JPH06315708A - Carrier for steel in hot rolling - Google Patents

Abstract

PURPOSE:To restrain the finish-rolling temperature of the tail end part of a steel strip from lowering by arranging approach tables before a final finish- rolling in multiple steps in a vertical direction. CONSTITUTION:Rack shaped approach tables 2 are provided behind a rough rolling mill 1. Materials are carried by operating elevating tables (f), (f') into or out of the approach tables 2a, 2b, 2c. A heat retaining cover (d) is provided on the upper approach table 2b to be interrupted thermally from the outside air. The material carried into each step is insulated thermally by the mutual radiation heat. The tail end part of the material (a) being finish-rolled, too, is insulated thermally by the radiation heat of the material (b) carried into the approach table 2b. Consequently, the temperature of the tail end can be elevated by 20 deg.C by the temperature on the finished outlet side. Further, the surface dignity is improved by the decrease in load of the finishing mill roll.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rough bar conveying device in the production of steel strip by hot rolling.

[0002]

2. Description of the Related Art In the approach table before finish rolling, the temperature of the entire length and width is kept uniform to secure the finish rolling temperature necessary for metallurgy, and the tail end
It is necessary to prevent the deterioration of the sheet passing property due to the temperature decrease at the plate edge. Conventionally, in an approach table consisting of a large number of transport roller rows installed before the finish rolling process, the sheet bar that has undergone rough rolling is wound into a coil in order to keep the strip total length at a uniform temperature, and A coil box is arranged as a device that suppresses the run-down phenomenon (temperature drop from the plate front end to the tail end) of the finish rolling mill entrance side temperature by completely blocking heat radiation.

Generally, when a coil box is applied, it has a heat retaining effect for the entire length, but when the rough bar is wound, friction between the plates causes scratches and the like on the surface, and it is applied to a strict surface flaw material. In this case, the surface quality of the steel strip was affected.
In addition, for the innermost winding when the rough bar is wound, heat is generated inward, and the time between rough rolling and finish rolling is the longest, and the temperature drop at the tail end during stripping. Has a problem that it becomes significantly large. Further, the coil box does not have a heat-retaining function at the edge portion, and in order to make the widthwise temperature distribution of the plate uniform, it is necessary to separately install a device for locally heating the end portion of the plate. Further, it is difficult to increase the finish rolling pitch by applying the coil box.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems and improves the approach table before the final finishing rolling step to allow a plurality of high temperature semi-finished products (coarse bars) before the finishing rolling step. By stocking them and heating each other with heat, the temperature drop in the plate longitudinal direction (thermal rundown) is minimized, and by shortening the conveyance interval of the finishing front approach table, idle between bars can be reduced. To aim.

[0005]

In order to achieve the above object, the present invention provides a method for manufacturing a steel strip by hot rolling, comprising:
A gist of a steel material conveying device in hot rolling is characterized in that approach tables on the front surface of final finish rolling are arranged in multiple stages in the vertical direction.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 1 is a layout view of a rack-shaped approach table 2 provided between a rough rolling mill 1 and a finish rolling mill (not shown) according to the present invention.
Stages (2a, 2b, 2c) are installed. Elevating tables f and f '(tilting table type), one end of which moves up and down with respect to the center of the line as the base point, are installed on the front and rear sides of the approach table 2. By this operation, the material is approached at each stage. (2a, 2b, 2c) can be selectively loaded or unloaded.
A heat insulating cover d is provided on the upper approach table 2b so as to be thermally shielded from the outside air. FIG. 2 is a view taken along the line AA of FIG.

The roughly rolled material (rough bar) is successively carried into the approach table 2 of each stage by the operation of the lifting table f ', and the materials carried into each stage are kept warm by the radiation heat of each other.
The material a in FIG. 1 is the one during finish rolling,
The tail end of the material a can also be retained by the radiant heat of the material b that has already been carried into the approach table 2b. The material to be carried in next can approach the approach table 2a, that is, the rear of the material a, and if there is the material c already carried in the approach table 2c, the tail ends of the respective materials b, c. Can also be retained by the radiant heat of the entering material a.

In order to carry in from the rough mill to the approach table and to carry out from each stage to the finishing mill, in addition to the means for individually raising and lowering the raising and lowering tables f and f'as shown in FIG. , A fixed table G alternately as shown in (b).
Alternatively, a three-dimensional structure in which an elevating table H that moves in the vertical direction is arranged can be used.

[0009]

By applying the present invention, the tail end temperature can be improved by about 20 ° C. at the finish outlet temperature as compared with the conventional one, and as a result, the reduction of the finish rolling temperature at the tail end can be suppressed. At the same time, the effect of improving the surface quality by reducing the load on the finish rolling mill and reducing the narrowing to the side guides by improving the temperature at the tail end is achieved. On the other hand, by shortening the conveyance interval on the front surface of the finish rolling mill, idle between bars can be reduced and production efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a layout explanatory diagram of a rack-structured table transfer facility.

FIG. 2 is a view on arrow AA of FIG. 1 (a sketch in the rolling direction).

FIG. 3 is a schematic diagram in the case of a vertically elevating table structure.

[Explanation of symbols]

 1 Rough rolling mill 2a, 2b, 2c Approach table a, b, c Material (rough bar) d Heat insulation cover G Fixed table H Lift table

Claims (1)

[Claims] 1. A steel material conveying device in hot rolling, wherein in the production of steel strip by hot rolling, approach tables on the front surface of final finishing rolling are arranged in multiple stages in the vertical direction.