JPH0399714A - Supporting roll for metallic strip - Google Patents

Abstract

PURPOSE:To prevent the slip of a metallic strip and to prevent sticking of foreign matter by further forming a resin layer on a roll which is coated with a chromium plating layer on the dulled surface. CONSTITUTION:A dulled base metal 1 for roll is coated with the chromium plating layer 2 on which resin 3 is applied after that. Therefore, it can be prevented that iron soap and other solid foreign matter are stuck on the supporting rolls such as deflecter rolls and bridle rolls, etc. of process line for metallic strip. Thus, the generation of defects like press marks due to foreign matter on the surface of the metallic strip is prevented. And, the frequency of roll change because of preventing the generation of the press marks can be remarkably reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a supporting roll for metal strips that prevents foreign matter from adhering to the surface of a roll having a dull pattern such as a deflector roll or a priddle roll.

<Prior Art> Generally, as a means of preventing slippage between a roll and a metal strip such as a copper strip, a method is used in which the roll surface is provided with dowels. Further, as a means to reduce the wear and deterioration of the round edges, methods such as thermal spray coating of ceramics or composite materials, Cr plating coating, etc. have been taken. However, when these rolls are used in environments where they get wet with rolling oil or water during cold rolling, or where steel plates are cleaned with alkaline liquid, solids such as iron soap, calcium soap, and other foreign substances may be deposited on the roll surface. (=J) Due to the bonding process, scratches and scratches due to slipping occur on the steel plate.

The reason for the adhesion of these solid substances is that, in the case of thermal spray coating, for example, minute protrusions are generated on the roll surface in addition to the original dots, as shown in FIG. 4, making it easier for foreign substances to mechanically adhere. In addition, in the case of Cr plating, as shown in FIG. 5, there is a relatively smooth round pattern, but this is because chromium and various soaps or other foreign substances chemically react with each other and form an "iron".

Therefore, as a method for reducing the mechanical adhesion of conventional thermal spray coatings, Japanese Patent Application Laid-Open No. 102222/1983 proposes to remove minute protrusions after thermal spraying ceramics to form a round, smooth, dull pattern. Figure 6 shows an example of a rounded, smooth surface with minute protrusions removed after ceramic spraying.

Next, Fig. 7 shows the measurement results of the friction coefficient of the roll corresponding to Figs. 4, 5, and 6, and the roughness Ra of the roughness of the dull surface where minute protrusions were removed by polishing after ceramic spraying is shown.
Even though the coefficient of friction is the same as in other cases, the coefficient of friction is small, so it cannot be expected to prevent slippage, which is the original purpose of the dull eye. Furthermore, since the microprotrusions cannot be completely removed, it is inevitable that foreign matter will land on the surface. In this respect, the technique proposed in Japanese Unexamined Patent Publication No. 102222/1988 still has room for improvement.

<Problems to be Solved by the Invention> An object of the present invention is to propose a support roll for a metal strip that can prevent the metal strip from slipping and prevent foreign matter from getting stuck.

Means for Solving the Problems> The present invention solves the above problem, that is, in order to prevent foreign matter from mechanically or chemically adhering to the roll having a dull texture, a Cr plating layer is provided on the surface of the dull texture. This is a support roll for a metal slip, characterized in that the coated roll is further coated with a resin layer.

<Function> FIG. 1 shows a conceptual diagram of the present invention. A roll base material J that has been dulled is coated with a Cr plating layer 2 and then coated with a resin 3. Figure 2 shows the roughness profile of one call at this time, and it can be seen that smooth dowels are formed. For this reason, foreign matter
, the first place is effectively prevented.

Furthermore, the results of measuring the friction coefficient are shown in FIG.

It has a coefficient of friction that is almost the same as that of Cr plating alone, and therefore slips are effectively prevented.

Note that FIG. 3 does not show the dullness in the case of only Cr plating before coating with resin, but shows the roughness of the roll P1-I fill.

Resins that can be used in the present invention include fluororesins, phenol resins, epoxy resins, etc., but it is desirable to select a resin that does not cause chemical reactions or liquefaction depending on the usage environment and temperature. Further, as a method of coating the resin layer, there are spraying, coating, etc., and any method may be used.

Moreover, the j+7 depth of the resin layer is preferably 3 to 10 μm.

If it is less than 3 pm, insufficient coverage may occur in some areas, and if it exceeds 10 μm, the roughness may decrease, which is not preferable.

<Example> Cr plating with a thickness of about 50 μI was applied to the surface of a roll that had been dulled to an Ra of 5 to 6 pm using an alumina grid material. Next, spray fluororesin on top of this to a thickness of 13 pm.
It was painted to look like this.

When this roll was applied to the roll on the exit side of a steel sheet cold rolling equipment, it took about a month because in conventional Cr plating, iron soap from rolling oil and water would adhere and fill the dull holes, causing slippage. However, by using the roll of the present invention, the adhesion of iron soap was eliminated.
I was able to use it for 4-5 months.

<Effects of the Invention> According to the present invention, it is possible to prevent iron soap and other solid foreign matter from adhering to support rolls of a metal strip processing line, such as deflector rolls and predol rolls. As a result, it is possible to prevent defects such as scratches on the surface of the fully bent strip due to foreign matter. Furthermore, the frequency of replacing the rolls to prevent the occurrence of overflow can be significantly reduced.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of the cross section of the dull roll of the present invention, Figure 2 is the roughness profile of the roll of the present invention, Figure 73 is the roughness profile of the Cr-plated roll, and Figure 4 is the roughness profile of the ceramic spray roll. , Figure 5 shows the roughness profile of the Cr-plated roll, Figure 6 shows the roughness profile of the ceramic thermal spray roll after removing minute protrusions, Figure 7 shows the friction coefficient of each roll, and Figure 8 shows the roughness profile of each roll. I? f? It is a graph showing coefficients. 1... Roll mother +4, 2... Cr plating coating layer, 3... Def 1: ]n coating layer.

Claims (1)

[Claims] A support roll for a metal strip, comprising a roll whose dull surface is coated with a Cr plating layer, and further coated with a resin layer.