JPH062284B2 - Local cooling prevention method for rough rolled material in continuous hot rolling line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention is directed to a roughing in a continuous hot rolling line in which a trailing edge of a preceding rolled material and a leading edge of a trailing rolled material are sequentially joined and continuously rolled. The present invention relates to a method for preventing local cooling of rolled material.

(B) Conventional technology In recent years, continuous hot rolling has been proposed in order to improve stripability, reduce scrap loss, and improve work efficiency. This continuous hot rolling is a rough rolling mill and a finish rolling mill,
The trailing end of the preceding rolled material and the leading end of the trailing rolled material are joined together by welding or the like, and finish rolling is continuously performed.

In a conventional typical continuous hot rolling line, the rough rolled material rolled by a rough rolling machine (not shown) is not once wound into a coil by a winding machine, but the coil of the rough rolled material is The trailing end portion of the preceding material and the leading end portion of the following material are joined to the joining machine, passed through the looper, and continuously fed to the finish rolling machine.

In such a continuous hot rolling line, when a rolled material is joined by a joining machine, the rolled material is kept stationary for a short time (about 10 seconds). At this time, since the rolled material is stopped while being pinched by the pinch rollers, table rollers, clampers, etc., the rolled material is locally cooled (about 150 to 200 ° C. lower). Due to this local cooling, the dimensional accuracy of the thickness and width of the rolled material and the quality of the rolled material are reduced during finish rolling.

(C) Problems to be Solved by the Invention A problem to be solved by the present invention is that in a continuous hot rolling line, when the rolled materials are joined by a joining machine, local cooling of the rolled material is not caused. It is in.

(D) Means for Solving the Problems The method for preventing local cooling of a rough rolled material of the present invention is an in-line coil between the outlet side of a rough rolling mill and the inlet side of a finish rolling mill in a continuous hot rolling line. A coil to wind the rough rolled material into a coil, at least two cradles are provided on the outlet side of the in-line coiler, and the rough rolled material is applied to the finish rolling machine while rewinding the coil by the cradle. Sending out, a joining machine is provided on the exit side of the cradle to sequentially join the trailing end of the preceding rolled material and the leading end of the trailing rough rolled material, and a looper is provided on the exit side of the joining machine for the rough rolled material. Adjusting the feed amount and separating the pinch roller and the table roller arranged between the joining machine and the looper from the preceding material when the trailing end of the preceding material reaches the joining machine. , The tip of the trailing material Separating the pinch roller and the table roller arranged between the splicer and the cradle when they reach the splicer from the trailing material, and the trailing edge of the preceding material and the trailing material. The above problem is solved by returning the pinch roller and the table roller to their original positions after the completion of joining with the tip portion of the material.

(E) Embodiment An embodiment of the method of the present invention will be described with reference to FIG. In a continuous hot rolling line to which the method of the present invention is applied, a rough rolled material 5 rolled by a rough rolling mill (not shown)
Is coiled around the in-line coiler 1. The coil 2 of the rough rolled material 5 is transferred from the in-line coiler 1 onto the cradle 3 by the transformer 11 or the like, rewound from there and sent to the joining machine 4. In the joining machine 4, the trailing end portion of the preceding material 5a and the leading end portion of the following material 5b are joined and passed through the looper 6 and continuously fed to the finish rolling mill (not shown). In the figure, reference numeral 7 is a pinch
A roller, 8 is a table roller, and 9 is a clamper.
In the illustrated embodiment, the transfer of the coil 2 between the two cradle 3 is also performed by another transfer arm 10 or the like.

Generally, the processing time for finish rolling, winding, etc. is short for a thick rolled product (for example, plate thickness 3.2 mm), while the processing time for a thin rolled product (for example, plate thickness 1.6 mm) is short. Becomes longer. On the other hand, a heating slab is regularly sent from the slab heating furnace to a rough rolling mill at a constant pitch of 1-2 minutes and wound around the inline coiler 1. The storage capacity of the conventional looper 6 is about 20 seconds at maximum.

If there is only one cradle 3, if the treatment time is too long, the rolled material cannot be absorbed by the looper 6, and if the treatment time is too short, the storage capacity of the looper 6 is insufficient and the next material The material passes through before it is sent, making it impossible for the joining machine 4 to join the materials.

Therefore, in the method of the present invention, at least two cradle 3 are provided so that the cradle 3 has a buffer function that is insufficient with the looper 6, and the cradle 3 is combined so that materials under any conditions can be joined.

The present invention, in the rough rolling mill, by reducing the plate thickness as much as possible, reduce the number of stands of the finish rolling mill in the next step,
Aiming at the effect of making a compact rolling mill. When the plate thickness of the rough rolled material becomes thin, the temperature of the material decreases, and there is a risk of lowering the temperature to a required finish rolling temperature or less during finish rolling in the next step (decrease in mechanical properties, defective shape, etc.). After the rough rolling, the coil is quickly wound into a coil, and it is necessary to provide an in-line coiler in order to prevent the coil temperature from lowering due to the heat of the coil itself.

In the method of the present invention, when the rolled materials 5a and 5b are joined, the pinch roller 7 and the table roller 8 are moved to the retracted position as shown by the broken line in the drawing to minimize contact with the rolled material. There is also a feature.

When the trailing end of the preceding material 5a reaches the joining machine 4, the clamper 9 of the joining machine 4 clamps the trailing end, and at the same time, the pinch roller 7 arranged between the joining machine 4 and the looper 6. And the table roller 8 is retracted to the position shown by the broken line.

When reaching the tip end joining machine 4 of the trailing material 5b, the tip end is pinched by the clamper 9 of the joining machine 4 and at the same time,
The pinch roller 7 and the table roller 8 arranged between the joining machine 4 and the cradle 3 are retracted to the position shown by the broken line.

As a result, the following material 5b between the cradle 3 and the joining machine 4 is almost supported by the cradle 3 and the clamper 9. Further, the preceding material 5 a between the joining machine 4 and the looper 6 is almost supported by the clamper 9 and the looper 6.

In order to prevent local cooling by the clamper 9, it is preferable to provide a heat insulating material on the grip surface of the clamper 9.

The rear end of the preceding material 5a and the front end of the following material 5b are joined by the joining machine 4
After being joined by the
The roller 7 and the table roller 8 are returned to the original position shown by the solid line.

As a moving mechanism for the pinch roller 7 and the tail roller 8, a conventional fluid pressure cylinder, a screw feeding mechanism, a link mechanism or the like can be used.

(F) Effects The following effects are obtained when the method of the present invention is compared with the conventional example.

In the conventional method, local cooling of 150 to 200 ° C. occurred, but according to the present invention, it could be reduced to 20 to 30 ° C. As a result, it is possible to improve the dimensional accuracy of the width and thickness of the product and to homogenize the quality.

INDUSTRIAL APPLICABILITY The present invention can reduce the number of stands of the finish rolling mill in the next step and realize a compact mill by producing a coil having a plate thickness as thin as possible in the rough rolling mill.

Even if the plate thickness is thin with a rough rolling mill, the rough rolled material after rough rolling is wound into a coil with an in-line coiler.
The coil temperature does not drop.

Although the simple looper 6 is adopted in order to achieve a compact mill, the looper alone may not be able to cope with the adjustment of the coil digestion amount. By installing two or more cradle units, the mill as a whole can sufficiently cope with the amount of coil digestion.

In addition to the above, since the coils are joined in the thin plate state by the joining machine 4, the joining of the plates can be performed easily and reliably, and the hot rolling can be continuous.

At that time, local cooling of the coil temperature can be prevented for the above reason.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a continuous hot rolling facility for carrying out the method of the present invention. 1: In-line coiler 2: Coil 3: Cradle 4: Joiner 5: Rough rolled material 5a: Leading material 5b: Trailing material 6: Looper 7: Pinch roller 8: Table roller 9: Clamper

Front page continuation (72) Inventor Yoshinori Imai, 3rd light, Oshima, Kashima-machi, Kashima-gun, Ibaraki Sumitomo Metal Industries, Ltd. (72) Masami Oki, 3rd light, Oshima, Kashima-machi, Kashima-gun, Ibaraki Prefecture Industrial Co., Ltd. Kashima Steel Works

Claims (1)

[Claims] 1. In a continuous hot rolling line, an in-line coiler is provided between an exit side of a rough rolling mill and an inlet side of a finishing rolling mill to wind a rough rolled material into a coil. At least two cradles are provided on the output side of the coil, the rough rolled material is sent out to the finish rolling machine while the coil is rewound by the cradle, and a joining machine is provided on the output side of the cradle so that the The end and the tip of the trailing rough rolled material are sequentially joined, a looper is provided on the exit side of the joining machine to adjust the feed amount of the rough rolled material, and the trailing end of the preceding material reaches the joining machine. The pinch roller and the table roller arranged between the joining machine and the looper at a time of being separated from the preceding material, and when the tip of the trailing material reaches the joining machine, the joining machine Placed between the cradle and The pinch roller and the table roller separated from the trailing material, and after the completion of joining the trailing end portion of the preceding material and the leading end portion of the trailing material, A method for preventing local cooling of a rough rolled material by returning to a position.