JPH04300004A - Method for cold rolling and its work roll - Google Patents

Abstract

PURPOSE:To improve the surface gloss of a product and the efficiency in rolling work, in regard to the cold rolling of a sheet metal. CONSTITUTION:By using a plating bath in which solid particles are uniformly dispersed so that projections having 0.1-10mum size may be formed on the surface of a work roll at approximately uniform spaces of 0.1-60mum, composite platings are applied on the surface of the work roll. Consequently, the minute projections are formed on the surface of the work roll at approximately uniform spaces. A metal plate which is rolled with the work roll having minute projections shows the uniform distribution of oil pits and improved gloss on the surface of the plate.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a cold rolling method and a work roll for cold rolling, and particularly to a method for rolling a thin plate made of stainless steel or ordinary steel with excellent surface gloss, and a work roll used for the rolling. .

0002

BACKGROUND OF THE INVENTION Some thin metal plates, such as stainless steel plates, used in electronic parts, ornaments, home appliances, and other products are required to have high surface gloss. It is known that the surface roughness of work rolls and rolling lubrication are greatly involved in surface gloss. Therefore, conventionally, work rolls with smooth surfaces are used. For example, the surface roughness of the work roll of a Sendzimir mill used for rolling stainless steel sheets is about 0.05 Ra. In addition, as a rolling lubricating oil, mineral oil, natural oil or fat, synthetic ester, or a mixture of these oils with low viscosity (for example, 15 cSt) may be used.
The following) are used (Onodera, Shido, Tomari;
1986 Spring Plasticity Lecture, 1978, 107).

0003

[Problem to be solved by the invention] When cold rolling is carried out using smooth work rolls with small surface roughness, oil pits (tiny depressions that form oil pools on the plate surface) are uneven on the plate surface. distributed in As a result, only a nearly constant gloss level corresponding to the surface roughness of the work roll can be obtained.
It was not possible to improve the glossiness. Furthermore, when a low-viscosity rolling lubricant is used to increase gloss, the oil film becomes thinner and the coefficient of friction increases. Therefore, seizure was likely to occur as the rolling load increased. For this reason, high-speed or high-reduction rolling cannot be performed, leading to a decrease in work efficiency.

The present invention aims to provide a cold rolling method and a work roll for cold rolling that can improve surface gloss and rolling efficiency.

[0005]

[Means for Solving the Problems] The cold rolling method of the present invention uniformly rolls solid fine particles so that protrusions of 0.1 to 10 μm are formed on the work roll surface at approximately uniform intervals of 0.1 to 60 μm. Composite plating is applied to the work roll surface using a plating bath dispersed in Then, the plate material is rolled using a composite plated work roll.

[0006] Furthermore, the work roll for cold rolling of the present invention is coated with a composite plating in which fine solid particles are uniformly dispersed.
Protrusions of 1 to 10 μm are formed on the work roll surface at substantially uniform intervals of 0.1 to 60 μm.

The size of the projections, 0.1 to 10 μm, is adjusted depending on the size of the solid particles. Further, the distance between the protrusions from 0.1 to 60 μm is adjusted by the amount of solid fine particles per unit volume of the plating bath. For example, if the amount of solid particles is increased, the spacing becomes smaller. If the size and spacing of the protrusions are outside the above range, the surface gloss will deteriorate. The metal matrix for composite plating includes Cr, Cu, and N.
i, Co, Ni-P or Ni-Co are suitable. In addition, as the solid fine particles to be dispersed in the plating bath, SiC
, BN, Al2 O3 or ZrO2. In order to uniformly disperse the solid particles in the plating bath, plating is performed while stirring the plating bath using a stirring device such as a stirrer.

[0008]

[Operation] When composite plating is applied to a work roll using a plating bath in which fine solid particles are uniformly dispersed, fine protrusions are formed on the roll surface at approximately uniform intervals. A plate material rolled by a work roll having such minute protrusions has oil pits distributed almost uniformly. As a result, the diffused reflection of light due to the uneven distribution of oil pits is reduced, and the glossiness of the plate surface is improved.

[0009]

[Example] Ni-
Composite plating was performed using P as a metal matrix and dispersing SiC powder. The particle size of the SiC powder was 0.5 μm. The plating bath for forming composite plating contains 700 g/l of nickel sulfamate and 2 nickel chloride.
0g/l, boric acid 50g/l, hypophosphorous acid 1g/l
, saccharin soda 5g/l and SiC 100g
/l of the mixed solution was used. Composite plating was performed while preventing agglomeration of solid particles by stirring using a stirrer. The plating bath temperature was 60°C and the current density was 8A/dm2. The size of the protrusions on the work roll with composite plating is 0.3 to 0.5 μm, and the distance between the protrusions is 0.5 to 0.5 μm.
It was 1 μm.

[0010] Using the above work roll, the plate thickness was 0.15 m.
A stainless steel plate (SUS304) having a diameter of 1.5 m was rolled at a reduction ratio of 20%. The lubricating oil was a 10% water emulsion of mixed oil (mineral oil + synthetic ester). The particle size of the SiC powder was adjusted within the range of 0.1 to 2 μm to obtain various surface roughnesses of the rolled plates. The relationship between surface roughness and gloss of a rolled plate is shown in FIG. 1 in comparison with the conventional method. As is clear from FIG. 1, the gloss of the rolled plate is improved by 20 to 30% compared to the conventional method. Here, the conventional method is a method in which composite plating is not applied and rolling is performed using ordinary forged steel cold rolling rolls with adjusted surface roughness.

[0011]

[Effects of the Invention] According to the present invention, a plate material is rolled by a work roll on which microprotrusions are formed at almost uniform intervals on the roll surface, so oil pits are uniformly distributed and the glossiness of the plate surface is improved. . Therefore, high gloss can be obtained without using especially low-viscosity rolling lubricating oil during rolling, making it possible to perform high-speed or high-reduction rolling. As a result, it is possible to improve rolling efficiency. Note that there is a method of forming unevenness by irradiating the surface of the work roll with a laser. Although the same effect can be obtained with this method, the method using composite plating of the present invention can form microprotrusions at substantially uniform intervals on the roll surface at a lower cost.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between surface roughness and glossiness of a rolled plate.

Claims (2)

[Claims] Claim 1: In cold rolling of a thin plate, 0.1 to 1
Composite plating is applied to the work roll surface using a plating bath in which solid fine particles are uniformly dispersed so that protrusions of 0 μm are formed on the work roll surface at approximately uniform intervals of 0.1 to 60 μm. A cold rolling method characterized by rolling a plate material using work rolls. Claim 2: Protrusions of 0.1 to 10 μm and 0.1 to 60 μm are formed by composite plating in which fine solid particles are uniformly dispersed.
A work roll for cold rolling, characterized in that approximately uniform intervals are formed on the work roll surface.