JPH03287795A - Bright ni plated steel strip and production thereof - Google Patents

Abstract

PURPOSE:To obtain a bright Ni plated steel strip having corrosion resistance, workability and satisfactory surface luster by subjecting the surface of a steel base such as a cold rolled steel strip to mat Ni plating and the plated surface to bright Ni plating. CONSTITUTION:A coil 11' of a steel base 11 such as a cold rolled steel strip or a stainless steel strip is uncoiled and subjected to mat Ni plating preferably in about 1.5-3.0mum thickness in a first electroplating apparatus 15. Bright Ni plating is then carried out preferably in about 0.5-1.5mum thickness in a second electroplating apparatus 16. A bright Ni plated steel strip 10 capable of maintaining corrosion resistance and workability due to the mat Ni plating layer and having satisfactory surface luster due to the bright Ni plating layer can be obtd.

Description

[Detailed description of the invention] Good! Field of the Invention The present invention relates to a bright Ni-plated steel strip and a method for manufacturing the same, and is particularly suitable for being wound into a coil, and
Even when deep drawing is performed using the bright Ni-plated steel strip, the luster can be maintained.

BACKGROUND OF THE INVENTION Conventionally, products have been produced in which cold-rolled steel strips and stainless steel strips are plated with Ni. These Ni-plated products can be broadly divided into functional parts, which place emphasis on corrosion resistance and processability, and decorative parts, which place emphasis on surface gloss. In general, Ni-plated steel strips used for functional parts are manufactured by matte Ni plating in order to maintain the required corrosion resistance and workability, while Ni-plated steel strips used for decorative parts are manufactured using matte Ni plating. Manufactured with gloss N1 plating, whether semi-gloss or specular.

However, due to recent technological innovations and labor-saving efforts, even when used as functional parts, there is a demand for Ni-plated steel strips that not only have corrosion resistance and workability, but also have surface gloss. A simple method for manufacturing a bright Ni-plated steel strip having corrosion resistance and workability comparable to that of Ni-plated steel strip is also desired.

By the way, when producing a bright Ni-plated steel strip by applying bright Ni plating, most of the bright Ni plating used is based on organic additives, so the Ni plating is affected by the action of the organic additive (brightener). It often hardens (H 400-500) or the sulfur in the additive eutectoids with Ni, impairing the corrosion resistance of the film. Therefore, after the steel strip base is treated to increase the adhesion with the Ni plating, all the necessary amount of plating is covered with bright Ni plating, but the bright Ni plating layer is hard. Because it is brittle, it has poor workability when manufactured into a product, and when processed, it is prone to peeling and cracking, and its corrosion resistance is also significantly impaired.

Problems to be Solved by the Invention In order to solve the problems caused by the above-mentioned bright Ni plating method, a puff polishing method and an annealing treatment method are sometimes used, but both have their own problems.

That is, in the puff polishing method, after applying matte Ni plating which has excellent corrosion resistance and workability, the surface is given gloss by puff polishing. However, when using the puff polishing method, a puff polishing process is required as a secondary process in addition to the Ni plating process, which is disadvantageous in terms of cost, and in terms of quality, the gloss imparted by puff polishing is temporary. in,
It has the disadvantage of oxidizing and discoloring over time.

On the other hand, in the annealing treatment method, after applying matte Ni plating, annealing treatment is performed in a neutral or reducing atmosphere to bond the substrate and Ni.
By forming a diffusion layer between the plated layer, corrosion resistance and workability are improved, and surface gloss is obtained by temper rolling, but this method has the following drawbacks.

■First of all, when using this annealing treatment method, the final step is temper rolling, so the surface gloss of the Ni-plated copper strip produced is not sufficient.In particular, when the Ni-plated steel strip is deep-drawn, the surface gloss is There is a drawback that there is no more For example, when the positive side part of a battery casing is manufactured by deep drawing, the degree of processing in the deep drawing part is so great that it loses its luster, and the positive side part of the battery has no visible gloss. There is a drawback that the product value decreases.

(2) When a diffusion layer is provided by annealing, it is extremely difficult to make the thickness of the diffusion layer constant. That is, in the case of batch annealing, coiled Ni-plated steel strips are usually stacked and annealed in an annealing container, so that
The coil is heated gradually from the outside to the inside, and from the top to the bottom of the stack. For example, if the temperature is set to 600°C, there will be parts as low as 550°C inside the coil and in the bottom. As described above, due to the different temperature distribution, diffusion starts quickly in the outside and upper part of the coil where the temperature is high, while diffusion starts later in the inside and lower part of the coil. Uniformity occurs. On the other hand, in the case of continuous annealing, the temperature is set at a high temperature in order to heat in a short time, for example, annealing is performed at 800°C for about 1 minute. The thickness of the diffusion layer cannot be controlled. However, it is essential that the diffusion layer has a constant thickness, and if the thickness of the diffusion layer is uneven,
Problems arise with products manufactured through post-processing such as pressing. That is, where the diffusion layer is thin, the corrosion resistance is poor, and where the diffusion layer is thick, cracks occur during processing, significantly impairing the corrosion resistance.

The present applicant previously proposed Japanese Patent Application No. 1-228077 as a solution to the above-mentioned non-uniformity of the diffusion layer that occurs during annealing. According to the invention, it is possible to obtain a diffusion layer of a constant thickness, and also to obtain a Ni-plated steel strip that maintains surface gloss even when deep drawing is performed. However, this invention has the drawback of high cost because it requires a multi-step process of -second matte plating annealing, second matte plating, and tertiary bright plating on the substrate.

Therefore, the present invention eliminates the drawbacks that could not be solved by the conventional methods consisting of the above-mentioned bright plating method, puff polishing method, annealing treatment method, etc., and provides a Ni-plated steel strip that maintains corrosion resistance and workability and has a glossy surface. The purpose of this invention is to provide a manufacturing method thereof.

Means for Solving the Problems In order to achieve the above object, the present invention provides a method of applying matte Ni plating to a certain thickness on the surface of a cold-rolled steel strip or stainless steel strip, and then applying matte Ni plating to the surface of the matte Ni plating. It is coated with a certain thickness of bright Ni plating, and has corrosion resistance and workability equivalent to or better than matte Ni-plated steel strip.
The present invention provides a bright Ni-plated steel strip that is characterized by having surface gloss not only before processing but also after deep drawing, and a method for manufacturing the same.

The bright Ni-plated steel strip according to the present invention described above is provided in a coiled state.

Furthermore, the present invention provides a battery case formed using the above-described bright Ni-plated steel strip, and the battery case includes at least a positive side portion formed by deep drawing the bright Ni-plated steel strip. It is something.

The thickness of the matte Ni plating described above is 1.0 to 10μ, preferably 1.5 to 3.0μ, and the thickness of the glossy Ni plating is 0.5 to 3.0μ, preferably 0.5 to 3.0μ. It is 1.5μ.

As the matte and bright Ni plating methods described above, electroplating is preferably used, but other suitable plating methods such as electroless plating and vapor deposition plating can also be used.

As described above, according to the present invention, a bright Ni-plated steel strip can be easily produced, and the bright Ni-plated steel strip has corrosion resistance and workability due to the presence of the matte Ni plating layer, and Due to the presence of a glossy Ni plating layer on the surface, it does not change over time and has sufficient surface gloss even when deep drawing is performed, and is particularly suitable for use as a material for battery cases.

EXAMPLES Hereinafter, examples of the present invention will be explained in detail based on the drawings. FIG. 1 is a cross-sectional view of a bright Ni-plated steel strip lO produced by the method according to the present invention, and 11 is a plain cold-rolled steel sheet or Steel base made of stainless steel plate, 12A, 12
B is a matte Ni plating layer with a substantially constant thickness that is laminated on both sides of the steel substrate 11, and 13 is a matte Ni plating layer of approximately constant thickness that is laminated on the surface of the matte Ni plating layer 12A on one side (the surface that becomes the front side in use). Thick glossy Ni plating layer.

As shown in FIG. 2, the above-mentioned bright Ni-plated steel strip 10 is first electroplated on its surface by the first electroplating device 15 while unwinding the steel base 11 from the steel base coil body 11'. lO~lOμ, preferably 1.
Made of steel with matte electrolytic Ni plating with a thickness of 5 to 3.0μ! Matte Ni plating layers 12A, 42 on both surfaces of l
B is attached. As the matte electroplating method, electroplating using a conventional plating bath such as Watt bath or sulfamic acid is used.

Continuing with the first plating process, the steel substrate 11 with the matte Ni plating layers 12A and 12B adhered to both sides is transported to the second plating device 16, where it is coated with bright electrical Ni plating for the second time.
Apply plating. The bright electrolytic Ni plating is performed only on the surface side of the one matte Ni plating layer 12A, and the bright Ni plating layer 13 is attached to the surface of the matte Ni plating layer 12A. In addition, the matte Ni plating layer 12 that will be on the back side during use
Bright N1 plating is not applied to the B side.

The thickness of the bright Ni plating layer 13 is 0.5 to 3.0 μm, preferably 0.5 to 1.5 μm, and is usually 1/3 of the amount added.
of organic additives and the flow rate was increased from 150 m/min to 200 m/min.
Electroplating is performed using a high-speed bright Ni plating bath. In particular, the second electroplating process was performed at a high current density of 75 A/dm"-100 A/dm', and
The degree of adhesion of the second bright Ni plating layer 13 is increased.

The second glossy electrolytic Ni plating has been applied to the steel cable. Matte Ni plating layer 12A% 12B on the violet surface.

A bright Ni-plated steel strip with the bright Ni-plated layer 13 attached! 0 is wound as a coil body 10'.

According to the above manufacturing method, the steel substrate 11 can be made into a bright Ni-plated steel strip IO with only one plating process, and the matte Ni-plated layer 12A and the bright Ni-plated layer are double plated. 13, the bright Ni-plated steel strip IO
It is possible to manufacture a coil body lO° by winding it.

In the embodiment described above, the matte Ni plating layers 12AS and 12B are formed on both sides of the steel base 11, and the bright Ni plating layer 13 is formed only on the surface of one of the matte Ni plating layers 12A. As shown in the figure, it is also possible to form bright Ni plating layers 13A and 13B on both surfaces of both matte Ni plating layers 12A and 12B. Further, as shown in FIG. 5, a matte Ni plating layer 12 is formed only on one side of the steel substrate 11, and a glossy Ni plating layer 12 is formed on the surface of the matte Ni plating layer.
An i-plated layer 13 can also be formed.

The bright Ni-plated steel sheet lO produced by the above method forms a bright Ni-plated layer 13 of a constant thickness with a constant thickness of a dull Ni-plated layer 12 interposed on the steel substrate every day, so The presence of 12 provides corrosion resistance and processability. Furthermore, due to the presence of the glossy plating layer 13, the surface has sufficient gloss, and the gloss is not impaired by changes over time.

Moreover, the bright Ni plating layer 13 is replaced by the matte Ni plating layer 1.
2, both plating layers 12 and 13 peel off during press processing, and the bright Ni plating layer peels off, exposing the non-glossy Ni plating layer 12 on the surface, resulting in a glossy surface. It will not damage. Moreover, since the bright plating layer 13 is thinner than when the entire amount of plating is applied with bright Ni plating, cracks are less likely to occur.

For the above reasons, the battery case 1 as shown in FIG. 6 can be suitably formed by press working the bright Ni-plated steel strip 10 according to the present invention as a raw material. That is, the entire battery case l is formed by pressing the bright Ni-plated steel strip lO as shown in the figure, and the positive side portion 2 of the battery case l has a step bent at an approximately right angle by deep drawing. A shaped portion 3 is formed.

When the above-mentioned pressing process, especially deep drawing process, is applied, the entire amount of conventional glossy Ni plating layer 13 on the surface layer is replaced with glossy N.
Cracks may occur, although the incidence is lower than in the case of an i-plated layer.

In that case, the corrosion resistance is covered by the matte Ni plating layer 12 below the bright Ni plating layer 13, and the corrosion resistance is not impaired by the occurrence of cracks. Furthermore, in general, the higher the sulfur content of the Ni plating film, the lower the natural potential. Therefore, when a corrosion hole (pinhole) penetrating the bright Ni plating layer 13 reaches the matte Ni plating layer 12, the bright Ni plating layer 13 A potential difference is generated between the matte Ni plating layer 12 and the base matte Ni plating layer 12 is protected from anodic corrosion by the bright Ni plating layer 13, which slows corrosion in the direction of the steel substrate 11, resulting in corrosion resistance. can be held better.

(Experimental Example 1) A bright Ni-plated steel plate (A) obtained by a double plating method in which matte Ni plating and bright Ni plating were applied to the surface of a steel base according to the present invention, and a matte puff polishing method described in the conventional example. A bright Ni-plated steel sheet (B) obtained by the method and a bright Ni-plated steel sheet (C) obtained by the annealing treatment and temper rolling method were provided.

These bright Ni-plated steel plates (A), (B), and (C) are 1
It was cut into a size of 00WxlOOL, left in the air, and the oxidation (discoloration) situation was measured using the following gloss meter.

Gloss meter: Nippon Heavy Industries Co., Ltd. model VGS-ID type standard value: Stainless steel BA finish (bright annealing) mirror surface 104
0° The results are shown in Table 1 below.

Table 1 In Table 1 on the previous page, ◎ indicates specular gloss with a gloss level of 800°, Q indicates medium gloss with a gloss level of 600°, △ indicates low gloss with a gloss level of 500°, × indicates gloss with a gloss level of 300° Represents none.

(Experiment Example 2) Bright Ni-plated steel plate (A) formed by the double plating method according to the present invention formed in Experiment Example 1 above, bright Ni-plated steel plate (B) formed by the conventional matte puff polishing method, and annealing treatment treatment. A case for an alkaline single battery was formed using a bright Ni-plated steel plate (C) produced by rolling. The glossiness of the top portion (ten pole side) of the battery case was measured using the same glossmeter as in Experimental Example 1.

The measurements were carried out immediately after the top part was deep-drawn, one month after cleaning (triclean cleaning, alkaline degreasing, or Freon cleaning), and one month later, and two months later. Evaluation of glossiness is based on Experimental Example 1
This is done in the same way as ◎, ○, △, and ×. The results are shown in Table 2 on the next page.

Table 2 As is clear from Table 2 above, in the conventional puff polishing method and temper rolling method, no organic matter is mixed, so the top part is pressed down with a mold from the top during deep drawing, resulting in a glossy surface. It falls off and inevitably becomes oxidized (discolored). In the double plating method of the present invention, since gloss is produced by mixing an organic substance, the surface layer hardness is much higher than that of matte Ni. That is, the bright Ni plating of the present invention has a surface hardness of 400 to 5.
00HV, whereas matte Ni plating has a surface hardness of 200 to 300. As described above, since the surface hardness of the present invention is high, the gloss level does not change even if the top portion is pressed with a mold during drawing.

Effects of the Invention As is clear from the above explanation, according to the present invention, a matte Ni plating layer is provided with a constant thickness on the surface of a steel substrate, and a bright Ni plating layer with a constant thickness is provided on the surface of the steel substrate. Because it has a heavy plating structure, the matte Ni plating layer can maintain corrosion resistance and workability, and the glossy Ni plating layer can provide sufficient surface gloss, making it suitable for use in functional parts with conventional matte Ni plating. It can be used for both decorative parts with bright Ni plating, and
It can be particularly suitably used in applications that require both functionality and decoration, for example, as a material for battery cases. In addition, the coil body wound with the bright Ni-plated steel strip has various advantages such as it does not take up much space during manufacturing, transportation, storage, etc., and it can be handled as a container. It is.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a bright Ni-plated band according to the present invention.
FIG. 2 is a schematic diagram showing a method for manufacturing the bright Ni-plated steel strip, FIG. 3 is a front view of a coil body made of the bright Ni-plated steel strip, and FIGS. 4 and 5 are other embodiments of the present invention. FIG. 6 is a cross-sectional view of a bright Ni-plated steel strip showing an example of the bright Ni-plated steel strip.
It is a cross-sectional view of a battery case formed from an i-plated steel strip.Battery case, 2...Press side part, 10...
Bright Ni-plated steel strip, 10゛... Bright Ni-plated strip coil body, 11...
Steel base, 12... Matte Ni plating layer, 13... Bright Ni plating layer.

Claims (1)

[Claims] 1. A matte Ni plating layer of a certain thickness is provided on the surface of a steel substrate such as a cold-rolled steel strip or a stainless steel strip, and a matte Ni plating layer of a certain thickness is provided on the surface of the matte Ni plating layer. A bright Ni-plated steel strip characterized by having a Ni-plated layer. 2. A matte Ni plating layer of a certain thickness is provided on the surface of a steel substrate such as a cold rolled steel strip or a stainless steel strip, and a bright Ni plating layer of a certain thickness is provided on the surface of the matte Ni plating layer. A battery case that is formed using a bright Ni-plated steel strip and includes at least a positive side portion that is bent into a step shape and formed by pressing the bright Ni-plated steel strip. 3. Glossy Ni plating, in which a constant thickness of matte Ni plating is applied to the surface of a steel substrate such as a cold-rolled steel strip or stainless steel strip, and then a constant thickness of bright Ni plating is applied to the surface of the matte Ni plating. Method of manufacturing plated steel strip.