JPH0519123Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to vertical rolls.

(Prior art) As a method of rolling a slab for hot rolling into a thick plate, the slab is rolled in the width direction using a vertical roll having a groove whose cross-sectional shape can be modified into an edge shape with four corners cut off. The thick plate rolling method was developed in 1974.
It is disclosed in Publication No. 7504.

Furthermore, as a conventional technology, as shown in Japanese Utility Model Application Publication No. 62-202902, there is a vertical roll in which a slope of 10° to 30° is attached to the outer edge of the hole, and the bottom of the hole is V-shaped. .

(Problem to be solved by the invention) The technology disclosed in the above-mentioned Japanese Patent Publication No. 54-7504 is as shown in FIG.
A groove 5 having a pair of inclined surfaces 4A and 4B formed at an angle of θ with respect to a surface 3 perpendicular to the surface 3, that is, a surface parallel to the front and back surfaces of the slab, is used to roll the slab in the width direction. In this case, the inclination angle θ is 40° ~
It is said that a range of 80° is desirable.

However, when the slab is rolled in the width direction with such a vertical roll 1, dot bones 7, 7 with a large height H are generated at the four corners of the slab 6, as shown in FIG. There is a problem in that wrinkle defects occur when the dock bone portions 7, 7 are subjected to reduction during horizontal rolling in the process.

Furthermore, as a conventional technology, the problem with the technology shown in Japanese Utility Model Application Publication No. 62-202902 is that since the shape of the bottom of the hole is V-shaped, the end of the slab is vertical as shown in Figure 6. When it is pressed by a roll, the more it is pressed, the more the dot bone A grows on the inner edge of the hole. As a result, after finishing rolling, a cross-sectional defect called folding occurs at the side edge of the sheet in the width direction, and it cannot be said that this is a vertical roll that solves the problem.

(Means for Solving the Problems) The present invention has been made to advantageously solve the problems of the prior art, and has the following features: A pair of sloped slopes and an angle of 10° to 20° to the outside thereof perpendicular to the roll axis.
A vertical roll characterized in that it is provided with a hole having a pair of inclined slopes.

(2) The distance between the contact points of the two slopes is made equal to the thickness of the material to be rolled, and a plurality of the grooves are provided corresponding to the thickness of the material to be rolled. Vertical roll.

(3) The vertical roll according to claim (1) or (2), wherein the contact points of the two slopes are each rounded with a radius of curvature of 10 to 50 mm.

The main points are as follows.

(Function) When forming the end of a slab using vertical rolls, the end of the slab rises along the slope of the groove, creating a dog bone, but in the case of a conventional groove, the height of the dog bone becomes large. Then, during the subsequent rough rolling step, horizontal rolling, the material is locally reduced and wrinkles are generated on the surface.

Since the present invention has two stages of groove-shaped inclined surfaces, when the slab end is formed using the vertical roll of the present invention, the slab end gently swells along the two-stage inclined surface, and the dogbone height increases. Since the thickness can be lowered, flaws caused by dog bones will not occur.

The distance between the contact points of two continuous slopes of the groove according to the present invention is preferably matched to the thickness of the slab;
Therefore, in order to accommodate changes in slab thickness, it is effective to provide a plurality of holes in the roll axis direction according to the present invention.

(Example) FIG. 1 is a front view showing an example of the present invention, showing the hole shape of a vertical roll, and FIG. 2 is a diagram illustrating the state of forming a dog bone.

As shown in FIGS. 1 and 2, in the present invention, the groove 5 of the vertical roll 1 has a pair of inclined surfaces 8A and 8B with an inclination angle of θ ₁ , and It is formed by a pair of inclined surfaces 9A and 9B having an inclined angle of θ ₂ .

The inclination angle θ ₁ according to the present invention is within the range of 30° to 60°,
The inclination angle θ ₂ shall be determined within the range of 10° to 20°.

If the angle of inclination θ ₁ is less than 30°, or conversely exceeds 60°, embedding flaws and seam flaws will occur. Furthermore, if the inclination angle θ ₂ is less than 10°, the circumferential speed difference between the rolled material and the rolls will become excessive, causing seizure defects due to friction, and if this angle exceeds 20°, the height h of the dog bone 7A will increase. This causes flaws to occur when the dogbone portion is subjected to reduction during horizontal rolling in the subsequent rough rolling process.

The reason why the shape of the bottom of the hole is flat is that the central part of the end of the slab is under contact pressure, so the dot bones that occur inside the inner edge of the hole are always rolled and cannot grow or occur. . This is an epoch-making technology that can completely suppress the formation of dock bone cross-sectional defects (or wrinkle defects) inside the inner edge of the hole. Furthermore, since the shape of the bottom of the hole is not V-shaped but flat, the structure is less likely to cause stress concentration, resulting in a long life.

In the present invention, the distance t between the contact point 10A between the two slopes 8A and 9A and the contact point 10B between the slopes 8B and 9B is made equal to the thickness of the rolled material, that is, the slab thickness t ₁ in FIG. is valid. For this reason, as shown in FIG. 3, the groove shape according to the present invention is 5A,
It is desirable to provide multiple stages like 5B.

In addition, when forming continuously using a main hole type roll, stress on the roll surface can be reduced by providing a slight roundness with a radius of curvature of 10 to 50 mm between the inclined surfaces 8A and 9A, 8B and 9B. Relaxation is effective in preventing roll skin roughness. If the radius of curvature is smaller than 10 mm, the stress relaxation effect is insufficient;
If it is larger than mm, the load and torque during molding will be excessive.

(Effects of the invention) As described above, according to the invention, the occurrence of roll-in flaws and seam flaws can be prevented by slanting the pair of inclined surfaces forming the hole pattern of the vertical roll in two stages. At the same time, it is possible to prevent the occurrence of wrinkle flaws that occur when an excessively large dogbone is subjected to reduction during horizontal rolling after end forming. Furthermore, by providing multiple stages of the grooves according to the present invention, changes in the thickness of the material to be rolled can be accommodated without changing the rolls.

[Brief explanation of drawings]

Fig. 1 is an embodiment of the present invention, a front view showing the hole pattern of the vertical roll, Fig. 2 is an embodiment of the invention, an explanatory diagram of the dogbone forming situation, and Fig. 3 is another embodiment of the invention. FIG. 4 is a front view of a vertical roll having a plurality of grooves, FIG. 4 is a front view showing the grooves of a conventional vertical roll, and FIG. 5 is an explanatory diagram showing the state of dogbone formation by the roll. FIG. 6 is an explanatory diagram showing a conventional example. 1... Vertical roll, 5A, 5B... Hole type, 8
A, 8B, 9A, 9B...slope, 10A, 10
B...Contact point.

Claims (1)

[Claims for Utility Model Registration] (1) A pair of slopes inclined at an angle of 30° to 60° with respect to the plane perpendicular to the roll axis, and continuing from the slopes, a surface perpendicular to the roll axis on the outside thereof. 10° to 20°
A vertical roll comprising: a groove having a pair of inclined slopes; and a bottom of the groove is flat. (2) The vertical roll according to claim 1, wherein the distance between the contact points of the two slopes is equal to the thickness of the material to be rolled, and a plurality of the holes are provided corresponding to the thickness of the material to be rolled.