JPS62130294A - Electrically conductive roll - Google Patents

Abstract

PURPOSE:To obtain an electrically conductive roll having superior corrosion and wear resistances as well as satisfactory electric conductivity by forming the roll shell of an electrically conductive roll used in an electrolyte soln. such as an electroplating soln. with a Cu alloy having a specified composition. CONSTITUTION:At least the roll shell of an electrically conductive roll is formed with a Cu alloy consisting of, by weight, 25-45% Zn, 0.5-5% Sn, 0.02-0.3% P, <=0.1% Pb, 0.1-1.0% Al and the balance Cu. For example, the roll shell 4 is produced by centrifugally casting the Cu alloy having satisfactory electric conductivity, corrosion and wear resistances. The electrically conductive roll is provided with main roll shafts which support and guide the shell 4 in a plating bath and supply electric current to the shell 4 through the slip rings of brushes 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objects of the Invention) The present invention relates to an energized roll used in electrolyte solutions such as electroplating.

(Prior art and interlayer points) A current-carrying roll in electroplating etc. is used in a plating bath.
For example, it supports and guides a belt-shaped object to be plated, such as a rolled copper product or a steel plate, and also energizes it. During use, this current-carrying roll is subject to corrosion from the plating solution and abrasion from the edges of the plated object that slide into contact with the surface. Such corrosion and abrasion cause unevenness on the surface of the roll shell, and these unevenness cause the surface to be plated. It may be transferred to the plating layer on the body, significantly impairing the plating quality. For this reason, at least the roll shell, which is the outermost layer of the current-carrying roll, must have excellent corrosion resistance and wear resistance. Conventionally, such roll shells have been made of stainless steel (SO5
), nickel-based or nickel-containing corrosion-resistant materials such as Hastelloy C1 high-purity nickel, or copper or steel coated with industrial chromium are used. The above-mentioned energizing rolls made of corrosion-resistant materials such as stainless steel and Hastelloy C1 high-purity nickel have good general corrosion resistance, but they lack galvanic corrosion resistance and abrasion resistance, are expensive, and have high electrical resistance. I can't say it's appropriate. In addition, copper or steel plated with industrial chromium has excellent wear resistance, but it has poor corrosion resistance and the plating properties are not stable, so it lacks reliability (slight changes in the plating process Cracks, pinholes, film hardness, etc. change and are not stable).

For this reason, conventional energizing rolls have a short service life and must be replaced frequently, which inevitably lowers the operating rate each time.

(Structure) The present invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a current-carrying roll that is excellent in both corrosion resistance (particularly electrolytic corrosion resistance) and wear resistance, and also has good electrical conductivity. It is an object. That is, in the present invention, at least the roll shell of the current-carrying roll contains 25 to 45% Zn and 0.9% Sn.
5-5%, PO002-0.3%, PbO, 1% or less,
An energized roll and roll used in an electrolyte solution for electroplating, etc., characterized in that it is made of a copper alloy containing 0.1 to 1.0% Al, with the remainder consisting essentially of Cu and unavoidable impurities. The hardness of the outer surface of is Shore hardness 2
The present invention relates to the above-mentioned current-carrying roll having a surface roughness Ra of 5 or more, and the above-mentioned current-carrying roll having an outer surface roughness of Ra50 to 10μ.

(Detailed Description of the Present Invention) The roll shell, which is at least the outermost layer of the current-carrying roll of the present invention, is made of a copper alloy, and the copper alloy contains Zn25 to Zn45.
Contains %.

The reason why the Zn content is 25 to 45% is that if it is less than 25%, the acid resistance will drop sharply, and if it exceeds 45%, the electrical conductivity and acid resistance will deteriorate.

, this brass containing 25 to 45% of Zn contains 0.5 to 0.5% of Sn.
Contains 5%. This improves sulfuric acid resistance and mechanical wear resistance.

The reason why Sn is set at 0.5 to 5% is that if it is less than 0.5%, it will not have this effect, and if it exceeds 5%, it will suddenly become brittle.

By adding 0.02 to 0.3% of P to Zara,
Oxidation resistance is significantly improved. In particular, it is maximum at around 0.05 to 0.2%. However, if this P exceeds 0.3%, it becomes brittle and is not suitable as a current-carrying roll. Conversely, if it is less than 0.02%, there will be no significant effect on oxidation resistance.

Further, the Pb content is 0.1% or less. pb is 0.1
If it exceeds %, acid resistance and abrasion resistance decrease, which is not preferable. Furthermore, by adding 0.1 to 1.0% of A1, the dezincing resistance is significantly improved. A1 addition amount 0.
If it is less than 1%, there is no effect, and if it exceeds 1.0%, the acid resistance during immersion will be significantly lowered.

The energized roll is manufactured using the centrifugal casting method, which maintains the uniformity of the roll shell surface structure (uniform crystal grains).
Further, it is preferable because it is easy to obtain roundness, has high hardness, and is inexpensive.

FIG. 1 shows an example of the roll of the present invention. The roll shell 4 is made of the copper alloy of the present invention, which has good corrosion resistance, wear resistance, and electrical conductivity, by centrifugal casting. This energized roll supports the roll shell 4 in the plating bath.

It is provided with a roll main shaft 6 for guiding and supplying electricity to the roll shell through the slip ring of the brush 1.

An auxiliary energizing plate 5 inside the baffle plate lid is provided inside the roll shell 4 so that the roll shell 4 can be cooled more effectively. This serves to minimize the potential difference between the central portion of the roll shell's four widths and both end portions, thereby reducing local electrolytic corrosion. Cooling water is supplied through one channel port 2, passes through the inside of the roll shell, and is discharged through a cooling water discharge lower on the opposite side.

The hardness of the outer layer of the current-carrying roll of the present invention is preferably made of a hard material having a Shore hardness of 25 or more, thereby providing a roll with high wear resistance. Further, the surface roughness of the roll shell is Ra: 50 to 10μ. If Ra is less than 10μ, a water film is formed when the plating solution adhering to the strip surface comes into contact with the surface of the energized roll shell, which is undesirable because it tends to cause surface abnormalities such as voltage drop and pitting. Also 5
If it exceeds 0μ, a pattern due to the uneven portions will be printed on the strip, causing surface abnormalities. This phenomenon is particularly noticeable when high-speed plating is performed using high current density.

(Example) Next, an example will be described.

A roll shell was made using the alloy composition shown in Table 1 using the centrifugal casting method, a part of which was cut, and the sample material (size,
20t x 50mm x 50mm).

The electrolytic corrosion weight loss was determined by applying a current of 500 mA to a copper sulfate plating solution shown below using a platinum plate as a counter electrode, and after 24 hours, measuring the weight of the sample before and after one current application, and using the difference as the electrolytic corrosion weight loss.

Below is a margin test 1 ~ Plating solution copper sulfate bath (1) Copper sulfate 250 g / Q Sulfuric acid 100 g / n pH 0,2 Solution temperature 40 ± 2 ° C
While rotating at m, apply a load of 2 kg/d,
, G, P 50A mating material (Il] 50 mm) and 2
The sample material was worn for 4 hours, and the weight loss due to abrasion of the sample material was measured.

1) Test material dimensions 20φ x 5 areas 2) Plating solution Test plating solution cylinder 1 The energizing rolls made of the copper alloy of the present invention (sample numbers 1 to 10) have the capacity shown in Table 1, compared with conventional materials. Example (sample numbers 11-16
), it has excellent electrolytic corrosion resistance and wear resistance, and high electrical conductivity, and is particularly suitable for current-carrying rolls used in electrolyte solutions for electroplating and the like.

Margin below

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view schematically showing an energizing roll. 1 varnish spring 2: Waterway mouth 3: Electrical auxiliary conductor 4: Roll shell 5: Auxiliary energizing board inside the baffle plate lid 6: Roll spindle

Claims (3)

[Claims] (1) At least the roll shell of the energized roll is Zn25
~45% by weight (hereinafter abbreviated as "weight") Sn0.5-5
%, P0.02-0.3%, Pb0.1% or less, Al0
．． 1. A current-carrying roll used in an electrolyte solution for electroplating, etc., characterized in that it is made of a copper alloy containing 1 to 1.0% of Cu, with the remainder consisting essentially of Cu and unavoidable impurities. (2) The energized roll according to claim 1, wherein the outer surface of the roll has a Shore hardness of 25 or more. (3) The current-carrying roll according to claim 1 or 2, wherein the outer surface of the roll has a surface roughness Ra of 50 to 10μ.