JPH0220321B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an edger rolling method for rolling a rolled material from the width direction in a thick plate rolling process, a rough rolling process of hot strip rolling, a blooming process, etc. It is.

(Prior art) For example, in the rough rolling step of hot strip rolling, after rolling the rolled material to a thickness that can be rolled in a subsequent continuous finishing mill, width adjustment rolling is performed to obtain a predetermined product width. It will be done. In this width adjustment rolling, that is, edger rolling, when width adjustment rolling is performed using a vertical scale breaker (VSB) or a pair of cylindrical vertical rolls as an edger, the width reduction is the rolling amount in the width direction. If the amount is too large, as shown in FIG. 8, the rolled material S conveyed on the table rollers 2 will be subjected to the width reduction force F by the pair of vertical rolls 1 and will be deformed in an upward curve as shown by S', resulting in extreme deformation. In such cases, buckling occurs, so the amount of width reduction has been limited. For example, when hot rolling is performed using a continuously cast slab, the amount of width reduction during rough rolling is at most
The width reduction was limited to about 50 to 60 mm, and it was desired to increase the width reduction in order to improve the operating rate of continuous casting equipment.

For this reason, it has been proposed to attach a presser roll that presses the center of the rolled material. For example, JP-A-47-36144, JP-A-55-
16719, JP-A-55-6023, JP-A-58-61999, etc. All of these have a structure in which the rolled material is pressed by rolls from above and below in order to suppress buckling due to vertical curvature during width reduction.

(Problems to be Solved by the Invention) However, in the conventional method, the pressing force is very high because the rolled material (indicated by S' in FIG. 8) that is curved in the width direction is held down by width reduction. growing. Therefore, the structure of the presser roll becomes complicated and strong, making it difficult to install the vertical roll in the stand, and furthermore, since the rolled material is pressed by the presser roll from above and below, the structure becomes even more complicated.

As described above, it must be said that the conventional edger rolling method is extremely insufficient for avoiding the buckling phenomenon, and at present no concrete solution has been found.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an edger rolling method that suppresses the occurrence of the buckling phenomenon and allows a large reduction.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides an edger rolling method in which a rolled material progressing on a table roller is rolled to a required width by a width reduction stand having a pair of vertical rolls. , pressing the center part of the upper surface of the rolled material from above to cause the rolled material to be deformed to curve convexly downward in the width direction;
Width reduction is performed with the pair of vertical rolls tilted in a vertical plane parallel to the traveling direction of the rolled material so that their upper parts face in the opposite direction to the traveling direction,
The central part of the rolled material is supported by table rollers, and rolling is performed while restricting the expansion of deformation due to width reduction.

(Example) Next, an example of the present invention will be described with reference to the drawings.

In FIGS. 3 and 4, a pair of vertical rolls 1 having smooth surfaces are placed in advance in a vertical plane parallel to the traveling direction of the rolled material S (from left to right in FIG. 3) so that the upper part thereof is in the traveling direction. It is tilted at an appropriate angle of θ° with respect to the vertical line so that it faces in the opposite direction (the entrance side of the rolled material). When the rolled material S is bitten by the vertical roll 1 in this inclined state, as shown in FIG.
The rolled material S is rolled down in the width direction by the rolling force F of the vertical rolls 1. At this time, an upward component fR of the frictional force f generated between the vertical roll 1 and the rolled material S acts on the end of the rolled material S. Therefore, a moment acts on the rolled material S due to the resultant force of the force fR and the rolling force R, which causes the rolled material S to convexly curve downward in the width direction. The rolled material S tries to curve and deform in a downward convex manner, but since it is supported by the table roller 2, the curved deformation is restrained to a certain extent and does not progress any further. As a result, the rolled material S can be reduced in width to a large extent without buckling.

However, before the rolled material S enters the width reduction stand, there are cases where it has already been greatly curved upward in the width direction due to the influence of the heating furnace (FIG. 5). In such a case, even if the vertical roll 1 is tilted, it may not be possible to completely prevent buckling from occurring.

Therefore, as shown in FIGS. 1 and 2, a presser roll 3 is provided above the rolled material S so as to be movable in the vertical direction by a cylinder 4, and a table roller 2 facing the presser roll 3 is placed at both ends of the presser roll 3. It is formed so that the diameter becomes narrower toward the center. Then, by pressing the center part of the upper surface of the rolled material S downward with the presser roll 3, width reduction is performed while the rolled material S is kept in a downwardly convexly curved state.

As a result, even if the rolled material S curved upward in the width direction enters the width reduction stand, buckling does not occur and wide rolling is possible.

The present inventors conducted a model experiment of the present invention using hot steel under the following conditions, and measured the presser roll pressure with a pressure gauge.

Vertical roll diameter 100mmφ Vertical roll surface Knurling process Rolled material size Plate thickness 9mm, plate width 200mm, plate length 500mm Reduction amount 15mm Vertical roll inclination angle 0°, 5° inclination on the entry side Rolled material Continuously cast killed steel press Rolling temperature: 880℃ Rolling speed: 20m/min Table barrel length: 150mm Presser roll diameter: 50mm Barrel: 50mm As a result, as shown in Figure 6, when the inclination angle of the vertical roll is 0°, that is, the conventional vertical In the case of vertical rolls, the rolled material S curved upward convexly in the width direction and buckled, but nearly 1 ton of pressure from the presser roll was required to suppress it. On the other hand, when the method according to the present invention was applied and the vertical roll was tilted 5° toward the entrance side, the pressure on the presser roll was significantly reduced to 0.1 ton or less.

FIG. 7 shows another embodiment of the present invention, which is substantially the same as the embodiment described above except for the use of a vertical roll 5 with an enlarged diameter at the bottom, and corresponding parts are given the same numbers. The explanation will be omitted. That is, the vertical roll 5 has a flange 6 continuous and integrally formed with an inclined part 7 on the lower side thereof, and the lower end of the inclined part 7 is at the same level as the pass line of the rolled material S or below it. It is now located in

When the rolled material S is bitten by this pair of vertical rolls, the lower edges of both side ends of the rolled material S first collide with the inclined portion 7, and the vertical component of the collision force at this time causes the rolled material S to Both ends are lifted up to the small diameter end of the inclined portion 7. Then, with both ends of the rolled material S lifted up, the pressed roll 3 is used to hold the rolled material S.
When the central part of S is pressed downward, the rolled material S becomes
As shown by S', a gentle curved deformation convex downward will occur.

Next, when the rolled material that has been curved and deformed in a downwardly convex manner is rolled down in width, the deformation tends to further increase, but since the central part of the rolled material S' is already supported by the table roller 2, The expansion of the deformation is regulated and a restraint state is established, so that the deflection does not increase any further.

Therefore, rolling down in the width direction is performed while buckling is prevented.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, the amount of width reduction, which was conventionally considered to be about half of the plate thickness, is significantly increased, and stable edger rolling becomes possible. At the same time, it is also possible to improve the width accuracy of the rolled material, which improves the yield of products.

In addition, as for pressing the center part of the upper surface of the rolled material, for example, using a presser roll, it is sufficient to curve the rolled material convexly downward in the width direction, and the presser roll only in the upper part is sufficient. The presser roll has a simple structure and is small, and has the advantage that it can be easily installed not only on the entrance side of the width reduction stand but also between the width reduction stands.

[Brief explanation of drawings]

FIG. 1 is a front view showing a rolling state by an edger rolling mill applying the method according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a side view showing a rolling state by an inclined edger rolling mill. FIG. 4 is a front view of FIG. 3, FIG. 5 is a diagram showing a rolled material curved upward in the width direction, and FIG. 6 is an experimental result to confirm the effect of the method according to the present invention. 7 are front views showing other embodiments of the method according to the present invention,
FIG. 8 is a front view showing the rolling state by the conventional edger rolling method. 1... Vertical roll, 2... Table roller, S... Rolled material, 3... Presser roll, 4... Cylinder.

Claims (1)

[Claims] 1. In an edger rolling method in which a rolled material traveling on a table roller is rolled to a required width by a width reduction stand having a pair of vertical rolls, the center part of the upper surface of the rolled material is pressed from above to give the rolled material in the width direction. At the same time as causing a downwardly convex curve deformation, the pair of vertical rolls is tilted in a vertical plane parallel to the traveling direction of the rolled material so that its upper part faces in the opposite direction to the traveling direction. An edger rolling method characterized in that rolling is carried out while the central part of the rolled material is supported by table rollers and expansion of deformation due to width reduction is controlled.