JPS6163303A - Method for forming rolling material having rectangular cross section - Google Patents

Abstract

PURPOSE:To prevent a rolling material, from being broken by projecting parts, by restricting the material by means of flat parts, by forming the projecting parts, corresponding to the grooved parts of upper and lower work rolls, at both end-parts of the material, and further forming flat parts at the outsides of the projecting parts. CONSTITUTION:Projecting parts Wa are formed at the end parts of a rolling material W, by grooves 2a, 3a provided to work rolls 2, 3 respectively, and flat parts Wb are formed at the outsides of parts Wa respectively by a rolling reduction in the thickness direction of material W. Accordingly, the material W is restricted by the flat parts Wb so as not to largely deform in its width direction, and stresses produced in the width direction of material W are compensated with each other in the inside of material W near to the projecting parts Wa, to prevent the material W from breaking at the position where the thickness of material W changes suddenly. Further, the material W is prevented from meandering because the end parts of material W are restricted. Therefore, the restriction on the enlargement of projecting parts Wa is eliminated, and the cross section of material W is effectively formed into a rectangular one by enlarging the parts Wa.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for reducing edge drop of a rolled material and rectangulating the cross section of the rolled material during hot rolling or cold rolling.

[Conventional technology]

In hot rolling or cold rolling, edge drops may occur due to deflection, wear, etc. of work rolls.

Conventionally, the following methods have been attempted as methods for reducing edge drops. That is, a rolling mill 13 is provided upstream of the finishing mill, as shown in FIG. By rolling the rolled material W with this rolling mill 13, a raised part P is formed at the end of the rolled material W. Thereafter, the rolling material W is horizontally rolled in a finishing rolling mill 14 at a later stage as shown in FIG.
In this method, the cross section of the rolled material is made rectangular by flattening it. FIG. 5 is a view from the entry side of the finishing mill 140.

[Problem that the invention seeks to solve]

However, in the above method, the taper part 11&,
If the taper amount of 12a is increased, not only will the rolled material W become more likely to meander, but since the taper is used to build up the wall thickness, the stress in the width direction of the sheet will increase, especially in the case of cold rolling. This causes problems such as easy breakage at parts where the plate thickness suddenly changes. Therefore, the amount of taper cannot be very large,
As a result, the bulge becomes smaller, and when a large rolling reduction is applied in the subsequent stage, the bulge at the end disappears soon and does not work effectively to make the cross section of the rolled material rectangular. In the end, there was a problem that sufficient rectangularization could not be achieved.

An object of the present invention is to provide a method for solving such problems, reducing edge drop, and making the cross section of a rolled material rectangular.

[Means for solving problems]

The method for rectangulating the cross section of a rolled material according to the present invention includes the following rolling mill upstream of the finishing rolling mill. That is, the upper and lower work rolls have grooves along the circumferential direction on the circumferential surfaces of the rolls near mutually opposite ends, and the rolled material is rolled in the thickness direction on the roll circumferential surfaces further toward the ends of these grooves. A rolling mill is provided which has a parallel section for producing the work rolls and is equipped with these work rolls so that they can be shifted in the axial direction. Then, by this rolling mill, the rolled material is rolled into a cross-sectional shape having convex portions corresponding to the grooves of the work roll at both ends and flat portions corresponding to the parallel portions at the further end side, Thereafter, the convex portions are flattened by horizontal rolling using a finishing mill at a later stage.

[For production]

In the method of the present invention, a convex portion is formed at the end of the rolled material by grooves formed in the work roll, and a flat portion is formed on the outside by rolling down in the thickness direction, so that the rolled material is wide at the flat portion. It is restrained so that it does not deform significantly in the direction,
The stress generated in the width direction of the rolled material is canceled out within the rolled material near the convex portion. Therefore, the rolled material will not break at a portion where its wall thickness suddenly changes.

Furthermore, since the ends are restrained, meandering of the rolled material is also prevented. Therefore, there is no restriction on increasing the size of the convex portion, and the convex portion can be made larger.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a state in which a rolled material W is being rolled by a rolling mill 1 disposed upstream of a finishing rolling mill. First, to explain the rolling mill IK, 2 and 3 are upper and lower work rolls, 4 and 5 are backup rolls, and work roll 2
, 3 are provided so as to be shiftable in the (F) and (B) directions in the figure.A V-shaped groove 2a is formed on the roll circumferential surface near the right end of the upper work roll 20 in the figure, and the grooves 2& A parallel part 2b that can roll down the rolled material W in the thickness direction is formed on the peripheral surface of the roll on the end side. Therefore, this work roll 2 is nothing but one in which #2b is formed at a predetermined distance from the end of the roll, that is, the width of the parallel portion 2b.

Also, regarding the lower work roll 3, the upper work roll 2
Similar to the upper work roll 2, a groove portion 3a and a parallel portion 3b are formed at the opposite end.

First, when rolling with this rolling mill 1, the work rolls 2 and 3 are shifted in accordance with the width of the rolled material W, and as shown in the figure, the end of the rolled material W is exactly on the work roll 2.
, 3, and rolling is performed. When rolled in this manner, the rolled material W has a cross-sectional shape that has convex portions Wh corresponding to the grooves 2b and 3b on the end surface, and further has a flat portion Wb corresponding to the parallel portions 2b and 3b on the end side. Becomes the property of

Next, the rolled material W having such a cross-sectional shape is passed between the upper and lower work rolls 7.8 of the finishing rolling mill 6 in the latter stage as shown in FIG. A rolled material W having a rectangular cross section is obtained.

In this case, as mentioned above, there is no risk of meandering or damage even if the 1b portion W& is increased, so the sizes of the grooves 2 &,' 3a of the work rolls 2, 3 are set to increase the convex portion W&. However, a large cross-sectional shape of the convex portion Wa is obtained in the first stage of rolling. By doing so, even if the rolling reduction amount is large in the subsequent rolling, effective rectangularization can be achieved. Furthermore, by rolling with this method, the raised portion is rolled down in the next flat pass, and the rolling mass flow flows in the width direction, so the width of the thin plate can be adjusted.

〔Effect of the invention〕

As explained above, the method for rectangularizing a rolled material of the present invention involves forming convex portions on the rolled material/edges using the grooves formed in the work rolls, and rolling down the outside of the rolled material in the thickness direction. Since the flat portion is formed, meandering and damage of the rolled material can be prevented. Therefore, the convex portion can be made larger, and the cross section of the rolled material can be more effectively made rectangular. It is also possible to control the width of the rolled material.

[Brief explanation of the drawing]

Figures 1 to 3 are for explaining one embodiment of the present invention. Figure 1 is a front view showing the state in which rolling is being performed by the rolling mill in the previous stage, and Figure 2 is a front view showing the state in which the rolling machine is being rolled by the rolling mill in the former stage, and Figure 2 is the finishing rolling process in the subsequent stage. Figure 3 is a rear view showing the state in which the machine is about to horizontally roll the material, Figure 3 is a diagram showing the cross section of the rolled material obtained through these processes, Figures 4 and 5 are for explaining the conventional example. , FIG. 4 is a front view showing a state in which rolling is being performed by a rolling mill in the former stage, and FIG. 5 is a rear view showing a state in which rolling is to be performed in a finishing rolling mill in a subsequent stage. 1... Rolling mill, 2, 3... Work roll, 2a. 3a...Groove portion, 2b, 3b...Parallel portion, 6...Finishing mill, W...Rolled material,
W&...Convex portion, W'b...Flat portion. Figure 3=〒=

Claims (1)

[Claims] The upper and lower work rolls have grooves extending along the circumferential direction on the roll circumferential surfaces near mutually opposite ends, and parallel grooves are formed on the roll circumferential surfaces further toward the ends of the grooves so that the rolled material can be rolled down in the thickness direction. A rolling mill that has a convex part corresponding to the groove part of the upper and lower work rolls at both ends, and which is parallel to the end part side, is used to roll the rolled material using a rolling mill that has a convex part that corresponds to the groove part of the upper and lower work rolls at both ends. A method for making a cross-section of a rolled material into a rectangular shape, comprising rolling the material into a cross-sectional shape having a flat part corresponding to the part, and then flattening the convex part by horizontal rolling using a finishing rolling mill in a subsequent stage.