JP2003053408A - Method for rolling weld zone between metallic materials different in condition of base metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling method of a weld zone between metallic materials different in the conditions of base metal for reducing difference between the set value of thickness and the actual value of thickness in the weld zone and a clip part and reducing tension fluctuation even in the case a preceding metallic material and the succeeding metallic material are welded and the clip is inserted in the tip part of the succeeding metallic material or the preceding metallic material. SOLUTION: In the case the preceding metallic material 1a and the succeeding metallic material 1b which is wider than the preceding metallic material, when rolling a flying thickness changing section 3, the setting of the screw-down location on the basis of the thickness is set by fixing to the width a of the preceding metallic material 1a and also the setting of the screw-down location on the basis of the thickness and quality is set by changing to the thickness and the quality of the succeeding metallic material 1b. When rolling the succeeding metallic material 1b in the section from the terminal point 3b of the flying thickness changing section 3 to the terminal point 2b of the clip 2, the setting of the screw-down location on the basis of the width is set by changing to the width b of the succeeding metallic material 1b and also the setting of the screw-down location on the basis of the thickness and the quality is set by fixing to the thickness and the quality of the succeeding metallic material 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rolling a weld zone of metal materials having different base material conditions.

[0002]

2. Description of the Related Art For example, in cold rolling, a tail end portion of a leading metal material and a tip end portion of a trailing metal material are welded and joined to each other on the entrance side of a rolling mill to form one strip plate. A continuous rolling method is employed in which a metal material is continuously rolled without being caught in each coil and slipping out. By adopting this continuous rolling method, it is possible to improve the rolling efficiency as compared with the case where rolling is performed for each coil, and reduce the plate thickness defect that occurs at the tip of the coil to improve the product yield. it can.

In this continuous rolling method, in the welded portion of the metal material, the difference between the set value of the plate thickness and the actual value of the plate thickness is reduced and the fluctuation of the tension is reduced to stabilize the same without breaking. Rolling is an important point. On the other hand, in JP-A-60-221109, a welding point reaches a gap position of a rolling roll as a method of continuously rolling metal materials having different base material conditions (sheet quality, sheet thickness, and sheet width). Previously, there has been proposed a method of starting the reduction position change so that the welding point passes through the gap position of the rolling roll, preferably at about half the time required to change the reduction position. By this method, even if metal materials with greatly different base material conditions are welded and rolled, it is possible to change the running plate thickness stably, and it is possible to freely select the combination of rolled materials. The effect that management can be simplified can be obtained.

Further, in Japanese Patent Laid-Open No. 3-275206, when rolling a welded portion of a metal material having different base material conditions, a rolling position (a rolling position at which each target plate thickness is obtained with each metal material before and after the welding point ( (Hereinafter referred to as an appropriate reduction position), the appropriate reduction position is on the tightening side of the metal material (hereinafter referred to as the high-pressure reduction position material), the appropriate reduction position S _H , and the appropriate reduction position is the open side. there towards metallic material (hereinafter, a low pressure position material hereinafter) proper pressing position on the side S _L, the rolling mill constant K, the material constants of the high pressure position material M _H, material constants M _L of low pressure position materials, high pressure Allowable thickness deviation Δh of the lower position material in the positive direction
_{From H} , the allowable plate thickness deviation Δh _{L in} the negative direction of the low-pressure position material, and by the roll gap transfer function, the reduction position S _A that achieves Δh _H and S _B that realizes Δh _L are obtained. When the welding point passes through the rolling roll gap position, the rolling reduction position S _C that realizes the breaking limit sheet thickness on the low pressure side material side is obtained by the target sheet thickness, sheet width, target tension, tensile yield stress, etc. of the sheet. Base metal condition for starting to change the rolling position toward the proper rolling position of the metal material before and after the welding point before the welding point passes through the rolling roll gap position so that the rolling position S _R has a predetermined relationship. Various methods of rolling welded parts of different metal materials have been proposed. By this welding part rolling method, even when continuously rolling metal materials having different base material conditions, the difference between the set value of the plate thickness and the actual value of the plate thickness is reduced and the same material is broken at the welded part. It is possible to carry out stable rolling without any increase, and it is possible to reduce the cost by improving the yield and improving the productivity.

[0005]

However, the conventional methods for rolling welded portions of metal materials having different base material conditions have the following problems. That is, the preceding metal material 101
In the case where a and the following metal material 101b are welded,
As shown in FIG. 3, clips 102 may be inserted at both ends in the width direction of the welded portion 101c prior to rolling in order to prevent a threading problem.

This is the same when the preceding metal material Sa and the following metal material Sb having different base material conditions that require the change of the running plate thickness are welded in the welded portion 101c.
As shown in FIG. 4, when the plate width of the trailing metal member 101b increases from the plate width of the preceding metal member 101a, the trailing metal member 101
Clips 10 having different plate widths on both sides in the width direction at the tip of b
2 and the preceding metal material 101a as shown in FIG.
When the plate width of the trailing metal material 101b becomes narrower than the plate width of No. 2, the clips 102 having the plate width difference are inserted at both ends in the width direction at the tail end of the preceding metal material 101a.

Here, in the conventional method, when changing the running plate thickness when the plate width of the trailing metal member 101b increases from the plate width of the preceding metal member 101a shown in FIG. Since the setting of the rolling position based on the plate width on the material 101b side is set on the basis of the plate width of the stationary part where the clip 102 is not inserted, the portion of the trailing metal material 102 in which the clip 102 is inserted ( It was supposed that the reduction position was too closed for the part where the plate width was small). For this reason, the front and rear tensions during the rolling of a portion having a small strip width are reduced, and the sheet thickness of the portion becomes excessively thin, which may cause drawing breakage due to low tension.

Further, when changing the running plate thickness when the plate width of the trailing metal member 101b is narrowed from the plate width of the preceding metal member 101a shown in FIG. 5, the preceding metal member 101a in rolling is also changed.
Since the setting of the rolling-down position based on the plate width on the side is set based on the plate width of the stationary portion where the clip 102 is not inserted, the rolling-down is performed on the portion of the preceding metal material 101a in which the clip 102 is inserted. The position was supposed to be too closed. For this reason, the front and rear tensions during the rolling of a portion having a small strip width are reduced, and the sheet thickness of the portion becomes excessively thin, which may cause drawing breakage due to low tension.

When changing the running plate thickness when the plate width of the preceding metal member 101a shown in FIG. 5 becomes narrower than the plate width of the trailing metal member 101b, the backward tension, the rolling position, and the outlet plate thickness of the rolling mill are changed. The relationship of the deviation (difference between the set value of the plate thickness and the actual value of the plate thickness) will be described in detail with reference to FIG. Note that the preceding metal material 101a and the following metal material 101b are different only in the plate width and have the same plate thickness and plate quality.

First, the preceding metal material 101a and the following metal material 1
The metal band which is welded to 01b advances and the preceding metal material 1
When the starting point 102a of the clip 102 of 01a reaches the stand of the rolling mill (when t ₁ time has passed after the predetermined position in the longitudinal direction of the preceding metal material 101a has passed through the stand of the rolling mill), the width of the strip by the clip 102 is increased. Becomes smaller and the rolling-down position is closed too much accordingly, and the rearward tension decreases (see FIG. 6B). Clip 10
The second end points 102b are located at both ends in the width direction of the welded portion 101c. Next, since the backward tension gradually decreases as the metal band advances, the rolling position is opened as an operation for recovering the tension (see FIG. 6C). After that, when the starting point 103a of the running thickness change section 103 reaches the stand of the rolling mill (when t ₂ time has passed after the predetermined position in the longitudinal direction of the preceding metal material 101a passed through the stand of the rolling mill), Since the plate width of the trailing metal material 101b is narrower than that of the preceding metal material 101a, the reduction position is started so as to further open the reduction position (see FIG. 6C). When controlling the change of the running plate thickness, welding is performed at a time approximately half the time required to change the rolling position (after a lapse of t ₃ hours after the predetermined position in the longitudinal direction of the preceding metal material 101a has passed through the stand of the rolling mill). The reduction position is started to be changed so that the section Sc passes through the stand of the rolling mill. Then, the rolling-down position is opened larger than the original rolling-down change amount, so that the rear tension becomes too large and overtension occurs (see FIG. 6B). Next, when the end point 103b of the running thickness change section 103 passes through the stand of the rolling mill (t ₄ hours have passed since the predetermined position in the longitudinal direction of the preceding metal material 101a passed through the stand of the rolling mill). At the time point), the change of the rolling position is ended, and the operation of closing the rolling position to the original position is started as an operation to recover the overtension (see FIG. 6C). As a result, the rear tension is stabilized, but the exit side plate thickness deviation of the rolling mill becomes large (the plate thickness becomes too thin) due to the closing of the above-mentioned reduction position too much (see FIG. 6 (D)). The deviation of the strip thickness on the delivery side of the rolling mill increases due to the excessive opening of the rolling position (the strip thickness becomes excessive, see FIG. 6D).

As described above, in the conventional method, there is a possibility that large tension fluctuations may occur and not only the breakage due to the low tension but also the breakage due to local overtension. Therefore, the present invention has been made in view of the above-mentioned problems, and an object thereof is to weld a leading metal material and a trailing metal material that is wider or narrower than the leading metal material to obtain a trailing metal material. Alternatively, even if clips with different plate widths are inserted at both ends of the preceding metal material in the width direction, the difference between the set value of the plate thickness and the actual value of the plate thickness should be reduced at the welded part and the clip part. Another object of the present invention is to provide a method for rolling a welded portion of a metal material having different base material conditions, which can reduce the fluctuation of tension and stably roll the material without breaking it.

[0012]

In order to solve the above-mentioned problems, a method for rolling a welded portion of a metal material having different base material conditions according to claim 1 of the present invention is a tail end portion of a preceding metal material and the preceding metal material. The leading end of the trailing metal material wider than the metal material is welded, and the leading edge of the trailing metal material is clipped on both sides in the width direction, and the preceding metal material and the trailing metal material are inserted. When rolling the welded part with a rolling mill with changing the running plate thickness, when rolling the running plate thickness changing section of the preceding metal material and the following metal material, setting the rolling position based on the plate width Is fixed to the plate width of the preceding metal material, and the setting of the rolling position based on the plate thickness and the plate quality is performed from the plate thickness and the plate quality of the preceding metal material to the plate thickness and the plate quality of the following metal material. Set from the end point of the running thickness change section to the end point of the clip. During rolling of the trailing metal material between, the setting of the rolling position based on the sheet width is changed from the sheet width of the preceding metal material to the sheet width of the following metal material, and the sheet thickness and sheet quality are set. The setting of the rolling-down position based on is fixed to the plate thickness and plate quality of the trailing metal material.

According to a second aspect of the present invention, the method for rolling a welded portion of a metal material having different base material conditions includes a tail end portion of a preceding metal material and a trailing metal material having a width narrower than that of the preceding metal material. Weld the tip part, insert the clip of the plate width difference on both sides in the width direction at the tail end of the preceding metal material, and change the running plate thickness at the welded part of the preceding metal material and the trailing metal material. When rolling the preceding metal material in the section from the start point of the clip to the start point of the running plate thickness changing section when rolling with a rolling mill, the rolling position is set based on the strip width to set the preceding metal. While changing and setting from the plate width of the material to the plate width of the following metal material, the setting of the rolling position based on the plate thickness and the plate quality is fixed and set to the plate thickness and the plate quality of the preceding metal material, When rolling the section for changing the running plate thickness of the preceding metal material and the following metal material, based on the plate width The setting of the rolling reduction position is fixedly set to the plate width of the trailing metal material, and the setting of the rolling position based on the plate thickness and plate quality is performed from the plate thickness and plate quality of the preceding metal material to the following metal material. It is characterized in that it is set by changing the plate thickness and plate quality of.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a rolling position, a rear tension, and a delivery plate when changing the running plate thickness when the plate width of the preceding metal material is widened from the plate width of the preceding metal material to which the first embodiment of the present invention is applied. It is a schematic explanatory drawing which shows the relationship of thickness deviation (difference between the set value of board thickness, and the actual value of board thickness).

The tail end portion of the leading metal material 1a shown in FIG. 1A and the trailing metal material 1b having a wider plate width than the leading metal material 1a.
The tip of the, before rolling with a rolling mill (not shown)
Welding is performed by a welding machine (not shown), and then the clips 2 having different plate widths are inserted at both ends in the width direction of the trailing metal material 1b. The starting point 2a of the clip 2 is located at both ends in the width direction of the welded portion 1c, and the ending point 2b is at the trailing metallic material 1.
It is located at both ends of the maximum width of b. In the leading metal material 1a and the trailing metal material 1b in FIG. 1A, for convenience, the plate quality is the same, and the trailing metal material 1b is made slightly thinner than the leading metal material 1a, and the trailing metal plate 1a. The following metal material 1b and the preceding metal material 1a have the same thickness.

The preceding metal material 1a and the following metal material 1b
Metal strips welded to and are progressing and running thickness change section 3
When the starting point 3a of the rolling machine reaches the stand of the rolling mill (when _a time t _a has passed after the predetermined position in the longitudinal direction of the preceding metal material 1a passed through the stand of the rolling mill), as shown in FIG. The change of running plate thickness is started in the rolling mill. When rolling the running distance change section 3 by the rolling mill, the setting of the rolling position based on the sheet width is fixed to the sheet width a of the preceding metal material 1a, and the rolling position based on the sheet thickness and sheet quality is set. From the thickness and quality of the preceding metal material 1a, the following metal material 1b
The sheet thickness and the sheet quality are changed and set, and the sheet rolling position is determined in consideration of both the sheet rolling position based on the set sheet width and the sheet rolling position based on the sheet thickness and the sheet quality. In the case shown in FIG. 1 (B),
Although the plate quality of the trailing metal material 1b is the same as that of the preceding metal material 1a, the rolling position opens from S _A to S _B because the plate thickness is thinner than that of the preceding metal material 1a. At this time, since the setting of the rolling position based on the plate width is fixed to the plate width a of the preceding metal material 1a, the portion of the trailing metal material 1b in which the clip 2 is inserted in the running distance change section 3 (the plate width (A small portion) is appropriate for the reduction position, and the reduction position will not be closed or opened too much. Therefore, the running thickness change section 3
From the time when the starting point 3a of the rolling mill passes the stand of the rolling mill (after the lapse of time t _a ) to the time when the termination point 3b passes through the stand (after the lapse of time t _c ), the reduction position becomes appropriate, and
As shown in (C), the fluctuation of the rear tension also becomes small. As a result, as shown in FIG. 1D, the deviation of the outgoing plate thickness in the running plate thickness changing section 3 is also reduced.

The end point 3b of the running plate thickness changing section 3
Passes through the stand of the rolling mill (after t _c time elapses),
The change of the running plate thickness is completed, but the change of the rolling position is started again. The trailing metal material 1b in the section from the end point 3b of the running plate thickness changing section 3 to the end point 2b of the clip 2
At the time of rolling, the rolling position based on the strip width is changed from the strip width a of the preceding metal material 1a to the strip width b of the trailing metal material 1b, and the rolling position based on the strip thickness and strip quality is set. The setting is fixedly set to the plate thickness and plate quality of the trailing metal material 1b, and the rolling position is determined in consideration of both the rolling position based on the set plate width and the rolling position based on the plate thickness and the plate quality.
In the case shown in FIG. 1B, since the plate width b of the trailing metal material 1b is wider than the plate width a of the preceding metal material 1a, the rolling position closes from S _B to S _c . At this time, the setting of the reduction position based on the plate width is set by changing from the plate width a of the preceding metal material 1a to the plate width b of the following metal material 1b, but the reduction position is the running plate thickness change section. Since the end point 3b of 3 passes through the stand of the rolling mill and the end point 2b of the clip 2 passes through the stand, it linearly closes from S _B to S _c. Clip 2 from the end point 3b of the thickness change section 3
The rolling-down position becomes appropriate for the section up to the end point 2b, and the rolling-down position does not close or open too much. Therefore, from when the end point 3b of the running thickness change section 3 passes through the stand of the rolling mill (after t _c time has elapsed) to when the end point 2b of the clip 2 passes through the stand (t.
Up to (after elapse of _d hours), the fluctuation of the backward tension also becomes small as shown in FIG. As a result, as shown in FIG. 1D, the running plate thickness changing section 3 in which the clip 2 is inserted is provided.
The exit side plate thickness deviation in the section from the end point 3b to the end point 2b of the clip 2 is also small.

[0018] When the end point 2b of the clip 2 is passed through the stand (t _d time after), changing the pressing position is terminated, pressing position is rolling subsequent after row metal material 1b is fixed to the S _c To be done. Also at this time, of course, the fluctuation of the rear tension is small as shown in FIG. 1 (C), and the delivery side plate thickness deviation is also small as shown in FIG. 1 (D). Therefore, according to the rolling method shown in FIG. 1, the leading metal material 1a and the trailing metal material 1b having a width wider than that of the leading metal material 1a are welded to each other at both ends in the width direction at the tip of the trailing metal material 1b. Even when the clip 2 having the plate width difference is inserted in the welded portion 1c and the clip 2
In the above, the difference between the set value of the plate thickness and the actual value of the plate thickness can be reduced and the fluctuation of the tension can be reduced so that the same material can be rolled stably without breaking.

In the example shown in FIG. 1, the leading metal material 1a and the trailing metal material 1b have the same plate quality, and the entry side plate thickness of the trailing metal material 1b is slightly higher than that of the leading metal material 1a. Although the outgoing side plate thickness is the same for the trailing metal member 1b and the preceding metal member 1a, if the plate quality is different or the trailing metal member 1b has the incoming plate thickness as the preceding metal member 1a. It may be thicker in comparison, or may have the same plate thickness. Further, the outgoing side plate thickness is the following metal material 1b and preceding metal material 1a.
However, the trailing metal material 1b may be thinner or thicker than the preceding metal material 1a. This way,
Depending on the plate quality and the plate thickness, the running plate thickness changing section 3 and the end point 3b of the running plate thickness changing section 3 to the end point 2 of the clip 2
A difference occurs in the manner of changing the rolling position in the section up to b. In addition, the rolling positions of the preceding metal material 1a and the following trailing metal material 1b before reaching the running plate thickness changing section 3 also differ.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a diagram showing a rolling position, a rearward tension, when changing the running plate thickness when the plate width of the preceding metal material is narrowed from the plate width of the preceding metal material, to which the second embodiment of the present invention is applied.
It is a schematic explanatory drawing which shows the relationship of a delivery side board thickness deviation. Figure 2
The tail end portion of the preceding metal material 1a shown in (A) and the leading end portion of the following metal material 1b having a narrower plate width than the preceding metal material 1a are welded by a welding machine before being rolled by the rolling machine. After that, clips 2 having a plate width difference are inserted at the tail end of the preceding metal material 1a and on both sides in the width direction. Start point 2 of clip 2
a is located at both ends of the maximum width of the preceding metal material 1a and is located at the end point 2b.
Are located at both widthwise ends of the welded portion 1c. This Figure 2
In the preceding metal material 1a and the following metal material 1b in (A), for convenience, the plate quality is the same and the entry side plate thickness is the following metal material 1
It is assumed that b is slightly thinner than the preceding metal material 1a, and the outgoing plate thickness is the same for the trailing metal material 1b and the preceding metal material 1a.

The preceding metal material 1a and the following metal material 1b
When the metal band obtained by welding and joining advances and the starting point 2a of the clip 2 reaches the stand of the rolling mill (the preceding metal material 1a
2), when t _e has passed since the predetermined position in the longitudinal direction of the rolling mill passed the stand of the rolling mill, as shown in FIG.
The reduction position starts to be changed. When rolling the preceding metal material 1a in the section from the starting point 2a of the clip 2 to the starting point 3a of the running plate thickness changing section 3, the rolling position is set based on the sheet width to set the sheet width of the preceding metal sheet 1a. It is set by changing from a to the plate width b of the trailing metal material 1b, and the setting of the rolling position based on the plate thickness and plate quality is fixed and set to the plate thickness and plate quality of the preceding metal material 1a. The reduction position is determined in consideration of both the reduction position based on the plate width and the reduction position based on the plate thickness and plate quality. In the case shown in FIG. 2B, since the plate width b of the trailing metal material 1b is narrower than the plate width a of the preceding metal material 1a, the rolling position opens from S _D to S _E. At this time, the setting of the rolling position based on the plate width is changed from the plate width a of the preceding metal material 1a to the plate width b of the trailing metal material 1b, but the rolling position is set to the starting point 2a of the clip 2. Is linearly opened from S _D to S _E after passing through the stand of the rolling mill and before the starting point 3a of the running thickness change section 3 passes through the stand.
The rolling position becomes appropriate for the section from the starting point 2a of the clip 2 in which the clip 2 is inserted to the starting point 3a of the running plate thickness changing section 3, and the rolling position will not be closed too much or opened too much. . Therefore, from the time when the starting point 2a of the clip 2 passes the stand of the rolling mill (after elapse of t _e time) to the time when the starting point 3a of the running strip thickness change section 3 passes through the stand (after elapse of t _f time). Up to), the fluctuation of the backward tension also becomes small as shown in FIG. As a result, as shown in FIG. 2D, the deviation of the outgoing plate thickness in the section from the starting point 2a of the clip 2 in which the clip 2 is inserted to the starting point 3a of the running plate thickness changing section 3 is also reduced.

Then, the starting point 3a of the running plate thickness changing section 3
Reaches the stand of the rolling mill (after t _f time has elapsed),
As shown in FIG. 2B, the running plate thickness change is started in the rolling mill. During rolling of the running metal sheet thickness changing section 3 of the preceding metal material 1a and the following metal material 1b, the setting of the rolling position based on the plate width is fixed to the plate width b of the following metal material 1b, and The setting of the rolling position based on the thickness and the plate quality is changed from the plate thickness and plate quality of the preceding metal material 1a to the plate thickness and plate quality of the following metal material 1b, and the rolling position based on the set plate width and The reduction position is determined in consideration of both the reduction position based on the plate thickness and the plate quality. In the case shown in FIG. 2B, the plate quality of the trailing metal material 1b is the same as that of the preceding metal material 1a,
Since the entrance side plate thickness is thinner than the preceding metal material 1a, the rolling position opens from S _E to S _F. At this time, since the setting of the rolling position based on the plate width is fixed to the plate width b of the trailing metal material 1b, the portion of the preceding metal material 1a in which the clip 2 is inserted in the running distance change section 3 (plate width (A small portion) is appropriate for the reduction position, and the reduction position will not be closed or opened too much. Therefore, from the time when the starting point 3a of the running plate thickness changing section 3 passes through the stand of the rolling mill (after elapse of t _f time) to the time when the ending point 3b passes through the stand (t _h
After the elapse of time), the reduction position becomes appropriate, and Fig. 2 (C)
As shown in, the fluctuation of the rearward tension is also small. As a result, as shown in FIG. 2 (D), the deviation of the outgoing plate thickness in the running plate thickness changing section 3 is also reduced.

The end point 3b of the running plate thickness changing section 3
Passes through the stand of the rolling mill (after the time t _h ),
After changing the running plate thickness, the rolling position is fixed at S _F and the succeeding trailing metal material 1b is rolled. At this time, of course,
As shown in FIG. 2 (C), the fluctuation of the rear tension is small, and as shown in FIG. 2 (D), the deviation of the outlet plate thickness is also small.
Therefore, according to the rolling method shown in FIG. 2, the preceding metal material 1a
Even when the following metal material 1b having a width narrower than that of the preceding metal material 1a is welded and the clips 2 having the plate width difference are inserted at both ends in the width direction at the tail end of the preceding metal material 1a, the welding is also performed. Part 1
In c and the clip 2, the difference between the set value of the plate thickness and the actual value of the plate thickness can be reduced and the tension fluctuation can be reduced to stably roll the same material without breaking it.

In the example shown in FIG. 2, the leading metal material 1a and the trailing metal material 1b have the same plate quality, and the trailing metal material 1b has a slightly different inlet plate thickness as compared with the leading metal material 1a. It is assumed that the thickness is thin and the outgoing side metal thickness is the same for the trailing metal material 1b and the leading metal material 1a. However, when the material quality is different or the trailing metal material 1b has a thickness different from the leading metal material 1a. And the plate thickness may be the same. Further, although the trailing metal material 1b and the leading metal material 1a have the same thickness, the trailing metal material 1b may be thinner or thicker than the leading metal material 1a. By doing so, the section from the starting point 2a of the clip 2 to the starting point 3a of the running plate thickness changing section 3 and the reduction position in the running plate thickness changing section 3 are changed according to the plate quality and the plate thickness. There is a difference in the way. Further, there is a difference in the rolling positions of the preceding metal material 1a before reaching the starting point 2a of the clip 2 and the following metal material 1b subsequent thereto.

[0025]

As described above, according to the method of rolling a welded portion of a metal material having different base material conditions according to claim 1 of the present invention, a preceding metal material and a rear metal material wider than the preceding metal material are used. Even when the line metal material is welded and the clip of the plate width difference is inserted at both ends in the width direction at the tip of the trailing metal material, the set value of the plate thickness and the actual value of the plate thickness at the welded part and clip It is possible to perform stable rolling without breaking the same material by reducing the difference between the same and the tension fluctuation.

According to the second aspect of the present invention, the method for rolling a welded portion of a metal material having different base material conditions welds a leading metal material and a trailing metal material having a width narrower than the leading metal material. However, even if clips with a plate width difference are inserted on both sides in the width direction at the tail end of the preceding metal material, the difference between the set value of the plate thickness and the actual value of the plate thickness should be reduced at the welds and clips. In addition, it is possible to reduce the fluctuation of tension and stably roll the material without breaking it.

[Brief description of drawings]

FIG. 1 is a drawing position, rear tension, and exit plate when changing the running plate thickness when the plate width of a preceding metal material is widened from the plate width of a preceding metal material to which the first embodiment of the present invention is applied. It is a schematic explanatory drawing which shows the relationship of thickness deviation.

FIG. 2 is a diagram showing a rolling position, a rear tension, and a delivery side plate when changing the running plate thickness when the plate width of the preceding metal material is narrowed from the plate width of the preceding metal material to which the second embodiment of the present invention is applied. It is a schematic explanatory drawing which shows the relationship of thickness deviation.

FIG. 3 is a schematic plan view showing an example in which clips are inserted at both widthwise ends of a welded portion before rolling.

FIG. 4 is a schematic view of a case in which a preceding metal material and a following metal material having a width wider than the preceding metal material are welded, and a clip having a plate width difference is inserted at both ends in the width direction at the tip of the following metal material. It is a top view.

FIG. 5 is a schematic view of a case in which a preceding metal material and a trailing metal material having a width narrower than the preceding metal material are welded, and clips having a plate width difference are inserted at both tail ends of the preceding metal material in the width direction. It is a top view.

FIG. 6 is a diagram showing the relationship between the backward tension, the rolling position, and the deviation of the outlet plate thickness when changing the running plate thickness when the plate width of the preceding metal material is narrowed from the plate width of the preceding metal material to which the conventional rolling method is applied. It is a schematic explanatory drawing which shows.

[Explanation of symbols]

1a, 101a Leading metal material 1b, 101b trailing metal material 1c, 101c welds 2,102 clips 2a, 102a Clip start point 2b, 102b Clip end point 3,103 Running thickness change section 3a, 103a Starting point of running thickness change section 3b, 103b End point of running thickness change section

Claims (2)

[Claims] 1. A tail end portion of a leading metal material and a leading end portion of a trailing metal material having a width wider than that of the leading metal material are welded to each other so that the leading end of the trailing metal material extends on both sides in the width direction. When inserting the clip of the difference, when rolling the welded portion of the preceding metal material and the trailing metal material with a rolling mill accompanied by changing the running plate thickness, the running plate thickness of the preceding metal material and the following metal material During rolling of the changed section, the setting of the reduction position based on the plate width is fixedly set to the plate width of the preceding metal material, and the setting of the reduction position based on the plate thickness and plate quality is set to the plate thickness of the preceding metal material. And the plate quality is changed to the plate thickness and plate quality of the trailing metal material and set, and the trailing metal material in the section from the end point of the running plate thickness change section to the terminal point of the clip is set. At the time of rolling, the reduction position is set based on the strip width from the strip width of the preceding metal material to the strip width of the following metal material. Welding of metal materials with different base metal conditions, characterized in that the setting of the rolling position based on the plate thickness and plate quality is fixed and set to the plate thickness and plate quality of the following metal material Department rolling method. 2. A tail end portion of a preceding metal material and a leading end portion of a trailing metal material having a width narrower than that of the preceding metal material are welded together to form a plate width on both sides in the width direction at the tail end of the preceding metal material. When inserting a clip of difference, when rolling the welded portion of the preceding metal material and the trailing metal material with a rolling mill accompanied by changing the running plate thickness, from the start point of the clip to the starting point of the running plate thickness changing section During the rolling of the preceding metal material in the section up to, the setting of the reduction position based on the plate width is changed by setting the plate width of the preceding metal material to the plate width of the following metal material, and the plate thickness. And the setting of the rolling position based on the sheet quality is fixedly set to the sheet thickness and sheet quality of the preceding metal material, and when rolling the section for changing the running sheet thickness of the preceding metal sheet and the following metal sheet, The setting of the rolling position based on the width is fixed to the width of the trailing metal material, and the thickness and The setting of the rolling position based on the sheet quality is performed by changing the sheet thickness and sheet quality of the preceding metal sheet to the sheet thickness and sheet quality of the following sheet metal sheet and setting the sheet metal sheet with different base sheet conditions. Welding part rolling method.