JPH10180451A - High-speed non-polishing welding method for electrolytic chromated steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately perform high-speed welding of a non-polished electrolytic chromate-treated steel sheet without causing problems such as dust generation when manufacturing a can body by wire seam welding. 15 electrolytic chromate treated steel sheets
In the method of manufacturing a can body by wire seam welding at a wire feed speed of at least m / min, the wire of the electrode on the inner surface side of the can body has a cross-sectional area of 0.5 to 3.0 mm ² and should be in contact with a steel plate. The outer shape of the portion in the width direction of the welded portion has a linear portion having a length of 1.0 to 4.0 times the thickness of the steel plate, and the wire of the electrode on the outer surface side of the can body is welded to the portion to be brought into contact with the steel plate. The outer shape in the width direction is arc-shaped, and the overlap width W of the steel plate in the welded portion and the length L of the linear portion of the wire of the electrode on the inner surface of the can body satisfy L ≦ W <L + 1.5. It is characterized by.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed non-polishing welding method for manufacturing a can body of a metal container by wire seam welding an electrolytic chromated steel sheet.

[0002]

2. Description of the Related Art When manufacturing a can body of a metal container, the thickness of the can is reduced to 0.
As a method of performing wire seam welding on a thin-plated steel sheet having a thickness of 5 mm or less, a method is known in which a lap width (lap width) of the steel sheet is set wider than a weld bead width (wire width). This method is mainly used in early wire seam welding, in which the inner and outer surfaces of the can body are welded with wires of the same shape. The reason why the lap width of the steel sheet was set wider than the weld bead width by this method was that at the time, the control technology of the weld bead position and the wrap width of the steel sheet was not sufficiently established,
This is because the wrap width could not be reduced.
However, in this method, if the lap width is too large than the weld bead width, the non-welded edges of both edges of the thin plate bend around the welded portion, causing poor repair of the welded portion and deterioration of the corrosion resistance of the can body.

[0003] Further, since the welding conditions could not be stabilized, usable steel sheets have metallic tin on the surface layer,
Tinplate, which had small electric resistance (contact resistance) and was advantageous for fluctuation of welding current, was mainly used. In addition, electrolytic chromate-treated steel sheets such as tin-free steel (TFS) with high contact resistance
When welding at a wire feed speed of m / min or more, remove the insulating film (chromium metal layer and chromium hydrated oxide layer) at the welded part by welding or other method before welding to reduce the contact resistance. Was needed. Further, since a material having a small contact resistance, which is advantageous for the fluctuation of the welding current, is to be welded, if the contact area between the wire and the steel plate is large, a problem arises that the welding current required for proper heat generation becomes too large. In order to avoid such a problem, a wire having an arcuate outer shape in a weld width direction of a portion to be contacted with the steel plate has been used so that the contact area between the wire and the steel plate can be stably and relatively small.

[0004] In contrast to such a conventional wire seam welding method (wide lap welding), a wire seam welding method for a can body, which is currently the mainstream, is a narrow width lap welding as shown in Japanese Patent Publication No. 54-213213. is there. This is a welding method in which the lap width of a steel sheet is reduced to less than half of the welding bead width, and the progress of lap management technology has made such a welding method possible. The advantage of this wire seam welding method is that since the lap width of the steel sheet is smaller than the weld bead width, it is welded including the edges of both edges of the thin plate, so there is no fear of poor repair of the welded part and deterioration of the corrosion resistance of the can body That is the point.
In addition, since the current is effectively concentrated on the plate / plate interface, appropriate heat generation can be obtained with a small current even with a material having a small contact resistance.

[0005] In recent years, regulations on contamination of containers with foreign substances have become strict, and it has become necessary to clean the welding environment. For this reason, there is a growing need to weld an electrolytic chromate-treated steel plate such as TFS, which has been conventionally polished and welded immediately before welding, without welding, and at a high speed in terms of workability.

[0006]

However, when an electrolytic chromate-treated steel plate such as TFS having a high contact resistance is welded at high speed without polishing by narrow lap welding as described above, it is immediately called dust at the plate / plate interface. There is a problem that welding defects occur. In other words, in this welding method, the entire lap portion including the edge portion of the steel plate is welded because the wrap width of the steel plate is small, and the weld portion is mashed with high pressure,
When excessive heat is generated, dust is immediately generated. For this reason, the conventional narrow width lap welding is not suitable for non-polishing high-speed welding of a material having a high contact resistance such as an electrolytic chromated steel sheet.

On the other hand, when the electrolytic chromate-treated steel sheet is welded at high speed without polishing by the conventional wide-width lap welding as described above, under the current conditions that can ensure appropriate heat generation at the plate / plate interface, dust is generated at the wire / plate interface. There is a problem that occurs. This is because in narrow lap welding, the current density at the wire / plate interface is smaller than that at the wire / plate interface, so that the current density at the wire / plate interface can be reduced and heat generation can be suppressed. This is because the current density at the wire / plate interface is increased due to the larger energization area at the plate / plate interface, and excessive heat is generated.

Further, in the wire seam welding method, it is difficult to improve the cooling capacity of the wire / plate interface on the inner surface of the can body due to structural restrictions of the welding machine. Therefore, there is a problem that foreign matter is mixed into the can and a weldable current range cannot be secured due to the generation of dust. As described above, with the conventional wire seam welding method, it was practically difficult to manufacture a can body by performing non-polishing high-speed welding on an electrolytic chromate-treated steel sheet. Therefore, an object of the present invention is to provide a wire seam welding method capable of appropriately performing high-speed welding of a non-polished electrolytic chromate-treated steel sheet without causing a problem such as generation of dust when manufacturing a can body of a metal container by wire seam welding. To provide.

[0009]

In order to solve such problems, the wire seam welding method of the present invention has the following features. (1) In a method of manufacturing a can body by wire seam welding a non-polished electrolytic chromate-treated steel sheet at a wire feed speed of 15 m / min or more, the electrode wire used on the inner side of the can body is perpendicular to its longitudinal direction. The cross-sectional area is 0.
5 to 3.0 mm ² , wherein the outer shape in the width direction of the welded portion of a portion to be brought into contact with the electrolytically chromated steel sheet to be welded has a length of 1.0 to 4.0 times the thickness of the electrolytically chromated steel sheet to be welded. The wire of the electrode used on the outer surface side of the can body has an arc-shaped outer shape in the width direction of the welded portion at a portion to be brought into contact with the steel plate to be subjected to electrolytic chromate treatment. Overlap width W (m
m) satisfies L ≦ W <L + 1.5 in relation to the length L (mm) of the linear portion of the electrode wire used on the inner surface side of the can body. High-speed non-polishing welding method.

(2) In the welding method of the above (1), the wire of the electrode used on the inner surface side of the can body is attached to both ends of the linear portion in the width direction of the welded portion of the portion to be brought into contact with the electrolytically chromated steel sheet to be welded. A high-speed non-polishing welding method for an electrolytic chromate-treated steel sheet, comprising an arc-shaped portion having a radius of curvature R of 0.1 mm or more.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the optimum width of lapping (lap width) of steel sheets for suppressing the generation of dust at the plate / plate interface during non-polishing high-speed welding of electrolytic chromated steel sheets is studied. As a result, in order to avoid the generation of dust by avoiding the mash at the plate / plate interface, the overlap width of the steel plate is set to the contact width of the wire / plate interface in the weld width direction in relation to the wire used on the inner surface of the can body. Equal or better. However, if the overlap width of the steel sheet is 1.5 mm or more wider than the contact width of the wire / plate interface, a problem of warpage of the steel sheet edge portion occurs, so that repair of the welded portion becomes difficult.
For this reason, it is not preferable to make the overlapping width of the steel sheets 1.5 mm or more larger than the contact width of the wire / plate interface. here,
When the overlap width of the steel plate is equal to or larger than the contact width of the wire / plate interface in the weld width direction as described above, it is difficult to reduce the amount of electricity at the wire / plate interface,
In particular, excessive heat generation at the wire / plate interface on the inner surface side of the can body poses a problem.

Therefore, as a result of a study for optimizing the wire shape in order to reduce the current density at the wire / plate interface, excessive current generation was suppressed by reducing the current density at the wire / plate interface on the inner surface side of the can body. In order to achieve this, a wire having a linear portion in the width direction of the welded portion of the portion to be brought into contact with the steel plate on the inner surface side of the can body, that is, a wire in which the contact portion with the steel plate in the width direction of the welded portion becomes linear Was found to be effective. On the other hand, the use of a wire having the above-described linear portion on the outer surface of the can body has a problem in that the discoloration range due to welding is increased and the appearance of the welded portion is impaired. It is preferable to use a conventionally used wire having an arc shape (convex arc shape) in a width direction of a welded portion of a portion to be brought into contact with a steel plate, so that welding can be performed without impairing the appearance of the welded portion.

The use of the above-mentioned arcuate wire on the outer surface of the can body increases the current density at the wire / plate interface on the outer surface of the can body. Along with using a wire with a shape with
According to the conventional method, the effect of improving the balance of heat generation on the inner and outer surfaces of the can, which tends to cause the heat generation center to be biased toward the inner surface of the can, can also be obtained. Furthermore, when using a wire having a linear portion in the width direction of the welded portion on both the inner surface of the can body and the outer surface of the can body, the steel plate and the wire do not uniformly hit unless the positions of the electrodes and the like are strictly adjusted. This may cause cracking during can molding. On the other hand, by using a combination of a wire having a linear portion and a wire having an outer shape in the welded portion width direction on the inner and outer surfaces of the can body in combination with the arc-shaped wire, the above-described non-uniform contact of the wire is also prevented. Can be.

When a high contact resistance material having a chromium hydrated oxide layer such as an electrolytic chromated steel sheet is subjected to wire seam welding, the length L of the linear portion in the width direction of the welded portion of the wire used on the inner surface side of the can body is determined. If the thickness is less than 1.0 times the thickness of the steel sheet, the width of the formed nugget is narrow, and the welding strength required for an actual can cannot be sufficiently obtained. On the other hand, if the length L of the linear portion exceeds 4.0 times the thickness of the steel sheet, the effect of expanding the nugget width is not only saturated, but also the pressing force and current required for welding become unnecessarily large. Not preferred.

Therefore, in the welding method of the present invention, the outer shape of the electrode wire used on the inner surface side of the can body in the width direction of the welded portion of the portion to be brought into contact with the steel plate to be subjected to electrolytic chromate treatment is the plate of the steel plate to be subjected to electrolytic chromate treatment. 1.0 ~ of thickness
On the condition that it has a linear portion having a length of 4.0 times, the overlap width W (mm) of the electrolytically chromated steel sheet to be welded at the welded portion is determined by the straight line of the electrode wire used on the inner surface side of the can body. The condition is that L ≦ W <L + 1.5 is satisfied in relation to the length L (mm) of the shape portion. Also, regarding the wire of the electrode used on the outer surface side of the can body, the outer shape in the width direction of the welded portion at the portion to be brought into contact with the electrolytically chromated steel plate to be welded is assumed to be an arc shape (convex arc shape) such as an arc shape. .

FIG. 1 shows an example of a welding situation according to the method of the present invention in a state where a welded portion is cross-sectionally shown.
Is a wire of an electrode (upper electrode wheel) on the inner surface side of the can body, and 2 is a wire of an electrode (lower electrode wheel) on the outer surface side of the can body.
The outer shape of the portion in contact with the steel plate in the width direction of the welded portion has a linear portion 3. On the other hand, the outer shape of the portion of the wire 2 that should come into contact with the steel plate in the weld width direction is arc-shaped. For comparison, FIG. 3 shows a welding situation (cross section of a welded portion) according to the conventional method. In FIG. 3, 5 is a wire of an electrode (upper electrode wheel) on the inner surface side of the can body, and 6 is a wire of an electrode (lower electrode wheel) on the outer surface side of the can body. Are all arcuate in the weld width direction.

It is preferable that arc-shaped portions (convex portions) such as arcs are formed at both ends of the linear portion in the width direction of the welded portion of the wire on the inner surface of the can body. FIG. 2 shows an example of a welding situation according to the method of the present invention using a wire having such an arc-shaped portion in a state where a welded portion is cross-sectionally shown.
Reference numeral 4 denotes arc-shaped portions formed at both ends of the linear portion 3 of the wire 1. If such an arc-shaped portion 4 is not provided in the wire 1, if the vertical axes of the upper and lower electrode rings are displaced, the end of the weld bead is flawed, and the flaw is formed when the flange is formed after welding. There is a risk of cracking from the part. In particular, when the electrolytically chromated steel sheet to be welded is a thin material having a thickness of 0.5 mm or less, such cracks are likely to occur. Therefore, it is preferable to form the arc-shaped portions 4 at both ends of the linear portion 3.
Further, it is preferable that the radius of curvature R of the arc-shaped portion is 0.1 mm or more in order to obtain the above-described effect.

The cross-sectional area of the wire used on the inner surface side of the can body (cross-sectional area in a cross section perpendicular to the longitudinal direction of the wire) is 0.5 to
3.0 mm ² . The cross-sectional area of this wire is 0.5 mm ²
If it is less than 1, the heat capacity is small and the wire / plate interface cannot be sufficiently cooled. On the other hand, the cross-sectional area of the wire is 3.0
If the thickness exceeds mm ² , the cooling effect from the viewpoint of heat conduction is not only saturated, but also an expensive copper wire is unnecessarily used, which impairs economic efficiency. The wire is preferably composed mainly of copper from the viewpoint of heat conduction.

In the present invention, the cross-sectional shape of the wire used for the electrode on the inner surface of the can body is arbitrary as long as the above conditions are satisfied. For example, the cross-sectional shape as shown in FIG. (A cross-sectional shape perpendicular to the cross-section). Among these, (a) and (b) are modified examples of the wire cross-sectional shape shown in FIG. 1, and (c) and (d) are modified examples of the wire cross-sectional shape shown in FIG. In carrying out the wire seam welding method of the present invention, considering that tinplate welding and electrolytic chromate-treated steel plate polishing welding are also performed using the same welding machine from the viewpoint of operability, the can body inner surface side electrode A plurality of separate wire forming rolls are arranged immediately before the can body outer surface side electrode and the wire can be appropriately switched, or a forming roll having a plurality of grooves can be formed by a can body inner side electrode and a can body outer surface. It is desirable to arrange them immediately before the side electrodes.

[0020]

EXAMPLE A steel body was subjected to wire seam welding using an electrolytic chromate-treated steel sheet shown in Table 5 as a raw material and using a Fuji welder type welding machine having a large overlapped steel sheet width compared to the welding wire width. In this embodiment, the welding speed is 4 to 10 m / min.
100 continuous cans were made and the current range (AC
The presence or absence of R) and the corrosion resistance of the obtained can body were evaluated. In addition,
In the evaluation of the cans, all the cans in which the current was unstable (the can bodies made first and last when the can bodies were continuously made) were excluded from the evaluation.

The wire of each electrode was provided with a plurality of grooves on a wire forming roll immediately before the wire was supplied to the electrode so as to have a desired sectional shape. FIG. 5 shows a cross-sectional shape (a cross-sectional shape at a cross-section perpendicular to the longitudinal direction of the wire) of the wire used in this example. Of these, A is a wire having a sectional shape used in the conventional method, and B and C are
Is a wire having a sectional shape used in the method of the present invention. In the example of the present invention, these wires A to C were used in a combination as shown in FIGS. The ACR is a current range between the lower limit of the current where the appropriate welding strength cannot be obtained and the upper limit of the current that causes excessive heat generation. The lower limit current is evaluated by a tear test and the upper limit current is evaluated based on the presence or absence of splash or dust. Was evaluated. ○: Sufficient weldable current range is available △: Weldable current range is available but narrow ×: No weldable current range

The corrosion resistance is determined by filling a water-soluble content into a container manufactured based on each can body except for the can at all times at room temperature.
The rusting state of the weld repaired part after storage for months was evaluated by the following. ：: no rusting ×: rusting occurred Note that in Examples where there was no weldable current range, the corrosion resistance could not be evaluated because substantial canning could not be performed. The results of evaluating the ACR and the corrosion resistance are shown in Tables 1 to 4 together with the type of the material steel sheet and the welding conditions.

As shown in Tables 1 to 4, all of the examples of the present invention have a sufficient welding current range, and the manufactured can bodies have excellent corrosion resistance. On the other hand, Comparative Example 4 and Comparative Example 6 in which a wire (wire A) whose outer shape in the width direction of the welded portion of the portion to be brought into contact with the steel plate was used for both electrodes on the inner surface side of the can body and the outer surface side of the can body. In Comparative Example 12, since excessive heat generation occurs at the wire / plate interface on the inner surface side of the can body, ACR was not properly obtained. In Comparative Examples 1 to 3, a wire having an outer shape in a width direction of a welded portion of a portion to be brought into contact with a steel plate as a wire of an electrode on an inner surface side of a can body was used, and an electrode on an outer surface side of the can body was used. As the wire, a wire having an arcuate outer shape in a weld width direction of a portion to be in contact with a steel sheet is used, but the effect of the present invention is sufficiently obtained because other conditions do not satisfy the scope of the present invention. Not been.

In Comparative Example 2, the length L (mm) of the linear portion of the wire on the inner surface side of the can body and the overlap width W (mm) of the steel plate were used.
Is W> L + 1.5, the edge of the steel plate at the welded portion rises up, causing a problem in the sealability of the welded portion, resulting in poor corrosion resistance. In Comparative Examples 1 and 3, since the cross-sectional area of the wire on the inner surface side of the can body is less than 0.5 mm ² , the cooling capacity of the wire / plate interface is insufficient, and dust is generated. Therefore, an appropriate ACR has not been obtained. Further, in Comparative Example 3, since the length L of the linear portion of the wire on the inner surface side of the can body is less than 1.0 times the thickness of the steel plate, sufficient welding strength required as an actual can cannot be obtained. Further, in Comparative Example 3, the relationship between the length L (mm) of the linear portion of the wire on the inner surface of the can body and the overlap width W (mm) of the steel plate is W> L + 1.5, which is outside the range of the present invention. .

In Comparative Example 5, as the electrode wire on the inner surface of the can body, a wire having an arcuate outer shape in the width direction of the welded portion at the portion to be brought into contact with the steel plate was used. This is an example in which a wire having a straight portion is used in the welded portion in the width direction of the portion to be contacted. In this comparative example, the tendency of excessive heat generation on the inner surface side of the can is promoted.
Is not obtained properly. Note that the conventional example is an example in which wire seam welding is performed at a low welding speed of 15 m / min or less. If the welding speed is low as described above, it is possible to perform the non-polishing welding of the electrolytic chromate-treated steel sheet by the conventional technology. Is shown.

[0026]

[Table 1]

[0027]

[Table 2]

[0028]

[Table 3]

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

As described above, according to the present invention, when producing a can body of a metal container by wire seam welding using an electrolytic chromate-treated steel sheet as a raw material, non-polishing electrolysis is performed without causing problems such as generation of dust. Chromate treated steel plate can be appropriately welded at high speed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a welding situation according to the method of the present invention in a state where a welded portion is cross-sectionally shown.

FIG. 2 is an explanatory view showing another example of a welding situation according to the method of the present invention in a state in which a welded portion is sectioned.

FIG. 3 is an explanatory view showing a welding state according to a conventional method in a state where a welded portion is sectioned.

FIG. 4 is an explanatory view showing an example of a cross-sectional shape of a wire used on the inner surface side of a can body in the method of the present invention.

FIG. 5 is an explanatory diagram showing a cross-sectional shape of a wire used in an example.

[Explanation of symbols]

 1, 2, wire, 3 linear part, 4 arc part

Continuing from the front page (72) Inventor Naoyuki Oba 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Toyofumi Watanabe 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Stock In company

Claims (2)

[Claims] 1. An unpolished electrolytic chromate treated steel sheet
In a method of manufacturing a can body by wire seam welding at a wire feed speed of at least m / min, a cross-sectional area of a wire of an electrode used on the inner surface side of the can body in a cross section perpendicular to the longitudinal direction is 0.5 to 3 mm. a .0mm ^2,
The outer shape of the portion to be brought into contact with the electrolytically chromate-treated steel sheet to be welded has a linear portion having a length of 1.0 to 4.0 times the thickness of the electrolytically chromated steel sheet to be welded, The wire of the electrode used on the outer surface side has an arc-shaped outer shape in a welded portion width direction at a portion to be brought into contact with the electrolytically chromated steel sheet to be welded, and the overlap width W (mm) of the electrolytically chromated steel sheet at the welded portion is High-speed non-polishing welding of an electrolytic chromate-treated steel sheet, wherein a relation of L ≦ W <L + 1.5 is satisfied in relation to a length L (mm) of the linear portion of an electrode wire used on the inner surface side of the can body. Method. 2. A wire of an electrode used on the inner surface side of the can body has a radius of curvature R of 0.2 at both ends of a linear portion in a width direction of a welded portion of a portion to be brought into contact with the electrolytically chromated steel sheet to be welded.
2. The method according to claim 1, wherein the arc-shaped portion has a length of 1 mm or more.
2. A high-speed non-polishing welding method for an electrolytic chromate-treated steel sheet according to item 1.