GB2069906A

GB2069906A - Method for working surface of cold rolling work roll

Info

Publication number: GB2069906A
Application number: GB8038693A
Authority: GB
Original assignee: Sumitomo Metal Industries Ltd
Current assignee: Nippon Steel Corp
Priority date: 1980-02-27
Filing date: 1980-12-03
Publication date: 1981-09-03
Also published as: FR2476524B1; DE3100927A1; FR2476524A1

Abstract

The surface of a cold rolling work roll R is roughened by a beam working apparatus comprising a work table T, a working chamber installed on said work table and having a working beam generator 3 and a work support 2 mounted movably in three perpendicularly intersecting directions x, y and z on said work table and supporting the cold rolling work roll rotatably. Roughening operation of the roll surface is performed by projecting the working beam e.g. electron or laser onto the roll surface while moving the work support and rotating the roll. <IMAGE>

Description

SPECIFICATION Method for working surface of cold rolling work roll The present invention relates to a method for working the surface of a roll for use in the temper rolling step of cold rolling thereof by a working beam such as an electron beam or a laser beam.

In the manufacture of cold rolled steel sheets are included such steps as impressing pear-skin pattern on the surface of the steel sheet and as working a patterned steel sheet (such as checkers and waves) for the purpose of improving the workability and the coatability of the steel sheet by the press. In these steps, the pattern is transferred to the surface of the steel sheet upon rolling by a roll of the surface having fine depressions and rises, that is the shape of the depressions and rises on the surface of the roll are transferred faithfully onto the surface of the steel sheet. Accordingly, the topographical features of the roll surface such as the resultant figures of the roughening process or wavy figures are combined faithfully with the finished condition of the surface of the steel sheet.Therefore, the roughened condition of the roll surface has a considerable effect on the surface of the product. Some of the conventional methods for, for example, roughening the roll surface include shot blasting process in which particles of a material are injected onto the roll surface to create depressions and rises thereon by the impact upon the impingement of the particles with the roll surface, and electrical discharge machining process. While the shot blasting process is commonly used and low in cost, it has a disadvantage of lack of uniformity in the surface configuration and roughness. On the other hand, while the electric discharge machining process is capable of satisfy the requirement for uniformity in the surface roughness to a certain extent, it is considerably expensive in equipment.

The object of the present invention is to cope with problems in these conventional machining methods and to provide a method for working a roll to have the highly uniformly roughened surface, using a working beam such as an electron beam or a laser beam.

The means of working a solid body by the working beam such as the electron beam or the laser beam is a known technique having the principle described below. For example, when an electron beam impinges upon a solid body at a high velocity, the electron stops at the thin surface layer of the solid body and imparts 99% or more of its energy to the layer in the form of heat.

Accordingly, when the electron beam is converged finely by an electromagnetic lens to focus on the surface of the solid material, a relatively large energy is concentrated to a very small area of the surface of the solid at which the material is volatized by the very high temperature to thereby render the desired working operation. Likewise, when the strong laser beam is converged finely by an optical lens to focus on the surface of the solid material, a relatively large energy is concentrated to a very small area of the surface of the solid at which the material is volatized by the very high temperature to thereby render the desired working operation.

Accordingly, the principal object of the present invention is to perform working operation on the roll surface with a high uniformity utilizing the properties of the working beam such as the electron beam or laser beam, and a beam working apparatus is provided for this purpose.

The invention will be better understood from the following description taken in connection with the accompanying drawings in which: Fig. 1 is a schematic illustration of the construction of the beam working apparatus for use in the practice of the method according to the present invention; Fig. 2A is a plan view of the basic working pattern by the method according to the present invention; Fig. 2B is a magnified plan view of the pattern of Fig. 2A; Fig. 3A is a plan view of a modification of the working pattern by the method according to the present invention; Fig. 3B is a magnified plan view of the pattern of Fig. 3A; Fig. 3C is a magnified sectional view of the pattern of Fig. 3A; Fig. 4A is a plan view of another modification of the working pattern by the method according to the present invention; Fig. 4B is a magnified plan view of the pattern of Fig. 4A;; Fig. 5A is a plan view of a further modification of the working pattern by the method according to the present invention; Fig. 5B is a magnified plan view of the pattern of Fig.

Fig. 6A is a microscopic view of the surface of a work roll roughened by the conventional shot blasting; Fig. 6B is a microscopic view of the surface of a work roll roughened by the conventional electric discharge machining; Fig. 6C is a microscopic view of the surface of a work roll roughened by the method according to the present invention; Fig. 7A is a measurement diagram on a record paper of a roughness meter showing the surface condition of a work roll roughened by the shot blasting process; Fig. 7B is a measurement diagram on a record paper of a roughness meter showing the surface condition of a work roll roughened by the electric discharge machining process; and Fig. 7C is a measurement diagram on a record paper of a roughness meter showing the surface condition of a work roll roughened by the method according to the present invention.

The beam working apparatus used in the method is of the construction having a working chamber 1 mounted on a work table T. The beam working apparatus generates a working beam such as an electron beam or a laser beam to thereby work the surface of a cold rolling work roll R supported within the working chamber 1.

In the case where the working beam is an electron beam, it is desirable that the pressure within the working chamber 1 is reduced to 1 x 10-1 torr or lower by a vacuum pump 1 1. In the case where the working beam is a laser beam, it is not necessary to evacuate the working chamber 1.

A work support 2 for the roll R to be worked is provided within the working chamber 1. The work support 2 is provided with drive unit 21 and 22 for adjusting movement along horizontal x, y directions and a vertical z direction and is adapted to support the roll R horizontally for rotatable drive. Further, the working chamber 1 is provided with an entrance 12 through which the roll R is carried into and out of the working chamber by a charging means (not illustrated) such as a truck.

On the top of the working chamber 1 is mounted integrally a working beam generator 3 for generating the working beam such as the electron beam or the laser beam. The working beam generator 3 may be of a known construction including a beam gun, a beam strength adjusting element, a beam convergence adjusting element, a beam position deflection adjusting element, and the like. The beam generator 3 is so positioned that the converged end of the working beam 31 generated thereby corresponds to the position of the working surface of the roll R supported by the work support 2. The working chamber 1 is provided with an observation system 4 for observing the process of the working therein.

In the case where the laser beam is used, the laser beam generator 3 may be located separately from the working chamber 1 to guide the laser beam to the roll R to be worked by an optical system such as a fiber glass, a reflector 41 or the like.

In the working operation, the roll R mounted on the work support 2 is worked along the overall circumference while being rotating little by little, and then the work support is shifted one pitch longitudinally of the roll R for the next overall circumferential working thereof. Alternatively, the working beam generator 3 may be adjusted in deflection so as to cope with the change in the working position in a limited range. Further, the strength of the working beam, which is a deciding factor of the working depth, can be regulated by adjusting the beam gun.

In the beam working method according to the present invention, since it is possible to work accurately regular patterns in a very short period of time by using the means of a beam scanning type which burns any desired patterns by scanning an area of the order of 0.1-500 mm with a beam converged to 100 ,um or less, longitudinal and lateral working pitches P1 and P2, respectively, and working diameter D can be easily set, for example, in the basic case of working circular depressions as shown in Figs. 2A and 2B.

Accordingly, in the beam working method according to the present invention it is made possible to work various patterns such as a parallel groove pattern having predetermined width B and depth d of the grooves as shown in Figs. 3A, 3B and 3C, a checkers groove pattern as shown in Figs 4A and 4B, and a regular groove pattern with changed width of the grooves as shown in Figs. 5A and 5B.

In the conventional shot blasting process, the worked roll surface locked uniformity in the surface configuration and roughness as shown in Figs. 6A and 7A. The conventional electric discharge machining process was, while satisfying the requirement for uniformity to some extent as shown in Figs. 6B and 7B, not sufficiently satisfactory. The method according to the present invention, however, was capable of providing a sufficiently satisfactory regular pattern as shown in Fig. 6C and a sufficiently uniform surface roughness as shown in Fig. 7C.

The method according to the present invention, which is capable of providing a roll having a highly uniformly worked surface, has further advantages such that press-workability and coatability of the steel sheet rolled thereby are increased, wearresistance of the roll itself is increased to thereby reduce the physical unit of the rolls, and the number of the rolls to be held can be reduced.

Further, in the method according to the present invention, both the machining of the roll and the roughening work of the roll can be performed simultaneously.

While we have described and illustrated the several preferred examples of practice of the method according to the present invention, it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously practiced within the scope of the invention as

Claims

claimed. CLAIMS

1. A method for working the surface of a cold rolling work roll, comprising the steps of: providing a working chamber having a working beam generator on a work table; mounting a work support movably in three perpendicularly intersecting directions x, y and z on said work table within said working chamber; attaching the roll to be worked rotatably on said work support; and roughening the surface of the roll by projecting said working beam thereonto while moving said work support and rotating said roll.

2. A method for working the surface of a cold rolling work roll as set forth in Claim 1, in which said working beam is an electron beam.

3. A method for working the surface of a cold rolling work roll as set forth in Claim 1 , in which said working beam is a laser beam.

4. A method of working the surface of a cold rolling work roll substantially as herein described with reference to, and as shown in, Figures 1 to 2B; 1, 3A-3C; 1, 4A, 4B; 1, 5A, 5B of the accompanying drawings.