JPH0366404A - Surface roughening method for cold rolling roll - Google Patents

Abstract

PURPOSE:To give a wear resistance in the state of just as a dull working face by executing an ion implantation after executing a laser dull working or electric discharging dull working on the surface of a cold rolling roll. CONSTITUTION:A laser dull working or an electric discharging dull working is executed on a cold rolling roll 1 and after forming the surface roughening it is put in an evacuated iron implantation device and the surface quality is improved by driving the composite of N, Cr, Ti, etc., for instance, with its ionization into a specific zone from the surface. Since, therefore, the unevenness of the cold rolling roll 1 formed by the laser dull working or electric discharging dull working is hardened just as the same unevenness by the ion implantation, a roll excellent in the brightness of reflectivity, pressing property, drawability and painting adhesion, also having a long roll life can be obtd.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a cold rolling roll such as a temper rolling roll, which is roughened by laser dulling or electric discharge dulling, and then subjected to ion implantation. The present invention relates to a surface roughening method for obtaining a cold rolling roll with wear resistance imparted by roughening.

[Prior Art] Rolled steel plates are required to have various qualities and characteristics, such as material, physical properties, shape, and dimensions, one of which is surface quality. Surface quality includes aesthetics, or the cleanliness of the edges, paintability, or the adhesion of paint or enamel, workability, or the difficulty of processing such as press working or DI processing, corrosion resistance, mainly rusting, and optical properties, or visibility. There are many factors such as reflection and absorption of light and infrared rays, shaft sealing, etc., and there are many factors that determine these, such as the physical, mechanical, and chemical properties of the surface.
One of them is surface geometry, ie surface roughness.

The most common method of imparting roughness to the surface of a rolled product is to process the surface of a cold rolling roll or temper rolling roll to a predetermined roughness, then rolling a steel plate with this roll at a predetermined pressure to roughen the plate surface. This is a method that transfers the roughness of the mouth/ru surface.

Conventionally widely used methods for roughening the roll surface include shot blasting and electrical discharge machining, and in recent years, laser tar machining, which can process regular dull motifs, has been attracting attention. There is. The life of dull rolls used for rolling is a very important factor and depends on the wear resistance and deformation resistance of the surface irregularities during rolling.

Shot blasting is very simple and has the advantage of work-hardening the roll surface and improving the wear resistance of the roll, but it also has the advantage of uneven roughness and hard rolls. However, it requires a long processing time and has the drawbacks that it is difficult to create deep roughness.

In electrical discharge machining, roughness is suppressed by changing the applied voltage and frequency between a rotating roll and an axially moving electrode, but the range of the spark that determines the size of the crater depends on the electrode. Since it is determined by the geometry, it is difficult to obtain detailed pitch small roughness beyond a certain limit. Further, although the temperature is controlled because electrical discharge machining is performed in oil, the cooling rate on the machined surface is low, and the convex portions produced by electrical discharge machining are soft. Therefore, the initial wear of the rolls during rolling is severe, and the roughness of the transferred plate surface changes significantly.

The laser processing method irradiates the roll surface with a laser point by point in the atmosphere and creates craters by melting.
It is possible to easily and regularly create motifs using dowels of the same shape. On the other hand, the cooling rate after melting is slower than that of electrical discharge machining, and the roll life is short.

From the above, looking at the laser dull processing method in particular as a solution to extend roll life, after crater creation, the cooling rate is increased by forced air cooling, water cooling, etc. As shown in Figure 2, methods are being considered to extend the life of the roll by increasing the surface hardness, such as applying chrome plating after laser dulling.

[To be solved by the invention: JA problem] Laser dull processing and electric discharge dull processing can form an uneven pattern on the roll surface, and the life of the unevenness is the life of the dull roll, and the sharpness of the steel plate, It is no exaggeration to say that it affects pressability, drawability, and paint adhesion.

When chrome plating is applied after this dulling process, since the surface is plated, the unevenness becomes gentle and the recesses are filled (Fig. 3).

Therefore, the key points in dulling are the surface roughness of the roll, and especially the crater pitch, diameter, and depth for laser dulling, in order to transfer the roll dullness to the steel plate. Therefore, even if processing conditions for the dull are set to obtain these necessary conditions, desired characteristics cannot be obtained because the conditions vary greatly depending on the plating thickness. On the other hand, it may be possible to carry out dull processing that takes into account the plating, but
In this case, since the amount of dull processing becomes large, there are problems in terms of processing time and energy loss. In addition, in order to obtain the necessary conditions, it is necessary to set the settings after two steps of dulling and plating, which is technically difficult and may lead to errors. For this reason, it is necessary to obtain the necessary conditions and impart wear resistance etc. in a single step of barrel processing.

The present invention performs surface modification on the roll surface that has been subjected to laser dull processing or electric discharge dull processing without applying any cosmetic treatment.
It is an object of the present invention to provide a method for roughening a roll, which causes less wear during rolling and less decrease in roughness by imparting wear resistance.

[Means for Solving the Problems] The roll surface roughening method of the present invention for achieving this object includes laser dulling or electric discharge dulling on the roll surface when roughening the cold rolled roll. The method is characterized in that after the ion implantation is performed, ion implantation is performed.

[Operations and Examples] Fig. 1 shows a microscopic observation of the surface of the hole 1 which was subjected to ion implantation after laser dulling. Note that FIG. 25 shows a product that has only undergone laser dull processing, and FIG. 3 shows a product that has been subjected to chrome plating 2 after laser dull processing.

The surface of the roll 1 that has been subjected to ion implantation is the same as the surface that has only been laser dulled, and the region 3 in which wear-resistant metal ions are implanted inside the surface and modified by ion implantation.
is obtained. One example is shown below.

After performing laser dulling or electric discharge dulling on a cold rolling roll to form a rough surface, it is placed in an ion implantation device evacuated to about 10-''' Torr, and then heated to, for example, 8% C.
The surface is modified by ionizing and implanting a composite such as r, Ti', Sn, or Ti+C into a region several tens to several thousand angstroms from the surface. Since this is processed without increasing the temperature E, there is no change after modification. Therefore, the unevenness of the cold rolling roll formed by laser dulling or electric discharge dulling is hardened by ion implantation with the same unevenness.

[Effects of the Invention] The present invention allows wear-resistant metal ions to be injected into the surface of the roll while leaving the uneven pattern formed by laser dulling or electric discharge dulling on the roll surface, thereby improving the image clarity, pressability, and Rolls with excellent drawability and paint adhesion and long roll life can be obtained.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) are schematic plan views and cross-sectional views of the roll surface with ion implantation after laser dulling according to the present invention, and FIG. 2 is a cross-sectional view of the roll surface subjected to laser dulling only.
FIG. 3 is a sectional view of the surface of a roll which has been chromed after laser dulling according to the prior art. 1... Roll, 2... Chrome plating, 3... Area modified by ion implantation.

Claims (1)

[Claims] 1. When roughening the cold rolling roll, after applying laser dulling or electric discharge dulling to the roll surface,
A method for roughening the surface of a cold rolling roll, characterized by performing ion implantation.