JPS6045715B2 - Manufacturing method for energizing conductor roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a current-carrying conductor roll with significantly improved corrosion resistance.

The current-carrying conductor roll is coated with electroplating such as lead plating, tin plating, alloy plating, composite plating, etc.
When manufacturing surface-treated steel sheets, there is a member for electrolyzing the steel sheet material by using it as a cathode.

Therefore, the energizing conductor roll is subject to mechanical wear due to constant contact with the steel plate and slippage occurring during such contact, and in particular, significant wear is experienced at the portion that contacts the edge of the steel plate. In addition, contact with the plating solution is unavoidable, and particularly in the case of an acidic bath, the above-mentioned mechanical wear is significantly accelerated. The material of the current-carrying conductor roll is made of iron or iron alloy, plated with copper or copper alloy to improve conductivity, or made of copper alloy. Therefore, it is used with hard chrome plating. Although hard chromium-plated current conductor rolls have sufficient hardness and no problems with wear resistance, they do not have sufficient corrosion resistance, and for example, in zinc and tin plating lines, acid Since it is a bath, it has the disadvantage of being easily corroded. In particular, in the case of a plating bath containing halogen, if the current-carrying conductor roll is plated with hard chrome, there is a fatal drawback in that it is quickly corroded even with almost no mechanical friction. Furthermore, in recent years, plating has been diversified to meet various uses, such as various alloy plating, multilayer plating, composite plating, etc.
In these plating applications, there is a demand for current-carrying conductor rolls that have particularly excellent corrosion resistance. In view of the above-mentioned current situation, the inventor of the present invention conducted extensive research on methods for improving the corrosion resistance of current-carrying conductor rolls, and as a result, the present inventors determined that the current-carrying conductor rolls should be nickel-plated or nickel-plated.
The present inventors have discovered that corrosion resistance can be significantly improved by applying nickel-tungsten alloy plating on top of phosphorus alloy plating and heat-treating it, which led to the completion of the present invention. That is, the present invention forms a nickel plating layer or a nickel-phosphorus alloy plating layer on the circumferential surface of a current-carrying conductor roll, and then coats the plating layer with a nickel-tungsten alloy plating containing 20 to 4% tungsten. A method for manufacturing a current-carrying conductor roll, characterized by forming a nickel plating layer or a nickel-phosphorus alloy plating layer on the circumferential surface of the current-carrying conductor roll, and then depositing tungsten on the plating layer. The present invention relates to a method for manufacturing a current-carrying conductor roll, which comprises forming a nickel-tungsten alloy plating layer containing 20 to 4% by weight of nickel and tungsten alloy, and then heat-treating the layer. In the current-carrying conductor roll of the present invention,
First, nickel plating or nickel-phosphorus alloy plating is applied on the peripheral surface.

In other words, the static adhesion, hardness, and thermal expansion between the current-carrying conductor roll made of iron or iron alloy or on which copper or copper alloy plating is applied and the nickel-tungsten alloy plating layer applied later. Nickel plating or nickel-plating is used as an intermediate layer to buffer dynamic adhesion due to differences in ratio, etc. and to ensure sufficient adhesion.
A phosphorus alloy plating layer is provided. The thickness of the nickel plating or nickel-phosphorus alloy plating layer is not particularly limited and is appropriately selected from a wide range, but is preferably 10
~100 μm. Next, nickel-tungsten alloy plating is applied on the nickel plating or nickel-phosphorus alloy plating layer.

The amount of tungsten in the nickel-tungsten alloy in the present invention is about 20 to 40% by weight, preferably 36% by weight.
~3% heel weight.

If the weight is less than %, the corrosion resistance and abrasion resistance will not be sufficient. Also, 40% by weight. If it exceeds the limit, the formation of a plating layer becomes a problem. The thickness of the nickel-tungsten alloy plating layer is usually about 20 to 500 pm, preferably 30 to 100 pm.
It is μm. If the thickness is less than 20 μm, the surface protection effect will not be sufficiently exhibited.

Moreover, if the thickness exceeds 500 μm, cracks may occur due to stress or the like. The nickel or nickel-phosphorus alloy layer and the nickel-tungsten alloy layer in the current-carrying conductor roll of the present invention are formed by pretreatment and plating operations according to conventional methods.

That is, the parts other than the circumferential surface of the current-carrying conductor roll made of iron or iron alloy or plated with copper or copper alloy are masked with a suitable coating material such as vinyl chloride resin paint, and then Degrease and degrease according to the usual method.
Perform acid treatment, water washing, etc. sequentially. These series of treatments include alkaline degreasing → water washing → electrolytic degreasing → water washing → acid treatment →
An example may be washing with water. In this series of treatments, alkaline degreasing is carried out using, for example, 20 to 200 g/e of caustic soda, 1 to 150 g/e of sodium carbonate, 0 to 10 g of sodium orthosilicate,
This is carried out by immersing the masked conductor roll in a degreasing bath (about PHIO to U) containing 0 g/l and a surfactant of 0.5 to 30 g/f at a temperature of about 20 to 80°C for about 5 to 6 particles. . After washing the conductor roll with water, it is subjected to electrolysis in a bath similar to that described above at a cathode current density of about 1 to 30 A/Dd, a temperature of about 30 to 70° C., and a time of about 1 to 30 minutes. After further washing the conductor roll with water, hydrochloric acid,
It is activated by immersing it in a solution containing about 5 to 50% water such as sulfuric acid at room temperature for about 1 to 10 minutes. The conductor after pretreatment
The roll is nickel plated, the yang joint is electroplated,
In the case of nickel-phosphorus alloy plating, chemical plating is performed.

The conditions for nickel plating may be the same as those for normal nickel plating. For example, nickel sulfamate 400
PH2.8-3 in a plating bath containing g/e1 boric acid 25g/e1 nickel bromide 4g/f and other additives
．． 2. The conductor is electrolytically plated at a temperature of 50 to 55°C and a cathode current of 1 to 3 A/Dd.
A nickel plating layer is formed on the circumferential surface of the roll. Further, the conditions for nickel-phosphorus alloy plating may be the same as those for normal nickel-phosphorus alloy plating.

For example, it contains nickel sulfate 90g/e, sodium hypophosphite 30g/e, sodium succinate 6g/e and other additives, pH 4.8-5.8 and temperature 90-95.
A nickel-phosphorus alloy plating layer is formed on the circumferential surface of the conductor roll by immersing it in a plating bath at a temperature of .degree. If necessary, the conductor roll plated with nickel or nickel-phosphorus alloy is pretreated in the same manner as described above, and then subjected to a conventional method.
Perform nickel-tungsten plating.

For example, nickel sulfate 5-30g/', sodium tungstate 25-55g/f1 citric acid 40-70g/'
' and a small amount of cationic surfactant or other surfactant in a plating bath with a pH of 8.6 to 9.0 and a temperature of 50 to 60.
By performing electrolytic plating under the conditions of °C and a cathode current of 5 to 10 A/d, 60 to 8% nickel and 40% tungsten are deposited on the nickel plating or nickel-phosphorus alloy plating on the circumferential surface of the conductor roll. A nickel-tungsten alloy plating layer of ~2 weight percent is formed. It goes without saying that the above bath composition can be changed as appropriate as long as the nickel or nickel-phosphorus alloy or nickel-tungsten alloy plating layer of the present invention is formed. After the conductor roll on which the plating layer has been formed is washed with water and dried, the masking coating material is removed, thus obtaining the current-carrying conductor roll of the present invention.

The current-carrying conductor roll of the present invention will be explained with reference to the drawings.

That is, in FIG. 1, a nickel plating or nickel-phosphorus alloy plating layer 2 and a nickel-tungsten alloy plating layer 3 are applied on the circumferential surface of a current-carrying conductor roll 1. In the present invention, after the formation of the plating layer, further heat treatment (baking) is performed according to a conventional method.
It can increase hardness and improve wear resistance. For example, 4 due to oxyacetylene flame, oxypropane flame, etc.
Heat treatment is performed by flame treatment at about 50 to 500°C for about 1 to 2 hours. Alternatively, heat treatment such as high frequency induction heating may be used. The current-carrying conductor roll of the present invention has excellent corrosion resistance and high hardness (wear resistance) due to the nickel-tungsten alloy plating layer, which extends the lifespan of the current-carrying conductor roll compared to the conventional one. To make it significantly longer than it is. That is, whereas conventional rolls mainly made of hard chrome plating had poor corrosion resistance, especially acid resistance, the current-carrying conductor roll of the present invention is resistant to acids as well as alkalis and salts. It shows extremely excellent corrosion resistance even at high temperatures, and has good corrosion resistance not only at room temperature but also at high temperatures. In addition, the hardness is comparable to that of hard chrome plating, and even higher hardness can be obtained when heat treated. The current-carrying conductor roll of the present invention coated with a nickel-tungsten alloy plating layer having the above-mentioned excellent properties has a longer service life than conventional hard chrome plated ones, for example in acid baths such as zinc and tin plating lines. In fact, it has a particularly remarkable effect of being 20 to 10 long.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Stainless steel conductor roll (diameter 30
A 20 μm nickel plating layer is applied on the circumferential surface of h×width 50−), and a 30 μm nickel-tungsten alloy (tungsten content: 3% heel weight) plating layer is further applied on top of the nickel plating layer to obtain the current-carrying conductor roll of the present invention. I got it.

Using this in a zinc-nickel alloy plating line,
When we measured the usable time before it became unusable,
It had been hot for 100 hours.

The main composition of the line plating bath is zinc sulfate (ZnsO4.
7H20) 300g/', nickel sulfate, (NlSO4
・7H20) 100g/e and sodium sulfate (Na2
SO4) was 50 g/e, and the pH was 2.0. In addition, the plating conditions were a current density of 6 A/Drrl and a temperature of 50
It was 'C. Example 2 A 25 μm nickel layer was applied to the circumferential surface of a current-carrying conductor roll (diameter 300V! x width 50?) made of iron and copper plated, followed by a 30 μm nickel layer. Plating a tungsten alloy (tungsten content 37% by weight) layer,
This was flame-treated for 1 hour with an oxypropane flame at a surface temperature of about 500'C while cooling the inside of the current-carrying conductor roll with water to obtain a current-carrying conductor roll of the present invention.

When this was used under the same conditions as in Example 1, the usable time was 1 hour. Example 3 A current-carrying conductor of the present invention was prepared in the same manner as in Example 1 except that the thickness of the nickel-tungsten alloy plating layer was 50 pm.
Got the roll.

When this was used under the same conditions as in Example 1, the usable time was 1 hour. Comparative Example 1 1 on the circumferential surface of the current-carrying conductor roll used in Example 1
A conductor roll for comparison was prepared by applying hard chrome plating of 00 μm.

When this was used under the same conditions as in Example 1, the usable time was only 5 hours.

[Brief explanation of the drawing]

FIG. 1 shows a conductor roll of the present invention. In Figure 1, only the plated portion is shown in cross section.
1...Conductor roll for energizing, 2...
- Nickel plating or nickel-phosphorus alloy plating layer, 3...Nickel-tungsten alloy plating layer.

Claims (1)

[Claims] 1. Forming a nickel plating layer or a nickel-phosphorus alloy plating layer on the circumferential surface of a current-carrying conductor roll,
A method for manufacturing a current-carrying conductor roll, which comprises then forming a nickel-tungsten alloy plating layer containing 20 to 40% by weight of tungsten on the plating layer. 2. Forming a nickel plating layer or a nickel-phosphorus alloy plating layer on the circumferential surface of the energizing conductor roll,
A method for manufacturing a current-carrying conductor roll, which comprises forming a nickel-tungsten alloy plating layer containing 20 to 40% by weight of tungsten on the plating layer, and then heat-treating the layer.