JPS5824514B2 - Current roll for electroplating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a current-carrying roll for electroplating used in electroplating of steel (IJ) or subsequent chemical conversion treatment and heat treatment.

For example, energizing rolls for electroplating are widely used in the plating section and chemical processing section of IJ plating lines. Traditionally, mirror finish rolls, dull rolls, or rolls with regular intersecting and communicating grooves have been used to finish the surface of energizing rolls. It's here.

Mirror-finished rolls contact the entire surface of the IJ tube, so arc spots are less likely to occur due to local contact between the IJ tube and the roll surface, but slips are more likely to occur because the friction between the strip and the roll is small, and the surface of the strip is more likely to slip. There is a defect in that slip defects occur.

Also, the intersecting and continuous groove roll is advantageous for arc spots, but in addition to the defect that marks of the communication groove remain on the surface of the IJ knob, it also has the disadvantage that extremely advanced technology is required for roll processing. be.

For this reason, dull rolls are generally used, but these known dull rolls have a surface roughness of about 4μ, but P
The PI was as low as 130, and there were many problems as a current-carrying roll.

The problem with ordinary shot blast finishing is that arc spots are likely to occur because wear occurs unevenly.

The inventors of the present invention have conducted various experiments and studies to solve the above-mentioned problems with dull rolls, and have found that the generation of arc spots can be prevented if the surface profile of the dull roll is defined within a certain range.

The gist thereof is a current-carrying roll for electroplating having a dull roll surface with a roll surface roughness of 3.0 to 5.0 μRa and a cutoff level of 1.2 to 1.3 μ and a PP of 1150 or higher.

The reason for numerically limiting the present invention as described above will be explained in detail.

The unit Ra of roll surface roughness is the center line average roughness of 3.0μ.
If the roughness is less than Ra, slips are likely to occur between the IJ knob and the roll, and if the roughness is 5.0μ or more, the surface gloss of the plated product will deteriorate.

The cut-off level is the peak of each mountain that determines the roughness cut to a certain height standard.If it is less than 1.2μRa, the undulations of the reference line are counted, and the undulations of the reference line are counted at 1, 3μ&
If this value is exceeded, the number of mountains that have an effect will be unfairly undercounted.

That is, the cutoff level of 1.2 to 1.3 μRa is the range in which the number of peaks that bring about the effect can be accurately counted.

At such a cutoff level of 1.2 to 1.3 μRa, a PP of 1150 or more is required.

Furthermore, PPI is the number of ridges per inch of length (Pear
If the PPI is less than 150, the cross-sectional area of each peak becomes large, and generally the cross-sectional area of the peaks varies widely, making the state of wear non-uniform and making arc spots more likely to occur.

The dull roll according to the present invention moves the electrodes of an electrolytic copper plate arranged at equal intervals in the axial direction of the roll immersed in oil and rotates, and repeats the spark phenomenon caused by the discharge in the oil, so that the surface of the roll is spirally shaped. Manufactured using electric discharge dull machining method.

It is also produced by shot blasting using a grid with a grain size selected within a certain range, but arc spots are significantly reduced when such a roll is used as a current carrying roll for electroplating.

Next, examples of the present invention will be described.

Using various dull rolls as energized rolls in electric tin plating lines, the frequency of occurrence of arc spots, the occurrence of slip defects between the strip and the roll, and the surface gloss of plated products were investigated.

As is clear from the above results, roll numbers 3 to 5 according to the present invention are electric discharge dull processed rolls (10 rpm in processing oil).
An electrode plate with a thickness of 2 mm and a width of 40 nrn was placed in the axial direction of a rotating roll, and while moving at a constant speed of 20 + m1, a high frequency pulse power source was applied 300,000 to 2,000 times/.
(manufactured by discharging in oil by repeatedly turning the voltage ON and OFF at a rate of seconds).
(Manufactured by repeating voltage ON and OFF at a rate of ,000 to 900 times/second), it is superior in arc spot generation, slip flaw generation, and surface gloss of plated products.

The frequency of occurrence of arc spots and slip defects in the table is based on the results of threading 1000 coils of tin plated products, and the surface gloss of plated products is the result of visual judgment.

[Brief explanation of drawings]

FIG. 1 shows the effect of PPI of around 150 on the frequency of occurrence of arc spots and slip flaws and on the surface gloss of plated products with respect to the surface roughness of energized dull plates.

Claims (1)

[Claims] 1 Roll surface roughness 3. An energizing roll for electroplating, characterized in that it has a dull roll surface shape with a cutoff level of 1.2 to 1.3μ and a PP of 1150 or more.