JPH0957451A - Seam welding method for steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seam welding method for a steel sheet in which no tears are generated in a weld zone by adjusting the ratio of the circumferential speed of a rotation type rolling reduction roll to the traveling speed of a frame corresponding to the total value of the preceding steel sheet thickness and the succeeding steel thickness. SOLUTION: When welding electrode rolls 2, 2' are advanced in the sheet width direction and achieve the welding of a lapped part of a preceding steel sheet 3 and a succeeding steel sheet 4, the weld zone is flattened by rolling reduction rolls 1, 1' following the welding. The welding is achieved adjusting the circumferential speed of the rolling reduction rolls 1, 1' through limitation of the traveling speed of frames 5, 5' and the thickness of the lapped part of the steel sheets. The seam welding is achieved so that the ratio of the circumferential speed S of the rotation type rolling reduction roll to the traveling speed R of the frame satisfy the inequalities: S/R>=1.1 when 0.4mm<=(t1 +t2 )<=2.0 mm, and 0.9<=S/R<1.1 when 2.0mm<(t1 +t2 ), where t1 +t2 is the total value of the thickness of the preceding and succeeding steel sheets. Tear of the weld zone by the rolling reduction roll can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lap welding method for steel sheets, and more specifically, it connects a preceding steel sheet and a following steel sheet by welding using a welding machine in a steel sheet processing facility such as a continuous annealing pickling facility. Involved in technology.

[0002]

2. Description of the Related Art In order to treat a steel sheet in a continuous annealing pickling equipment, etc., a leading steel sheet and a trailing steel sheet are superposed and welded into one on the entrance side of the equipment, and continuously passed. Is common. Then, in such equipment, since the surface of the rolling roll placed in the subsequent line is not flawed, the welding electrode roll is run and welded, and then immediately on the lap welding portion (hereinafter, simply referred to as a welding portion). So-called lap seam welding is performed in which a separately provided reduction roll (which is lined up and suspended on the same pedestal as the welding electrode roll) is made to follow and the welding portion is pinched and smoothed ( For example,
(See Japanese Patent Application Laid-Open No. H11-11278). That is, as shown in FIG. 2, the seam welding apparatus is provided with the inlet side clamps 8 and 8'and the outlet side clamps 7 for fixing the rear end of the preceding steel plate 3 and the rear end of the following steel plate 4, respectively. , 7 ', a pair of welding electrode rolls 2 and 2', and reduction rolls 1 and 1 '. The overlap margin of the steel plates is properly clamped by the reduction rolls 1 and 1'after welding. As a result, the surface is smooth and slightly raised, so that the above-described flaws on the surface of the rolling roll can be prevented.

By the way, when rolling down the welding portion 9 with the rolling rolls 1 and 1 ', when the peripheral speed of the rolling rolls 1 and 1'is smaller than the traveling speed of the mounts 5 and 5', the welding portion 9 is formed. It tends to be torn and it becomes difficult to connect steel plates together. This inconvenience is caused when the plate thickness of one of the steel plates 3 and 4 is as thin as 0.2 to 1.0 mm, or when the reduction rolls 1 and 1 ′ are mounted on the welded portion 9 immediately after the reduction roll 1, It tends to occur when the peripheral speed of 1'is unstable. Therefore, conventionally, when the drive devices 6 and 6'for rotation are installed on the reduction rolls 1 and 1'and welding is performed by the welding electrode rolls 2 and 2 ', when the pedestals 5 and 5'run, the vertical reduction is performed. The rolls 1 and 1 ′ are brought into contact with each other so that the peripheral speed of the reduction rolls 1 and 1 ′ is synchronized with the traveling speed of the mounts 5 and 5 ′ (see Japanese Patent Laid-Open No. 11278/1990 mentioned above).

[0004]

However, the method of installing a driving device on the reduction roll to synchronize the rotation peripheral speed of the reduction roll with the traveling speed of the carriage is not effective for stabilizing the rotation peripheral speed of the reduction roll. However, when the plate thickness of the steel sheet was as thin as 0.2 to 1.0 mm, there was still a tendency that cracking of the welded portion occurred.

In view of such circumstances, the present invention has a plate thickness of 0.
It is an object of the present invention to provide a seam welding method for a thin steel plate that does not cause a break in the welded portion even if the steel plate is as thin as 2 to 1.0 mm.

[0006]

Means for Solving the Problems The present invention to achieve the above object is to perform welding in which a trailing end of a preceding steel plate and a leading end of a following steel plate are superposed on a processing line of a steel plate, and that portion travels in the plate width direction. Immediately after welding with an electrode roll, the welded portion is lined up on the same stand as the welding electrode roll, followed by a suspended rotating type rolling roll, and pressed in seam welding of a thin steel plate to clamp and unify the steel plate. A seam welding method for thin steel plates, characterized in that the ratio between the peripheral speed S of the formula rolling roll and the traveling speed R of the gantry is adjusted in accordance with the total thickness of the preceding and following steel plates.

Further, according to the present invention, the seam welding method for a thin steel sheet according to claim 1, wherein the ratio of the peripheral speed S of the rotation type reduction roll to the traveling speed R of the gantry satisfies the following expression. Is preferred. When 0.4 mm ≦ (t ₁ + t ₂ ) ≦ 2.0 mm, (S
/R)≧1.1 2.0 mm <(t ₁ + t ₂ ), 0.9 ≦ (S /
R) <1.1 where (t ₁ + t ₂ ) is the total thickness of the preceding and following steel plates.

According to the present invention, a drive device for rotating the roll is provided on the pressing roll that presses the welded portion, and the peripheral speed of the pressing roll is multiplied by the traveling speed of the gantry by the total value of the plate thicknesses at the front and rear ends. It is set whether or not to rotate, and it is rotated at that peripheral speed to clamp the weld and weld, so that the shearing force does not occur in the weld and the problem that the weld roll is torn off can be prevented. became. The total value of both plate thickness is 0.
In the range of 4 mm or more and 2.0 mm or less, the reduction roll peripheral speed is 1.1 times or more of the gantry traveling speed, and in the range of 2.0 mm or more, 0.9 times or more and less than 1.1 times is suitable. The reason for this is that tearing of the weld does not occur in this region.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIG. 1 shows how a thin steel sheet seam welding method according to the present invention is carried out. FIG. 1 shows a superposed portion 9 of the preceding steel plate 3 and the following steel plate 4, that is, a welded portion 9.
The steel plates 3 and 4 move in a direction perpendicular to the plane of the drawing. Welding electrode rolls 2 and 2'and reduction rolls 1 and 1'which are paired up and down with steel plates 3 and 4, respectively.
Are arranged, but they are lined up and suspended on the same pedestal 5, 5 '. Therefore, the welding electrode roll 2,
When 2'progresses the overlapping portion 9 in the plate width direction and welds it, the pressing rolls 1, 1'compress the welding portion 9 following the welding. In the present invention, this reduction roll 1,
Welding is performed while adjusting the peripheral speed of 1'by limiting the traveling speed of the gantry 5, 5'and the plate thickness of the steel plate overlapping portion 9.

For example, two steel plates 3 having a thickness of 0.2 mm,
When welding No. 4, assuming that the gantry 5, 5'is advanced at a speed of 10 m / min, the total plate thickness value is 0.4 mm. Therefore, the peripheral speed of the reduction rolls 1 and 1 ′ is 1.1 ×
The rolling roll 1, so that the speed is about 10 m / min,
The drive devices 6 and 6 ′ of 1 ′ were adjusted. FIG. 3 shows the result of one implementation of the present invention. In welding stainless steel plates having plate thicknesses of 0.2 mm, welding of a case in which the peripheral speed of the reduction rolls 1 and 1'is equal to the traveling speed of the gantry 5 and 5'and a case of 1.1 times the traveling speed of the gantry. The occurrence rates of partial tears are shown in comparison. At that time, the traveling speed of the gantry is 10 m /
Welding tests are conducted 10 times each under two conditions of min and 15 m / min. As is apparent from FIG. 3, when the peripheral speed of the reduction rolls 1 and 1 ′ is equal to the traveling speed of the gantry 5 and 5 ′, when the traveling speed of the gantry 5 and 5 ′ is 1.1 times, the welded portion is The tear-off rate at 9 was significantly reduced,
The tear-off rate was zero.

[0011]

As described above, according to the present invention, when seam-welding a portion where thin steel sheets are superposed on a line, the circumferential speed of the reduction roll is determined by the total value of the thicknesses of the superposed steel sheets. By doubling the setting, it is possible to prevent tearing of the welded part by the reduction roll.

[Brief description of drawings]

FIG. 1 is a front view of seam welding of a thin steel plate according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a state in which seam welding of a conventional thin steel plate is performed.

FIG. 3 is a diagram comparing a tearing occurrence rate of a welded portion between the method of the present invention and the conventional method.

[Explanation of symbols]

 1 Rolling roll (top) 1 'Rolling roll (bottom) 2 Welding electrode roll (top) 2'Welding electrode roll (bottom) 3 Leading steel plate 4 Trailing steel plate 5 Frame (top) 5' Frame (bottom) 6 Rolling roll Driving device (upper) 6'Driving device for rolling down (lower) 7 Outer side clamp 8 Inlet side clamp 9 Overlapping part (welding part) 10 Frame advancing direction 11 Steel plate advancing direction

Claims (2)

[Claims] 1. A back end of a preceding steel plate and a front end of a following steel plate are superposed on a steel plate processing line, and that portion is welded by a welding electrode roll running in the plate width direction, and then the welded portion is immediately In seam welding of thin steel plates, which are arranged on the same base as the welding electrode rolls and are suspended and rotated by a rotating type reduction roll, which is pressed and clamped, the peripheral speed S of the rotating type reduction roll and the traveling speed R of the base A seam welding method for thin steel sheets, characterized in that the ratio of the above is adjusted according to the total thickness of the preceding and following steel sheets. 2. The seam welding method for a thin steel sheet according to claim 1, wherein the ratio of the peripheral speed S of the rotation type reduction roll and the traveling speed R of the gantry satisfies the following expression. When 0.4 mm ≦ (t ₁ + t ₂ ) ≦ 2.0 mm, (S
/R)≧1.1 2.0 mm <(t ₁ + t ₂ ), 0.9 ≦ (S /
R) <1.1 where (t ₁ + t ₂ ) is the total thickness of the preceding and following steel plates.