JPS5938860B2 - Manufacturing method of composite roll for rolling with uneven outer shell layer thickness - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the provision of a composite roll for rolling in which the thickness of the outer shell layer is not constant.

For example, recently it has been proposed to use composite rolls for rolling such as work rolls of quadruple rolling mills that employ the roll bending method, with the outer shell layer of the body having a thickness that is not constant in the axial direction. .

In other words, by changing the thickness of the outer shell layer in the direction of the axis of the body, the rigidity of the roll is partially changed, which facilitates the deformability of the roll by bending and flattening it. A new composite roll technology has been established by the present inventors that can contribute to improving shape control ability in rolling, reducing penguin load, reducing edge drop of rolled material, etc.

By the way, currently, the common methods for manufacturing composite rolls are centrifugal casting or hollow casting, but in principle, with these methods, the thickness of the outer shell layer in the roll body remains constant. The reality is that existing casting techniques cannot produce the desired composite roll whose outer shell layer thickness is not constant.

This is based on the fact that even in the case of the casting method described above, the inner circumferential surface of the previously cast outer shell layer must be uniform in its axial direction.

Therefore, the present invention was made with the aim of establishing a manufacturing technology exclusively for this type of composite roll in order to obtain a desired composite roll in which the thickness of the outer shell layer is not constant. First, by casting or mechanical cutting, a composite roll material having a circumferential surface or circumferential surface on the outer peripheral surface of the body and an outer shell layer thickness of which is not constant is cast or formed, and then the body of this roll material is Add forging or rotary forging to the outer shell layer to pressurize the outer peripheral surface to a flat surface while pushing the outer shell layer thickness into the core material thickness while maintaining the original outer shell layer thickness distribution. It is characterized by:

The present invention will be described in detail below. In order to manufacture the composite roll for the purpose, Mizuyoshi firstly, as the first step,
The present invention is characterized by obtaining a composite roll material having a circumferential convex portion or a circumferential surface on the outer circumferential surface of the body and having an irregular outer shell layer thickness.

There are two methods for manufacturing this roll material: one is direct casting, and the other is casting cutting.

First, we will explain the case of direct casting. In this case, as shown in Fig. 1, Fig. 2, or Fig. 3, the casting mold (in the illustrated example, a centrifugal casting mold) is used. A mold is constructed by arranging a body chiller 1 having a circumferential surface B or a circumferential convex portion A on the inner circumferential surface thereof.

In this case, it goes without saying that 2 and 2 in the figure are sand molds for forming the neck part similar to the conventional ones, and for convenience of taking out the casting, the horizontal part 3 in the case of Fig. 1 and the sand mold in the case of Fig. 2 are used. In this case, it is necessary to use four vertically divided chillers.

Therefore, if a mold having such a curvature on the inner surface of the body chiller is used, first the outer shell layer 5 is cast, and then the core material 6 is cast, as in the conventional method, and the result corresponds to FIG. 1 or 2. and the fourth
As shown in the figure or FIG.
Alternatively, a composite roll material having a circumferential surface B and an outer shell layer whose thickness is not constant (the inner circumferential surface of the outer shell layer is uniform) is cast.

Note that although the illustrated example shows the case of centrifugal force casting, this can be similarly applied to the medium plate casting method.

Next, another cutting process for obtaining this composite roll material will be described.

In this case, a conventional casting mold (one in which the inner circumferential surface of the body chiller 1 does not have curvature in Figures 1 and 2) is used, and according to the usual composite roll casting method, as shown in Figure 6. After a composite roll casting having a flat outer circumferential surface of the body and a constant thickness of the outer shell layer 5 is cast, it is mechanically cut as shown by dotted lines a and b in the figure.

In this way, as in the case of casting, the composite roll material having the circumferential protrusion A or the circumferential surface B on the outer circumferential surface of the body shown in FIG. 4 or FIG. It is formed.

Therefore, as the second step of the present invention, plastic working is applied to the roll material having the circumferential convex portion A or the circumferential surface B on the outer circumferential surface of the body obtained in the first step, and the outer shell layer thickness is not constant. It is characterized by obtaining the desired composite roll.

In other words, if forging or rotary forging, which is known in the field of roll processing technology, is applied to this roll material on the roll body having the circumferential convex portion A or the circumferential surface B, the original outer shell layer thickness distribution (the central part of the body The thickness of the outer shell layer 5 is approximately the same as that of the core material, or the thickness of the outer shell layer at both ends of the torso is approximately the same as that of the core material. It is easily possible to push it to the 6th side.

Therefore, when the outer circumferential surface of the body of the roll material is pressure-formed to a flat surface, the processed composite roll has a circumferential convex portion on the original outer circumferential surface on the inner circumferential surface side of the outer shell layer 5 that joins with the core material 6. It is possible to obtain a circumferential convex portion A' or circumferential surface B that is symmetrical to A or circumferential surface B.

FIGS. 7 and 8 schematically illustrate this forging process. In the case of a roll material having a convex peripheral surface on the outer circumferential surface of the body as shown in FIG. 4, the central part is pressurized P. In addition, in the case of a roll material having a circumferential surface B on the outer circumferential surface of the body as shown in FIG. Moreover, it is possible to obtain a structure having a circumferential convex portion A' or a circumferential surface B on the inner circumferential surface side of the outer shell layer 5 which is joined to the core material 6.

Note that when the body of the roll material is pressure-formed, the roll is elongated in the axial direction so that the outer shell layer 5 substantially corresponds to the wall thickness volume that is pushed into the core material 6.

The structure of the composite roll manufactured by the method of the present invention described above is as shown in FIGS. 9 and 10, in which the inner peripheral surface of the outer shell layer 5 has a circumferential convex portion A' having an appropriate curvature. Alternatively, since it has a circumferential surface, it is possible to make the thickness of the outer shell layer 5 a desired non-uniform distribution in the axial direction of the body.

It goes without saying that the curvature of the circumferential convex portion A' or the circumferential surface B of the outer shell layer 5 depends on that of the circumferential convex portion A or the circumferential surface B of the outer circumferential surface of the body of the original roll material.

The present invention is as described above, and includes a step of manufacturing a composite roll material having a circumferential convex portion or a circumferential surface on the outer circumferential surface of the body and an uneven thickness of the outer shell layer, and a process of forging or rotary forging the body of the roll material. By combining this with the process of adding and pushing the outer shell layer into the core layer in a predetermined state, it is possible to easily produce products with uneven outer shell layer thickness, which could not be obtained with conventional composite roll manufacturing methods. This makes it possible to industrially provide the new type of rolling roll described above.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views showing one example of a mold used for implementing the present invention, and FIG. 3 is a cross-sectional view of FIG. 2. FIGS. 4 and 5 are half-sectional side views showing the composite roll material used in the present invention. FIG. 6 is a sectional view for explaining the case where the composite roll material is formed by cutting. FIG. 7 and FIG. 8 are cross-sectional views for schematically explaining the plastic working of the roll material according to the present invention. 9 and 10 are half-sectional side views of a composite roll obtained by the present invention, in which the outer shell layer thickness is not constant. 1...Chiller, 2...Sand mold, 5...
...Outer shell layer, 6...Core material, A, N'...
... Circumferential convex portion, B, I3'... Circumferential surface.

Claims (1)

[Claims] 1. In manufacturing the composite roll, the casting mold is
A body chiller having a circumferential surface or circumferential surface on the inner circumferential surface is disposed, and a composite roll material having an outer shell layer having an uneven thickness and having a circumferential surface or circumferential surface on the outer circumferential surface of the body is cast. Forging or rotary forging is applied to the body of the material to push the thickness of the outer shell layer into the thickness of the core material, while maintaining the original thickness distribution of the outer shell layer, until the outer peripheral surface becomes a flat surface. A method for manufacturing a composite roll for rolling, which is characterized by pressure forming and has an uneven outer shell layer thickness. 2. In manufacturing a composite roll, a composite roll casting having a flat outer peripheral surface of the body and a constant thickness of the outer shell layer is cast according to the usual composite roll casting method, and then cutting is performed on the composite roll casting. In addition, a composite roll material having a circumferential surface or circumferential surface on the outer circumferential surface of the body and an uneven outer shell layer thickness is formed, and the body of this roll material is forged or rotary forged to form the outer shell layer. The outer shell layer thickness is not constant, which is characterized by pressure forming the outer peripheral surface to a flat surface while pushing the wall thickness into the core material thickness while maintaining the original outer shell layer thickness distribution. Manufacturing method for composite rolls for rolling.