比透磁率がワイヤ長
手方向のフラツクス率のばらつき（Ｒ／）に及
ぼす影響を調べた実験結果のグラフであり、この
図からも明らかな様に比透磁率が1.1以下である
フラツクスを使用することによつて、フラツクス
率のばらつきを実質上皆無にすることができる。
即ち比透磁率1.1という値は磁性を僅かに帯び
る性質を有することを意味するが、「複合ワイヤ
の製造」という目的のもとでは実質上非磁性のも
のとして支障なく使用し得るものである。
上記の様な目的にかなうフラツクス原料として
は、TiO2、ZrO2、CaCO3、Al2O3、SiO2、CaO、
CaF2、MgO、MgCO3等の非磁性原料が挙げられ
る。しかしフラツクス中には前述の様な理由から
鉄系等の原料も相当量配合しなければならず、こ
れら鉄系原料としては非磁性（比透磁率が1.1以
下のものを言う：以下同じ）のものを選択使用し
なければならない。そこでこの様な目的にかなう
鉄系原料を明らかにすべく色々研究を行なつたと
ころ、鉄中に含まれるＣ及びMnの量が〔Mn
（％）＋14×Ｃ（％）≧18（％：重量）〕で規定される
要件を満足するものは、比透磁率が1.1以下であ
りフラツクス原料として支障なく使用し得ること
が確認された。しかしMn量が30重量％を超える
鉄粉では、鉄粉に要求される機能、即ち溶着速度
の増大及び溶接作業性の向上を期待し得なくなる
ので、Mn量は30重量％以下のものを使用すべき
である。また鉄粉中のＣ量が多すぎると、溶接金
属の耐割れ性や溶接作業性が劣悪になるので１重
量％以下にしなければならない。尚鉄粉中の酸素
量低減及び溶製時の作業性改善を図る為、数％の
Siを含有させることも有効である。
また酸化鉄源としては、Fe2O3を主成分とする
赤鉄鉱やベンガラを使用する必要がある。
更に非磁性のNi源としては、Ni−Mg合金
（Mg含量：20重量％以上）等を使用することが
できる。
本発明は以上の様に構成されるが、要は充填用
のフラツクス原料として比透磁率が1.1以下であ
る実質的に非磁性のものを使用しているので、シ
ーム溶接時に帯鋼突合せ部にフラツクスの一部が
吸着されてブリツジ現像を起こす恐れがなく、溶
接欠陥のない高品質の複合ワイヤを得ることがで
きる。しかもシーム溶接工程でフラツクスが磁力
の影響で流動する様な現象が起こらないので、フ
ラツクス率のばらつきや成分偏析等を生じる恐れ
もない。またシーム溶接工程で消磁の為の設備及
び操作が全く不要であるので、比較的簡単な設備
で安定した品質の複合ワイヤを優れた生産性のも
とに製造し得ることになつた。
次に実験例を挙げて本発明の効果を一層明確に
する。
実験例
第１表に示す成分組成のフラツクス原料を充填
剤とし、第１〜３図に示した様な抵抗溶接法又は
第４図に示した様なTIG溶接法によつてシーム溶
接を行ない、引続いて伸線加工を行なつて1.2mm
φの複合ワイヤを製造した。但し使つた帯鋼及び
シーム溶接条件は次の通りとした。
〔抵抗溶接の場合〕
鋼製鞘材：軟鋼2.0mm厚×14mmφ
溶接条件：電流55000(A)、速度60ｍ／分
〔TIG溶接の場合〕
鋼製鞘材：軟鋼0.7mm厚×4.5mmφ
溶接条件：電流400A、速度10ｍ／分、シールド
ガスAr−５％H2
得られた各複合ワイヤのシーム溶接部の欠陥の
有無、及び各ワイヤを用いて下記の条件で溶接実
験を行なつた結果を第１表に一括して示す。
〔溶接実験条件〕
電流：280A、（DC・RP）
電圧：29V
ワイヤ突出長さ：20mm
シールドガス：CO2 25／min
溶接姿勢：下向
The present invention relates to a method for manufacturing a composite wire for welding, in particular, there is no welding defect in the seam welded part of the metal shell, there are very few problems such as segregation of flux components as a filler and non-uniform filling rate, and there is good workability. The present invention relates to a method for manufacturing composite wires that allows welded joints of excellent quality to be obtained under the following conditions. As is well known, a composite wire is made by filling a metal sheath such as mild steel with flux, and a composite wire is made by filling a tubular metal sheath with granular flux and then drawing it to a predetermined cross-sectional area. The wire and band-shaped metal material are bent into a tubular shape, filled with powder flux, and the butted portions are joined, followed by drawing to a predetermined cross-sectional area to create composite wires. It will be done. A detailed examination of the seam in the composite wire obtained using the latter band-shaped outer sheath material reveals that minute gaps remain along the seam line; however, the composite wire obtained using the former tubular outer sheath material Since there are no gaps in the longitudinal direction of the metal jacket, (a) the filling flux does not absorb moisture and the amount of diffusible hydrogen in the weld metal can be reduced to the same level as with solid wire, and (b) copper plating can be performed. So it is rust resistant, conductive,
It is possible to enjoy features such as excellent feedability. However, the manufacturing procedure involves filling a metal tube with granular flux and then drawing the wire, as described above, and there are many problems as described below. () The flux filling operation is extremely complicated and takes a long time, and productivity is low because continuous operation is difficult. () It is difficult to fill the flux uniformly over the entire length of the metal tube. () It is difficult to butt weld metal tubes filled with flux, and there are also difficulties in continuous wire drawing. () Degreasing and descaling of the inside and outside of metal pipes is complicated. In other words, there are too many issues that need to be resolved before composite wires using tubular sheathing materials can be put on the actual production line, and in reality we have no choice but to rely on the latter method of producing composite wires using strip-like sheathing materials. .
Therefore, it is necessary to establish a means for eliminating the gap between the seams in the latter composite wire. By the way, the currently widely used seam welding methods include pulse TIG welding, plasma welding, resistance welding,
Although laser welding and the like are considered, resistance welding and TIG welding are currently considered the most preferred methods. For example, FIGS. 1 to 3 show a seam welding method using resistance welding. First, in FIG. A plurality of pairs are arranged along the running direction of the steel 7. Each squeeze roller 6
The edge of the squeeze roller 6 becomes more open toward the steel strip introduction side (lower left side in the figure), and the distance between the squeeze rollers 6, which are disposed opposite to each other with the wire 3 in between, gradually becomes narrower toward the front in the direction in which the wire travels. . In manufacturing the wire 3 from the steel strip 7, the steel strip 7 is continuously introduced between the squeeze rollers 6 from the direction of arrow A, and is gradually curved to form a cavity in the length direction. After the flux F is charged into the cavity and the steel strip 7 is further curved to form a tubular shape, the electrode roller 2 connected to the welding power source 5 via the control device 4 is inserted into the butt portion 7a of the steel strip 7. The wire 3 is obtained by continuously resistance welding the abutted portions 7a.The electrode roller 2 may be, for example, the conceptual diagram of FIG. is a hollow support shaft, and 10 is a bearing). Then, the energizing rollers 2a, 2b are connected to the abutting portion 7a of the steel band 7.
Resistance welding is performed by contacting the opposite side edges (ears) of the steel strip so as to straddle the two sides, and applying a welding current to the butt portion 7a. Incidentally, the packed flux contains various powder raw materials depending on the purpose, and ferromagnetic raw materials such as iron powder and iron oxide are often blended. In other words, iron powder is important for increasing welding speed, improving workability, and adjusting flux rate, etc., and iron oxide is useful for improving the physical properties of generated slag, improving welding workability, and improving bead shape. Furthermore, Ni is sometimes added for the purpose of improving constant temperature toughness. On the other hand, when a welding current is passed through the butt part of the steel strip during resistance welding as described above, an effective current flows directly below the power supply point as shown by the dashed line in Fig. 2 (cross-sectional explanatory diagram showing the vicinity of the welding point), and the welding A reactive current flows around the point as shown by the two-dot chain line in FIG. 2, and a magnetic field is generated in the weld zone by these currents. The ferromagnetic component and the steel strip are magnetized by this magnetic field, and the ferromagnetic component is attracted to the opposing surface of the steel strip abutting portion 7a to form a bridge F'. is mixed in. Therefore, if resistance welding is continued as it is, poor fusion will occur at the seam welding part of the wire 3, which will cause a breakage accident during wire drawing of the wire 3, as well as frequent occurrence of spatter during resistance welding. Problems such as unstable welding and electrode burnout may occur. Also, some of the other raw materials attached to the ferromagnetic material are dragged and brought to the welding point.
This contributes to the above problem. Furthermore, some magnetized ferromagnetic components move within the curved steel strip even if they do not float up to the butt part of the steel strip.
This causes problems such as segregation of chemical components and non-uniform flux rates. In addition, in the method of TIG welding the steel strip butt portions, as shown schematically in FIG. 4, the TIG welding torch 11 is directed immediately after the downstream side of the steel strip butt portion 7a and welding is performed by applying current, but in this case as well, resistance welding is performed. A similar problem occurs. In order to deal with these problems, (1) a method of installing a degaussing coil near the downstream side of the electrode roller, and (2) a method of installing a degaussing coil near the downstream side of the electrode roller, which straddles the weld line and contacts both ends of the steel strip. position the body,
(3) A method in which the filled flux is granulated and fired into coarse particles using a fixing agent such as water glass in advance, ( 4) When filling the curved steel strip with flux, the ferromagnetic component is concentrated in the core part of the flux layer, and the non-magnetic component is charged around it to spread the ferromagnetic component in the circumferential direction or Methods to prevent longitudinal movement have been proposed, but all of them have drawbacks such as requiring large-scale equipment and complicated equipment control and handling, making them impractical. It was scarce. Therefore, although the above-mentioned method is an extremely effective method for efficiently manufacturing a composite wire without gaps, it has hardly been put into practical use. The inventors of the present invention have focused on these circumstances and have conducted various studies in an attempt to solve the above-mentioned problems and establish a technology that can manufacture composite wires of excellent quality with high productivity. It's here. We then came up with the idea that if we selectively use only non-magnetic materials as raw materials for the filling flux, we could solve the aforementioned problems caused by the magnetization of the flux components, and based on this idea, we proceeded with practical research. As a result, the present invention was achieved. That is, the manufacturing method of the composite wire for welding according to the present invention is as follows: 30 (weight%)≧Mn≧[18-14×C (weight%)] C≦1.0 (weight%) Mn-containing nonmagnetic iron powder 5 ~50% by weight
The gist is that a substantially non-magnetic flux made of a powder raw material with a relative magnetic permeability of 1.10 or less is filled into the metal shell, and then the metal shell is seam welded. In the present invention, the proportion of the Mn-containing non-magnetic iron powder in the total flux is determined by the required characteristics as an iron powder-based flux, that is, welding speed, welding workability,
Taking into consideration the effect of improving the physical properties of the produced slag, bead shape, etc., the content was determined to be in the range of 5 to 50% by weight. In the present invention, the relative magnetic permeability of the flux raw material refers to the ratio of the magnetic permeability of the flux raw material to the magnetic permeability of a vacuum, and (A) the relative magnetic permeability of the flux raw material and
(B) Between the defect occurrence rate of seam welds and the above (A) and (C)
It was confirmed that there is a certain correlation between the variation in flux rate in the longitudinal direction. That is, Figure 5 shows (A) the relative magnetic permeability of the flux raw material and (B) the incidence of defects (poor fusion and cracking) in seam welds by resistance welding [(defect length)/(welding length)] It is a graph showing the results of an experiment investigating the relationship between However, mild steel was used as the strip steel, and iron powder was used as the magnetic material for the flux raw material, and the relative magnetic permeability was adjusted by adding Mn and C (the iron powder content in the flux was 5 to 50%). 50% by weight).
The relative magnetic permeability can be measured by winding a magnetizing coil around the annular tube filled with the sample, concentrating the probing coil in one place, attaching a magnetometer to it, changing the magnetizing current with a variable DC power supply, and measuring the flux meter each time. A magnetization curve was created by reading the value of , and the relative magnetic permeability was determined from the slope of the curve. As is clear from FIG. 5, if the relative magnetic permeability of the flux exceeds 1.1, welding defects begin to occur, but if it is below 1.1, no welding defects occur at all. Furthermore, Figure 6 is a graph showing the results of an experiment that investigated the effect of the relative magnetic permeability of flux on the variation (R/) of flux rate in the longitudinal direction of the wire.As is clear from this figure, when the relative magnetic permeability is 1.1 or less, By using a flux having the following properties, it is possible to substantially eliminate variations in the flux rate. That is, a value of relative magnetic permeability of 1.1 means that it has a property of being slightly magnetic, but for the purpose of "manufacturing composite wire", it can be used without any problem as it is substantially non-magnetic. Flux raw materials that meet the above purpose include TiO 2 , ZrO 2 , CaCO 3 , Al 2 O 3 , SiO 2 , CaO,
Examples include non-magnetic raw materials such as CaF 2 , MgO, and MgCO 3 . However, for the reasons mentioned above, it is necessary to mix a considerable amount of iron-based raw materials into the flux. You have to choose what you use. Therefore, various studies were conducted to find iron-based raw materials that could meet these purposes, and it was found that the amount of C and Mn contained in iron was [Mn
(%) + 14 × C (%) ≧ 18 (%: weight)], it was confirmed that the relative magnetic permeability was 1.1 or less and that it could be used as a flux raw material without any problems. However, iron powder with a Mn content of more than 30% by weight cannot be expected to provide the required functions of iron powder, that is, increase in welding speed and improve welding workability, so use powder with a Mn content of 30% by weight or less. Should. Furthermore, if the amount of C in the iron powder is too large, the cracking resistance of the weld metal and welding workability will deteriorate, so it must be kept at 1% by weight or less. In order to reduce the amount of oxygen in iron powder and improve workability during melting, a few percent of
It is also effective to include Si. Further, as a source of iron oxide, it is necessary to use hematite or red iron oxide whose main component is Fe 2 O 3 . Further, as a non-magnetic Ni source, a Ni-Mg alloy (Mg content: 20% by weight or more) or the like can be used. The present invention is constructed as described above, but the point is that a substantially non-magnetic material with a relative magnetic permeability of 1.1 or less is used as the flux raw material for filling, so that it can be applied to the butt part of the steel strip during seam welding. There is no risk that part of the flux will be adsorbed and cause bridge development, and a high-quality composite wire without welding defects can be obtained. Moreover, since the flux does not flow under the influence of magnetic force during the seam welding process, there is no risk of variations in flux rate or component segregation. Furthermore, since there is no need for demagnetizing equipment or operations in the seam welding process, it is now possible to manufacture composite wires of stable quality with relatively simple equipment and with excellent productivity. Next, experimental examples will be given to further clarify the effects of the present invention. Experimental example A flux raw material having the composition shown in Table 1 was used as a filler, and seam welding was performed by resistance welding as shown in Figures 1 to 3 or TIG welding as shown in Figure 4. Subsequently, wire drawing is performed to 1.2mm.
A composite wire of φ was manufactured. However, the steel strips and seam welding conditions used were as follows. [For resistance welding] Steel sheath material: Mild steel 2.0mm thick x 14mmφ Welding conditions: Current 55000(A), speed 60m/min [For TIG welding] Steel sheath material: Mild steel 0.7mm thick x 4.5mmφ Welding conditions : Current 400A, speed 10m/min, shielding gas Ar-5%H 2 Check the presence or absence of defects in the seam welds of each composite wire obtained, and the results of welding experiments using each wire under the following conditions. All are shown in Table 1. [Welding experiment conditions] Current: 280A, (DC/RP) Voltage: 29V Wire protrusion length: 20mm Shielding gas: CO 2 25/min Welding position: Downward
【表】
第１表において、実験No.８〜12は本発明の要件
を満たす実施例であり、フラツクス原料の比透磁
率がすべて1.1以下であるので、シーム溶接を
TIG溶接及び抵抗溶接のどちらで行なつた場合も
円滑に溶接を行なうことができ、且つシーム部に
溶接欠陥は認められない。しかもフラツクス充填
率が均一でばらつきがない為、溶接試験結果も良
好である。
これに対し実験No.１〜７は好適要件を欠く比較
例で、下記の如く欠陥が認められる。
実験No.１：強磁性の鉄粉を使用した為シーム溶接
部に割れが発生した。
実験No.２：鉄粉中のMn及びＣ量が少なく比透磁
性が1.1を超えている為、やはりシーム溶接部
に欠陥が発生した。
実験No.３：酸化鉄源として磁性のFeOを主成分と
するスケールを使用した為、シーム溶接部に欠
陥が発生した。
実験No.４：Ni源として強磁性の純Ni粉を使用し
た為、シール溶接部に欠陥が認められた。
実験No.５：Si源として強磁性のFe−Si（27％）を
使用した為、シーム部に欠陥が発生した。
実験No.６、No.７：フラツクス原料の比透磁率は何
れも1.1以下であり、一応本発明の要件を満た
しているが、No.６はMn量の多いFe−Mn（32
％）を使用した為、鉄粉本来の効果が希釈され
て溶接作業性に問題が生じ、又No.７ではＣ量の
多い鉄粉を使用した為、溶接実験でスパツタ及
びヒユームが多発した。[Table] In Table 1, Experiment Nos. 8 to 12 are examples that meet the requirements of the present invention, and since the relative magnetic permeability of the flux raw materials are all 1.1 or less, seam welding is not performed.
Whether TIG welding or resistance welding is used, welding can be carried out smoothly, and no welding defects are observed at the seam. Moreover, since the flux filling rate is uniform and there is no variation, the welding test results are also good. On the other hand, Experiments Nos. 1 to 7 are comparative examples lacking favorable requirements, and defects are observed as described below. Experiment No. 1: Cracks occurred in the seam weld due to the use of ferromagnetic iron powder. Experiment No. 2: Since the amount of Mn and C in the iron powder was small and the relative permeability exceeded 1.1, defects also occurred in the seam weld. Experiment No. 3: Because scale containing magnetic FeO as the main component was used as the iron oxide source, defects occurred in the seam weld. Experiment No. 4: Because ferromagnetic pure Ni powder was used as the Ni source, defects were observed in the seal weld. Experiment No. 5: Because ferromagnetic Fe-Si (27%) was used as the Si source, defects occurred at the seam. Experiment No. 6 and No. 7: The relative magnetic permeability of the flux raw materials is 1.1 or less, which basically satisfies the requirements of the present invention, but No. 6 was made of Fe-Mn (32
%), the original effect of the iron powder was diluted, causing problems in welding workability, and in No. 7, iron powder with a large amount of C was used, resulting in frequent spatter and fumes during welding experiments.
【図面の簡単な説明】[Brief explanation of the drawing]
第１〜３図は抵抗溶接を利用したシーム溶接法
を例示するもので、第１図は概念図、第２図はシ
ーム溶接状態を示す要部見取り図、第３図は同じ
く要部横断面図である。第４図はTIG溶接を利用
したシーム溶接例を示す概念図、第５，６図はフ
ラツクス原料の比透磁率とシーム溶接部の欠陥発
生率及びフラツクス率のばらつきとの関係を示す
実験結果のグラフである。
１……基台、２……電極ローラ、３……ワイ
ヤ、４……制御装置、５……溶接電源、６……ス
クイズローラ、７……帯鋼。
Figures 1 to 3 illustrate the seam welding method using resistance welding. Figure 1 is a conceptual diagram, Figure 2 is a sketch of the main part showing the seam welding state, and Figure 3 is a cross-sectional view of the main part. It is. Figure 4 is a conceptual diagram showing an example of seam welding using TIG welding, and Figures 5 and 6 are experimental results showing the relationship between the relative magnetic permeability of the flux raw material, the defect occurrence rate of the seam weld, and the variation in flux rate. It is a graph. DESCRIPTION OF SYMBOLS 1... Base, 2... Electrode roller, 3... Wire, 4... Control device, 5... Welding power source, 6... Squeeze roller, 7... Steel strip.