JP2647482B2 - Sealing treatment method for ceramic spray coating - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sealing a ceramic sprayed coating that can be advantageously applied to the production of runner vanes for movable blade pumps such as axial fan blades and compressor blades. .

[Conventional technology]

Ceramic spray material is a material with excellent wear resistance.
Recently used for various products.

For example, recently, movable blade pumps have come to be frequently used by taking advantage of the feature that the load fluctuation follow-up control operation of fluid transportation can be easily performed.In the transportation of slurry solution containing crystals of earth and sand, ash, and other compounds, The problem often arises that the movable wing is severely worn. For this reason, it has been strongly desired to select a material having excellent wear resistance and corrosion resistance. However, a material having excellent wear resistance does not always satisfy the corrosion resistance. Unless the properties are satisfied, there are many environments where the problems of corrosion and wear have not been solved. On the other hand, there has been proposed a method of improving the wear resistance by applying a ceramic spray to the surface of the liquid contact portion of a material which does not satisfy the wear resistance.

However, the currently developed thermal spraying technique does not provide a non-porous coating, which hinders application to products that require corrosion resistance. In order to solve this problem, a so-called so-called sealing treatment method for sealing pores formed in the thermal spray coating has been proposed.

Conventionally, the sealing method proposed is epoxy resin,
There is a method of applying a thermosetting resin such as a polyester resin or a silicone resin or an emulsion of an acrylic resin or a vinyl acetate resin, or a method of dipping and impregnating such a resin in a diluted solution.

[Problems to be solved by the invention]

In the conventional method of applying or impregnating a resin solution, when the dilution ratio of the resin is reduced, the viscosity of the solution increases, so that it is difficult to enter the pores of the thermal spray coating, and only covers the very surface layer of the thermal spray layer. It is easy to be in a state, and conversely, when the dilution rate is increased, it is easy to enter deep into the pores, but after the solution is volatilized by drying, holes are formed again in the pores,
It is difficult to fill the entire pores with resin. Therefore, even if the ceramic sprayed material is sealed, the interface between the sprayed ceramic and the base material will be corroded in an environment that comes into contact with the aqueous solution, making it a product that requires long-term durability, such as a runner vane for a movable blade pump. Is difficult to apply.

In view of the above technical level, the present invention solves the conventional drawbacks in the method for sealing a ceramic sprayed material, completely encloses the pores of the ceramic sprayed coating formed on the surface of the runner vane of the movable blade pump with resin, and performs corrosion. An object of the present invention is to provide a sealing treatment method which is capable of preventing the penetration of an ionic liquid and has excellent corrosion resistance.

[Means for solving the problem]

The present invention provides a first step of drying the reduced pressure while heating the runner vane on which the ceramic sprayed coating is formed when sealing the sprayed ceramic coating formed on the surface of the runner vane of the movable blade pump. A second step of flashing the monomer and adsorbing the monomer into the pores of the sprayed coating in the state of being sprayed, impregnating the pores of the sprayed coating with a solution obtained by mixing the polymerization catalyst with the monomer while maintaining the reduced pressure state A third step of polymerizing the monomer of the thermal spray coating impregnated with the solution obtained by mixing the monomer with a polymerization catalyst under a partial pressure in which the monomer vapor is balanced with respect to temperature and pressure. This is a method for sealing the thermal spray coating.

As the ceramic sprayed material in the present invention, any ceramic material having excellent wear resistance, such as alumina, tungsten carbide, zirconia, and titania, can be used. Further, many monomers such as styrene and methyl methacrylate can be used as the monomer, and many organic peroxides such as benzoyl peroxide and parkyl peroxide can be used as the polymerization catalyst. The mixing amount of the polymerization catalyst can be arbitrarily selected depending on the type of the product.
Preferably it is used in an amount ranging from 0.5 to 5.0% by weight.

[Action]

In the present invention, in order to completely fill the resin deep into the fine pores, drying under reduced pressure is performed while heating for the purpose of completely removing water adsorbed in the pores in the first step. If water remains, in the monomer impregnation step, not only does it hinder the monomer from filling the entire pores,
In order to inhibit the wetting of the ceramic and the monomer, when the monomer is impregnated and polymerized, it is difficult for the ceramic and the resin to adhere to each other.

The second step is a process for facilitating the impregnation of the monomer into the pores, by flashing the monomer under reduced pressure, and introducing the vapor of the monomer into the pores,
This is a step of wetting the ceramic surface in the pores with the monomer.
This step not only functions to complete the impregnation of the monomer in the next step, but also enhances the adhesion between the resin in which the monomer has been polymerized and the ceramic, thereby completely closing the pores.

The third step is a step of impregnating a monomer mixed with a polymerization catalyst. By completely immersing the portion of the runner vane where the ceramic sprayed coating is formed in the monomer solution mixed with the polymerization catalyst and reducing the pressure, the pores of the ceramic sprayed coating can be impregnated with the monomer mixed with the polymerization catalyst.

The fourth step is a step in which the monomer impregnated in the pores of the ceramic sprayed coating is all polymerized without vaporizing acid. In order to prevent the impregnated monomer from evaporating acid, it is preferred that the monomer be transferred into a vessel adjusted to an equilibrium partial pressure at the temperature and pressure at which the impregnated monomer is polymerized, and held until the polymerization is completed.

As described above, by continuously processing from the first step to the fourth step, the pores of the ceramic sprayed coating can be completely sealed, and a runner vane having a ceramic sprayed coating excellent in corrosion resistance can be provided.

〔Example〕

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS.

1 and 2 are views showing an embodiment of a run-number vane of a movable vane pump. FIG. 1 is a front view of a shaft attached to a pump body, and FIG. 2 is a top view of the shaft. FIG. Fig. 3 shows the entire surface excluding the runner vane shaft.
FIG. 4 is a view in which a runner vane sprayed with alumina having a thickness of 0 μm is viewed from above with respect to the axis, and FIG. 4 is an enlarged view of a part of a cross section taken along the line AA ′ in FIG.

FIG. 5 to FIG. 8 are views showing an embodiment in which the alumina sprayed runner vanes are sealed using a styrene monomer. FIG. 5 is a view showing an aspect of a vacuum drying step of the sprayed runner vanes, FIG. Fig. 7 shows an embodiment in which a monomer is adsorbed into pores of an alumina-sprayed coating film by flashing of styrene monomer. Fig. 7 shows immersion of runner vanes sprayed with alumina in a solution obtained by adding benzoyl peroxide as a polymerization catalyst to styrene monomer by 3 wt%. FIG. 8 shows an embodiment in which a styrene monomer containing benzoyl peroxide is impregnated under reduced pressure, and FIG. 8 shows an embodiment in which the monomer impregnated in the pores of the coating film of the alumina sprayed runner vane is vaporized in styrene monomer vapor. is there.

1 to 8, reference numeral 1 denotes a runner vane main body (made of SCS14) of a movable vane pump, 2 denotes an alumina sprayed coating film sprayed on a tip of the runner vane, 3 denotes a pressure-reduced container with a lid, and 4 denotes monomer injection with a stick. Vessel 5, vacuum pump 6, styrene monomer solution containing benzoyl peroxide, 8 styrene monomer vapor, 9
Is a container for styrene monomer evaporation.

A runner vane was prepared by spraying 500 μm of alumina onto the tip of a runner vane having a length of 400 mm. The runner vane was heated to 100 ° C., then placed in a container 3 capable of being depressurized by a vacuum pump 6, and heated to 100 ° C. Dry under reduced pressure at 1 Torr for 10 minutes while warming. (FIG. 5) Next, while maintaining the reduced pressure, the temperature was lowered to room temperature, and then the screw 5 of the styrene monomer injector 4 previously set on the upper part of the container 3 was opened, and the styrene monomer was coated on the surface of the thermal spray coating film. After flushing so as not to contact, the cock 5 connected to the vacuum pump 6 was closed and held for 10 minutes. (FIG. 6) Next, a styrene monomer containing 3% by weight of benzoyl peroxide is put into the monomer injector 4, and the nut 5 connected to the vacuum pump 6 is opened to reduce the pressure inside the container. Open the test runner vane until 3% by weight of benzoyl peroxide
After injecting styrene monomer containing
Hold for 10 minutes. (FIG. 7) Next, after releasing the reduced pressure, the runner vane was taken out, transferred to the lidded container 3 in which the evaporation container 9 containing the styrene monomer was set, and kept at 50 ° C. for 24 hours. (FIG. 8) The sprayed alumina spray runner vanes, the sprayed alumina spray runner vanes not subjected to the sealing treatment, and the sprayed alumina spray runner vanes coated with a cold-curable epoxy resin on the surface were attached to a movable blade pump. As a result of performing a durability evaluation test for 6 months while circulating the sulfuric acid solution, the runner vanes subjected to the above sealing treatment did not show any abnormality in the adhesive surface, whereas those without the sealing treatment did not. The coated epoxy resin was peeled off from the bonding surface between the coating film and the base material.

(Example II)

In the same manner as in Example I, a test ceramic sprayed material subjected to a sealing treatment was prepared by changing the styrene monomer to a methyl methacrylate monomer. This was subjected to a corrosion test under the same conditions as in Example I. As a result, good corrosion resistance was exhibited, as in the case of sealing with a styrene monomer.

〔The invention's effect〕

The present invention allows a runner vane having a ceramic sprayed coating formed thereon to be applied to a corrosive environment where a runner vane having a conventionally formed ceramic sprayed coating cannot be applied. The industrial effect that the runner vane on which the thermal spray coating is formed can be applied is great.

[Brief description of the drawings]

FIG. 1 and FIG. 2 are views showing aspects of a movable wing runner vane.
FIG. 3 is a view showing a state in which a part of the runner vane is thermally sprayed with a ceramic, FIG. 4 is an enlarged view of a part of a section taken along the line AA 'in FIG. 3, and FIGS. FIG. 5 is a diagram showing an embodiment of a treatment method, FIG. 5 is a diagram showing an embodiment of a vacuum drying step of sprayed runner vanes, and FIG. 6 is a diagram showing an embodiment in which a monomer is adsorbed into pores of an alumina sprayed coating film by flashing a styrene monomer. FIG. 7 shows a styrene monomer in which 3 wt% of benzoyl peroxide was added as a polymerization catalyst, and a runner vane sprayed with alumina was immersed in the solution.
FIG. 8 is a diagram showing an embodiment in which a styrene monomer containing benzoyl peroxide is impregnated under reduced pressure, and FIG. 8 is a diagram showing an embodiment in which a monomer impregnated in pores of a coating film of an alumina sprayed runner vane is vaporized in styrene monomer vapor.

Continued on the front page (72) Inventor Shigeo Hasegawa 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Inside of Hiroshima Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Haruo Kitamura 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Inside Heavy Industries, Ltd. (72) Inventor Chotaro Nishida 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Heavy Industries, Ltd. (72) Inventor Higashizo Tanori 2-1-1, Araimachi Shinhama, Takasago City, Hyogo Prefecture (56 References JP-A-1-263259 (JP, A) JP-A-57-70275 (JP, A) JP-A-54-106052 (JP, A)

Claims (1)

(57) [Claims] A first step of drying the reduced pressure while heating the runner vane on which the ceramic sprayed coating is formed, when performing the sealing treatment of the ceramic sprayed coating formed on the surface of the runner vane of the movable blade pump; In the held state, the second step of flushing the monomer and adsorbing the monomer in the pores of the sprayed coating, while maintaining the reduced pressure state, the solution in which the polymerization catalyst is mixed with the monomer is introduced into the pores of the sprayed coating. A third step of impregnating, and a fourth step of polymerizing the monomer of the thermal spray coating impregnated with the solution obtained by mixing the monomer with a polymerization catalyst under a partial pressure in which the monomer vapor is balanced with respect to temperature and pressure. Sealing method for ceramic spray coating.