JP2989440B2 - Chrome plating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chromium plating method in which chromium plating is performed directly on a metal surface on which it is said that chromium plating cannot be performed directly on the metal surface under vibration stirring.

[0002]

2. Description of the Related Art In hard chromium plating, it is unavoidable that fine cracks are formed in the plating film. In a corrosive environment, these cracks become points of corrosion, and the cracks occur frequently along the cracks. Corrosion progresses. In order to suppress such corrosion even a little, underplating treatment of copper, nickel or the like has conventionally been indispensable in hard chrome plating. For example, chromium plating on iron-based metals is often used for the purpose of rust prevention and decoration. However, if chromium plating is performed directly on iron-based metals, cracks occur and the rust-prevention effect is low. First, copper plating was performed, followed by nickel plating, and then chrome plating was performed. Degreasing of iron-based metal surface → washing with water →
Pickling → water washing → copper strike → copper plating → water washing → nickel plating → water washing → chrome plating. Nevertheless, it has not been possible to completely avoid the occurrence of cracks yet, and it is difficult to obtain satisfactory plating. Plating on plastics is mainly performed for decorative purposes. Chemical plating (usually chemical copper plating or chemical nickel plating) is performed, followed by copper plating, then nickel plating, and then chrome plating. Have been done. Degreasing of plastics surface → pre-etching → etching → catalyzing → accelerate → electroless copper plating → water washing → copper plating → water washing → nickel plating → water washing → chrome plating. Also in this case, cracks occur when chromium plating is suddenly performed on the chemical plating layer. Also, in the case of plating on zinc-based metal, after plating copper on zinc-based metal and then nickel plating,
Chrome plating is performed. Degreasing of zinc-based metal surface → water washing → pickling → water washing → copper strike → copper plating → water washing → nickel plating → water washing → chrome plating. Al, Al alloy, C
The same applies to u and Cu alloys. In this way, it is possible to perform chrome plating directly on metal surfaces such as iron-based metals, plastics and zinc-based metals, copper-based metals, and aluminum-based metals that are not considered to be directly chrome-plated. If possible, a step of copper plating or nickel plating is not required as a pre-stage of chromium plating, and the industrial significance is extremely large. It would be even better if the chrome plating process itself could be sped up faster than ever.

[0003]

The object of the present invention is to provide a conventional method for performing chromium plating on metal surfaces, such as iron-based metals, plastics, zinc-based metals, copper-based metals, and aluminum-based metals, for which direct chromium plating was considered impossible. An object of the present invention is to provide a novel chromium plating method in which a certain pre-plating step is omitted, the chromium plating speed is increased, and further, microcracks do not occur in the obtained chromium plating layer.

[0004]

The first aspect of the present invention is to provide a vibrating blade without a pretreatment of pre-plating a metal other than chromium on a metal surface whose chromium plating cannot be performed directly on the metal surface. 15 ~ 60Hz, amplitude 2 ~
The present invention relates to a chromium plating method in which chromium plating is performed directly while applying a vibration of 30 mm to vibrate and stir the treatment liquid. In the second aspect of the present invention, when performing chromium plating on an iron-based metal surface, the vibration blades are subjected to 15 to 60 Hz and an amplitude of 2 to 2 without passing through a copper plating step and a nickel plating step.
The present invention relates to a chromium plating method in which chromium plating is performed directly while applying a vibration of 30 mm to vibrate and stir the treatment liquid. A third aspect of the present invention is to perform chromium plating on the surface of plastics, and apply a vibration of 15 to 60 Hz and an amplitude of 2 to 30 mm to the vibrating blade on the electroless copper plating layer without passing through a copper plating step and a nickel plating step. And directly performing chromium plating while vibrating and stirring the treatment liquid. A fourth aspect of the present invention is that, when performing chromium plating on a zinc-based metal surface, the treatment liquid is vibrated by applying vibration of 15 to 60 Hz and amplitude of 2 to 30 mm to the vibrating blade without passing through nickel plating after the copper plating step. The present invention relates to a chromium plating method characterized by performing chromium plating directly on a copper plating layer while stirring. A fifth aspect of the present invention is that, when performing chromium plating on a copper-based metal surface, the vibrating blade is subjected to a vibration of 15 to 60 Hz and an amplitude of 2 to 30 mm without subjecting to nickel plating, and the chromium plating is performed directly while vibrating and stirring the treatment liquid. The present invention relates to a chromium plating method characterized by performing plating. A sixth aspect of the present invention is that, when performing chromium plating on the surface of an aluminum-based metal, the vibrating blade can be provided with 15 to 6
The present invention relates to a chromium plating method, wherein chromium plating is performed directly while applying vibration at 0 Hz and an amplitude of 2 to 30 mm to vibrate and stir the treatment liquid. According to the present invention, it has been discovered that chromium plating can be performed directly on the object to be plated under vibration agitation on the metal surface which has been considered to be incapable of direct chromium plating on the metal surface. This is a major feature in that the previously required pre-plating step for chromium plating has been omitted, and the speed of chromium plating has been greatly improved.

[0005] The vibration stirring means used in the present invention is 15 to 6
This is a new stirring means developed by the present inventors based on transmitting vibration from a vibration motor, which generates vibration at 0 Hz, preferably 20 to 40 Hz, to a vibration plate in a liquid and transmitting this vibration to the liquid. The idea is that of
As disclosed in Japanese Patent Application No. 275130, the modified agitating means was filed on Sep. 14, 1992 as Japanese Patent Application No. 4-286544. Further, a technique related to vibration stirring is disclosed in Japanese Patent Application Nos. 5-116566 and 5-1390.
No. 28 has been filed. It is surprising that, in this vibration stirring, when the vibration by the diaphragm is transmitted to the entire system, the whole system is promptly homogenized as compared with the stirring by the screw. The amplitude of the diaphragm is not particularly limited, but is usually 2 to 30 mm, preferably 10 to 15 mm.

FIGS. 1 and 2 show a plating apparatus provided with vibration stirring means used in the present invention. 3 and 4, the plating electrodes are omitted. The vibration stirring means
The vibration generated by the vibration motor 26 is transmitted to the vibration blade groups 22, 22,... Via the vibration frame 23 and the vibration rod 21. As shown in FIGS. 2 and 3, the vibrating blade group is
Install on both sides of the. Vibration from vibration motor 26 is tank 2
The vibration frame 23 is attached to the gantry via a spring 24 and a pedestal 25 so as not to affect the body 9. Reference numeral 27 denotes an electrode, and reference numeral 28 denotes a heater for maintaining a liquid temperature. The vibrating blade may be horizontal, but is preferably mounted with a slight inclination. The degree of the inclination is preferably set at an angle of 0 to 45 °, preferably 10 to 20 ° with respect to the horizontal direction. In this embodiment, the angle is set at 15 °. The width of the vibrating blade is not particularly limited, but the effect is sufficiently exhibited if it is at least about 30 mm. Usually 30 to 100 mm, preferably 50 to 80 mm
It is about. Although the interval between the stirring blades is not particularly limited, it is usually 10 to 80 mm, preferably 30 to 40 mm, and in this example, the interval was 35 mm. The positions of the left and right vibrating blades 22 may be the same height, but may be provided at slightly shifted positions. The uppermost vibrating blade is preferably located at a position about 100 mm below the liquid level. If it is provided above this, it slightly varies depending on its amplitude, but it is not preferable because the liquid scatters. The lowest vibrating blade is preferably located at a position about 50 mm above the bottom. The vibrating blade of the present invention had a width of 80 mm, a length of 400 mm, and an interval of 35 mm.

The method of providing the vibration plate in the vibration stirring means is as follows.
It can be roughly divided into three types. (1) 2 to 10 cm wide along the periphery of the plating tank
A type in which a number of diaphragms are provided at the top and bottom,
(Refer to 3) (Vertical vibration) (2) A type in which one or two diaphragms are provided on almost the entire bottom of the plating tank at the bottom of the plating tank (see FIG. 4) (Vertical vibration) (3) Sideways on the bottom of the plating tank Type with a vibrating plate that vibrates in the direction (see Figs. 5 to 9). (4) Instead of a propeller agitating blade at the center of the plating tank, vibration of an arbitrary shape with a size equal to or less than the length of the propeller There is a type in which a large number of plates are provided vertically (see Japanese Patent Application No. 4-286544), but the type (1) is particularly preferred. The position of the plating electrode can be above the vibrating plate, or inside or outside the vibrating plate.

The diaphragm may be vibrated uniformly as described in the above-mentioned publication or the specification. However, one or two portions of the diaphragm are connected to a vibration axis to vibrate. You can also. In this case, when the liquid tank is rectangular, two vibrating axes may be provided one by one at both ends of one side of the diaphragm, but one vibrating shaft may be provided at the center of the side. Also, one vibration axis may be provided at one corner of the diaphragm. Corners other than the diagonal sides of the side where the vibration axis is attached or corners where the vibration axis is attached are supported by fixed axes. An elastic body on the fixed shaft,
For example, it is preferable to fix the diaphragm via rubber, a spring, an air spring, or the like, but it is also possible to rely on the elasticity of the diaphragm itself. FIG. 5 shows a specific example thereof. Vibration rods 1 and 2 are provided via vibration transmission rods 5 connected to the vibration motor by any means, and the vibration plates 6 are fixed to the vibration rods 1 and 2 by using rubber pieces 8 and 9, while the fixed rods are fixed. 3,4
The supporting rubber pieces 10, 1 for supporting the vibration of the diaphragm 6
1 is fixed, and the diaphragm 6 is connected thereto. The diaphragm 6
Vibration transmitting rods 1 and 2 with supporting rubber pieces 10 and 11 as fulcrums
The fan is vibrated so as to lift the fan in accordance with the vertical axis. By holding the fan in the tank, it is possible to mix and agitate liquids, powders, granules and the like.

FIGS. 6 to 9 show an outline of a plating apparatus provided with a transverse vibration stirring means used in the present invention. FIG. 6 shows a top view of the lateral vibration stirring device used in the present invention, and FIG. 7 shows a cross-sectional view thereof. Numeral 31 denotes a vibration motor for generating vibration in the lateral direction, and numeral 32 denotes a U-shaped vibration transmitter for transmitting the vibration, which is transmitted directly to the tank or any supporting member or via the slide bearing 13 or the like. Installed.
33 is a support for preventing the vibration generated by the vibration motor 31 from attenuating, and 34 is a vibrating blade 36
This is a vertical vibration transmitter that serves to suspend the vibrator 35 with a mark and transmit the vibration of the U-shaped vibration transmitter to the vibrator 35. The vibrating blade 36 has a function of imparting a vibrating stirring action to liquid, powder, and the like in the tank by the vibration of the vibration motor 31. On both sides of the support 33, elastic bodies 38, 38 such as springs are provided, so that the vibration of the U-shaped vibration transmitter 32 is not attenuated and the weight of the vibration motor 31 is substantially the same. The noise generated by unnecessary vibrations is minimized. Through the U-shaped vibration transmitter, the weight of the vibration motor installed on one side of the tank and the elastic body provided on the opposite side thereof and the holding mechanism thereof are almost balanced. It is preferable that it is adjusted as follows.

Any number of vibrating blades may be attached to the vibrator. The vibrating blades are mounted vertically or obliquely on the vibrator (see FIGS. 10A to 10D). The vibrating blade can be attached to the vibrator by welding or can be detached. In particular, it is preferable to employ a method in which the blades are attached to the vibrator in a push-in manner, because the size of the vibrating blades and the number of the vibrating blades can be changed according to the required stirring conditions. Further, it is also possible to change the mounting angle of the blade. When the size of the tank is 800 mm in width, 1000 mm in length, and 1100 mm in depth, for example, 80 mm in width and 50 in length at 50 mm intervals.
By attaching a vibrating blade having a thickness of 0 mm and a thickness of 0.15 mm, a sufficient stirring effect can be obtained.

The presence of the support which receives the two ends of the U-shaped vibration transmitter via the elastic body makes it possible to prevent the lateral vibration generated by the vibration motor from attenuating. It is preferred to have a similarly robust structure. For example, it is possible to use an H-shaped steel material or a reinforcing steel bar, a concrete wall containing a steel frame, or the like, which is formed by laying a foundation on the ground and standing vertically on the foundation. When the vessel wall is sufficiently firm, the vessel wall can be used as a support.

The elastic body serves to receive the vibration of the vibration transmitter and repel the vibration from the support, and preferably has a strong spring force. For example,
As shown in FIG. 8, a spring in which a spring 38 made of spring steel and having a diameter of 3 to 10 mm is fitted around a round bar 37 can be used as the elastic body. It is preferable that the elastic body is installed in contrast to the vibration motor side of the support and the opposite side. 8 has such a structure, and the spring is fixed by a stopper plate 39. FIG.

In the present invention, aeration means can be additionally provided in addition to the vibration stirring means.

The composition of the chromium plating bath used in the present invention is as follows:
Various compositions of conventional chromium plating baths can be used. Representative formulation, (a) chromic acid (CrO ₃₎ 100~500g / l sulfuric acid 0.5~7.7g / l (b) chromic acid (CrO ₃₎ 200~300g / l sulfuric acid 0.25~3g / l fluorosilicate sodium (Na ₂ SiF ₆₎ 0.5~20
g / l

In the present invention, the iron-based metal is iron or an alloy mainly containing iron, the zinc-based metal is zinc or an alloy mainly containing zinc, and the copper-based metal is mainly copper or copper. An aluminum-based metal is aluminum or an alloy containing aluminum as a main component. As the plastics, any plastics such as ABS, polyethylene, and polypropylene can be used as a control.

[0016]

【Example】

Example 1 (plating on iron-based metal) (hanging type) Basic process: degreasing → water washing → pickling → water washing → chrome plating Applicable equipment: FRP plating tank with vibration stirring means shown in the figure (capacity 200 liters) The frequency was 27 Hz. Anode: titanium coated with indium oxide Liquid temperature: 60 ° C. Plated object: steel disc (diameter 55 mm) (thickness 5 mm) Plating bath composition: CrO ₃ 300 g / l H ₂ SO ₄ 3 g / l or more When chromium plating was performed directly on steel under the conditions, a current density of 80 A / dm ^{2 was obtained,} and plating was performed in this state for 20 minutes. As a result, a crack-free chromium plating layer having a thickness of 7 μm at the center and a thickness of 20 μm at the outer periphery could be obtained. Plating was achieved at a higher speed than without vibration stirring. JIS
The salt spray test passed after 96 hours. Further, when no vibration stirring was performed, the current density was reduced to 40 A / dm ² , and the time required for the chromium plating step to obtain the same film thickness was 場合 of that when no vibration stirring was performed.

Comparative Example 1 Example 1 was repeated except that no vibration stirring was performed. As a result, a chromium plating film having a current density of 40 A / dm ² and a film thickness of 11 μm was obtained, but had many cracks and failed the JIS salt spray test completely after 96 hours.

Example 2 (Plating on iron-based metal) (suspension type) The frequency was 28 Hz, the current density was 60 A / dm ^2, and the object to be plated was an iron shaft (diameter 10 mm, length 135 m).
m) was chromium plated. Chrome plating thickness is 2
No cracks were observed at 0 to 22 μm.
The JIS salt spray test passed even after 96 hours.

Comparative Example 2 Example 2 was repeated except that no vibration stirring was performed. As a result, a chromium plating film having a current density of 40 A / dm ² and a film thickness of 11 μm was obtained, but had many cracks and failed the JIS salt spray test completely after 96 hours.

Comparative Example 3 (plating on iron-based metal) (hanging type) Basic process: degreasing → water washing → pickling → water washing → copper strike → copper plating → water washing → nickel plating → water washing → chrome plating Using a body to be plated, chrome plating was performed on a copper-nickel plated one as usual (no vibration stirring). Copper sulfate plating bath Copper sulfate 230g / l Sulfuric acid 50g / l Brightener small amount Liquid temperature 25 ° C Cathode current density 3A / dm ² hours Nickel plating bath Nickel sulfate 240g / l Nickel chloride 45g / l Boric acid 30g / l Brightener small amount liquid Temperature 50 ° C. Current density 5 A / dm ² Chromium plating bath A surge bath composed of CrO ₃ 300 g / l H ₂ SO ₄ 3 g / l was used. Solution temperature: 60 ° C. Current density: 50 A / dm ² Plating time: 30 minutes As a result, a chromium plating layer having a thickness of 25 μm was obtained.
Many microcracks were observed. The salt spray test of JIS failed after 96 hours.

Embodiment 3 (Barrel Plating on Iron Products) The barrel plating apparatus used in this embodiment is shown in FIG. 11 (top view) and FIG. 12 (cross-sectional view). The vibration stirring means converts the vibration generated by the vibration motor 56 into the vibration frame 53,
The vibration is transmitted to the vibrating blade groups 52, 52,. The vibrating blade group is installed on both sides of the circulation tank 59 as clearly shown in FIGS. In order to prevent the vibration from the vibration motor 56 from affecting the main body of the circulation tank 59, the vibration frame 53 is attached to the main body via a spring 54 and a pedestal 55. The degree of inclination of the vibrating blade was set at 15 ° with respect to the horizontal direction. The width of the vibrating blade was 80 mm, and the interval between the stirring blades was 35 mm. As shown in FIG. 12, the vibrating blade portion is provided between the barrel 63 and the electrode 57. The barrel 63 is an octagonal cylindrical body having a large number of holes having a diameter of 3 mm and made of a hard vinyl chloride resin having a capacity of about 3 liters. As an article to be plated, an iron cylinder having a diameter of 20 mm and a length of 20 mm was used. This is not plated with copper or nickel. The composition of the chromium plating bath was as follows. Chromic anhydride (CrO ₃ ) 250 g / l Sulfuric acid (H ₂ SO ₄ ) 2.5 g / l Cathode current density 25 A / dm ² , plating temperature 60 ° C., barrel rotation speed 6 r. p. m. For one hour. In addition,
The article to be plated was filled so as to be 1/3 of the barrel volume. After the plating was completed, washing with water, acid neutralization, washing with water, and drying were performed. As a result, in the case where the vibration stirring is not performed, the current density does not increase and almost no chromium plating film can be formed, whereas in the case of the third embodiment, the chromium film having a thickness of 10 μm is formed uniformly. This film thickness was almost the same as in the case of plating using a hanging tool.

Example 4 (Barrel plating on iron products) Example 1 was repeated except that a chromium plating bath having the following composition was used, the cathode current density was 50 A / dm ² , and the plating temperature was 55 ° C. Chromic anhydride (CrO ₃ ) 260 g / l Potassium silicofluoride (K ₂ SiF ₆ ) 4 g / l Potassium dichromate (K ₂ Cr ₂ O ₇ ) 25 g / l Sulfuric acid (H ₂ SO ₄ ) 1 g / l The chromium plating layer was formed about 1.3 times faster than in Example 1.

Example 5 (Plating on plastics) Basic process: degreasing → pre-etching → etching → catalyzing → accelerate → electroless copper plating → chrome plating Polyacetal disc (diameter 20 mm, thickness 20 m)
m) was subjected to chemical plating (chemical copper plating) to activate the surface, and then this was directly subjected to chromium plating under vibrational stirring. The plating conditions were the same as in Example 1, and the plating time was 20 minutes. The thickness of the chromium plating layer was 20 μm, and no generation of microcracks was observed. JI
The result of the salt spray test by S was still passed after 96 hours.

Comparative Example 4 (Plating on plastics) Basic process: degreasing → pre-etching → etching → catalyzing → accelerate → electroless copper plating → copper plating → nickel plating → chrome plating Same polyacetal disc as in Example 2 Comparative Example 1
In the same manner as described above, copper plating and nickel plating were performed, and then chromium plating was performed (no vibration stirring). After plating for 20 minutes,
The thickness of the chromium plating layer was 11 μm, and the presence of microcracks was recognized. The result of the salt spray test according to JIS was rejected after 96 hours.

Example 6 (Plating on zinc-based metal) (hanging method) Basic process: degreasing → water washing → pickling → water washing → copper strike → copper plating → water washing → chrome plating Copper-plated zinc-based metal disc ( Chromium plating was performed for 20 minutes in the same manner as in Example 1 except that the frequency was 28 Hz (diameter: 20 mm, thickness: 20 mm). As a result, no occurrence of microcracks was observed and JIS
Was passed after 96 hours in the salt spray test.

Comparative Example 5 (Plating on zinc-based metal) (suspension method) Basic process: degreasing → water washing → pickling → water washing → copper strike → copper plating → water washing → nickel plating → water washing → chrome plating Copper strike treatment Zinc-based metal disc (diameter 20
mm, thickness 20 mm) by the same basic process as in Comparative Example 1 and copper plating → nickel plating → chrome plating. The chromium plating time was 20 minutes. As a result, microcracks occurred in the chromium plating layer.

Example 7 (Plating on aluminum-based metal) (suspension method) An aluminum die-cast product (diameter 55 mm, thickness 5 mm) using CrO ₃ 300 g / l H ₂ SO ₄ 1 g / l as a chromium plating bath In the same manner as in Example 1, plating was performed on the sample at a frequency of 27 Hz, a liquid temperature of 60 ° C. and a current density of 80 A / dm ² for 20 minutes. A crack-free chromium plating layer having an average thickness of 15 μm was obtained. Usually, it is not necessary to provide a treatment layer such as a zinc substitution method or a zinc alloy substitution method which has been conventionally performed as an intermediate treatment, and a corrosion-resistant plating layer free from microcracks can be obtained at a high speed. In addition,
Ordinary degreasing, water washing, and activation treatments are carried out by ordinary methods.

[0028]

【effect】

(1) In the present invention, the use of vibration stirring can simplify the pre-plating step that has been required until now when chromium plating is performed on iron-based alloys, plastics, or zinc-based metals. This simplification of the process leads to a drastic improvement in working efficiency, and also eliminates the need for a pre-plating solution. (2) According to the present invention, the use of the vibration stirring makes it possible to obtain a plating speed almost twice as fast as the chromium plating speed in the conventional method. This is closely related to the fact that a high current density can be achieved by vibratory stirring. For example, in the conventional chromium plating, the current density is 40 A / dm ² , and the chromium plating thickness is 11 in 20 minutes.
In contrast, the chromium plating of the present invention has a current density of 80 A / dm ² and a chromium plating thickness of 22 in 20 minutes.
Since it is μm, it is possible to perform chrome plating of twice the thickness in the same time. In other words, it is clear that the plating rate has doubled. (3) The obtained chromium plating layer did not have microcracks unlike the conventional product, and the durability was further improved as compared with the conventional product.

[Brief description of the drawings]

FIG. 1 is a top view of a vibration stirrer used in an embodiment of the present invention.

FIG. 2 is a side view of the vibration stirrer used in the embodiment of the present invention.

FIG. 3 is a side view of the vibration stirrer used in the embodiment of the present invention as viewed from the other side.

FIG. 4 is a perspective view of only a main part of the vibration stirrer used in the embodiment of the present invention.

FIG. 5 is a perspective view showing a modified example of the vertical vibration stirring means that can be used in the plating method of the present invention.

FIG. 6 is a top view of the lateral vibration stirrer used in the embodiment of the present invention.

FIG. 7 is a sectional view of FIG. 6;

8 is an enlarged sectional view of a portion A in FIG.

FIG. 9 is a schematic diagram of a vibration transmission mechanism and a vibrator.

FIGS. 10A to 10D show various modes of attaching the vibrating blade to the vibrator. FIGS.

FIG. 11 is a top view of a barrel plating apparatus provided with a vibration stirrer.

FIG. 12 is a sectional view of FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration bar 2 Vibration bar 3 Fixed bar 4 Fixed bar 5 Vibration transmission bar 6 Vibrating plate 7 Tank bottom 8 Supporting rubber piece 9 Supporting rubber piece 10 Supporting rubber piece 11 Supporting rubber piece 21 Vibrating rod 22 Vibrating blade 23 Vibration Frame 24 Spring 25 Pedestal 26 Vibration motor 27 Electrode 28 Heating heater 29 Plating bath 31 Vibration motor 32 U-shaped vibration transmitter 33 Support 34 Vertical vibration transmitter 35 Vibrator 36 Vibrating blade 37 Round bar 38 Spring 39 Stop plate Reference Signs List 40 heater 41 electrode 42 tank 43 slide bearing 51 vibrating rod 52 vibrating blade 53 vibrating frame 54 spring 55 pedestal 56 vibrating motor 57 electrode 59 tank 62 rotating shaft 63 barrel

Claims (6)

(57) [Claims] 1. A vibrating blade having a frequency of 15 to 60 Hz without a pretreatment of plating a metal other than chromium in advance on a metal surface on which the chromium plating cannot be directly performed. A chromium plating method, wherein chromium plating is performed directly while applying a vibration having an amplitude of 2 to 30 mm to vibrate and stir the treatment liquid. 2. In performing chromium plating on a surface of an iron-based metal, a vibration liquid having a vibration of 15 to 60 Hz and an amplitude of 2 to 30 mm is applied to the vibrating blade without passing through a copper plating step and a nickel plating step to vibrate and agitate the treatment liquid. A chromium plating method characterized by performing chrome plating directly. 3. When performing chromium plating on the surface of plastics, the vibrating blade may be coated on the electroless copper plating layer by 15 to 6 without passing through a copper plating step and a nickel plating step.
A chromium plating method, wherein chromium plating is performed directly while applying vibration at 0 Hz and an amplitude of 2 to 30 mm to vibrate and agitate the treatment liquid. 4. When performing chromium plating on the surface of a zinc-based metal, a vibration liquid having a vibration of 15 to 60 Hz and an amplitude of 2 to 30 mm is applied to the vibrating blade without passing through nickel plating after the copper plating step to vibrate and stir the treatment liquid. A chromium plating method characterized by performing chromium plating directly on a copper plating layer. 5. When chromium plating is performed on the surface of a copper-based metal, the vibrating blade is not plated with nickel, and
A chromium plating method, wherein chromium plating is performed directly while applying a vibration of up to 60 Hz and an amplitude of 2 to 30 mm to vibrate and stir the treatment liquid. 6. In performing chromium plating on the surface of an aluminum-based metal, chrome plating is performed directly by applying vibration of 15 to 60 Hz and amplitude of 2 to 30 mm to the vibrating blades without passing through a base plating and vibrating and stirring the treatment liquid. A chromium plating method characterized by performing.