JP2001152307A - Method of forming corrosion resisting combined coating standing long use, and member having the composite coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of forming a combined coating having corrosion resistance and capable of standing long use. SOLUTION: The surface of a base material to which prior working for thermal spraying is applied is thermally sprayed with single metal, alloy, cermet or ceramics. Then a highly penetrative sealing solution forming oxide ceramics is applied or impregnated to or into the above surface and aging or heat treatment is performed to carry out sealing. Subsequently, a solution in which vitreous substance-forming components are dissolved or suspended is applied by brush coating or atomization and then dried at ordinary temperature or fired at <=900 deg.C to form a vitreous surface layer film. The resultant coating exhibits excellent corrosion resistance to molten metal, acid, alkali, or corrosive gas and can greatly improve the service life of the base material for use under these environments.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprayed coating which is required to have corrosion resistance and abrasion resistance even when exposed to a corrosive solution or a corrosive gas, especially a chemical bath such as a molten metal bath, an acid and an alkali. The present invention relates to a method for producing a film having a strong resistance to a chloride-containing liquid such as an aqueous solution or seawater, a sulfide-containing liquid, or a corrosive gas, and having a high voltage resistance and a resistance to corona discharge.

[0002]

2. Description of the Related Art The present invention relates to a method disclosed in Japanese Patent Laid-Open No.
This is a further improvement of the invention described in JP-A-58034. In the prior invention, at the stage of forming a sprayed coating having a thickness equal to or less than the final thickness, the coating is sealed, and the sprayed coating is further formed.The corrosion resistance is improved as compared with the conventional method, but still under severe use conditions. A sufficient effect could not be expected.

[0003] The invention disclosed in Japanese Patent Application Laid-Open No. 9-217163 discloses an undercoat sprayed on the surface of a steel base material, on which a metal, oxide, boride, carbide and carbide cermet is selected. Spraying a mixture of at least one selected material and a glass material. However, according to the present invention, a vitreous mixed coating is formed by thermal spraying. Was leaving.

[0004] As an invention which focuses on the formation of a vitreous film so as not to generate through-holes, a method disclosed in
Re-published patent W096 / 276 published internationally on March 12
No. 94 (published on April 28, 1998)
A base material having an undercoat sprayed film formed on its surface is subjected to glass lining or enamel coating containing a glassy raw material containing an oxide as a main component, glass ceramics,
A technique of forming a film by firing at 1000 ° C. for 0.5 to 10 hours or immersing in a molten vitreous raw material is described. In this method, there is no through-hole in the surface glass coating, so that it seems that there is no through-hole. However, when the relatively easily wearable glass film is consumed, through-holes are generated again, and there is a disadvantage that the corrosion resistance is lost.

[0005]

In the above prior art, how to form a composite coating consisting of a thermal spray coating and a vitreous coating that is difficult to avoid and has no through pores and can withstand long-term use; It is required to establish a technique for eliminating through pores in the thermal spray coating itself and through pores in the vitreous coating. Moreover, the peel resistance is high in practical use,
It is necessary to have strong resistance to thermal shock and to have excellent wear resistance and corrosion resistance. SUMMARY OF THE INVENTION An object of the present invention is to solve the problems in the prior art and to provide a method for forming a film that can exhibit excellent properties.

[0006]

Means for Solving the Problems In order to achieve the above object, the present inventors have made intensive studies and as a result, performed a sealing treatment on the ceramic or cermet sprayed film itself formed on the surface of the base material, and further performed a sealing treatment on the surface. It has been found that it is effective to form a vitreous film to form a composite film, and the present invention has been completed.

The present invention has been made based on the above findings,
A single metal, alloy, cermet, or ceramic is sprayed onto the surface of the base material that has been pre-processed for thermal spraying, and a highly permeable sealing liquid that forms a sealing material in the pores of the sprayed coating is applied or impregnated. After aging or heat treatment to perform pore sealing, a solution in which the vitreous forming component is dissolved or suspended is applied by brushing or spraying, and dried at room temperature or calcined at a temperature of 900 ° C. or less to obtain a vitreous material. The gist of the present invention is a method for forming a composite film having corrosion resistance characterized by forming a surface layer film and enduring long-term use, and a member characterized by having the composite film.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of the present invention will be described.
In the present invention, by eliminating through pores of the undercoat sprayed coating itself, and forming a vitreous coating thereon, even if the surface glassy coating that has been treated to eliminate through pores is locally worn, the overall It was developed with an emphasis on making it difficult for pores to form in the coating.

In the present invention, first, metal, ceramics or cermet is sprayed on the surface of the substrate. In the case of ceramic spraying, an undercoat is applied in advance if necessary. Since the surface as sprayed generally has a roughness Ra of 3 to 5 μm, depending on the product, the surface may be polished lightly or subjected to roughness adjustment blasting to obtain a roughness of Ra = 1 to 6 μm. I do. This is performed in order to enhance the adhesion to the next vitreous film. When Ra is small, the adhesion of the vitreous film decreases, and when Ra is too large, a problem may occur in the adhesion between the thermal spray coating and the vitreous film after the sealing treatment.

Next, a sealing agent is applied to the sprayed surface,
After impregnation and drying at room temperature or, if necessary, drying and baking at 450 ° C. or lower, a vitreous film is formed. As the sealing agent, a liquid material having high permeability when applied and generating oxide ceramics by heating is recommended. A gel in which the sealing component powder is suspended can also be used.

Depending on the type of the sealing agent and the vitreous film forming agent used, the sealing process and the vitreous film forming process to be described later are carried out by repeating the steps of coating, impregnating, drying or baking, or repeatedly throughout. . As the solution to be repeatedly applied, the same type or different types of liquids can be used in combination. As a result, the effect of the present invention can be made more remarkable.

When performing the sealing treatment, it is effective to carry out the treatment in a low-pressure atmosphere of 10 ^-1 Torr or less for the purpose of removing the gas in the pores in the film. Before the sealing treatment, the substrate is kept in this low-pressure atmosphere for at least about 15 minutes, and in this state, treatment such as coating and impregnation is performed. The sealing liquid is more volatile due to the reduced pressure, but suction is performed with a vacuum pump even during coating.
The coating may be performed by jetting from a nozzle, but when the coating is performed on the roll surface, it is preferable to perform the coating using a sponge roll or the like.

The sealing agent is preferably one that penetrates deeply into the thermal spray coating to form ceramics and seals. Therefore, the heat-resistant organic resin ceramic suspension is heated, and Cr _{2 is} heated.
Chromic acid for producing O ₃ , solution and colloidal solution of inorganic metal compound for producing metal oxide by firing, metal alkoxide alcohol solution, aqueous solution or alcohol solution of metal chloride, aqueous solution of metal phosphate, metal hydroxide Is recommended, an alcohol or water suspension containing ultrafine metal oxide powder, or a mixture of two or more of these.

The penetration of the sealant into the thermal spray coating is at least 8
When it is not less than μm, the sealing effect is enhanced. When the penetration depth is small, a synergistic effect with a glass film to be performed later cannot be expected. When a colloidal liquid is used as the sealing agent, it is preferable that the powder contains 5 to 50% by mass of ultrafine powder having a particle size of 5 to 50 nm. Then, an alkali metal silicate such as Na
The ₂ SiO ₃ is added at a weight ratio of 0.3 to 3.0. After sealing, it becomes Na ₂ O—SiO ₂ or the like and acts to increase the bonding force between ceramics.

As the inorganic binder, a phosphate compound or a silicate compound can be used. For example, NaPO ₃
Generates Na ₂ O by firing, and NaHSiO ₃ converts Na
It becomes ₂ O—SiO ₂ or the like and increases the bonding force between ceramics. The alkoxide alcohol-based material as a sealing agent has excellent permeability and drying properties, and is characterized in that it can be applied in a solution state, and can exhibit the sealing effect to the maximum. Especially S
Alkoxide alcohol solutions of i, Al, Ti, and Zr are typical and form oxides of the above metals, and are effective in sealing treatment. Of these, Si is a glass component and has a small coefficient of thermal expansion, so it may be better to keep the content relatively low.

The formation of the vitreous film after the sealing treatment is performed by brushing or spray-coating a solution obtained by dissolving a vitreous raw material in a solvent on the surface of the sprayed coating subjected to the sealing treatment and drying or drying the surface. Firing in accordance with A liquid in which the vitreous raw material powder is suspended may be used, and the firing is performed at 900 ° C. or lower. From the viewpoint of reducing the deformation of the base material, the heating temperature is preferably lower than the temperature required for vitrification.

The heat treatment of the vitreous film as required is performed by a simple heating method using a hot air generator or an infrared lamp, an in-furnace heating method or a burner heating method. It is selected depending on the material, the shape of the object to be coated, and the like.

As a raw material for forming the vitreous film, a material containing a thermal expansion coefficient component matching the thermal expansion coefficient of the thermal sprayed film ceramic component is selected. The thermal expansion coefficient of the thermal-sprayed ceramic is determined by its components, Al ₂ O ₃ , Z
relatively high as seen in rO ₂ etc. 5-10 × 10
It is about ^-6 / K.

Since the vitreous film forming liquid applied so as to form a finish layer must be nonporous, it is a solution containing a large amount of glass forming components such as SiO ₂ and B ₂ O ₃ . Further, the raw material once baked and vitrified may be pulverized and used as a viscous liquid. In that case, the composition is composed of 100% vitreous or a liquid obtained by mixing ceramics, cermet, metal (including alloy), natural mineral or processed powder of natural mineral with a total of 70% by mass or less of vitreous component. Various oxides in the vitreous SiO2 after firing
_2: 30-80 _mol%, Al _{2 O} 3: 8 mol% or less, Z
rO ₂ : 10 mol% or less, TiO ₂ : 15 mol% or less,
B ₂ O ₃ : 25 mol% or less, R _x O _y : 15 to 10 mol% (R is an alkali metal, an alkaline earth metal, C
One or more of r and Pb, O represents oxygen, and x and y represent the number of atoms. ) Is a liquid configured to be a vitreous main component. That is, the content of Al ₂ O ₃ , ZrO _2, etc., which has a high melting point and is hardly vitreous, is suppressed to be low,
It is intended to form a vitreous film mainly composed of SiO ₂ , B ₂ O ₃ or the like. Note that the component chemical formulas described in the claims and the text show typical compositions, and are not restricted by the atomic ratio of the chemical formulas.

The glassy film forming coating solution may be an organic metal compound, ie, a metal alkoxide alcohol solution or the like, or an organic and inorganic metal polymer solution, for example, a silicon polymer solution, silica gel, organopolysilane, polycarbosilane, polymetallocarbosilane, polysiloxane ( Silicon), polyborosiloxane, or the like. Further, these may contain 70% by mass or less of fine inorganic powder, that is, ceramic powder, metal powder or natural mineral powder, and the solution may be gelled and become colloidal.

The thickness of the vitreous film to be formed is also important, and the preferred range is 10 to 2000 μm. If it is too thin, there is no effect of the film.
The thermal stress during cooling is increased, and the peelability is increased. Similarly,
As a result of examining the total thickness of the composite film, it was confirmed that the preferable range was 20 to 2500 μm.

Examples of the ceramic film formed by spraying on the surface of the base material before forming the glass film include Al ₂ O ₃ and Al ₂ O ₃
—TiO ₂ , ZrO ₂ —Y ₂ O ₃ , CaO—SiO ₂ ,
_{Al 2 O 3 -ZrO 2, Cr} 2 O 3 -Al 2 O 3, Cr
₂ O ₃ or a composite oxide ceramic comprising at least one of Al, Ti, Cr, Fe and at least one of rare earth metals such as Y, Sc, Ce, La, etc., has a ceramic melting temperature, base It is selected in terms of the adhesion to the material, the difference in the coefficient of thermal expansion with the base metal, and the like. In particular, many of the double oxides have a low melting point, and have good adhesion to a vitreous film formed on the surface. Therefore, it is preferable that the content of the double oxide is 5% by mass or more. It goes without saying that the whole may be a double oxide.

In the case of a ceramic sprayed coating, metal or cermet coating spraying can be used in combination as an undercoat. In this case, it goes without saying that an undercoat material that improves the adhesion to the ceramic film is selected. Ni, C as undercoat materials
r, Co, Fe, Mn, Mo, W, Ti, Nb, Al,
One or more of Y, or the metal or alloy and C
r ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , Y ₂ O ₃ , Zr
O ₂ , Cr ₃ C ₂ , WC, NbC, WB, CrB, Ti
A cermet comprising at least one of B, MoB, and ZrB is a preferred component system and is used as a bonding material between a base metal and a ceramic sprayed coating, and the adhesion of the ceramic sprayed coating to the base can be improved. . It is sufficient that the thickness of the bond layer is 10 to 50 μm. It is also possible to apply a gradient spraying method in which a concentration gradient is provided as a component so that the ratio of the metal phase is high on the base material side and the content ratio of the ceramic component is high on the ceramic sprayed film side.

Cermet coatings formed by spraying on the surface of a substrate before forming a glass coating include Co, Cr, Ni, Mo,
1 selected from Fe, Al, Ti, Nb, W, Mn, and Y
At least one kind of metal or an alloy containing the same as a main component, and the ceramic component is composed of at least one of carbide, oxide, and boride.

As the metal phase, Co, Ni, Fe, Mn and the like are preferable as matrix components, and Cr, Mo,
W, Ti, Nb and the like effectively act to strengthen the metal phase, improve corrosion resistance, and the like. Ai, Ti, Y, and the like are components that have been shown to be effective in improving oxidation resistance and improving bonding strength with a ceramic phase.

As a ceramic component constituting the cermet film, since the film is formed by thermal spraying, a compound of a heavy metal gives relatively good results in terms of film adhesion. However, carbides, oxides, borides, etc. Can be used. However, since the subsequently formed vitreous film is an oxide-based film, the oxide-based film may be better in terms of its affinity. In some cases, carbides are preferable in terms of affinity with metals.

Among the ceramic components constituting the cermet coating, carbides include WC, Cr ₃ C ₂ , NbC,
As oxides, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Cr
₂ O ₃ and Y ₂ O ₃ are borides such as WB, CrB ₂ ,
TiB ₂ , MoB, ZrB and the like are used. These can be used alone or in various combinations. It goes without saying that this cermet film can be applied as an undercoat material for a ceramic film.

[0028]

As described above, in the composite coating formed according to the present invention, the sprayed coating applied to the substrate is sealed with an oxide ceramic, and the surface layer is coated with a vitreous coating. From, without through-pores, molten metal,
It exhibits excellent corrosion resistance to acids, alkalis, or corrosive gases, has a significantly improved service life for substrates used in these environments, has great industrial value, and is extremely useful in industry.

[0029]

EXAMPLES The excellent effects of the present invention will be specifically described with reference to examples, but the present invention is not limited by these examples. Example A composite coating composed of a thermal spray coating and a vitreous coating that had been subjected to a sealing treatment according to an example described later was prepared by each method, and their characteristics were confirmed.

(1) Undercoat thermal spraying example 1 (U-1) WC-12% Co-30% WB Particle size 10-50 μm, 50 μm film of spray granulated powder by high-speed gas spraying. spraying (2) undercoat sprayed example to a thickness _{2 (U-2) Cr 3} C 2 -25% NiCr size 10～45Myuemu, spraying spray granulation powder to be a 50μm thickness by the high velocity gas spraying ( 3) Undercoat thermal spraying example 3 (U-3) CoNiCrAlY (32% Ni, 21% Cr, 8% A)
1, 0.5% Y, the balance Co is a commercial product).
(4) Undercoat thermal spraying example 4 (U-4) CoCrAlY (23% Cr, 13% Al, 0.5%)
Y, commercial product of the balance Co) Particle size of 10 to 50 μm, powder was sprayed with high-speed gas
Thermal spraying to a thickness of 0 μm

(5) Thermal spraying example 1 without a top coat (C-
1) WC-12% Co-30% WB Spraying granulated powder with a particle size of 10 to 50 μm by high-speed gas spraying to a thickness of 50 μm. (6) Spraying without Top Coating Example 2 (C-2) Cr ₃ C ₂ -25% NiCr size 10～45Myuemu, spray (7) without top coat spraying example as a 50μm thickness by the high velocity gas spraying spray granulation powder 3 (C-3) WC- 25% NiCr ( commercially available) Particle size 10-45 μm, powder is sprayed with high-speed gas
Thermal spraying to a thickness of 0 μm

(8) Thermal spraying example 4 without top coat (C-
4) Cr ₃ C ₂ -25% (Hastelloy C) Spray granulated powder having a particle size of 10 to 45 μm by high-speed gas spraying so as to have a thickness of 50 μm. (9) Thermal spraying example 5 without top coat (M-1) 20 % Ni-Cr commercial powder is sprayed by high-speed gas spraying so as to have a film thickness of 50 µm. (10) Spraying without Top Coating Example 6 (M-2) CoNiCrAlY (32% Ni, 21% Cr, 8% A)
1, 0.5% Y, the balance Co is a commercial product).
Thermal spraying to a thickness of 0 μm

(11) Top Coating Thermal Spray Example 1 (T-1) Cr ₂ O ₃ and Y ₂ O ₃ were mixed in equal moles, molded, fired at 1600 ° C. for 4 hours in an oxidizing atmosphere, and crushed. Thermal spraying of a sprayed material having a particle size of 10 to 45 µm into a powder having a particle size of 10 to 45 µm by a plasma spraying machine so as to have a film thickness of 30 µm. (12) Top coat spraying example 2 (T-2) Al ₂ O ₃ -10% TiO ₂ (commercially available) Product) The above sprayed material is sprayed with a plasma spraying machine so as to have a thickness of 50 μm.

Example of sealing treatment (chemical component is mass%) (1) Example of sealing treatment (F-1) After impregnating the thermal sprayed coating with a 6% aqueous solution of dichromic acid,
Sealing by heat treatment for 1 hour (2) Sealing treatment example 2 (F-2) After impregnating the sprayed coating with a 10% alcohol solution of alkoxysilane-based SiO ₂ , heat treatment was performed at 180 ° C. for 1 hour for sealing. (3) Sealing treatment example 3 (F-3) A solution composed of inorganic colloid SiO ₂ : 30%, Na ₂ O: 0.5%, water remaining, Na ₂ O: 10%, SiO ₂ : 3
The spray coating is impregnated with a sealing liquid obtained by mixing an inorganic binder solution consisting of 0% residual water at a ratio of 1: 1 and then heat-treated at 450 ° C. for 1 hour for sealing.

(4) Sealing treatment example 4 (F-4) Sealing liquid in which a colloid aqueous solution containing 40% of ZrO ₂ colloid is mixed 1: 1 with a 20% alcohol-water mixed solution of alkoxysilane-based SiO _2. After impregnating the sprayed coating with
Sealing by heat treatment at 0 ° C. for 30 minutes (5) Sealing treatment example 5 (F-5) Anaerobic curable acrylic resin, 10% of ultrafine SiO ₂ powder
After brushing an organic solvent solution containing, later to stand at room temperature for 2 hours, heated to 80 ° C., 1 hour hold (6) sealing treatment Example 6 (F-6) 6% bichromate solution, 10 ^- After applying to the thermal spray coating in a chamber reduced to ¹ Torr, heat treatment is performed at 450 ° C. for 1 hour at normal pressure to seal. (7) Sealing treatment example 7 (F-7) Anaerobic curable acrylic resin, SiO ₂ 10% ultra fine powder
After applying the organic solvent solution to the sprayed coating in a room where the pressure was reduced to 10 ^-1 Torr, the solution was allowed to stand at room temperature and pressure for 3 hours.

Example of vitreous film (chemical component is mass%) (1) Example of vitreous film 1 (G-1) A 30% ethanol solution in which a silicon-based metal alkoxide and a zirconia-based metal alkoxide are mixed at a ratio of 3: 1. Powder of yttrium-stabilized ZrO ₂ (10-4
After adding 10% (0 μm diameter) by spray coating, the mixture is dried, and baked at 500 ° C. for 1 hour. This is repeated three times to form a film having a thickness of 50 μm. (2) Vitreous film example 2 (G-2) An organometallic polymer obtained by combining Al ₂ O ₃ and an epoxy-based organic compound (trade name: TX-300: [ 1.5% amine-based curing agent, and 10% of thinner
%, Diluted and coated by air spray to a thickness of 100 μm / time. After drying, the temperature was raised at a rate of 20 ° C./hour, and then baked at 180 ° C. for 4 hours. This is repeated twice 200
Formation of μm thick film

(3) Glassy Coating Example 3 (G-3) A coating agent (trade name: TX) obtained by adding a layered silicate mineral powder to an organic solvent solution of an organometallic polymer comprising a silicon polymer having a diphenyl oxide group and mixing the solution. -40
0: manufactured by Takayoshi Co., Ltd.), diluted with 15% of thinner and diluted with air spray to 100 μm.
/ Times coating. After drying at room temperature for 4 hours,
Similarly, the second layer 100 μm / time, the third layer 100 μm /
After the times of coating, drying and curing for 3 days room temperature the film and formation (4) Glass coating frit for high temperature gas corrosion (G-4) Product Name TX-800 :( Ltd.) Takayoshi Ltd. _(Na 2 0 ,
K ₂ O: 17 mol%, MgO, CaO: 9 mol%, Al
₂ O ₃ : 4 mol%, ZrO ₂ : 4 mol%, B ₂ O ₃ : 1
5 mol%, SiO 2: ₄₄ mol% Others 7 blended raw material powder so that the mole%, adding a slip viscosity adjusting additives and water, those wet mill buck) the glassy content weight of the same weight 8% Y ₂ O ₃ partially stabilized zirconia powder (10
~ 30 µm powder) Sprayed to a thickness of 50 µm, dried and fired at 800 ° C for 1 hour

(5) Acid-Resistant Glass Coating Frit (G-5) Na ₂₀ and K ₂ O: 17.5 so as to be an acid-resistant component.
Mol%, MgO, CaO: 2.5 mol%, Al ₂ O ₃ :
0.5 mol%, ZrO ₂ : 2.5 mol%, B ₂ O ₃ : 9
Mol%, SiO ₂ : 63 mol% and other 5 mol%, and a mixture obtained by adding a slip viscosity adjusting additive and water, mixing by a wet mill, spray-coating to a thickness of 50 μm, drying, and then adding 870 1 hour calcination (6) heat-resistant glass coating frit _{℃ (G-6) Na 2} 0, K 2 O: 17.5 mol%, MgO, CaO:
2.5 mol%, Al ₂ O ₃ : 0.5 mol%, ZrO ₂ :
The raw material powder was blended so as to be 2.5 mol%, B ₂ O ₃ : 9 mol%, SiO ₂ : 63 mol% and 5 mol%, and 20% of Cr ₂ O ₃ and water were added to the slip viscosity adjusting additive. Is mixed by a wet mill, spray-coated to a thickness of 70 μm, dried, and baked at 870 ° C. for 1 hour. (7) Glassy coating example 7 (G-7) Polycarbosilane is produced from polysilane by a thermal decomposition rearrangement reaction At the time, a titania-based metal alkoxide was added to form polytitanocarbosilane, and 40%
After brush coating, dry the solution and heat to 830 ° C

Example 1 Investigation of Corrosion Resistance of Molten Metal Substrate (material: SUS316L, dimensions: 30 mmφ × 300 m
An example of a composite film formed according to the present invention and a film example as a comparative example were formed on an m-bar), and test pieces for examining wettability and reactivity with a molten metal were prepared. In this case, the thickness of the sprayed coating (in each of U, T, and C) was 50 μm. Immersion in a molten zinc bath (450 to investigate the wettability and reactivity to molten metal)
C) The test results are shown in Table 1. No. 1-3 are examples of the present invention,
No. 4 to 7 are comparative examples.

[0040]

[Table 1]

After being immersed in a molten zinc bath for 20, 40, and 80 days, they were taken out and compared for wettability and reactivity.
It can be seen that the composite coating of thermal spray + sealing treatment + vitreous coating formed by the method of the present invention is much better than that of the comparative example. This example is a result of applying the present invention to a hot dip galvanizing bath.
Similar results were obtained when applied to a% aluminum plating bath.

Example 2 Investigation of corrosion resistance for boiler tubes Test pieces (material: SUS304, dimensions 50 mm × 30 mm ×
5 mmt), as in Example 1, a composite coating example formed according to the present invention and a coating example as a comparative example were formed.
The following molten salt powder was placed on these test pieces, and the temperature was kept at 500 ° C. in a gas component gas. Table 2 shows the results. N
o. Nos. 8 to 10 are examples of the present invention. 11 to 15 are comparative examples. Molten salt component NaCl: 7 molar KCl: 1 molar CaCl _2: 9 molar MgCl _2: 3 molar gas composition _{O 2: 7% CO 2:} 12% HCl: 500ppm SO 2: 100ppm H 2 O: 8% N 2: balance Processing temperature 500 ℃

[0043]

[Table 2]

Example 3 Investigation of Corrosion Resistance to Acidic Aqueous Solution An example of a composite coating formed according to the present invention and a coating as a comparative example were formed on the same test piece as in Example 2, and these were immersed in a 10% sulfuric acid solution. And the number of days until the sprayed coating peeled off was compared. Table 3 shows the results. No. 16-22
Is an example of the present invention; 23 to 26 are comparative examples.

[0045]

[Table 3]

The number of days required for the thermal spray coating to peel off is longer in the present invention example than in the comparative example, indicating that the corrosion resistance is excellent. This is a combined effect of the thermal spray coating being densified by the sealing treatment and the coating of the vitreous coating thereon, which is due to the more impeding the permeation of the sulfuric acid solution.

Example 4 Investigation of corrosion resistance to corrosive gas of 400 ° C. or less Test piece (material: SS400, dimensions: 50 mm × 30 mm × 5
mmt), a composite coating example formed according to the present invention and a coating example as a comparative example were formed in the same manner as in Example 2 or 3, and these test pieces were placed in a N ₂ atmosphere gas containing 1000 ppm of Cl ₂ gas at 350 mm. 7 days at 14 ° C, 14 days, 2 days
Exposure was performed for 8, 42, and 56 days to compare the surface conditions. Table 4 shows the results. No. Nos. 27 to 29 are examples of the present invention; 30 to 34 are comparative examples.

[0048]

[Table 4]

From the test results, it can be seen that, when kept at a high temperature in a corrosive gas atmosphere in which Cl ₂ gas is present, the examples of the present invention can be used for a long time.

Example 5 Investigation into the case where heat resistance is required when used in a place heated to 800 ° C. in the air or in the air with a lot of CO 2 or moisture, a test piece (material SS400, dimensions 50 mm × 30 mm × 5
mmt), a composite coating example formed according to the present invention and a coating example as a comparative example were formed, and these test pieces were tested under the following conditions. Table 5 shows the results. No. 35
Nos. To 36 are examples of the present invention; 37 to 39 are comparative examples. Gas composition O ₂ : 7% CO ₂ : 12% H ₂ O: 8% N ₂ : balance Treatment temperature 800 ° C

[0051]

[Table 5]

From the results shown in Table 5, it is understood that the composite film obtained according to the present invention can be used for a long time.

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[Procedure amendment]

[Submission date] March 13, 2000 (200.3.1)
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 5

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

When performing the sealing treatment, it is effective to carry out the treatment in a low-pressure atmosphere of 13.3 Pa or less for the purpose of removing gas in the pores in the film. Before the sealing treatment, the substrate is kept in this low-pressure atmosphere for at least about 5 minutes, and in this state, treatment such as coating and impregnation is performed. The sealing liquid is more volatile due to the reduced pressure, but suction is performed with a vacuum pump even during coating.
The coating may be performed by spraying from a nozzle, but when it is performed on the roll surface, it is preferably performed by a sponge roll tower.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0037

[Correction method] Change

[Correction contents]

(3) Glassy Coating Example 3 (G-3) A coating agent (trade name: TX) obtained by adding a layered silicate mineral powder to an organic solvent solution of an organometallic polymer comprising a silicon polymer having a diphenyl oxide group and mixing the solution. -40
0: manufactured by Takayoshi Co., Ltd.), diluted with 15% of thinner and diluted with air spray to 100 μm.
/ Times coating. After drying at room temperature for 4 hours,
Similarly, the second layer 100 μm / time, the third layer 100 μm /
After the times of the coating, 3 days at normal temperature forming a dried and cured by coating (4) glass for high temperature gas corrosion co computing frit (G-4) Product Name TX-800 :( Ltd.) Takayoshi Ltd. (Na ₂ O,
K ₂ O: 15 mol%, MgO, CaO: 9 mol%, Al
₂ O ₃ : 4 mol%, ZrO ₂ : 4 mol%, B ₂ O ₃ : 1
5 mol%, SiO 2: ₄₄ mol% Others 7 blended raw material powder so that the mole%, adding a slip viscosity adjusting additives and water, those wet mill buck) the glassy content weight of the same weight 8% Y ₂ O ₃ partially stabilized zirconia powder (10
Spray those ~30μm powder) were mixed to 50μm thick coating, after drying, 800 ° C., calcined 1 hour

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction contents]

[0040]

[Table 1]

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0045

[Correction method] Change

[Correction contents]

[0045]

[Table 3]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yusei Michikata 1-3-8 Yaesu, Chuo-ku, Tokyo Nippon Steel Hard Co., Ltd. (72) Inventor Yoshiro Takano 460-1 Oguro-cho, Matsusaka-shi, Mie, Japan Shares Company F-term in Takayoshi (reference) 4K031 AA02 AB05 AB08 AB09 BA05 CB11 CB14 CB21 CB22 CB23 CB24 CB26 CB27 CB39 CB42 CB44 CB45 DA04 FA01 FA07 FA08 FA10

Claims (20)

[Claims] 1. A highly permeable sealing in which a single metal, alloy, cermet, or ceramic is sprayed on the surface of a base material which has been pre-processed for thermal spraying, and then a sealing material is formed in pores in the thermal spray coating. After applying or impregnating the solution and performing aging or heat treatment to perform pore sealing, apply the solution in which the vitreous forming component is dissolved or suspended by brushing or spraying, and dry at room temperature or fire at a temperature of 900 ° C or less. A method of forming a composite film having corrosion resistance and long-term use, characterized in that a vitreous surface layer film is formed by performing the method. 2. The method according to claim 1, wherein when the thermal spraying material is ceramics, a single metal or an alloy or a cermet composed of a metal and ceramics is applied as an undercoat film. . 3. For each of the sealing treatment and the vitreous film forming treatment, the same kind of liquid is repeatedly applied and impregnated, or different kinds of liquids are repeatedly applied and impregnated, or a combination of this and a baking treatment is repeated. 3. The method for forming a composite film having corrosion resistance and enduring long-term use according to claim 1 or 2. 4. After performing the sealing treatment after forming the thermal spray coating, the coating is impregnated with a sealing liquid containing a material for forming a sealing material in the pores in the thermal spray coating, and then dried, and the vitreous material is dried. 3. A coating solution containing a film-forming component and dried at room temperature or calcined at a temperature of 900 ° C. or less.
Or a method for forming a composite film having corrosion resistance according to 3 and enduring long-term use. 5. The corrosion resistance according to claim 1, wherein the impregnation depth of the sealing liquid is increased by applying the sealing liquid in a reduced pressure atmosphere having an internal pressure lower than 10 ^-1 Torr. And a method of forming a composite film that can withstand long-term use. 6. The vitreous film-forming component liquid is formed by heating a liquid composed of a raw material mainly composed of various oxides for glass lining or a raw material mainly composed of various oxides for glass lining. A liquid mainly composed of powder that has been pulverized and then pulverized, and the vitreous film forming component is 100% vitreous or a ceramic, cermet, metal (including alloy), natural mineral or natural mineral. It consists of a liquid in which the processed powder is mixed with a glassy component of 70% by mass or less in total, and various oxides in the glassy material are baked, and SiO ₂ : 30 to 80 mol%, Al ₂ O ₃ : 8 mol% or less , ZrO ₂ : 10 mol% or less, TiO ₂ : 15 mol% or less, B ₂ O ₃ : 25 mol% or less, R _x O _y : 15
-10 mol% (R represents one or more of alkali metals, alkaline earth metals, Cr and Pb, O represents oxygen,
x and y indicate the number of atoms. The method for forming a composite film having corrosion resistance and long-term use according to any one of claims 1 to 5, which is a liquid configured to be a vitreous main component. 7. The vitreous film-forming component liquid may be an organometallic compound-containing solution, a solution containing either an organometallic polymer and an inorganic metal polymer, or a solution containing both, or 70% by mass of fine inorganic powder. The method for forming a composite film having corrosion resistance and long-term use according to any one of claims 1 to 6, which is a liquid contained below. 8. The thickness of the formed vitreous film is 10 to 10.
The method for forming a composite film having corrosion resistance and long-term use according to any one of claims 1 to 7, which is 2000 µm. 9. The total thickness of the composite coating is 20 to 2500 in total
The method for forming a composite film having corrosion resistance according to any one of claims 1 to 8, which is durable for a long time. 10. The ceramic coating initially sprayed is
Al ₂ O ₃ , Al ₂ O ₃ —TiO ₂ , ZrO ₂ —Y ₂ O
_{3, CaO-SiO 2, Al} 2 O 3 -ZrO 2, Cr 2
_{O 3 -Al 2 O 3, Cr} 2 O 3 or Al, Ti, C
Ceramics which are multiple oxides composed of at least one of r and Fe and at least one of Sc, Y and rare earth metals, or ceramics composed of oxides of Si and other metals containing 5 mass% or more of the multiple oxides The method for forming a composite film having corrosion resistance according to any one of claims 1 to 9 and enduring long-term use. 11. The undercoat material of the ceramic film to be initially sprayed is Ni, Cr, Co, Fe, Mn, M
o, W, Ti, Nb, Al, Y or one or more of the above metals or alloys and Cr ₂ O ₃ , Al ₂ O ₃ , T
iO ₂ , Y ₂ O ₃ , ZrO ₂ , Cr ₃ C ₂ , WC, Nb
The method according to any one of claims 2 to 10, which is a cermet comprising at least one of C, WB, CrB, TiB, MoB, and ZrB. 12. A cermet coating according to claim 11, wherein the cermet coating initially sprayed is a composite coating having corrosion resistance according to any one of claims 1 to 3 and enduring long-term use. Method. 13. The sealing liquid according to claim 1, which is applied or impregnated on a thermal sprayed coating, subjected to aging or heat treatment to perform sealing treatment, and then produces an oxide-based ceramic. 13. A method for forming a composite film having corrosion resistance according to any one of the above items 12 to 12, which can withstand long-term use. 14. The sealing agent is an oxide suspension of an organic resin solution, a chromic acid solution, an inorganic compound colloid solution, an alcohol solution of a metal alcohol compound, an aqueous solution or alcohol solution of a metal chloride, an aqueous solution of a metal phosphate, or a metal. 14. A colloidal hydroxide solution, an alcoholic or aqueous suspension of metal oxide fine powder, or a mixture of two or more thereof.
The method for forming a composite film having corrosion resistance according to any one of the above and enduring long-term use. 15. The corrosion resistance according to any one of claims 1 to 14, wherein the sealing liquid having good permeability has a penetration depth of 8 μm or more of the sprayed coating by sealing and impregnating,
A method for forming a composite film that can withstand long-term use. 16. The sealing agent is a colloidal solution of an inorganic compound, and the inorganic compound is SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂
Is a fine powder having a particle size of 5 to 50 nm and containing 5 to 50% by mass of this inorganic compound. Silicate is 0.3- by mass ratio
2. A liquid contained in a ratio of 3.0.
5. The method for forming a composite film having corrosion resistance according to any one of the above items 5 and enduring long-term use. 17. The method according to claim 1, wherein the inorganic binder contained in the sealing agent is a phosphate type or a nitrate type. 18. The corrosion resistance according to claim 1, wherein the metal alcohol compound used for the sealing agent is an alkoxide compound composed of at least one of Si, Al, Ti, and Zr. A method for forming a composite film that can withstand long-term use. 19. The sprayed coating surface roughness before the sealing treatment is adjusted to Ra = 1.5 to 6 μm.
The method for forming a composite film having corrosion resistance according to any one of the above and enduring long-term use. 20. A member having a corrosion-resistant composite film formed according to any one of claims 1 to 19 and enduring long-term use.