JP2661837B2 - Conductor roll for electroplating and method for manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductor roll used in an electrotin plating apparatus, an electrogalvanizing apparatus and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conductor rolls used in zinc and tin electroplating apparatuses include conductive Fe-based materials, Cu
Materials such as base materials and corrosion-resistant alloys such as Hastelloy are used. Each of the conductor rolls made of these materials is subjected to surface treatment such as Ni plating and Cr plating and used for use. However, the life is extremely short due to the effects of corrosion, abrasion, and adhesion of foreign matter. This is a disadvantage.

In general, such a conductor roll for electroplating is desired to have the following functions. If the electrical conductivity is at a level that sufficiently satisfies the required performance, the surface properties are unlikely to change due to corrosion, abrasion, etc., If foreign matter (for example, plated metal) adheres to the surface, or it is difficult to electrodeposit and adheres Can be easily removed. Conventionally, the following rolls have been proposed as rolls developed to satisfy these required performances. Japanese Patent Publication No. 61-21320,
On the conductor roll surface, metal carbide powder 10 ~ 90wt%,
A roll coated with a mixed powder consisting of a nickel chromium alloy powder, the remainder being sprayed. A roll described in JP-B-62-6756, which is formed by coating or coating a defective conductor such as a thin oxide film on fine irregularities on the roll surface and exposing only a part of the substrate. .

[0004]

However, the above-mentioned technique can improve the wear resistance without substantially impairing the electric conductivity because it contains a carbide. On the other hand, as shown in FIG. When used for a long time, carbide particles (A) fall off (B) due to wear, rolling fatigue, corrosion, etc.
However, the surface properties of the roll change. Foreign matter
(C) adheres to the pits after dropping, and there is a problem that dents (push flaws due to foreign matters) occur on the steel sheet.

[0005] In the case of the above-mentioned technology, the WC is similarly dropped and the surface roughness changes, and the active surface (good conductor portion) is exposed at the WC dropped portion. There was a problem that the metal component was electrodeposited.

In addition, the above-mentioned carbide falling-off phenomenon common to each of the prior arts and the adverse effects associated therewith occur rapidly, unlike ordinary wear, and are difficult to prevent in that dents of plated steel sheets are generated. This is an issue that needs to be improved.

An object of the present invention is to overcome the above-mentioned problems of the prior art, that is, the inevitable problems of the thermal spray coating containing carbide. That is,
An object of the present invention is to propose a conductor roll surface structure for electroplating which can maintain excellent film properties and a stable surface state for a long time without causing carbide particles to fall off.

[0008]

According to the study of the present inventors, it has been found that the above object can be advantageously realized by controlling the form of carbide dispersed in the thermal spray coating. That is, the present invention has been made by paying attention to the carbide form in the thermal spray coating, and the gist of the invention is that the carbide cermet powder having a particle size of less than 150 μm
60 wt% and 0.4 wt% or more of the resulting by spraying a mixed powder consisting of Nitsukerukuromu alloy powder 90～40Wt% containing C
980-1100 in a sprayed coating with a porosity of 1.0% or less.
50min. To 5hr heat treatment in vacuum or air atmosphere at ℃
Carbide that is re-precipitated by applying
This is a conductor roll for electroplating on which a reprecipitated carbide dispersion sprayed film is formed.

[0009] Such a conductor roll is
The surface of the roll body contains 90 to 40 wt% of nickel chromium alloy powder containing 10 to 60 wt% of carbide cermet powder with a particle size of less than 150 μm and C of 0.4 wt% or more, with the balance being inevitable.
The porosity is less than 1.0% by spraying mixed powder consisting of impurities
980 ~ 1100
Heat treatment in vacuum or air atmosphere at ℃ for 50min. ~ 5hr
By that, obtained by the production method of electroplating conductor roll, which comprises re-precipitated was re-precipitated carbides dispersed thermally sprayed coating by coating forming carbides.

[0010]

[0011]

According to the present invention, a C-containing cermet sprayed film is formed on the surface of the roll body of a conductor roll, and then the C in the film is refined by thermal decomposition to cause re-precipitation to be uniformly dispersed in the film. It is characterized by forming a thin film.

The thermal spraying material used in the present invention is a mixture of a nickel chromium alloy powder containing 10 to 60 wt% of a carbide cermet powder having a powder particle size of less than 150 μm and a balance of 90 to 40 wt% containing C of 0.4 wt% or more. Use powder.

When the amount of the carbide cermet in the mixed powder for thermal spraying is less than 10% by weight (that is, when the amount of the nickel-chromium alloy powder exceeds 90% by weight), the amount of dispersion of the carbide is small and the wear resistance of the film is not good. Will be enough. On the other hand, if the amount of the carbide cermet exceeds 60% by weight (that is, if the amount of the nickel chromium alloy powder is less than 40% by weight), the structure after the heat treatment becomes brittle, and the particle size of the carbide varies, and the original uniform It becomes impossible to obtain a proper surface property.

In the thermal spraying of the material, thermal spraying is performed so that the porosity of the coating layer becomes 1.0% or less, followed by heat treatment to decompose and refine the metal carbide and then reprecipitate it. By such a treatment, it is possible to form a sprayed coating in which fine reprecipitated carbide is uniformly dispersed in a matrix, and as shown in FIG. 2, it is effective in preventing the carbide from dropping off.

The reason why the porosity of the coating layer is set to 1.0% or less at the stage after the thermal spraying and before the heat treatment is that if the porosity at this stage exceeds 1.0 %, the porosity remains in the coating after the heat treatment. In addition, since a plurality of pores are aggregated to form large pores or to generate a large amount of residual pores, a state similar to the above-described carbide-dropped structure is obtained, and a surface state in which so-called plating components are easily electrodeposited is obtained. Because. In addition to this, if the porosity is too large, the oxygen component remaining in the pores becomes a hindrance factor for carbide reprecipitation.

The carbide cermet powder in the thermal spray mixed powder used in the present invention has a particle size of less than 150 μm. It is not only extremely difficult to form a thermal spray coating with a porosity of 1.0% or less when the particle size exceeds 150 μm, but also it is not completely decomposed in the carbide decomposition reprecipitation process and remains in the structure as residual carbide. , And segregation increases, making it impossible to obtain a target film structure.

As the C-containing nickel-chromium alloy powder in the thermal spray mixed powder used in the present invention, a powder containing 0.4 wt% or more of C is used. If the C content is less than 0.4 wt%, the amount of carbide that is decomposed and re-precipitated after the heat treatment is small, and therefore, the ratio of the metal carbide (cermet) remaining as it is or the alloying and electrical As the properties change, wear resistance is impaired. On the other hand, the upper limit is not particularly limited. However, if it exceeds 2 wt%, a structure in which carbides are excessively concentrated between grains and at each grain boundary during heat treatment, and the corrosion resistance is significantly adversely affected. preferable.

Next, in the present invention, the heat treatment for heat-treating the thermal sprayed coating layer to reprecipitate carbide is performed in a vacuum or air atmosphere at a temperature of 980 ° C. to 1100 ° C. for 50 m.
Perform in ~ 5hr. If the heat treatment temperature is lower than 980 ° C., the diffusion decomposition sintering reaction becomes insufficient. On the other hand, if the heat treatment temperature exceeds 1100 ° C., decarburization and oxidation of carbides occur, and outflow occurs due to a decrease in the viscosity of the coating layer. The reason for limiting the atmosphere and the heat treatment time as described above is that if the heat treatment time is less than 50 minutes, the decomposition and reprecipitation of carbides are insufficient, and if the heat treatment time exceeds 5 hours, a decarburization phenomenon occurs.

In the present heat treatment, in the case of heat treatment in the air, it is preferable that Si, B powder and the like are contained in the alloy component powder to suppress oxidation of Ni, Cr, and carbides by oxygen in the air. That is, in the heat treatment in vacuum, most of the oxygen present is contained in the coating as an oxide during thermal spraying, and the impediment to carbide precipitation is small due to the small absolute oxygen content. . However, in the heat treatment in the atmosphere, the supply of O ₂ from the outside causes the consumption of carbon to be severe. Therefore, in the heat treatment in the atmosphere, it is desirable to minimize the heat treatment time by heating as quickly as possible, and also to use a hydrocarbon reducing flame as the heating source to maintain the carburizing effect to some extent while maintaining the carburizing effect. Therefore, the inclusion of Si powder and B powder produces preferable results.

In the present invention, the grain size of the precipitated carbide decomposed and refined by the heat treatment is about 30 μm, and is mainly in the form of double carbide, that is, M ₂ —Cr ₂₃ —C ₇ , M ₆ —Cr _{6
-C 2, M-Cr 7 -C} 4, and has a M ₄ -Ni ₄ -Cr ₄ -Cr.

In the present invention, as a method of spraying the above-mentioned sprayed material on the surface of the roll body, a gas combustion spraying method can be applied. However, in order to obtain the predetermined effect of the present invention , a high-density gas energy spraying method, for example, HVOF (High Velocity Oxygen F
uel), HPSS (High PowerPlasma Spray System) is advantageously suited.

[0022]

EXAMPLES Example 1 A pipe material (STKM-13A) to be used as a roll body was processed to a predetermined size for use in an electroplating apparatus.
On its outer surface, 50wt% WC, 30wt% Ni, 18wt% Cr,
A mixed powder consisting of 0.7 wt% C and the balance of unavoidable impurities was sprayed. Thermal spraying is performed by setting the porosity to 0.7%, 1.0%, and 2.0% by high-density gas energy spraying, and spraying by setting the porosity to 5% by gas combustion flame spraying. Carried out. Next, a pipe with a thermal spray coating obtained by thermal spraying was manufactured without heat treatment and a pipe with a heat treatment at 1100 ° C. for 4 hours in a vacuum.
As shown in (1), the roll was inserted into the outside of the roll substrate by shrink fitting, the surface of the sprayed coating was polished, the surface was adjusted by shot blasting, and then applied to a conductor roll of an electroplating line by a halogen method. The particle size of the sprayed powder material used was 30 to 75 μm.

The above thermal spray coating was examined for adhesion of foreign matter, abrasion resistance, corrosion resistance, electrical conductivity and overall evaluation. Table 1 shows the results. As is clear from the results shown in this table, the heat-treated thermal sprayed coating with a porosity of 1.0% or less
In any of the test items, the rolls were superior to the comparative examples. The rolls of the present invention, which were heat-treated at a porosity of 1.0% or less, compared with the conventional rolls of about 6 weeks in terms of service life, showed that the carbides fell off. Has decreased, the occurrence of dents has sharply decreased,
In addition, the life was more than three times that of the comparative example.

[0024]

[Table 1]

Example 2 After a pipe material (STKM-13A) to be used as a roll body was processed to a predetermined size, 35 wt% WC powder, 35 wt% Ni, 17 wt% Cr, 0.5 wt. A mixed powder material consisting of wt% C and SiB powder, using three types of materials with WC particle size of 50, 100, 150μm and three types of materials with only Cwt% changed to 0.3%, for a total of six types of materials. The film was formed by thermal spraying using a high-density gas energy spray method, and then heat-treated at 1050 ° C. for 3 hours in an atmosphere of oxygen and acetylene reducing flame (in air). The porosity after spraying was 0.8% for WC particles of 50 μm, 1.0% for 100 μm, and 2.0% for 150 μm. As shown in FIG. 3, this was shrink-fitted and inserted into the outside of the roll base material, and the surface of the sprayed coating was polished.
After the surface was adjusted by shot blasting, it was applied to a conductor roll of an electroplating line by a halogen method. Table 2 shows the results of tests for plate flaws, abrasion resistance, corrosion (roughness), and electrical conductivity. As is evident from the results shown in Table 2, 0.5% C-containing 15%
Those containing carbide particles of less than 0 μm were superior to those of the comparative example in any of the test items, and the life of the roll of the comparative example was about 6 weeks.
The roll of the present invention containing 0.5% C and having a WC particle size of less than 150 μm was more than about three times as large.

[0026]

[Table 2]

[0027]

As described above, the conductor roll of the present invention does not cause the carbide particles in the film to fall off, is excellent in film properties such as abrasion resistance and corrosion resistance, and is also excellent in roll life. It is extremely suitable as a conductor roll for an electroplating apparatus. Further, according to the present invention, such a conductor roll can be produced extremely easily.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing the structure of a thermal spray coating of a conventional conductor roll.

FIG. 2 is a partial cross-sectional view showing the structure of a sprayed coating of the conductor roll of the present invention.

FIG. 3 is a conceptual diagram of shrinking conductor rolls.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuyuki Kuroki 1-1-1 Gyoda, Funabashi-shi, Chiba Tokaro Corporation Tokyo Plant (56) References JP-A-5-9699 (JP, A) Hei 4-346693 (JP, A) JP-A-1-198460 (JP, A) JP-A-63-199892 (JP, A)

Claims (2)

(57) [Claims] To 1. A roll body portion surface, and a Nitsukerukuromu alloy powder 90～40Wt% you containing <br/> carbide cermet powder 10 to 60 wt% and 0.4 wt% or more of C having a particle size of less than 150μm mixed In a sprayed film with a porosity of 1.0% or less, obtained by spraying powder , in a vacuum or air atmosphere at 980 to 1100 ° C
In 50min.~5hr re precipitated <br/> reprecipitated carbide dispersed thermally sprayed coating is formed comprising electroplating conductor roll comprising carbides cause the dispersed by heat treatment of the. 2. The surface of a roll body contains 90 to 40% by weight of nickel chromium alloy powder containing 10 to 60% by weight of carbide cermet powder having a particle size of less than 150 μm and 0.4% by weight or more of C,
The remainder is sprayed with mixed powder consisting of unavoidable impurities, resulting in pores.
Rate to form a 1.0% of the thermal spray coating, after which the sprayed skin
The film is placed in a vacuum or air atmosphere at 980 to 1100 ° C for 50 minutes.
~5hr by heat treatment, the method of manufacturing an electro-plating conductor roll, which comprises a re-carbide precipitates dispersed thermally sprayed coating by reprecipitation coating forming carbides.