JPH0360801A - Edging press method for hot slab - Google Patents

Abstract

PURPOSE:To prolong the service life of a press die without causing any heat cracking, etc., by reversing a die according to the temp. rise of a press die and changing the rolling reduction part thereof. CONSTITUTION:A press die 2 having pressing faces 2a, 2b inclined toward both end parts and a flat pressing face 2c connected thereto is prepared. An edging press thereby is executed and the rolling reduction part of the press die 2 is changed by its reversing at the time when the temp. especially at the rolling reduction part of the press die 2 rises to an expected target temp. Name ly the damaged part of the rolling reduction part at one side can be made extremely small even in the case of the edging by the same press die 2 being continued by alternately replacing the work face 2a and 2b of the press die 2. Consequently the service life of the press die 2 can remarkably be prolonged.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a hot strip width that is advantageous for synchronizing with a hot strip mill line to save energy and shorten the process. Regarding the reduction press method, the present invention aims to further extend the life of the press mold used in the width reduction press.

(Prior art) Regarding a width reduction press that reduces the width of a hot slab over its entire length by moving a pair of press dies that sandwich the conveyance path line of a hot slab on the left and right sides toward and away from each other, there is, for example, a method disclosed in Japanese Patent Application Laid-Open No. A technique as seen in Japanese Patent No. 63-140711 is known.

However, although such technology is advantageous in extending the life of press dies, it is necessary to prepare multiple press dies, and it is necessary to install incidental equipment to cool the press dies. Therefore, the device is complicated and the equipment cost is high. However, in the conventional width reduction press that uses a single press mold (see Japanese Patent Application Laid-Open No. 101201/1983), its lifespan is extremely short due to the heat crank caused by the rise in temperature of the press mold, and the press processing is difficult. In order to guarantee the quality of subsequent slabs, it is necessary to prepare a large number of molds, which not only has the disadvantage of increasing the mold consumption rate, but also requires frequent replacement, which reduces the operation rate of the mill line. This could be a cause of a decline.

(Problems to be Solved by the Invention) Even when performing a width reduction press using a set of press dies that sandwich the conveyance path line of a hot slab on the left and right sides, the press does not cause heat cracks or the like. It is an object of the present invention to propose a width reduction pressing method that can further extend the life of a mold.

(Means for Solving the Problems) This invention provides a means for moving a core hot slab during the conveyance process in the width direction over its entire length by moving a pair of press dies that sandwich the conveyance path line of the hot slab to the left and right to approach and separate them from each other. For rolling down the hot slab, a press die is used that has press working surfaces that are inclined towards both ends of the hot slab entry and exit sides, and a flat press working surface that connects to these in the central area. This is a method for width reduction pressing of hot slabs, which is characterized in that a pair of dies is prepared, and each of the press dies is appropriately inverted according to the temperature rise of the cough die due to width reduction pressing.

Now, FIG. 1 shows a width reduction press mold for a hot slab suitable for use in the present invention.
are a pair of press molds that sandwich the conveyance path line p of the hot slab 1 on the left and right sides, and the press molds 2 have pressing surfaces that are inclined toward the entrance and exit ends of the hot slab 1. 2a, 2b and a flat press working surface 2c connected to these in the central region, and the hot slab 1 can be reduced in the width direction by moving the press molds 2 toward and away from each other. . Further, as shown in FIGS. 2(a) and 2(b), this press mold 2 fits into a groove 38 formed in the inner block 3 and is attached to a rotary arm 5 having a rotary drive device 4 on its back surface. The press die, which is fixed and held fixed on the rotary arm 5 by the operation of the rotation drive device 4, is reversed every 180° to rotate the pressed part of the press die 2 (
(shaded area in the figure) can be changed as appropriate, and when there is a risk that the press die 2 will become hot due to the increase in processing amount during width reduction of the hot slab 1, and heat cracks may occur. The mold 2 is appropriately inverted and the width reduction press is continued.

(Function) As shown in Figure 3, normally used press dies have one rolling area (see the shaded area in Figure 3) that is used for width reduction of hot slabs. During long-time width reduction pressing using a die, the area becomes hot, and the occurrence of heat cracks is unavoidable, especially in machines equipped with two sets of press dies, making it difficult to improve the quality of the slab after width reduction pressing. In order to compensate, the damaged parts of the press mold had to be repaired by cutting or the like, or if the damage was particularly severe, it had to be replaced. In this invention, a press mold 2 has press working surfaces 2a and 2b that are inclined toward both ends (the angles formed with the flat press working surfaces are the same) and a flat press working surface 2C connected thereto. A width reduction press is performed using this, and when the temperature of the press mold 2, especially at the reduction part, rises to the desired target temperature, it is reversed as shown in Fig. 4 (a) and (b). Since the rolling part of the press die 2 was changed, that is, the machined surfaces 2a and 2b of the press die 1 were alternately exchanged, so that width reduction using the same press die 2 was continued. Even in this case, the damaged part of the rolled part on one side can be made extremely small, and there is no need for complicated equipment in which a plurality of molds 2 are provided above and below the molds and the molds are cooled alternately.

(Example) Size 220 mm x 1300 mm x 10800 mm
During the transportation process of the hot slab where the extraction temperature was 1200°C, the slab was subjected to a width reduction press with a width reduction of 1300 ITun.

As a result, in the case of a normal width reduction press in which the press die is not inverted, heat cracks, which pose a quality problem, occur at the reduction part of the die after 1,000 slabs are kneaded, but this invention If width reduction press is performed according to
There were no defects such as heat cracks, which would cause quality problems, compared to about 1,000 pieces.

(Effects of the Invention) Thus, according to the present invention, the life of the press mold can be significantly extended, and the throughput of hot slabs can be significantly increased without increasing the unit consumption. Furthermore, since the number of times the mold is replaced is small, productivity can be further improved if, for example, a hot strip line is connected downstream of this process.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of a press mold suitable for use in the present invention, Fig. 2 (a) and (b) are explanatory diagrams of the main parts of the press mold, and Fig. 3 is a schematic diagram of a conventional press mold. Figures 4(a) and 4(b) are explanatory views of the width reduction press of the present invention. 1...Hot slab 2...Press mold 2a,
2b, 2c...Press processing surface 3...Inner block 3a...Groove 4...Rotary drive device 5...Rotating arm p...Pass line Slurr between r and e in Figure 1 7-2 - Press type 4 2tr, 252c -- 1'L machining surface drawing, sl! '
A (No change in content) Fig. 2 (a) (b. a) (b) Procedural amendment (method) 1. Half-holiday indication flat bottom 1-year patent application No. 968,992, 2. Title of invention Method for pressing width reduction of hot slab 3. Relationship with the person making the amendment case

Claims (1)

[Claims] 1. In compressing the hot slab in the width direction over its entire length during the conveyance process by moving a pair of press dies that sandwich the conveyance path line of the hot slab on the left and right sides toward and away from each other, A pair of press dies each having a press working surface inclined toward both ends and a flat press working surface connected to the press working surface in the central region is prepared, and each press die is pressed by width reduction pressing. A hot slab width reduction pressing method characterized by appropriately inverting the mold as the temperature rises.