JP2526180B2 - In-line mill for continuous processing line and bright finish welding method for tension leveler - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for passing a bright finish welding portion in an in-line mill or tension leveler provided in a continuous heat treatment line or a continuous surface treatment line.

[0002]

2. Description of the Related Art Continuous heat treatment lines such as CAL, EGL,
In a continuous surface treatment line such as CGL, the steel strip can be continuously supplied by performing narrow lap seam welding of the preceding material and the following material on the line entry side.

[0003]

When a dry temper mill and a tension leveler are installed in the above line for in-line dry pressure regulation and adjustment, the narrow lap seam welded portion is It will definitely pass through the tension leveler.

However, in this narrow lap seam welding, the welded portion has a thickness of about 1.2 to 1.8 times the plate thickness, and when passing through the above, first, as shown in FIGS. 8 (a) and 8 (b), this welding is performed. A load is locally applied to the roll R by the portion A and a flaw I is formed on the surface of the roll R, and the flaw of the roll R is further transferred to the surface of the steel strip X other than the welded portion A to generate a touch mark M.

Even if the touch mark M is generated, the touch mark M cannot be seen due to the influence of diffused reflection light on a normal cold-rolled steel sheet because the surface is dull, but a bright finish of tinplate, lomo, zinc plating material, etc. In the case where the bright ground remains due to the material and laser dull finish (hereinafter referred to as the bright finish material), etc., the reflected light is almost regularly reflected,
The touch mark M is easy to see (if unevenness due to the touch mark M is formed on the surface, only that portion is diffusely reflected, and the touch mark M can be clearly confirmed), which impairs its commercial value.

The present invention was conceived in view of the above problems of the prior art. When the narrow lap seam weld portion passes through the dry temper mill and the tension leveler in the above continuous processing line, these rolls are flawed. This prevents the occurrence of touch marks on the bright finish material, and extends the life of these rolls and enables stable operation.

[0007]

Therefore, the method of the present invention comprises:
In a continuous processing line for a bright finish material with a dry temper mill and a tension leveler installed, when the narrow lap seam weld of the bright finish material passes through the temper mill roll, immediately after passing through the temper mill immediately before that , Open the mill roll gap to pass through the welded part, stop the stripping again, close the mill roll gap to restart stripping to the temper mill, and make the strip pass at a low speed when this stripping is restarted. Alternatively, the threading speed is reduced immediately before the weld passes through the tension leveler roll, the intermesh of the tension leveler is lowered to the slip limit immediately before this pass, and then the weld passes through the weld mesh, and then the original thread is passed. The basic feature is that the plate speed and intermesh are restored.

The present inventors carried out a quick open test of the mill or intermesh to prevent touch marks generated in a dry temper mill or a tension leveler. The above-mentioned configuration of the present invention was devised based on the results of the execution. It was done. Therefore, the test results will be described below.

First, the results of a quick open test performed on a dry temper mill will be described. The drive type of the mill is usually a backup roll drive in order to facilitate roll replacement, and as a result, as shown in FIG. 1, the upper backup roll and the upper work roll are stopped in proportion to the speed at which the roll is opened. It took a long time, and in the continuous annealing furnace, there were drawbacks such as a large capacity of the exit side looper.

Next, the results of the quick open test of the intermesh on the tension leveler will be described. If a tension leveler is applied again after performing this quick open, the leveler roll is an idle roll, so roll scratches may occur due to slip.Therefore, for the purpose of preventing this, the steel strip in the strip is stopped and the intermesh is stopped. Therefore, the continuous annealing furnace has a drawback that the outlet looper capacity becomes large as in the above case.

On the other hand, in addition to such a quick open test, the present inventors conducted an experiment to examine how the conditions of the dry temper mill and the tension leveler affect the generation of touch marks. It turned out that: That is, in the dry temper mill, as shown in FIG. 2, touch marks are generated regardless of the load and speed of the mill. Further, in the tension leveler, as shown in FIG. 3, the degree of flaws generated is affected by the intermesh of the tension leveler and the welding portion passing speed.

To summarize the gist of the above-mentioned constitution of the present invention derived from these experimental results, when the weld portion of the bright finish material passes through the dry temper mill, the mill roll is completely released from the finish material and allowed to pass. When the mill roll is re-contacted after passing, it is re-contacted in a state where the plate is stopped to prevent the occurrence of roll scratches, and when the welded portion passes through the tension leveler, the amount of intermesh and the welded portion passing speed are determined. In some cases, even if the finisher is brought into contact with the leveler roll, it is possible to prevent the touch mark from being generated, so that the speed during the passage is reduced and the intermesh is also reduced to the slip limit so that the welded portion is passed. To do so.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the method of the present invention will be described below with reference to the accompanying drawings.

FIG. 4 shows an outline of the equipment for the continuous annealing furnace for TIN. The TIN original sheet X rewound by the payoff reel 100 is subjected to narrow lap seam welding of the preceding material and the following material by the welder 101 on the way. And continuously passed through the inlet looper 102, heating furnace 103, soaking furnace 104, gas jet cooling zone 1
05, 1st overaging treatment furnace 106, 2nd overaging treatment furnace 107, quenching zone 108, air cooling zone 109, exit side looper 110, 2 stand dry temper mill 1, tension leveler 2 etc. Will be wound up on 111.

Among these, when the seam welded portion of the steel plate X passes through the dry temper mill 1 and the tension leveler 2 on the furnace exit side, the welding portion passing method of the present invention is carried out, and the method will be described in detail below. To do.

First, when the above-mentioned welded portion comes to the front of the dry temper mill 1, as shown in FIG. 5, the line speed on the delivery side is reduced, and immediately before the line is stopped, it is placed before and after the mill 1 shown in FIG. 6 (a). The anti-clipping roll ACR12 and the anti-cross brake roll ABR13 are rapidly lowered as shown in the figure (b), and at the same time the push-up cylinder is pushed.
14 is also rapidly lowered (a lower work roll bender is used to further accelerate the lowering speed, and the lower work roll and the backup roll are pushed down by the bender) to open the mill roll gaps of both stands. Anti-clipping roll ACR12 and anti-cross brake roll A above
BR13 is 10 from the normal pass line as shown in Fig. 6 (a).
Although it is at a high level of ~ 20 mm, at the time of quick opening,
By lowering it as shown in (b) of the figure, it will form a pass line so that you do not have to open the mill roll gap too wide. At this time, the mill roll gap is 2 mm above the steel plate X and 3 mm below, which is a total of 5 mm. The dry temper mill 1 is released from the elongation control (AEC) as shown in Fig. 5 by the above quick opening. Instead, the tension bridles 30 and 31 arranged before and after the mill control the tension of the mill. The tension of 1 will be controlled.

With the mill roll gap as described above, the welded part is passed at a low speed to the rear of both stands 10 and 11 of the mill.

After that, the outlet line is stopped again, the anti-clipping roll ACR12 and the anti-cross brake roll ABR13 are rapidly raised to return to the original state of FIG. The push-up cylinder 14 is also rapidly raised to bring the mill's roll gap to zero. However, if the rising speed of the push-up cylinder 14 is too high, a touch mark will be generated due to an impact when the mill roll kisses the steel plate X, so that a gap of 5 mm to 1 mm is generated as shown in FIG. During this period, the push-up cylinder 14 rises at a speed of 2 mm / sec. When this gap becomes 1 mm, the rise speed is reduced to 0.5 mm / sec to soften the impact during roll kissing and prevent touch marks from occurring. I have to.

After the mill roll gap becomes 0,
As shown in FIG. 5, the threading is restarted, but the threading speed at this time does not return to the original threading speed in accordance with the welding portion passing speed in the tension leveler 2 described later,
It should be about 45 mpm which is slower than that.

Next, the welded part is 4
When the plate is passed at a low speed of about 5 mpm, the tension leveler 2
The tension control of the tension leveler 2 is performed by controlling the tension of the tension bridles 31 and 32 arranged before and after the leveler. At the same time, the intermesh of the tension leveler 2, which was previously set to about 5 mm to 10 mm, was lowered to the slip limit of about 1 mm as shown in FIG. As shown in FIG. 3 described above, the welding part passing speed in the tension leveler is
At relatively low levels of 45 mpm and 90 mpm, touch marks will not occur even with bright finish materials such as TIN master plates if the intermesh is set to about 1 mm.

In this way, the welded portion is threaded to the exit side of the tension leveler 2.

Upon completion of this threading, as shown in FIG. 5, the tension control of the tension bridles 31 and 32 is returned to the elongation control of the tension leveler 2 again, and at the same time, the intermesh of the tension leveler 2 is returned to its original state. Restore.
Then, when the welding portion enters the tension reel 111 and winding is completed, the original speed is restored.

As described above, when the narrow lap seam welded portion of the TIN original plate X was passed through the dry temper mill 1 and the tension leveler 2, there was no print of the touch mark due to the passage of the welded portion to these work rolls. Therefore, the touch mark on the TIN original plate X was not confirmed. Further, since the touch marks are not printed on the work rolls, the life of each work roll of the dry temper mill 1 and the tension leveler 2 is extended.

[0024]

According to the welding portion passing method of the present invention described in detail above, when the narrow lap seam welding portion of the bright finish passes through the dry temper mill and the tension leveler, the welding portion is formed on the surface of these work rolls. Since scratches due to pressing do not occur and touch marks are repeatedly printed on the surface of the bright finish material, it is possible to improve product quality, extend work roll life, and enable stable operation. Become.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the speed when a roll is opened in a dry temper mill and the time required to stop the upper work roll and the upper backup roll corresponding to this release.

FIG. 2 is a graph showing a relationship between a passing speed and a load and a touch mark when passing through a welded portion in a dry temper mill.

FIG. 3 is a graph showing a relationship between a passing speed and an intermesh and a touch mark when passing through a welded portion in a tension leveler.

FIG. 4 is an explanatory diagram showing an outline of equipment of a continuous annealing furnace for a TIN original plate to which the method of the present invention is applied.

FIG. 5 is a process explanatory diagram showing an example of plate passing speed, mill roll gap, and intermesh control at the time of passing through a welded portion in a dry temper mill and a tension leveler.

FIG. 6 is an explanatory diagram showing a specific example of mill roll gap control when passing through a weld in a dry temper mill.

FIG. 7 is a graph showing a method of speed control of a push-up cylinder at the time of mill roll gap closing control of a dry temper mill.

FIG. 8 is an explanatory diagram showing a mechanism of touch mark generation when passing through a welded portion.

[Explanation of symbols]

 1 Dry Temper Mill 2 Tension Leveler 10, 11 Mill Stand 12 Anti Clipping Roll 13 Anti Cross Brake Roll 14 Push-up Cylinder X Master

Claims (1)

(57) [Claims] 1. A continuous processing line for a bright finish material, in which a dry temper mill and a tension leveler are installed, and when a narrow lap seam weld portion of the finish material passes through a temper mill roll, a plate is passed through the temper mill immediately before that. After stopping once, open the mill roll gap to pass through the welded portion, stop the sheet passing again, close the mill roll gap and restart sheet passing to the temper mill, and at the time of restarting this sheet passing, Either at low speed or while reducing the strip running speed immediately before the weld passes through the tension leveler roll, the intermesh of the tension leveler is passed through the weld after being lowered to the slip limit immediately before this passage, After that, the original strip speed and the intermesh were restored to the original one. Method for passing welded parts of bright finish materials for online mills and tension levelers.