JP6819712B2

JP6819712B2 - Welding method of mash seam welding

Info

Publication number: JP6819712B2
Application number: JP2019053706A
Authority: JP
Inventors: 裕也山下
Original assignee: JFE Steel Corp
Current assignee: JFE Steel Corp
Priority date: 2018-03-27
Filing date: 2019-03-20
Publication date: 2021-01-27
Anticipated expiration: 2039-03-20
Also published as: JP2019171471A

Description

本発明は、マッシュシーム溶接の溶接方法に関する。 The present invention relates to a welding method for mash seam welding.

酸洗ラインや冷間圧延ラインといった帯状板体の製造ラインでは、入側の溶接設備において、２つのコイル状の帯状板体（「コイル」ともいう。）の先端と尾端とを溶接によって接合させることで、複数のコイルを連続的に処理することが行われている。このような製造ラインで用いられる溶接方法の一つとして、重ね抵抗溶接の一種であるシーム溶接が挙げられる。また、シーム溶接の一つとして、電極輪で帯状板体同士の重ね代を圧下させながら溶接するマッシュシーム溶接が用いられることもある。
帯状板体の製造ラインにおけるシーム溶接機の溶接条件は、適切に決定することが困難であるため、良好な溶接部を得られるように、多量の実験データをもとに決定されることが一般的である。 In a strip-shaped plate manufacturing line such as a pickling line or a cold rolling line, the tips and tail ends of two coiled strip-shaped plates (also referred to as "coils") are joined by welding in the welding equipment on the entrance side. By doing so, a plurality of coils are continuously processed. One of the welding methods used in such a production line is seam welding, which is a type of lap resistance welding. Further, as one of the seam welding, mash seam welding may be used in which the electrode ring is used to reduce the overlap margin between the strip-shaped plates while welding.
Since it is difficult to properly determine the welding conditions of a seam welder in a strip-shaped plate production line, it is generally determined based on a large amount of experimental data so that a good welded portion can be obtained. Is the target.

例えば、特許文献１には、シーム溶接にて良好な溶接部を得るために、溶接電流、重ね代、溶接速度及びストリップ板厚によって決定されるパラメータが、適正な範囲内となるように溶接条件を設定する方法が開示されている。
また、引用文献２には、シーム溶接にて溶接中の板厚及び電極加圧力を測定し、溶接条件を制御する方法が開示されている。 For example, in Patent Document 1, in order to obtain a good welded portion by seam welding, welding conditions are set so that the parameters determined by the welding current, the lap allowance, the welding speed and the strip plate thickness are within an appropriate range. The method of setting is disclosed.
Further, Reference Document 2 discloses a method of controlling welding conditions by measuring the plate thickness and electrode pressing force during welding by seam welding.

特開平５−５７４５５５号公報Japanese Unexamined Patent Publication No. 5-574555 特公平４−５１２６８号公報Special Fair 4-51268 Gazette

しかしながら、実験データをもとに溶接条件を決定する方法では、多大な労力と時間とを要するという問題があった。
また、特許文献１の方法では、各種の溶接条件のパラメータのうち、全てを定量的に決定できるわけではないという問題点がある。さらに、電極加圧力や溶接電流、溶接速度、重ね代といったパラメータを決定したとしても、電極の径やストリップの強度等も溶接に影響を与える因子であるため、溶接機側で制御できるパラメータだけでは、必ずしも良好な溶接部を得ることができるとは言えない。
さらに、特許文献２の方法では、溶接中に測定される板厚及び電極加圧力から、溶接条件を制御しているが、これらの因子以外の条件も溶接に影響を与えるため、必ずしも良好な溶接部を得ることができるとは言えない。 However, the method of determining the welding conditions based on the experimental data has a problem that a great deal of labor and time are required.
Further, the method of Patent Document 1 has a problem that not all of the parameters of various welding conditions can be quantitatively determined. Furthermore, even if parameters such as electrode pressing force, welding current, welding speed, and stacking allowance are determined, the electrode diameter and strip strength are also factors that affect welding, so only the parameters that can be controlled on the welding machine side are sufficient. However, it cannot always be said that a good welded portion can be obtained.
Further, in the method of Patent Document 2, the welding conditions are controlled from the plate thickness and the electrode pressing force measured during welding, but conditions other than these factors also affect the welding, so that welding is not always good. It cannot be said that the part can be obtained.

溶接条件が適切でない場合、溶接時にナゲット（溶接部に発生する溶融凝固した部分）が十分に形成されずに未接合箇所が発生することや、溶融した母材が飛び散るチリが発生することで接合不良となることがある。 If the welding conditions are not appropriate, the nugget (the melted and solidified part generated in the welded part) is not sufficiently formed during welding and unjoined parts are generated, and the molten base metal is scattered and dust is generated to join. It may be defective.

そこで、本発明は、上記の課題に着目してなされたものであり、マッシュシーム溶接によって帯状板体を溶接する際に、簡易且つ適切に溶接条件を決定することができる、マッシュシーム溶接の溶接方法を提供することを目的としている。 Therefore, the present invention has been made by paying attention to the above problems, and welding of mash seam welding can easily and appropriately determine welding conditions when welding a strip-shaped plate body by mash seam welding. It is intended to provide a method.

本発明の一態様によれば、複数の帯状板体を重ね合わせ、上記複数の帯状板体が重ね合わさる接合部を一対の電極輪で圧下させながら、上記接合部に電流を流すことで溶接する、マッシュシーム溶接の溶接方法であって、それぞれの板厚が２．３ｍｍ以下の上記複数の帯状板体を溶接する際に、（１）式で算出される電流密度を、０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下とする、マッシュシーム溶接の溶接方法が提供される。なお、本明細書の説明において、単位のｍｐｍは、ｍ／ｍｉｎのことを示す。 According to one aspect of the present invention, a plurality of strip-shaped plates are overlapped, and a joint portion in which the plurality of strip-shaped plates are overlapped is pressed down by a pair of electrode rings, and an electric current is passed through the joint portion for welding. In the welding method of mash seam welding, when welding the plurality of strip-shaped plates having a thickness of 2.3 mm or less, the current density calculated by the equation (1) is 0.07 kA / (. Provided is a welding method for mash seam welding in which mpm · mm ² ) or more and 0.10 kA / (mpm · mm ² ) or less. In the description of the present specification, the unit mpm indicates m / min.

ｉ：電流密度（ｋＡ/（ｍｐｍ・ｍｍ^２））
Ｉ：溶接電流（ｋＡ）
Ｖ：溶接速度（ｍｐｍ）
Ｓ：電極輪接触面積（ｍｍ^２）
Ｓ_ａ：弧長接触領域の面積（ｍｍ^２）
Ｓ_ｈ：ヘルツ接触領域の面積（ｍｍ^２）
δ：重ね代（ｍｍ）
ｔ_０：溶接前の板厚（ｍｍ）
ｔ_ｗ：溶接後の板厚（ｍｍ）
Ｄ：電極輪の直径（ｍｍ）

i: Current density (kA / (mpm · mm ² ))
I: Welding current (kA)
V: Welding speed (mpm)
S: Electrode ring contact area (mm ² )
S _a : Area of arc length contact area (mm ² )
_Sh : Area of Hertz contact area (mm ² )
δ: Overlay allowance (mm)
t ₀ : Plate thickness (mm) before welding
t _w : Plate thickness (mm) after welding
D: Diameter of electrode ring (mm)

本発明の一態様によれば、複数の帯状板体を重ね合わせ、上記複数の帯状板体が重ね合わさる接合部を一対の電極輪で圧下させながら、上記接合部に電流を流すことで溶接する、マッシュシーム溶接の溶接方法であって、それぞれの板厚が２．３ｍｍ以下の上記複数の帯状板体を溶接する際に、（１）式で算出される電流密度を、０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下とする、マッシュシーム溶接の溶接条件の決定方法が提供される。 According to one aspect of the present invention, a plurality of strip-shaped plates are overlapped, and a joint portion in which the plurality of strip-shaped plates are overlapped is pressed down by a pair of electrode rings, and an electric current is passed through the joint portion for welding. In the welding method of mash seam welding, when welding the plurality of strip-shaped plates having a thickness of 2.3 mm or less, the current density calculated by the equation (1) is 0.07 kA / (. Provided is a method for determining welding conditions for mash seam welding, which is mpm · mm ² ) or more and 0.10 kA / (mpm · mm ² ) or less.

ｉ：電流密度（ｋＡ/（ｍｐｍ・ｍｍ^２））
Ｉ：溶接電流（ｋＡ）
Ｖ：溶接速度（ｍｐｍ）
Ｓ：電極輪接触面積（ｍｍ^２）
δ：重ね代（ｍｍ）
ｔ_０：溶接前の板厚（ｍｍ）
Ｄ’：荷重負荷した偏平後の電極輪の見かけの直径（ｍｍ）
ｔ_ｗ：溶接後の板厚（ｍｍ）
Ｄ：電極輪の直径（ｍｍ）
ν：電極輪のポアソン比（−）
Ｅ：電極輪のヤング率（Ｎ／ｍｍ^２）
Ｐ：電極輪の荷重（Ｎ）

i: Current density (kA / (mpm · mm ² ))
I: Welding current (kA)
V: Welding speed (mpm)
S: Electrode ring contact area (mm ² )
δ: Overlay allowance (mm)
t ₀ : Plate thickness (mm) before welding
D': Apparent diameter (mm) of the electrode ring after flattening under load
t _w : Plate thickness (mm) after welding
D: Diameter of electrode ring (mm)
ν: Poisson's ratio of the electrode ring (-)
E: Young's modulus of the electrode ring (N / mm ² )
P: Load of electrode ring (N)

本発明の一態様によれば、マッシュシーム溶接によって帯状板体を溶接する際に、簡易且つ適切に溶接条件を決定することができる、マッシュシーム溶接の溶接方法が提供される。 According to one aspect of the present invention, there is provided a welding method for mash seam welding, which can easily and appropriately determine welding conditions when welding a strip-shaped plate body by mash seam welding.

本発明の一実施形態における、溶接機を示す模式図である。It is a schematic diagram which shows the welding machine in one Embodiment of this invention. 溶接時の先行材、後行材、及び一対の電極輪との位置関係を示す拡大図である。It is an enlarged view which shows the positional relationship with the leading material, the trailing material, and a pair of electrode rings at the time of welding. 電極輪と鋼帯との接触を示す概念図である。It is a conceptual diagram which shows the contact between an electrode ring and a steel strip. 溶接時に電極輪が偏平した状態を示す説明図である。It is explanatory drawing which shows the flat state of the electrode ring at the time of welding. 電極輪荷重とヘルツ接触面積との関係の一例を示すグラフである。It is a graph which shows an example of the relationship between the electrode ring load and the Hertz contact area. 電流密度が（２）式の範囲となる、電極輪荷重及び溶接電流の範囲を示すグラフである。It is a graph which shows the range of the electrode ring load and the welding current which the current density is in the range of equation (2).

以下の詳細な説明では、本発明の完全な理解を提供するように、本発明の実施形態を例示して多くの特定の細部について説明する。しかしながら、かかる特定の細部の説明がなくても１つ以上の実施態様が実施できることは明らかである。また、図面は、簡潔にするために、周知の構造及び装置が略図で示されている。 In the following detailed description, many specific details will be described by exemplifying embodiments of the invention to provide a complete understanding of the invention. However, it is clear that one or more embodiments can be implemented without such particular detail description. Also, for the sake of brevity, the drawings are schematic representations of well-known structures and devices.

＜溶接条件の決定方法及び溶接方法＞
図１〜図４を参照して、本発明の一実施形態に係るマッシュシーム溶接の溶接条件の決定方法及び溶接方法を説明する。本実施形態では、図１に示すマッシュシーム溶接を行う溶接機１を用いて、帯状板体である鋼帯２を溶接する際の溶接条件を決定し、決定した溶接条件でマッシュシーム溶接を行う。本実施形態において、マッシュシーム溶接される鋼帯２は、板厚が２．３ｍｍ以下の材料である。板厚が２．３ｍｍ超となる場合、（１）式で算出される電流密度ｉが適正範囲となる領域が大きくなるため、より詳細な条件を追加する必要がある。 <Welding condition determination method and welding method>
A method for determining welding conditions and a welding method for mash seam welding according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. In the present embodiment, the welding machine 1 for performing mash seam welding shown in FIG. 1 is used to determine the welding conditions for welding the steel strip 2 which is a strip-shaped plate body, and the mash seam welding is performed under the determined welding conditions. .. In the present embodiment, the steel strip 2 to be mash seam welded is a material having a plate thickness of 2.3 mm or less. When the plate thickness exceeds 2.3 mm, the region where the current density i calculated by Eq. (1) is in the appropriate range becomes large, so it is necessary to add more detailed conditions.

溶接機１は、図１に示すように、一対の電極輪１１，１２を有する。一対の電極輪１１，１２は、同じ直径のロール状の電極であり、ｚ軸方向（図１の上下方向であり、鉛直方向）に対向して設けられ、上下一対の電極輪１１，１２ともいう。なお、図面において、ｘ軸及びｙ軸は、互いに直交し、且つｚ軸に直交する、水平方向に平行な軸である。一対の電極輪１１，１２は、不図示の駆動モータにそれぞれ接続され、駆動モータの駆動力を受けて、ｘ−ｚ平面においてロール形状の周方向に回転可能に構成される。また、一対の電極輪１１，１２は、不図示の電源装置に接続される。電極輪１１は、鋼帯２の位置をｚ軸の０（原点位置）としたときのｚ軸負方向側に配され、不図示の枠体等に固定される。一方、電極輪１２は、ｚ軸正方向側に配され、不図示の加圧シリンダーを介して、枠体に固定される。また、電極輪１１は、加圧シリンダーによって、ｚ軸方向に移動可能に構成される。さらに、電極輪１１，１２の材質は、銅もしくは銅合金からなる。 As shown in FIG. 1, the welding machine 1 has a pair of electrode rings 11 and 12. The pair of electrode rings 11 and 12 are roll-shaped electrodes having the same diameter, are provided so as to face each other in the z-axis direction (vertical direction in FIG. 1), and both the upper and lower electrode rings 11 and 12 are provided. Say. In the drawings, the x-axis and the y-axis are axes that are orthogonal to each other and orthogonal to the z-axis and are parallel to the horizontal direction. The pair of electrode wheels 11 and 12 are connected to drive motors (not shown), respectively, and are configured to be rotatable in the circumferential direction of the roll shape in the xz plane by receiving the drive force of the drive motor. Further, the pair of electrode rings 11 and 12 are connected to a power supply device (not shown). The electrode ring 11 is arranged on the negative side of the z-axis when the position of the steel strip 2 is 0 (origin position) of the z-axis, and is fixed to a frame or the like (not shown). On the other hand, the electrode ring 12 is arranged on the positive direction side of the z-axis and is fixed to the frame body via a pressure cylinder (not shown). Further, the electrode ring 11 is configured to be movable in the z-axis direction by a pressure cylinder. Further, the materials of the electrode rings 11 and 12 are made of copper or a copper alloy.

溶接機１は、酸洗ラインや冷間圧延ラインといった鋼帯２の製造ラインの入側に設けられる溶接設備である。このような製造ラインでは、製造ラインに先に投入された鋼帯２である先行材２１と、先行材２１の後に投入される鋼帯２である後行材２２とがマッシュシーム溶接によって接合されることで、複数の鋼帯２を連続して処理することができる。
この際、溶接機１による溶接では、図２に示すように、先行材２１の尾端部と、後行材の先端部とを所定の重ね代δで重ね合わせる。重ね代δは、鋼帯２の長手方向（図１，２におけるｙ軸方向）における長さでる。 The welding machine 1 is a welding facility provided on the entrance side of the production line of the steel strip 2 such as a pickling line and a cold rolling line. In such a production line, the leading material 21 which is the steel strip 2 introduced earlier in the production line and the trailing material 22 which is the steel strip 2 introduced after the preceding material 21 are joined by mash seam welding. As a result, a plurality of steel strips 2 can be processed continuously.
At this time, in the welding by the welding machine 1, as shown in FIG. 2, the tail end portion of the leading member 21 and the tip end portion of the trailing member are overlapped with a predetermined overlapping allowance δ. The stacking allowance δ is the length of the steel strip 2 in the longitudinal direction (y-axis direction in FIGS. 1 and 2).

そして、先行材２１の尾端部と後行材２２の先端部とが重ね合わさった箇所となる鋼帯２の接合部が、一対の電極輪１１，１２によって、圧下及び溶接されることで、先行材２１と後行材２２とが接合される。そして、一対の電極輪１１，１２による接合では、一対の電極輪１１，１２の間に鋼帯２の接合部が挟持された状態で、鋼帯２の接合部を一対の電極輪１１，１２で加圧及び通電することで、鋼帯２の抵抗発熱により接合部を加熱し、押しつぶす。さらに、この一対の電極輪１１，１２による接合を、一対の電極輪１１，１２を回転させ、鋼帯２の幅方向（図１，２におけるｘ軸方向）に移動させながら行うことで、鋼帯２の全幅にわたって、接合部の接合が連続的に行われる。これにより、先行材２１と後行材２２との間に、全幅にわたってナゲット２ａが形成される。なお、一対の電極輪１１，１２による溶接は、後述する電流密度となるように決定された溶接条件で行われる。ここで、溶接条件とは、溶接電流の電流値、溶接速度及び電極輪接触面積を少なくとも含む条件である。 Then, the joint portion of the steel strip 2, which is the portion where the tail end portion of the leading member 21 and the tip end portion of the trailing member 22 are overlapped, is reduced and welded by the pair of electrode rings 11 and 12. The leading member 21 and the trailing member 22 are joined. Then, in the joining by the pair of electrode rings 11 and 12, the joint portion of the steel strip 2 is sandwiched between the pair of electrode rings 11 and 12, and the joint portion of the steel strip 2 is joined by the pair of electrode rings 11 and 12. By pressurizing and energizing with, the joint is heated and crushed by the resistance heat generated by the steel strip 2. Further, the joining by the pair of electrode rings 11 and 12 is performed while rotating the pair of electrode rings 11 and 12 and moving them in the width direction of the steel strip 2 (the x-axis direction in FIGS. 1 and 2). The joints are joined continuously over the entire width of the band 2. As a result, the nugget 2a is formed over the entire width between the leading member 21 and the trailing member 22. Welding with the pair of electrode rings 11 and 12 is performed under welding conditions determined so as to have a current density described later. Here, the welding condition is a condition including at least the current value of the welding current, the welding speed, and the contact area of the electrode ring.

本実施形態におけるマッシュシーム溶接では、下記（１）式で示される溶接時の電流密度ｉ（ｋＡ/（ｍｐｍ・ｍｍ^２））が下記（２）式の条件を満たすように、溶接条件が設定される。（１）式において、Ｉは溶接電流（ｋＡ）、Ｖは溶接速度（ｍｐｍ）、Ｓは電極輪接触面積（ｍｍ^２）をそれぞれ示す。電極輪接触面積Ｓは、下記（３）式で示される面積であり、弧長接触領域の面積Ｓ_ａ（ｍｍ^２）と、ヘルツ接触領域の面積Ｓ_ｈ（ｍｍ^２）との和である。弧長接触領域の面積Ｓ_ａは、電極輪１１，１２によって変形が生じている鋼帯２の変形部の面積であり、下記（４）式で示される。弧長接触領域は、図３の符号ｄ_１で示される領域である。（４）式において、δは先行材２１と後行材２２との重ね代（ｍｍ）、ｔ_０は溶接前の鋼帯２（先行材２１と後行材２２とを合わせたもの）の板厚である溶接前の板厚（ｍｍ）、ｔ_ｗは溶接後の鋼帯２（先行材２１と後行材２２とを合わせたもの）の板厚である溶接後の板厚（ｍｍ）、Ｄは電極輪１１，１２の直径（ｍｍ）をそれぞれ示す。なお、溶接後の板厚ｔ_ｗは、理論的に、溶接時の荷重や鋼帯２の物性値（変形抵抗や引張強さ）により求めることが可能だが、より簡易的に決定するため、同様な条件で溶接を行った実験値を用いてもよい。また、ヘルツ接触領域の面積Ｓ_ｈは、電極輪荷重Ｆ（ｋＮ）、並びに母材である鋼帯２及び電極輪１１，１２の物性値から求められる領域の面積である。ヘルツ接触領域は、図３の符号ｄ_２で示される領域である。例えば、鋼帯２が、炭素濃度が０．１ｍａｓｓ％程度の低炭素鋼である場合、ヘルツ接触領域の面積Ｓ_ｈと電極輪荷重Ｆとの関係は、図５に示す関係となる。なお、図５において、鋼帯２（先行材２１及び後行材２２）の板厚は１．６ｍｍ、重ね代δは１．６ｍｍ、電極輪１１，１２の直径は３００ｍｍとした。また、図５において、鋼帯２の鋼種は、ＳＰＨＣとした。 In the mash seam welding in the present embodiment, the welding conditions are set so that the current density i (kA / (mpm · mm ² )) at the time of welding represented by the following equation (1) satisfies the following equation (2). Will be done. In equation (1), I indicates the welding current (kA), V indicates the welding speed (mpm), and S indicates the electrode ring contact area (mm ² ). The electrode ring contact area S is an area represented by the following equation (3), and is the sum of the area S _a (mm ² ) of the arc length contact region and the area S _h (mm ² ) of the Hertz contact region. Area S _a of the arc length the contact area is the area of the deformed portion of the steel strip 2 deformed by the electrode wheels 11 and 12 occurs, represented by the following equation (4). Arc length contact region is a region indicated by reference numeral d ₁ in FIG. In equation (4), δ is the overlap margin (mm) between the leading material 21 and the trailing material 22, and t ₀ is the plate of the steel strip 2 before welding (the combination of the leading material 21 and the trailing material 22). The thickness before welding (mm), _tw is the thickness of the steel strip 2 after welding (the combination of the leading member 21 and the trailing member 22), the thickness after welding (mm), D indicates the diameters (mm) of the electrode rings 11 and 12, respectively. Incidentally, the thickness t _w after welding, theoretically, but can be determined by the load and physical properties of the steel strip 2 at the time of welding (deformation resistance and tensile strength), to determine more simply, the same Experimental values obtained by welding under various conditions may be used. Further, the area S _h of Hertzian contact area, the electrode wheel load F (kN), and the area of the region obtained from physical properties of the steel strip 2 and the electrode wheels 11, 12 as the base material. Hertzian contact area is an area indicated by reference numeral d ₂ in FIG. For example, steel strip 2 is, when the carbon concentration is low carbon steel of about 0.1mass%, the relationship between the area S _h and the electrode wheel load F of Hertzian contact area have a relationship shown in FIG. In FIG. 5, the plate thickness of the steel strip 2 (preceding member 21 and trailing member 22) was 1.6 mm, the stacking allowance δ was 1.6 mm, and the diameters of the electrode rings 11 and 12 were 300 mm. Further, in FIG. 5, the steel type of the steel strip 2 is SPHC.

なお、（１）式で算出される電流密度ｉでは、溶接電流Ｉ、溶接速度Ｖ、電極輪荷重Ｆ及び重ね代の４要素が可変となる値であり、その他の要素については溶接機１及び鋼帯２の仕様に応じて予め決定される値となる。つまり、本実施形態では、電流密度ｉが０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下となるように、溶接電流Ｉ、溶接速度Ｖ、電極輪荷重Ｆ及び重ね代を決定することで、マッシュシーム溶接における溶接条件が決定される。なお、電流密度が０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）未満となる場合、ナゲット２ａが十分に形成されないため、未接合領域が発生し、接合部が破断する可能性がある。一方、電流密度が０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）超となる場合、溶接時に母材が溶融して飛び散る現象であるチリ（散り）が発生し、接合不良により接合部が破断する可能性がある。接合部が破断してしまうと、製造ラインが停止することから、製造ラインの稼働率の低下が問題となる。 In the current density i calculated by the equation (1), the four elements of the welding current I, the welding speed V, the electrode wheel load F, and the stacking allowance are variable values, and the other elements are the welding machine 1 and The value is determined in advance according to the specifications of the steel strip 2. That is, in the present embodiment, the welding current I, the welding speed V, and the electrode wheel load F so that the current density i is 0.07 kA / (mpm · mm ² ) or more and 0.10 kA / (mpm · mm ² ) or less. And by determining the stacking allowance, the welding conditions in mash seam welding are determined. If the current density is less than 0.07 kA / (mpm · mm ² ), the nugget 2a is not sufficiently formed, so that an unjoined region is generated and the joined portion may be broken. On the other hand, when the current density exceeds 0.10 kA / (mpm · mm ² ), dust (scattering), which is a phenomenon in which the base metal melts and scatters during welding, may occur and the joint may break due to poor joining. There is. If the joint is broken, the production line is stopped, which causes a problem of a decrease in the operating rate of the production line.

さらに、電極輪接触面積Ｓをより高い精度で求めるためには、（３）式及び（４）式の代わりに、下記（５）式及び（６）式を用いることが好ましい。溶接時において、一対の電極輪１１，１２の接触面は、荷重が掛かることで図４の点線に示すように偏平し、見かけ上の直径が大きくなり、接触面における曲率が小さくなる。（５）式は、荷重負荷後の電極輪１１，１２のこの偏平形状を考慮したものである。（５）式において、Ｄ’は、図４に示すように、荷重負荷後の偏平した電極輪１１，１２の見かけ上の直径であり、（６）式を用いて求められる値である。（６）式において、νは電極輪１１，１２のポアソン比（−）であり、Ｅは電極輪１１，１２のヤング率（Ｎ／ｍｍ^２）、Ｐは電極輪１１，１２に掛かる荷重（Ｎ）をそれぞれ示す。 Further, in order to obtain the electrode ring contact area S with higher accuracy, it is preferable to use the following equations (5) and (6) instead of the equations (3) and (4). At the time of welding, the contact surfaces of the pair of electrode rings 11 and 12 are flattened as shown by the dotted line in FIG. 4 when a load is applied, the apparent diameter becomes large, and the curvature at the contact surfaces becomes small. Equation (5) takes into consideration the flat shape of the electrode rings 11 and 12 after the load is applied. In the equation (5), as shown in FIG. 4, D'is the apparent diameter of the flat electrode rings 11 and 12 after the load is applied, and is a value obtained by using the equation (6). In equation (6), ν is the Poisson's ratio (-) of the electrode rings 11 and 12, E is the Young's modulus (N / mm ² ) of the electrode rings 11 and 12, and P is the load applied to the electrode rings 11 and 12 (. N) are shown respectively.

さらに、本実施形態では、（３）式及び（４）式の替りに、（５）式及び（６）式を用いることで、電極輪接触面積Ｓがより高い精度で求めることができる。そして、（５）式及び（６）式で決定される電極輪接触面積Ｓを用いて、（１）式の溶接時の電流密度ｉが（２）式の範囲となるように、溶接条件を決定することで、より良好な溶接部が得られる。 Further, in the present embodiment, the electrode ring contact area S can be obtained with higher accuracy by using the equations (5) and (6) instead of the equations (3) and (4). Then, using the electrode ring contact area S determined by the equations (5) and (6), the welding conditions are set so that the current density i at the time of welding of the equation (1) is within the range of the equation (2). By making a decision, a better weld can be obtained.

また、溶接条件においては、溶接電流Ｉは１９ｋＡ以上、５１ｋＡ以下とすることが好ましい。溶接電流Ｉが１９ｋＡ未満となる場合、ナゲット２ａが十分に形成されないため、未接合領域が発生し、接合部が破断する可能性がある。一方、溶接電流Ｉが５１ｋＡ超となる場合、溶接時に母材が溶融して飛び散る現象であるチリ（散り）が発生し、接合不良により接合部が破断する可能性がある。さらに、溶接電流Ｉは、３３ｋＡ以上、４１ｋＡ以下とすることが好ましい。このような範囲とすることで、通板に十分な接合部が形成される。溶接速度Ｖは、７．０ｍｐｍ以上９．８ｍｐｍ以下とすることが好ましい。溶接速度Ｖが７．０ｍｐｍ未満となる場合、入熱過大によりチリが発生し、接合部が破断する可能性がある。一方、溶接速度Ｖが９．８ｍｐｍ超となる場合、未接合領域が発生し、接合部が破断する可能性がある。電極輪荷重Ｆは、１５ｋＮ以上、３０ｋＮ以下とすることが好ましい。電極輪荷重Ｆが１５ｋＮ未満となる場合、軽圧下により接合部の段差が過大となり、製造ラインに疵を付ける可能性がある。一方、電極輪荷重Ｆが３０ｋＮ超となる場合、荷重が高すぎるために鋼帯と電極輪との接触面積が過大となり、鋼帯２の幅方向の全域にわたって溶接部の温度が一定とならない可能性がある。重ね代δは、１．２ｍｍ以上、２．３ｍｍ以下とすることが好ましく、例えば、１．６ｍｍ〜３．８ｍｍ程度の長さに設定される。重ね代δが１．２ｍｍ未満となる場合、接合部の長さが短いために強度が低くなり、接合部が破断する可能性がある。一方、重ね代δが２．３ｍｍ超となる場合、入熱不足により未接合が生じる可能性がある。 Further, under the welding conditions, the welding current I is preferably 19 kA or more and 51 kA or less. When the welding current I is less than 19 kA, the nugget 2a is not sufficiently formed, so that an unjoined region is generated and the joint portion may be broken. On the other hand, when the welding current I exceeds 51 kA, dust (scattering), which is a phenomenon in which the base metal melts and scatters during welding, may occur, and the joint portion may break due to poor joining. Further, the welding current I is preferably 33 kA or more and 41 kA or less. With such a range, a sufficient joint portion is formed in the through plate. The welding speed V is preferably 7.0 mpm or more and 9.8 mpm or less. If the welding speed V is less than 7.0 mpm, dust may be generated due to excessive heat input and the joint may be broken. On the other hand, when the welding speed V exceeds 9.8 mpm, an unjoined region is generated and the joined portion may be broken. The electrode ring load F is preferably 15 kN or more and 30 kN or less. When the electrode ring load F is less than 15 kN, the step at the joint becomes excessive due to light pressure, which may cause a flaw in the production line. On the other hand, when the electrode ring load F exceeds 30 kN, the contact area between the steel strip and the electrode ring becomes excessive because the load is too high, and the temperature of the welded portion may not be constant over the entire width direction of the steel strip 2. There is sex. The stacking allowance δ is preferably 1.2 mm or more and 2.3 mm or less, and is set to a length of, for example, about 1.6 mm to 3.8 mm. When the stacking allowance δ is less than 1.2 mm, the strength is low because the length of the joint is short, and the joint may break. On the other hand, when the stacking allowance δ exceeds 2.3 mm, unbonding may occur due to insufficient heat input.

図６には、電流密度ｉを０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）及び０．０１０ｋＡ/（ｍｐｍ・ｍｍ^２）とした場合における、電極輪荷重Ｆと溶接電流Ｉとの関係を示す。なお、図６における、他の溶接条件は、図５の条件と同じとした。また、図６において、電流密度ｉが０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）となる場合の電極輪荷重Ｆと溶接電流Ｉとの関係は、曲線ｌ_１、電流密度ｉが０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）となる場合の電極輪荷重Ｆと溶接電流Ｉとの関係は、曲線ｌ_２でそれぞれ表される。つまり、曲線ｌ_１と曲線ｌ_２とで挟まれた領域に設定することで、適切な条件でマッシュシーム溶接を行うことができる。また、図６の破線で示したハッチング領域に設定することで、鋼帯２の幅方向の全域にわたって溶接部の温度が一定となることから、より安定してマッシュシーム溶接を行うことができる。 FIG. 6 shows the relationship between the electrode ring load F and the welding current I when the current densities i are 0.07 kA / (mpm · mm ² ) and 0.010 kA / (mpm · mm ² ). The other welding conditions in FIG. 6 were the same as those in FIG. Further, in FIG. 6, the relationship between the electrode ring load F and the welding current I when the current density i is 0.07 kA / (mpm · mm ² ) is a curve l ₁ and the current density i is 0.10 kA / (. relationship mpm · mm ²⁾ and the electrode wheel load F when the welding current I is represented respectively by curves _{l 2.} That is, by setting the region sandwiched between the curve l ₁ and the curve l ₂ , mash seam welding can be performed under appropriate conditions. Further, by setting the hatching region shown by the broken line in FIG. 6, the temperature of the welded portion becomes constant over the entire width direction of the steel strip 2, so that mash seam welding can be performed more stably.

以上で、特定の実施形態を参照して本発明を説明したが、これら説明によって発明を限定することを意図するものではない。本発明の説明を参照することにより、当業者には、開示された実施形態とともに種々の変形例を含む本発明の別の実施形態も明らかである。従って、特許請求の範囲に記載された発明の実施形態には、本明細書に記載したこれらの変形例を単独または組み合わせて含む実施形態も網羅すると解すべきである。 Although the present invention has been described above with reference to specific embodiments, it is not intended to limit the invention by these descriptions. By reference to the description of the invention, one of ordinary skill in the art will appreciate other embodiments of the invention that include various modifications as well as the disclosed embodiments. Therefore, it should be understood that the embodiments of the invention described in the claims also include embodiments including these modifications described in the present specification alone or in combination.

＜実施形態の効果＞
（１）本発明の一態様に係るマッシュシーム溶接の溶接方法は、複数の帯状板体（例えば、鋼帯２である先行材２１と後行材２２）を重ね合わせ、複数の帯状板体が重ね合わさる接合部を一対の電極輪１１，１２で圧下させながら、接合部に電流を流すことで溶接する、マッシュシーム溶接の溶接方法であって、それぞれの板厚が２．３ｍｍ以下の複数の帯状板体を溶接する際に、（１）式で算出される電流密度を、０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下とする。なお、上記（１）の構成において、複数の帯状板体は、上記実施形態のように先行材２１と後行材２２との２枚の鋼帯２であることが好ましい。 <Effect of embodiment>
(1) In the welding method of mash seam welding according to one aspect of the present invention, a plurality of strip-shaped plates (for example, a leading member 21 and a trailing member 22 which are steel strips 2) are superposed to form a plurality of strip-shaped plates. This is a mash seam welding welding method in which the overlapping joints are pressed by a pair of electrode rings 11 and 12 and a current is passed through the joints, and each plate thickness is 2.3 mm or less. When welding the strip-shaped plate body, the current density calculated by Eq. (1) is 0.07 kA / (mpm · mm ² ) or more and 0.10 kA / (mpm · mm ² ) or less. In the configuration of the above (1), it is preferable that the plurality of strips are two steel strips 2 of the leading member 21 and the trailing member 22 as in the above embodiment.

上記（１）の構成によれば、電流密度を上記範囲内に制御することで、チリの発生や未接合箇所の発生を抑制することができるようになり、良好な溶接部を得ることができる。これにより、溶接異常や溶接破断といった、品質上または操業上のトラブルを抑止することができる。また、この制御は、多量の実験の結果を必要とせず、溶接に影響を与える多数の溶接条件を決定することができる。これにより、溶接条件を決定する際に係る労力を大幅に低減することができる。 According to the configuration of (1) above, by controlling the current density within the above range, it is possible to suppress the generation of dust and the generation of unjoined portions, and a good welded portion can be obtained. .. As a result, problems in quality or operation such as welding abnormality and welding breakage can be suppressed. Also, this control does not require a large amount of experimental results and can determine a number of welding conditions that affect welding. As a result, the labor involved in determining the welding conditions can be significantly reduced.

（２）上記（１）の構成において、複数の帯状板体の溶接前後の板厚及び物性値（溶接される帯状板体の変形抵抗及び引張強さ）、並びに電極輪１１，１２の直径に基づいて、電流密度が０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下となるように、溶接電流、溶接速度、重ね代及びヘルツ接触領域を決定する。なお、溶接後の板厚は、溶接時の帯状板体の変形抵抗や引張強さにより決定される。
（３）上記（２）の構成において、溶接電流を、３３ｋＡ以上、４１ｋＡ以下とし、ヘルツ接触領域の算出に用いられる、電極輪荷重を１５ｋＮ以上、３０ｋＮ以下とする。
上記（３）の構成によれば、溶接時の接合部の温度を一定にすることができ、より良好に溶接を行うことができる。 (2) In the configuration of (1) above, the plate thickness and physical property values (deformation resistance and tensile strength of the strip-shaped plate to be welded) before and after welding of the plurality of strip-shaped plates, and the diameters of the electrode rings 11 and 12 Based on this, the welding current, welding speed, overlay allowance, and hertz contact region are determined so that the current density is 0.07 kA / (mpm · mm ² ) or more and 0.10 kA / (mpm · mm ² ) or less. The plate thickness after welding is determined by the deformation resistance and tensile strength of the strip-shaped plate during welding.
(3) In the configuration of (2) above, the welding current is 33 kA or more and 41 kA or less, and the electrode wheel load used for calculating the Hertz contact region is 15 kN or more and 30 kN or less.
According to the configuration of (3) above, the temperature of the joint portion at the time of welding can be kept constant, and welding can be performed better.

（４）本発明の一態様に係るマッシュシーム溶接の溶接方法は、複数の帯状板体（例えば、鋼帯２である先行材２１と後行材２２）を重ね合わせ、複数の帯状板体が重ね合わさる接合部を一対の電極輪１１，１２で圧下させながら、接合部に電流を流すことで溶接する、マッシュシーム溶接の溶接方法であって、それぞれの板厚が２．３ｍｍ以下の複数の帯状板体を溶接する際に、（１）式で算出される電流密度を、０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下とする。
上記（４）の構成によれば、上記（１）の構成よりも、電極輪接触面積Ｓをより高い精度で求めることができるため、より良好な溶接部を得ることができる。 (4) In the welding method of mash seam welding according to one aspect of the present invention, a plurality of strip-shaped plates (for example, a leading member 21 and a trailing member 22 which are steel strips 2) are superposed to form a plurality of strip-shaped plates. This is a mash seam welding welding method in which the overlapping joints are pressed by a pair of electrode rings 11 and 12 and a current is passed through the joints, and each plate thickness is 2.3 mm or less. When welding the strip-shaped plate body, the current density calculated by Eq. (1) is 0.07 kA / (mpm · mm ² ) or more and 0.10 kA / (mpm · mm ² ) or less.
According to the configuration of the above (4), the electrode ring contact area S can be obtained with higher accuracy than the configuration of the above (1), so that a better welded portion can be obtained.

（５）上記（４）の構成において、複数の帯状板体の溶接前後の板厚及び物性値、並びに電極輪１１，１２の直径に基づいて、電流密度が０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下となるように、溶接電流、溶接速度及び重ね代を決定する。
（６）上記（５）の構成において、溶接電流を、３３ｋＡ以上、４１ｋＡ以下とする。
上記（６）の構成によれば、上記（３）と同様な効果が得られる。 (5) In the configuration of (4) above, the current density is 0.07 kA / (mpm · mm ²⁾ based on the plate thickness and physical property values of the plurality of strip-shaped plates before and after welding and the diameters of the electrode rings 11 and 12. ) Or more and 0.10 kA / (mpm · mm ² ) or less, determine the welding current, welding speed, and stacking allowance.
(6) In the configuration of (5) above, the welding current is 33 kA or more and 41 kA or less.
According to the configuration of the above (6), the same effect as the above (3) can be obtained.

１溶接機
１１，１２電極輪
２鋼帯
２ａナゲット
２１先行材
２２後行材 1 Welder 11, 12 Electrode ring 2 Steel strip 2a Nugget 21 Leading material 22 Trailing material

Claims

複数の帯状板体を重ね合わせ、前記複数の帯状板体が重ね合わさる接合部を一対の電極輪で圧下させながら、前記接合部に電流を流すことで溶接する、マッシュシーム溶接の溶接方法であって、
それぞれの板厚が２．３ｍｍ以下の前記複数の帯状板体を溶接する際に、（１）式で算出される電流密度を、０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下とする、マッシュシーム溶接の溶接方法。

ｉ：電流密度（ｋＡ/（ｍｐｍ・ｍｍ^２））
Ｉ：溶接電流（ｋＡ）
Ｖ：溶接速度（ｍｐｍ）
Ｓ：電極輪接触面積（ｍｍ^２）
Ｓ_ａ：弧長接触領域の面積（ｍｍ^２）
Ｓ_ｈ：ヘルツ接触領域の面積（ｍｍ^２）
δ：重ね代（ｍｍ）
ｔ_０：溶接前の板厚（ｍｍ）
ｔ_ｗ：溶接後の板厚（ｍｍ）
Ｄ：電極輪の直径（ｍｍ） It is a welding method of mash seam welding in which a plurality of strip-shaped plates are overlapped and a joint portion on which the plurality of strip-shaped plates are overlapped is pressed down by a pair of electrode rings while an electric current is passed through the joint portion. hand,
When welding the plurality of strip-shaped plates having a thickness of 2.3 mm or less, the current density calculated by Eq. (1) is 0.07 kA / (mpm · mm ² ) or more and 0.10 kA / (. Welding method of mash seam welding with mpm ・ mm ² ) or less.

前記複数の帯状板体の溶接前後の板厚及び物性値、並びに前記電極輪の直径に基づいて、前記電流密度が０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下となるように、前記溶接電流、前記溶接速度、前記重ね代及び前記ヘルツ接触領域を決定する、請求項１に記載のマッシュシーム溶接の溶接方法。 Wherein the plurality of strip-shaped plate member welding before and after the thickness and physical properties, as well as based on the diameter of the electrode wheels, the current density is 0.07kA / (mpm · mm ²⁾ or more 0.10kA / (mpm · mm ² ) The welding method for mash seam welding according to claim 1, wherein the welding current, the welding speed, the stacking allowance, and the Hertz contact region are determined as follows.

前記溶接電流を、３３ｋＡ以上、４１ｋＡ以下とし、
前記ヘルツ接触領域の算出に用いられる、電極輪荷重を１５ｋＮ以上、３０ｋＮ以下とする、請求項２に記載のマッシュシーム溶接の溶接方法。 The welding current is set to 33 kA or more and 41 kA or less.
The welding method for mash seam welding according to claim 2, wherein the electrode ring load used for calculating the Hertz contact region is 15 kN or more and 30 kN or less.

ｉ：電流密度（ｋＡ/（ｍｐｍ・ｍｍ^２））
Ｉ：溶接電流（ｋＡ）
Ｖ：溶接速度（ｍｐｍ）
Ｓ：電極輪接触面積（ｍｍ^２）
δ：重ね代（ｍｍ）
ｔ_０：溶接前の板厚（ｍｍ）
ｔ_ｗ：溶接後の板厚（ｍｍ）
Ｄ’：荷重負荷した偏平後の電極輪の見かけの直径（ｍｍ）
Ｄ：電極輪の直径（ｍｍ）
ν：電極輪のポアソン比（−）
Ｅ：電極輪のヤング率（Ｎ／ｍｍ^２）
Ｐ：電極輪の荷重（Ｎ） It is a welding method of mash seam welding in which a plurality of strip-shaped plates are overlapped and a joint portion on which the plurality of strip-shaped plates are overlapped is pressed down by a pair of electrode rings while an electric current is passed through the joint portion. hand,
When welding the plurality of strip-shaped plates having a thickness of 2.3 mm or less, the current density calculated by Eq. (1) is 0.07 kA / (mpm · mm ² ) or more and 0.10 kA / (. Welding method of mash seam welding with mpm ・ mm ² ) or less.

i: Current density (kA / (mpm · mm ² ))
I: Welding current (kA)
V: Welding speed (mpm)
S: Electrode ring contact area (mm ² )
δ: Overlay allowance (mm)
t ₀ : Plate thickness (mm) before welding
t _w : Plate thickness (mm) after welding
D': Apparent diameter (mm) of the electrode ring after flattening under load
D: Diameter of electrode ring (mm)
ν: Poisson's ratio of the electrode ring (-)
E: Young's modulus of the electrode ring (N / mm ² )
P: Load of electrode ring (N)

前記複数の帯状板体の溶接前後の板厚及び物性値、並びに前記電極輪の直径に基づいて、前記電流密度が０．０７ｋＡ/（ｍｐｍ・ｍｍ^２）以上０．１０ｋＡ/（ｍｐｍ・ｍｍ^２）以下となるように、前記溶接電流、前記溶接速度及び前記重ね代を決定する、請求項４に記載のマッシュシーム溶接の溶接方法。 Wherein the plurality of strip-shaped plate member welding before and after the thickness and physical properties, as well as based on the diameter of the electrode wheels, the current density is 0.07kA / (mpm · mm ²⁾ or more 0.10kA / (mpm · mm ² ) The welding method for mash seam welding according to claim 4, wherein the welding current, the welding speed, and the stacking allowance are determined so as to be as follows.

前記溶接電流を、３３ｋＡ以上、４１ｋＡ以下とする、請求項５に記載のマッシュシーム溶接の溶接方法。 The welding method for mash seam welding according to claim 5, wherein the welding current is 33 kA or more and 41 kA or less.