JPH0780512A - Die for edging press - Google Patents

Abstract

PURPOSE:To restrain a dog-bone in edging of a hot slab. CONSTITUTION:In an edging-press die for hot slabs with which the hot slab is edged into a prescribed width by approaching and separating the press dies 1, which are oppositely provided on both sides in the width direction of the slab, having an inclined part 2 where is widening inclined toward the slab entering side and parallel part 3 after the width is set corresponding to the edging amount of the slab while continuously or intermittently transporting the hot slab which is extracted from a heating furnace, plural projections 4 which are extended in the pass-line direction of the hot slab are provided in the inclined part 2 of the die 1 at necessary intervals in the thickness direction of die. And, small grooves 5 which are extended in the pass-line direction of the hot slab are provided in the parallel part 3. In this way, spreading amount in horizontal rolling after edging is remarkably reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die for a width reduction press of a hot slab extracted from a heating furnace in a hot rolling line.

[0002]

2. Description of the Related Art Hot rolled products are produced by heating a slab in a heating furnace and hot rolling with a rough rolling machine or a finish rolling machine to obtain a thickness of 1.0 to
It is manufactured by making a 25.4 mm strip, winding it on a coil, cooling it, and then treating it in various conditioning lines.
The slab width in the hot rolling is determined according to the coil width. The relationship between the slab width and the coil width is generally associated with the edger ability and the width accuracy. In terms of process operation, it is desirable to integrate slab sizes, and in particular because of the need to integrate continuous casting lots, the width reduction capacity of the edger tends to be increased.

The edger of the slab is classified into a width rolling method using a vertical rolling roll and a sizing press method in which a width reduction is performed by a width reduction press. In the sizing press, a pair of dies having a parallel portion and an inclined portion that is expanded and inclined toward the slab entrance side are arranged opposite to each other on a hydraulic cylinder attached to a fixed portion or a crankshaft driven by a motor, and between the dies. The slab is passed through continuously or intermittently, and the dies are moved toward and away from each other without restraining the upper and lower sides of the slab to perform width reduction to a predetermined width. These sizing presses are slightly inferior in rolling ability compared to width rolling with vertical rolling rolls, but on the other hand, the fish tail at the front and rear edges of the rolled material generated after hot rolling can be made small and the yield is good, and the dogbone The feature is that the cross-sectional shape of is less likely to be concentrated in the vicinity of the edge portion, and good flatness of the rolled material is easily obtained.

When the slab is subjected to width reduction by the sizing press, buckling occurs at the front and rear ends of the slab, a dog bone whose slab width direction end locally becomes thick, and a width direction central part over the entire length of the slab. The bulging becomes thicker or the restriction of the press equipment capacity causes the width reduction. For example, there is a problem that buckling at the front and rear ends deteriorates the sheet passing property after the sizing press, and in the worst case, the sheet passing becomes impossible. Also, if the width reduction in the sizing press is too large, dog bones and bulging also increase, twisting of the slab after pressing, buckling, etc. occur, making subsequent rolling difficult, and making the cross-sectional shape during horizontal rolling difficult. There is a problem that the correction cannot be completed. Further, when the thickness reduction in the slab width direction is performed by horizontal rolling, for example, the width of the dog bone or bulging in the plate width direction widens at the central portion in the longitudinal direction. As a result, the hot-rolled material has a narrow plate width at both ends in the longitudinal direction and a wide shape at the central portion side, and in order to keep the plate width as a product constant, the widened portion must be cut off. The problem is that the stay is reduced. Therefore, when the width of the slab is reduced by the sizing press, it is impossible to compress the width by a certain amount or more, which is an impediment factor for further integration of the slab width in continuous casting.

As a measure for suppressing the dog bone under the width reduction of the slab, a method of increasing the frictional force on the contact surface by roughening the parallel portion of the hot slab and the die (Japanese Patent Laid-Open No. 6-58242)
1-222604), as shown in FIG.
A mold in which a plurality of protrusions 55 extending in the pass line direction of the hot slab 54 are provided on the inclined portion 52 and the parallel portion 53 of No. 1 at required intervals in the mold thickness direction (actual open flat 3-7080).
No. 1) has been proposed.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The method disclosed in Japanese Patent No. 2604 increases the frictional force at the contact surface between the hot slab and the mold of the width reduction device, and can suppress the formation of dog bones, but the total thickness of the hot slab Since it is a dog bone against the above, the suppression power is limited to the weight reduction of the dog bone increase. Further, since the die disclosed in Japanese Utility Model Laid-Open No. 3-70801 has the protrusion 55 on the inclined portion 52 and the parallel portion 53, the recess 56 formed in the lower portion of the inclined portion 52 and the reduction at the parallel portion 53. When the protrusions 55 at the time do not overlap, a fold 57 is formed on the side surface of the hot slab 54, and a defect caused by the fold remains at the edge of the product after processing. Therefore, the defect is removed. A process may occur.

An object of the present invention is to provide a die for a width reduction press capable of suppressing the dogbone to be small in the width reduction of the hot slab.

[0008]

Means for Solving the Problems As a result of various tests and researches for achieving the above-mentioned object, the present inventors have found that the inclined portion of the mold has a pass line of the plate material at a required interval in the mold thickness direction. By providing a plurality of protrusions extending in the direction and forming fine grooves in the parallel part of the mold, a recess is formed on the side surface of the hot slab by the width reduction at the inclined part of the mold, and then provided in the parallel part of the mold. Deformation of the hot slab in the thickness direction is suppressed by the fine groove, and the formation of the dog bone can be divided in the thickness direction of the hot slab by the recess formed by the width reduction in the inclined part of the mold. It was confirmed that the dog bone of the can be made small, and the present invention was reached.

That is, according to the present invention, while the hot slab extracted from the heating furnace is continuously or intermittently fed, an inclined portion which is provided on both sides in the width direction of the slab and is inclined toward the slab entrance side is provided. The width of a press die having parallel parts is set according to the amount of slab width reduction, and then the width of the hot slab is reduced to a predetermined width by approaching and separating the slab. A plurality of protrusions extending in the pass line direction of the hot slab at required intervals in the die thickness direction are provided in the portion, and fine grooves extending in the pass line direction of the hot slab are provided in the parallel portion. It is a die for width reduction press.

[0010]

The die for the width reduction press according to the present invention is provided with a plurality of protrusions extending in the pass line direction of the hot slab at a predetermined interval in the die thickness direction on the inclined portion of the press die, and in the parallel portion. By providing the fine groove extending in the pass line direction of the hot slab, first, a plurality of concave portions are formed on the side surface of the hot slab by the width reduction of the inclined portion of the die, and then the fine groove formed in the parallel portion of the die. Thus, width reduction is performed to a predetermined width while suppressing the dog bone. When the width of the die is reduced in the parallel portion, the deformation of the hot slab in the thickness direction is suppressed by the fine groove, and the formation of the dog bone is performed by the plurality of recesses formed when the die is reduced in the width portion. Are divided in the thickness direction of the hot slab, and each dog bone can be made smaller. As a result, the width reduction in the horizontal rolling of the hot slab subjected to the width reduction pressing is suppressed to be small, and the width reduction can be efficiently performed.

[0011]

【Example】

Embodiment 1 Details of the present invention will be described below with reference to FIGS. 1 and 4 to 8 showing an embodiment. 1A and 1B show a die of a width reduction press of the present invention. FIG. 1A is a perspective view, FIG. 1B is a plan view, and FIG. 4 is parallel after width reduction by an inclined portion of the die of the present invention. Schematic diagram of the slab end face shape after width reduction and horizontal reduction by the part, FIG. 5 is a schematic diagram of the slab end face shape after width reduction by the inclined part of the conventional mold, after width reduction by the parallel part and after horizontal reduction, FIG. 6 is a schematic view of a width reduction state by a parallel portion of a mold of the present invention, FIG. 7 is a schematic view of a side surface of a slab after width reduction by a parallel portion of the mold of the present invention, and FIG. 8 is a mold of the present invention. It is a schematic diagram of the width reduction state by the parallel part at the time of the width reduction by an inclined part, and when a reduction center shifts.

In FIG. 1, 1 is a die for a width reduction press,
2 is an inclined part of the mold 1, 3 is a parallel part of the mold 1, 4 is a mold 1 provided on the inclined part 2, and a plurality of projections extending in the pass line direction of the hot slab at required intervals in the thickness direction, Reference numeral 5 denotes a fine groove extending in the pass line direction of the hot slab provided in the parallel portion 3. When the width of the hot slab is reduced by the die 1 of the width reduction press, as shown in FIG. The recesses 7 are formed by the protrusions 4 extending in the pass line direction of the hot slab 6 at required intervals in the thickness direction of the mold 1 provided in the inclined portion 2 of the mold 1. Next, the concave portions 7 of the hot slab 6 and the convex portions 8 between the 7 are width-reduced in the mold 1 by a parallel portion 3 having fine grooves 5 extending in the pass line direction of the hot slab 6, and further thickened by horizontal rolling (not shown). Although it is rolled in the vertical direction, the width W in horizontal rolling can be suppressed to be small. In the case of the conventional die, as shown in FIG. 5, the hot slab 21 width-reduced in the inclined portion is then width-reduced in the parallel plane to form the dog bone 22 on the side surface, and further thickened by the horizontal rolling not shown. Since it is rolled in the vertical direction, the dog bone 22 increases the width W in horizontal rolling.

In this case, the side surface of the hot slab 6 is formed on the side surface of the hot slab 6 as shown in FIG.
Of the hot slab 6 provided on the projection 4 extending in the pass line direction
The convex portions 8 on both sides of the concave portion 7 formed by are subjected to width reduction by the parallel portion 3 having fine grooves 5 extending in the pass line direction of the hot slab 6 in the mold 1, and as shown in FIG.
The convex portions 9 formed by the fine grooves 5 are formed on the convex portions 8 on both sides of the concave portion 7 on the side surface of the hot slab 6 to form a shape that prevents the side surface of the slab from wrapping around. Further, even if the rolling centers of the inclined portion 2 and the parallel portion 3 of the mold 1 are deviated from each other, as shown in FIG. Only the position of the convex portion 9 formed by the fine groove 5 is deviated, and a flaw such as a bald spot or a blur does not occur.

Example 2 As shown in FIG. 1, a slab having a thickness of 212 mm and a width of 1300 mm has a width of 30 mm on an inclined portion 2 of a mold 1 having a total length of 1400 mm, a thickness of 500 mm and a parallel portion length of 700 mm.
Two projections 4 with a height of 5 mm and a width of 40 m in the parallel part 3
m, a length of 500 mm, and a depth of 3 mm having four grooves 5 are used, the width reduction amount is 0 to 300 mm, and then 10% of the slab thickness is horizontally expanded after horizontal rolling. Was measured. The relationship between the width reduction amount and the width expansion amount is shown in FIG.
Shown in. Also, for comparison, as shown in FIG.
400mm, thickness 500mm, parallel part length 700mm
Using the conventional die 31 in which the slanted portion 32 and the parallel portion 33 of the die 31 were smoothed, the width reduction was performed under the same conditions, and the amount of width expansion after horizontal rolling 10% of the slab thickness was measured. The relationship between the width reduction amount and the width expansion amount is shown in FIG.

As shown in FIG. 2, when the die 1 of the present invention is width-reduced, the width expansion after horizontal rolling is 50% compared to the case where the die 31 of the prior art is width-reduced. Can be reduced.

[0016]

As described above, the mold of the present invention is
The shape of the dog bone generated during the width reduction of the hot slab can be optimized, and the width expansion amount in the horizontal rolling after the width reduction can be significantly reduced.

[Brief description of drawings]

FIG. 1 shows a die of a width reduction press of the present invention,
FIG. 3A is a perspective view and FIG. 2B is a plan view.

FIG. 2 is a graph showing a relationship between a width reduction amount and a width expansion amount in Example 2.

FIG. 3 is a perspective view of a conventional mold used in Example 2.

FIG. 4 is a schematic view of the slab end face shape after width reduction by the inclined portion of the mold of the present invention, after width reduction by the parallel portion and after horizontal reduction.

FIG. 5 is a schematic view of a slab end face shape after width reduction by an inclined portion of a conventional mold, after width reduction by a parallel portion, and after horizontal reduction.

FIG. 6 is a schematic diagram of a width reduction state by a parallel portion of the mold of the present invention.

FIG. 7 is a schematic view of the side surface of the slab after width reduction by the parallel portion of the mold of the present invention.

FIG. 8 is a schematic diagram showing a state of width reduction by the inclined portion of the mold of the present invention and a state of width reduction by the parallel portion when the center of reduction is displaced.

9A and 9B show a conventional width reduction by a mold having protrusions on an inclined portion and a parallel portion. FIG. 9A is a schematic diagram when the width is reduced, and FIG. 9B is a width reduction of the inclined portion and the parallel portion. It is a schematic diagram when a position shifts.

[Explanation of symbols]

 1, 31, 51 Mold 2, 32, 52 Inclined part 3, 33, 53 Parallel part 4, 55 Protrusion 5 Groove 6, 21, 54 Hot slab 7 Recessed part 8, 9 Convex part 22 Dogbone

Claims (1)

[Claims] 1. A hot slab extracted from a heating furnace is continuously or intermittently run, and a slab entrance side provided opposite to both sides in the slab width direction is provided with a sloped portion parallel to the slab entrance side and a parallel portion. After setting the width of the press die having the width corresponding to the slab width reduction amount, the width reduction of the hot slab is performed by bringing the width closer to and away from the slab to reduce the width to a predetermined width. A die for a width reduction press characterized in that a protrusion extending in the pass line direction of the hot slab is provided and a fine groove extending in the pass line direction of the hot slab is provided in a parallel portion.