JPH0320002Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a vertical roll caliber for chamfer rolling of thick plates. This invention relates to a vertical roll caliber for chamfer rolling of thick plate width edges, which is performed during forming rolling prior to tentering rolling, in order to prevent collapse and flaws.

(Prior art) In plate rolling, forming rolling is usually performed in the longitudinal direction for 1 to 4 passes to adjust the thickness, and the plate is turned 90 degrees in a horizontal plane to give the plate a predetermined width. The process consists of tenter rolling in the direction, and finish rolling in the longitudinal direction to obtain a predetermined thickness and length by turning the plate 90 degrees in the horizontal plane.

In the above-mentioned rolling process, the thick plate is rotated in a horizontal plane during tentering rolling, so the width side of the thick plate becomes the leading and trailing edge during tentering rolling. Each part undergoes uneven deformation, and as a result, when the width adjustment is completed, as shown in Figure 3 (a)
As shown in FIG. 2, the front and rear end surfaces of the rolled thick plate may have a double bulge 5 shape that is significantly elongated. When this double bulge 5 shape is rolled down in the next finish rolling step, it may develop into folds 6 as shown in FIG. 3(b). This insert 6
If the width extends to the inside, the width of this portion must be cut off, resulting in a decrease in yield.

In order to prevent the folding, a technique has been proposed in which the edge portion of the thick plate is chamfered in the forming and rolling process.

Conventionally, as shown in Fig. 4, in order to chamfer the edge portions of the plate width, a vertical roll machine with a horizontal V-shaped caliber attached to a vertical roll is used to roll the edge portions of the plate thickness in a vertically symmetrical manner. However, the temperature of a thick plate differs between the top and bottom surfaces, and in general, the top surface is easily heated in a heating furnace, so the temperature of the top surface is high.
Cooling water removes heat and creates a temperature difference between the upper and lower surfaces of the plate during rolling, and as a result, the temperature of the upper and lower surfaces generally increases. Therefore, at the end of tentering rolling, the top surface of the double bulge 5 shape generated at the front and rear ends of the thick plate stretches more than the bottom surface, as shown in FIG. 3(a), so the top surface becomes longer than the bottom surface. The third plate is placed on the side surface of the thick plate at the end of finish rolling.
A fold 6 having the shape shown in Figure (b) is produced.

As a countermeasure to the above, the present applicant has proposed a method of controlling the vertical position of a vertical roll with a caliber according to the temperature difference between the upper and lower sides of the thick plate, and chamfering the edge of the width of the thick plate, as disclosed in JP-A-60-184403. We proposed a technology that can effectively eliminate double bulges by making the amount asymmetric.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 113906/1983, the dog bone 7 produced at the thick plate width edge portion caused by chamfer rolling as shown in FIG. If this is done, biting will become difficult, and surface flaws will occur due to horizontal rolling when the dog bone 7 is rolled for tentering. proposed a technology in which the dogbone part is rolled down and then the width is rolled.

(Problems to be Solved by the Invention) According to the conventional technique, the horizontal V-shaped caliber attached to the vertical roll for chamfer rolling the width edge of the thick plate has a horizontal V-shaped caliber attached to the vertical roll in the direction of the roll axis as shown in FIG. The angle with respect to the vertical plane is around 60° both above and below (45°~
70°), so even if there is no particular problem on the upper side during tentering rolling, if the plate warps downward on the lower side, as shown in Figure 5 (a)
As shown in (b), the chamfering starting point 8 on the lower side of the thick plate collides with the table roller 4, and a henge-like flaw 9 is generated at the chamfering starting point 8, as shown in FIG. As the tentering rolling progresses, this sludge-like flaw 9 moves from the edge of the plate width to the center of the width, as shown in FIG.
There is a problem in that bald spots 9 occur between 80 and 100 mm, which further reduces the yield. This phenomenon occurs when the dog bone is removed by rolling in the same direction as the chamfer rolling after chamfer rolling as shown in the above-mentioned Japanese Patent Application Laid-Open No. 59-113906. This becomes a major problem because the corner of the chamfering starting point 8 becomes sharper. In addition, the above-mentioned Japanese Patent Application Publication No. 1986-
Problems may also occur with the technique disclosed in No. 184403;
When rolling was carried out in combination with No. 184403, it was possible to prevent bald spots on the width edge of the top surface of the plate, but it was not possible to completely prevent bald spots that occurred on the width edge of the bottom surface of the plate. .

(Means for Solving the Problems) The object of the present invention is to provide a vertical roll caliber that can eliminate and improve the drawbacks of the conventional vertical roll caliber for chamfering thick plate rolling. The above object can be achieved by providing a vertical roll having a caliber shape as described in the claims of the utility model registration.

That is, a vertical roll used when chamfering the edge portion of a thick plate with a vertical roll machine prior to the tentering rolling step in a series of rolling steps of thick plate rolling consisting of forming rolling, tentering rolling, and finishing rolling. In a vertical roll for chamfering thick plates including a horizontal V-shaped caliber attached to the outer circumferential surface: The angle of the horizontal V-shaped caliber attached to the outer circumferential surface of the vertical roll with respect to a plane perpendicular to the roll axis direction is 45 on the upper side. The present invention relates to a vertical roll for chamfering and rolling a thick plate, which includes a horizontal V-shaped caliber having an angle of 5° to 45° on the lower side.

Next, the present invention will be explained in detail.

In the present invention, as shown in FIGS. 5(a) and 5(b), the heave-like flaws that occur on the width edge portion of the lower surface of the thick plate are caused by the starting point 8 of the chamfered portion being placed on the table roller 4 during tenter rolling.
This was done based on the knowledge that the cause of the chamfering is collision with the plate, and the purpose of chamfering is to suppress double bulges, as shown in Figure 3 (a) and (b). Since the amount of bulging 5 on the side is relatively small, there is no need to chamfer too much, which improves the caliber shape. In the present invention, the above problem is solved by making the angle of the horizontal V-shaped caliber of the vertical roll with respect to a plane perpendicular to the roll axis direction to be large on the upper side and relatively small on the lower side.

As shown in Figure 1, the upper angle θ ₁ of the horizontal V-shaped caliber of the vertical roll was set at 45° to 70°, the same as in the conventional technology, and the lower angle θ ₂ was set at 5° to 45°. . If the upper angle θ ₁ is less than 45°, the depth D of the caliber shown in the figure increases, which affects the strength of the roll itself, and the width B of the caliber decreases, limiting the range of plate thickness that can be accommodated. Ru. Moreover, if θ ₁ exceeds 70°, the height H of the dogbone 7 will increase, which will cause problems in subsequent rolling. Therefore, the upper angle θ ₁ must be within the range of 45° to 70°, preferably around 60°. If the lower angle θ ₂ is less than 5°, there will be no chamfering effect, and if it exceeds 45°, it will not be useful for preventing flaws at the edge of the thick plate. Therefore, the lower angle θ ₂ needs to be within the range of 5° to 45°.

Although the caliber was described as having a horizontal V-shape, the second
As shown in the figure, the width B' of the bottom of the caliber may be made small enough to be able to chamfer the required amount of the plate to be rolled with this caliber, and the shape of the lower caliber is shown by the solid line. It may be a straight line or may be an arc connecting point E and point C as shown by a broken line. However, in the case of an arc shape, the center O of the radius of the arc must be at least outside the outer circumferential surface of the vertical roll.

Next, the present invention will be described with reference to embodiments.

A 1/10 lead model experiment was conducted. Horizontal V of vertical roll
The upper angle θ ₁ of the letter-shaped caliber is 60°, and the lower angle θ ₂ is changed from 10° to 60° in 10° increments to perform chamfering, and then it is rotated 90° in the horizontal plane to perform horizontal rolling. The chamfer starting point on the bottom of the lead model was observed. As a result, it was predicted that the occurrence of flaws could be prevented when the lower angle θ ₂ was approximately 45° or less.

Next, set the upper angle θ ₁ to 60° on the vertical roll of the actual machine,
A caliber with a lower angle θ ₂ of 10°, 30°, and 60° was attached, and a thick plate with a thickness of 180 mm and a width of 2000 mm was set to have a chamfer of 30 mm on both the top and bottom sides of the thick plate width edge. After chamfer rolling 8 thick plates and subsequent light rolling to remove dog bones, they were rotated 90 degrees in the horizontal plane and rolled with a width ratio of 1.8 to 2.4 (plate width 3600).
~ 4800 mm), and further turned 90° in the horizontal plane to perform finish rolling to a plate thickness of 18 to 25 mm. As a result, some folding was observed in the case where θ ₂ was 10 degrees and the tenting ratio was large, but there were no sagging defects that were a problem, and it did not affect the yield in particular.
Further, in the case where θ ₂ was 30°, no problematic folding or bald spots were observed. But θ ₂
Although there was no folding in the case where the angle was 60°, problematic bald spots appeared on the bottom surfaces of two sheets.

From the above results, by making the upper angle of the horizontal V-shaped caliber of the vertical rolls around 60 degrees and the lower angle around 30 degrees to make the lower angle smaller, thick plate width chamfering is possible during tentering rolling. This prevents bald spots caused by the collision of the starting point with the table roller, and reduces the difference between the upper bulge amount and the lower bulge amount in the thickness direction of the plate during tentering rolling. It was possible to prevent the plate width edge from folding.

(Effects of the invention) By implementing the invention, it is possible to prevent sludge-like flaws on the width edge portion that occur on the lower surface of the thick plate, and also to fully exhibit the effect of preventing the width edge portion from folding. The effect of contributing to yield improvement is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a vertical roll and a thick plate according to an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of a vertical roll according to another embodiment of the present invention, and Fig. 3 (a) shows the width. Fig. 4 is a longitudinal cross-sectional view of the width edge portion of the rolled plate showing folding after finish rolling; Fig. 4 is an example of an embodiment according to the prior art; Figure 5(a) is a vertical cross-sectional view showing the state where the starting point of the chamfered portion of the thick plate collides with the table roller during tentering rolling, and Figure 5(b) is the starting point of the chamfered portion. FIG. 6 is a plan view showing a heave-like flaw that occurs at the edge of the lower surface of a thick plate. 1... Thick plate, 2... Vertical roll, 3... Horizontal work roll, 4... Table roll, 5... Double bulge, 6... Folding, 7... Dog bone, 8
...Start point of width chamfer, 9...Skinned flaw.

Claims (1)

[Claims for Utility Model Registration] Prior to the tentering rolling step in a series of rolling steps for thick plate rolling consisting of forming rolling, tentering rolling, and finishing rolling, the edge portion of the thick plate width is chamfered and rolled using a vertical roll machine. In a vertical roll for thick plate chamfering rolling including a horizontal V-shaped caliber attached to the outer circumferential surface of the vertical roll used when rolling: A plane perpendicular to the roll axis direction of the horizontal V-shaped caliber attached to the outer circumferential surface of the vertical roll. A vertical roll for chamfering and rolling a thick plate, including a horizontal V-shaped caliber, characterized in that the upper side makes an angle of 45° to 70° and the lower side makes an angle of 5° to 45°.