WO2017098854A1 - Sealer, sealer coating solution, corrosion resistant film, high temperature member, and method for manufacturing high temperature member - Google Patents

Abstract

Provided is a sealer which is capable of sealing pores of a corrosion resistant film for a prolonged period of time and which does not corrode a substrate. The sealer is for sealing the pores of the corrosion resistant film and is characterized by comprising glass in which a proportion of alkali metal oxide in the composition is 20% by mass or less and a proportion of lead oxide therein is 2% by mass or more.

Description

Sealant, sealant coating solution, corrosion-resistant coating, high temperature member and method for producing high temperature member

The present invention relates to a sealing agent for filling pores of a corrosion-resistant film, and a corrosion-resistant film and a high-temperature member produced using the same.

In thermal power generation, coal, oil, and LNG are burned in a boiler, and the turbine is rotated using the high-temperature and high-pressure gas, or the turbine is rotated by steam generated using the heat of the high-temperature gas. Is going. For this reason, high temperature members such as gas turbines and heat transfer tubes are exposed to corrosive and oxidizing combustion gas atmospheres of oxygen, sulfur oxides, hydrogen sulfide, etc. at 500 to 1000 ° C. As a result, there is a problem of a decrease in life due to so-called high temperature corrosion.

Since the high temperature member deteriorates due to such acid gas corrosion, it is necessary to frequently replace the high temperature member. Since replacement of the high temperature member increases the power generation cost, a high temperature member that does not deteriorate for a longer period of time is required.

Therefore, it has been studied to prevent the deterioration by forming a corrosion-resistant film on the surface of these high-temperature members. In order to extend the life of the high-temperature member by the corrosion-resistant coating, it is important how to form a dense coating without pores. That is, if pores exist in the corrosion-resistant film, the acidic gas reaches the base material of the high temperature member through the pores, and the high temperature member is corroded.

JP 2001-152307 A JP-A-60-194063

For example, Patent Document 1 discloses a composite coating in which cermet or ceramics is formed by thermal spraying as a base layer, a sealing process is performed on the surface of the base layer with an oxide ceramic, and a glassy coating is further formed. The composite coating described in Patent Document 1 has no through pores and exhibits not only excellent corrosion resistance against corrosive gas, but also the service life of the substrate is remarkably improved. Examples of sealing agents include heat-resistant organic resin ceramic suspensions, chromic acid that generates Cr ₂ O ₃ by heating, inorganic metal compound solutions and colloidal solutions that generate metal oxides by firing, metal alkoxide alcohol solutions Metal chloride aqueous solution or alcohol solution, metal phosphate aqueous solution, metal hydroxide colloid solution, alcohol or water suspension containing metal oxide ultrafine powder, or a mixture of two or more of these are recommended . However, these sealing agents have a problem that gas is generated even after solidification and complete sealing cannot be performed. Moreover, although the use of Na ₂ SiO ₃ , NaPO ₃ , NaHSiO ₃ as an inorganic binder has been proposed, these include alkali metals. As described in Patent Document 2, since alkali metals cause high-temperature corrosion, if the above-described inorganic binder is used, these may corrode a base material or a coating film.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sealing agent that can seal the pores of the corrosion-resistant coating over a long period of time and does not corrode the substrate.

The sealing agent of the present invention is a sealing agent for sealing pores of a corrosion-resistant film, and the proportion of alkali metal oxide in the glass composition is 20% by mass or less, and the proportion of lead oxide is 2% by mass or more. It consists of glass which is. “Alkali metal oxide” refers to one or more of Li ₂ O, Na ₂ O, and K ₂ O.

The sealing agent of the present invention is a sealing agent for sealing pores of the corrosion-resistant film, and the proportion of alkali metal oxide in the glass composition is 20% by mass or less, and the proportion of lead oxide is 10% by mass. It is preferable to consist of the glass mentioned above.

The sealing agent having the above configuration does not corrode the base material because it has few alkali metal components. In addition, since it contains lead oxide, the softening point is low, and the pores of the corrosion-resistant film can be easily sealed.

In the present invention, the glass composition has a glass composition of PbO 10 to 90% by mass, ZnO 0 to 50%, B ₂ O ₃ 0 to 50%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na ₂ O + K ₂ O 0. It is preferable to contain up to 20%, SiO ₂ 0-50%, Al ₂ O ₃ 0-30%. Here, “MgO + CaO + SrO + BaO” means the total amount of MgO, CaO, SrO and BaO. “Li ₂ O + Na ₂ O + K ₂ O” means the total amount of Li ₂ O, Na ₂ O and K ₂ O.

If the above configuration is adopted, it becomes easy to produce a sealing agent made of glass.

The sealing agent of the present invention is a sealing agent for sealing pores of the corrosion-resistant film, and is made of glass containing PbO 5 to 50% and ZnO + B ₂ O ₃ 25 to 60% by mass percentage. preferable. Here, “ZnO + B ₂ O ₃ ” means the total content of ZnO and B ₂ O ₃ .

The sealing agent having the above-mentioned configuration is made of glass containing PbO that significantly lowers the softening point and ZnO or B ₂ O ₃ that has a lower effect of lowering the softening point than PbO at an appropriate ratio. Thereby, the pores of the corrosion-resistant film can be easily sealed, and the situation in which the viscosity of the glass is too low to react with the film or drop off from the surface of the film can be prevented.

In the sealing agent of the present invention, the glass has a glass composition of PbO 5-50% by mass, ZnO + B ₂ O ₃ 25-60%, ZnO 0-40%, B ₂ O ₃ 0-40%, MgO + CaO + SrO + BaO. It is preferable to contain 0 to 40%, Li ₂ O + Na ₂ O + K ₂ O 0 to 20%, SiO ₂ 0 to 40%, Al ₂ O ₃ 0 to 30%.

If the said structure is employ | adopted, it will become easy to produce the glass which has a suitable viscosity characteristic.
The sealing agent of the present invention is a sealing agent for sealing pores of the corrosion-resistant film, and is preferably composed of a mixture of two or more kinds of glasses having different softening points.

The sealing agent of the present invention adopting the above configuration is easy to adjust the viscosity of the sealing agent and seals the pores of the corrosion-resistant coating, and at the same time reacts with the coating or is washed away from the coating surface. It is possible to prevent.

In the sealing agent of the present invention, the difference in the softening point of the glass is preferably 50 ° C. or more. When the sealant is composed of three or more types of glass, “the difference between the softening points of the two types of glass is 50 ° C. or more” means that the glass in at least one combination among all the combinations of glasses that can be selected. It means that the difference in softening point is 50 ° C. or more.

If the above configuration is adopted, the pores of the corrosion-resistant film can be sealed, and at the same time, it can be easily prevented from reacting with the film or being washed away from the surface of the film.

The sealant of the present invention preferably contains PbO glass and ZnO—B ₂ O ₃ glass. Here, “PbO-based glass” refers to glass containing PbO as an essential component. “ZnO—B ₂ O ₃ glass” refers to a glass containing ZnO and B ₂ O ₃ as essential components.

If the above configuration is adopted, the pores of the corrosion-resistant film can be easily sealed because it consists of a PbO-based glass that significantly lowers the softening point and a ZnO—B ₂ O ₃ -based glass that has a higher softening point than PbO-based glass. At the same time, it becomes easy to prevent a situation in which the viscosity of the glass is too low to react with the coating or drop off from the coating surface.

In the sealant of the present invention, the PbO-based glass contains PbO 10 to 90% by mass, ZnO 0 to 50%, B ₂ O ₃ 0.5 to 40%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na _2. O + K ₂ O 0 to 20%, SiO ₂ 0 to 50%, Al ₂ O ₃ 0 to 30% are preferably contained. Here, “MgO + CaO + SrO + BaO” means the total content of MgO, CaO, SrO and BaO. “Li ₂ O + Na ₂ O + K ₂ O” means the total content of Li ₂ O, Na ₂ O and K ₂ O.

In the sealing agent of the present invention, the ZnO—B ₂ O ₃ based glass contains ZnO 1 to 75%, B ₂ O ₃ 5 to 40%, PbO 0 to 60%, MgO + CaO + SrO + BaO 0 to 80% by mass percentage, Li It is preferable to contain ₂ O + Na ₂ O + K ₂ O 0 to 20%, SiO ₂ 0 to 50%, and Al ₂ O ₃ 0 to 30%.

In the sealing agent of the present invention, the oxide composition of the glass mixture has a mass percentage of PbO 2 to 60%, ZnO 0.5 to 70%, B ₂ O ₃ 1 to 40%, MgO + CaO + SrO + BaO 0 to 80%, Li It is preferable to contain ₂ O + Na ₂ O + K ₂ O 0 to 20%, SiO ₂ 0 to 50%, and Al ₂ O ₃ 0 to 30%. Here, “the oxide composition of the glass mixture” means that the entire glass mixture is regarded as a single glass, and the ratio of the components contained therein is indicated by the oxide composition.

If the above configuration is adopted, it becomes easy to obtain a sealing agent having appropriate viscosity characteristics.

The sealant coating solution of the present invention contains any one of the above-mentioned sealants.

If the above configuration is adopted, it becomes easy to apply the sealing agent on the corrosion-resistant coating by a simple method such as brushing.

Corrosion-resistant film of the present _invention, one or more selected from ZrO 2, _Al 2 O ₃ and SiO ₂ by a corrosion-resistant coating comprising at least 50 mass%, powder consisting of any of the above sealing agent adhered to the surface It is characterized by. “Adhering to the surface” includes not only the state where the sealant powder is chemically and physically bonded to the corrosion-resistant coating, but also the state where the sealant powder is geometrically caught by the corrosion-resistant coating and does not fall off. .

Since the high-temperature member employing the corrosion-resistant coating having the above-described configuration can seal the pores of the corrosion-resistant coating using a high-temperature atmosphere at the time of use, it is possible to omit a prior firing step.

Moreover, the corrosion-resistant film of the present invention is a corrosion-resistant film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO ₂ , wherein some or all of the pores present on the surface are either of the above It is characterized by being filled with a sealing agent.

The high-temperature member employing the corrosion-resistant coating having the above-mentioned configuration is because the sealing agent is fixed in the pores of the corrosion-resistant coating, so that the sealing agent layer may fall off during installation during installation or use, The situation where it breaks can be avoided effectively.

Method for producing a corrosion-resistant film of the present _invention, characterized in that one or more selected from ZrO 2, _Al 2 O ₃ and SiO ₂ on a corrosion-resistant film containing more than 50 wt%, applying the sealing agent coating solution described above And

In the method for producing a corrosion-resistant film of the present invention, it is preferable to have a step of baking after applying the sealant coating solution.

The high temperature member of the present invention has a corrosion-resistant film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO _{2 on} the surface of the base material. The powder to be adhered to the surface of the corrosion-resistant film.

Since the high-temperature member having the above-described configuration can seal the pores of the corrosion-resistant film using a high-temperature atmosphere at the time of use, the preliminary firing step can be omitted.

The high-temperature member of the present invention has a corrosion-resistant film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO _{2 on} the surface of the base material, and pores existing on the surface of the corrosion-resistant film. A part or all of is filled with any of the above-mentioned sealing agents.

The method for producing a high-temperature member of the present invention includes a step of forming a corrosion-resistant film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO ₂ on a substrate, and the above-described method on the corrosion-resistant film. A sealing agent coating solution is applied. In addition, it is preferable to dry a sealing agent coating liquid after application | coating.

In the present invention, it is preferable to have a step of baking after applying the sealing agent coating solution (or after drying).

Sample No. It is a photograph which shows the result of SEM observation and EDS analysis by * 2000 of 1 corrosion-resistant film. Sample No. It is a photograph which shows the result of SEM observation by x500 of 1 corrosion-resistant film. Sample No. It is a photograph which shows the result of SEM observation by * 500 of 10 corrosion-resistant films. Sample No. It is a photograph which shows the result of SEM observation by X2000 and EDS analysis of 13 corrosion-resistant films. Sample No. It is a photograph which shows the result of SEM observation by * 500 of 13 corrosion-resistant films. Sample No. It is a photograph which shows the result of SEM observation by * 500 of 15 corrosion-resistant films. Sample No. It is a photograph which shows the result of SEM observation by X2000 and EDS analysis of 16 corrosion-resistant films. Sample No. It is a photograph which shows the result of SEM observation by * 500 of 16 corrosion-resistant films.

Hereinafter, embodiments of the present invention will be described.

The sealing agent of this invention seals the pore which exists in a corrosion-resistant film. The corrosion resistant coating to which the sealing agent of the present invention can be applied is not particularly limited, and can be used as a sealing agent for a corrosion resistant coating containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO ₂ .

The sealing agent of the present invention is a sealing agent for sealing pores of a corrosion-resistant film, and the proportion of alkali metal oxide in the glass composition is 20% by mass or less, and the proportion of lead oxide is 2% by mass or more. It consists of glass which is. The sealing agent of the present invention can be used as long as it satisfies the above-mentioned configuration. For example, the following sealing agents A to C can be preferably used.

It consists of a glass having a proportion of alkali metal oxide in the composition of 20% by mass or less and a proportion of lead oxide of 10% by mass or more. ... [Sealing agent A]

It consists of a glass containing PbO 5-50% by mass percentage, ZnO + B ₂ O ₃ 25-60%, Li ₂ O + Na ₂ O + K ₂ O 0-20%. ... [Sealing agent B]

It is composed of a mixture of two or more kinds of glasses having different softening points, and the oxide composition of the glass mixture has an alkali metal oxide ratio of 20% by mass or less and a lead oxide ratio of 2% by mass or more. ... [Sealing agent C]

Hereinafter, each sealing agent will be described in detail.

[Sealing agent A]
In the glass constituting the sealing agent, the proportion of the alkali metal oxide in the glass composition is 20% by mass or less. Alkali metal oxide is a component for lowering the viscosity of glass to achieve a low softening point, but it causes high temperature corrosion. Therefore, the total amount of alkali metal oxides (Li ₂ O + Na ₂ O + K ₂ O) contained in the glass composition is 0-20%, 0-15%, 0.01-10%, especially 0.1-9%. Preferably there is. The Li ₂ O content is preferably 0 to 20%, 0 to 15%, 0 to 10%, particularly preferably 0.1 to 5%, and the Na ₂ O content is preferably 0 to 20%, 0 to It is preferably 15%, 0.01 to 10%, particularly preferably 0.1 to 7%. The content of K ₂ O is preferably 0 to 20%, 0.01 to 10%, particularly preferably 0.1 to 7%.

In the glass constituting the sealant, the proportion of lead oxide in the glass composition is 2% by mass or more. Lead oxide is a component that contributes to glass formation as an intermediate oxide, and is a component for lowering the viscosity of glass and achieving a low softening point. Therefore, the content of PbO contained in the glass composition is 10% or more by mass percentage, preferably 20 to 90%, 30 to 85%, and particularly preferably 50 to 80%.

The glass constituting the sealant is, for example, as a glass composition, PbO 10 to 90% by mass, ZnO 0 to 50%, B ₂ O ₃ 0 to 50%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na ₂ O + K ₂ Those containing O 0 to 20%, SiO ₂ 0 to 50%, and Al ₂ O ₃ 0 to 30% can be used. The reason for limiting the glass composition as described above will be described below. In the following description, “%” means mass%.

PbO is as described above, and the description is omitted here.

ZnO is a component contributing to glass formation as an intermediate oxide. If the content of ZnO is too large, devitrification is likely to occur, and if the content is too small, the melting temperature becomes high and it becomes difficult to melt, or the glass becomes unstable. The content of ZnO is preferably 0 to 50%, 0.2 to 40%, 0.5 to 30%, particularly 1 to 20%.

B ₂ O ₃ is a glass network-forming oxide. B handling in the ₂ O ₃ of the content is too great water resistance is lowered normal humidity is difficult. B ₂ When the content of O ₃ is too small glass tends to be devitrified and becomes unstable. The content of B ₂ O ₃ is preferably 0 to 50%, 0.5 to 40%, 1 to 30%, particularly 2 to 20%.

MgO + CaO + SrO + BaO is preferably 0 to 80%, particularly preferably 0 to 25%. When there is too much MgO + CaO + SrO + BaO, it will become easy to devitrify.

MgO is a component that lowers the melting temperature of the glass and adjusts the thermal expansion coefficient. When there is too much content of MgO, it will become easy to devitrify, and when there is too little content, a melting temperature will become high and it will become difficult to fuse | melt. The MgO content is preferably 0 to 40%, 0 to 25%, particularly preferably 0 to 10%.

CaO is a component that lowers the melting temperature of the glass and adjusts the thermal expansion coefficient. When there is too much content of CaO, it will become easy to devitrify, and when there is too little content, a melting temperature will become high and it will become difficult to fuse | melt. The CaO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%.

SrO is a component that lowers the melting temperature of the glass and adjusts the thermal expansion coefficient. When the content of SrO is too large, devitrification is likely to occur, and when the content is too small, the melting temperature becomes high and it becomes difficult to melt. The SrO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%.

BaO is a component that lowers the melting temperature of the glass and adjusts the thermal expansion coefficient. When there is too much content of BaO, it will become easy to devitrify, and when there is too little content, a melting temperature will become high and it will become difficult to fuse | melt. The BaO content is preferably 0 to 50%, 0 to 40%, 0 to 30%, particularly preferably 0 to 25%.

Li ₂ O + Na ₂ O + K ₂ O is as described above, and a description thereof is omitted here.

SiO ₂ is a network-forming oxide of glass, and is a component that contributes to glass formation and simultaneously increases water resistance. If the content of SiO ₂ is too large, devitrification tends to occur, and if the content is too small, the water resistance becomes low and the glass becomes unstable. The content of SiO ₂ 0 to 50%, 0.5 to 40% is preferably in particular from 1 to 35%.

Al ₂ O ₃ is a component that increases water resistance and increases the viscosity of the glass. When the content of Al ₂ O ₃ is too large, devitrification tends to occur, and when the content is too small, the water resistance becomes low and handling at normal humidity becomes difficult. The content of Al ₂ O ₃ is preferably 0 to 30%, 0.1 to 20%, particularly preferably 0.5 to 10%.

In addition to the above components, P ₂ O ₅ , TiO ₂ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO, CuO, Y ₂ O ₃ , ZrO ₂ , SnO ₂ , and La ₂ are within a range that does not impair the desired characteristics. O ₃ , CeO ₂ , Bi ₂ O _{3 and the} like may be included up to 10% each.

The glass constituting the sealant preferably has a softening point of 700 ° C. or lower, 600 ° C. or lower, particularly 570 ° C. or lower. If the softening point is too high, the glass becomes difficult to be melted in the operating temperature range. The lower the softening point, the more advantageous. However, when the softening point is too low, the viscosity of the glass in the operating temperature range becomes too low, and the glass may be washed away from the surface of the corrosion-resistant coating. In such a case, the softening point is preferably 300 ° C. or higher, particularly 400 ° C. or higher.

The glass constituting the sealant preferably has a thermal expansion coefficient at 30 to 380 ° C. of 30 to 120 × 10 ⁻⁷ / K, particularly 60 to 110 × 10 ⁻⁷ / K. If the thermal expansion coefficient is too high or too low, cracks caused by the difference in thermal expansion from the base material become large, and there is a possibility that the surface of the corrosion-resistant coating will fall off during the cooling process of the power generation equipment.

The glass constituting the sealant is preferably a glass powder having an average particle size of 10 nm to 500 μm, particularly 1 to 100 μm. Here, the “average particle size” is defined by D50 calculated on the basis of the number of particles when the particle size of an arbitrary powder is measured by the laser diffraction scattering method.

[Sealing agent B]
In the glass constituting the sealant, the proportion of PbO in the glass composition is 5 to 50% by mass. PbO is a component that contributes to glass formation as an intermediate oxide, and is a component that lowers the viscosity of the glass to lower the temperature at which it softens and flows. If the content of PbO is too large, the temperature at which it softens and flows becomes too low, and there is a risk that it will be washed away from the surface of the corrosion-resistant coating. Therefore, the content of PbO contained in the glass composition is 5 to 50% by mass percentage, preferably 7 to 48%, 10 to 44%, particularly 18 to 42%.

In the glass constituting the sealing agent, the ratio of the total amount of ZnO and B ₂ O _{3 in} the glass composition is 25 to 60% by mass. ZnO and B ₂ O ₃ are components for lowering the viscosity of the glass to lower the temperature at which it softens and flows, but the effect of lowering the temperature at which it softens and flows is smaller than that of PbO. For this reason, it becomes possible to optimize the temperature at which the glass softens and flows by containing appropriate amounts of these components together with PbO. The content of ZnO + B ₂ O ₃ contained in the glass composition is 25 to 60% by mass percentage, preferably 28 to 55%, 30 to 52%, particularly preferably 30 to 47%. If the content of ZnO + B ₂ O ₃ is too large, the softening flow temperature becomes high, and there is a possibility that it cannot be sufficiently sealed. On the other hand, if it is too small, the softening flow temperature is too low, There is a possibility that the sealing agent reacts with the coating or falls off from the coating surface.

The glass constituting the sealant has, for example, a glass composition of PbO 5 to 50% by mass, ZnO + B ₂ O ₃ 25 to 60%, ZnO 0 to 40%, B ₂ O ₃ 0 to 40%, MgO + CaO + SrO + BaO 0 to Those containing 40%, Li ₂ O + Na ₂ O + K ₂ O 0-20%, SiO ₂ 0-40%, Al ₂ O ₃ 0-30% can be used. The reason for limiting the glass composition as described above will be described below. In the following description, “%” means mass%.

The content of PbO and ZnO ₊ B 2 _{O 3} are as described above, and a description thereof will be omitted.

ZnO is a component contributing to glass formation as an intermediate oxide. Moreover, it is a component for lowering | hanging the viscosity of glass and making the temperature which softens and flows low. If the content of ZnO is too large, devitrification is likely to occur, and if the content is too small, the melting temperature becomes high and it becomes difficult to melt, or the glass becomes unstable. The content of ZnO is preferably 0 to 40%, 0.5 to 35%, 5 to 30%, particularly preferably 10 to 25%.

B ₂ O ₃ is a glass network-forming oxide. Moreover, it is a component for lowering | hanging the viscosity of glass and making the temperature which softens and flows low. B handling in the ₂ O ₃ of the content is too great water resistance is lowered normal humidity is difficult. B ₂ When the content of O ₃ is too small glass tends to be devitrified and becomes unstable. The content of B ₂ O ₃ is preferably 0 to 40%, 0.5 to 35%, 5 to 30%, particularly 10 to 25%.

The content of MgO + CaO + SrO + BaO is preferably 0 to 80%, particularly preferably 0 to 25%. When there is too much MgO + CaO + SrO + BaO, it will become easy to devitrify.

MgO is a component that lowers the melting temperature of glass. When there is too much content of MgO, it will become easy to devitrify. The MgO content is preferably 0 to 40%, 0 to 25%, particularly preferably 0 to 10%.

CaO is a component that lowers the melting temperature of glass. When there is too much content of CaO, it will become easy to devitrify. The CaO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%.

SrO is a component that lowers the melting temperature of glass. When there is too much content of SrO, it will become easy to devitrify. The SrO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%.

BaO is a component that lowers the melting temperature of glass. When there is too much content of BaO, it will become easy to devitrify, and when there is too little content, a melting temperature will become high and it will become difficult to fuse | melt. The content of BaO is preferably 0 to 50%, 0 to 40%, 0 to 30%, particularly 1 to 25%.

Li ₂ O, Na ₂ O, and K ₂ O are components for lowering the viscosity of the glass to lower the temperature at which it softens and flows, but cause high-temperature corrosion. The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0 to 20%, 0 to 15%, 0.1 to 13%, particularly 1 to 12%. The Li ₂ O content is preferably 0 to 20%, 0 to 15%, 0 to 13%, particularly preferably 0.1 to 12%. The content of Na ₂ O is preferably 0 to 20%, 0 to 15%, 0.01 to 13%, particularly preferably 0.1 to 12%. The content of K ₂ O is 0-20% 0.01 to 10%, particularly preferably 0.1 to 12%.

SiO ₂ is a network-forming oxide of glass, and is a component that contributes to glass formation and simultaneously increases water resistance. If the content of SiO ₂ is too large, devitrification tends to occur, and if the content is too small, the water resistance becomes low and the glass becomes unstable. The content of SiO ₂ 0 to 50%, 0.5 to 40% is preferably in particular from 1 to 35%.

Al ₂ O ₃ is a component that increases water resistance and increases the viscosity of the glass. When the content of Al ₂ O ₃ is too large, devitrification tends to occur, and when the content is too small, the water resistance becomes low and handling at normal humidity becomes difficult. The content of Al ₂ O ₃ is preferably 0 to 30%, 0.1 to 20%, particularly preferably 0.5 to 10%.

In addition to the above components, P ₂ O ₅ , TiO ₂ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO, CuO, Y ₂ O ₃ , ZrO ₂ , SnO ₂ , and La ₂ are within a range that does not impair the desired characteristics. O ₃ , CeO ₂ , Bi ₂ O _{3 and the} like may be included up to 10% each.

The glass constituting the sealant is preferably a glass powder having an average particle size of 10 nm to 500 μm, particularly 1 to 100 μm.

[Sealing agent C]
The sealant is composed of a mixture of two or more kinds of glasses having different softening points. Although there is no restriction | limiting in the glass to be used, It is preferable to select glass so that the difference of the softening point of glass may be 50 degreeC or more, 70 degreeC or more, especially 90 degreeC or more. When the difference in softening point between the glasses is small, the adjustment range of the viscosity of the sealing agent is small.

As a combination of a glass having a relatively low softening point (hereinafter referred to as a low softening point glass) and a glass having a relatively high softening point (hereinafter referred to as a high softening point glass), for example, PbO-based glass and ZnO—B ₂ O ₃ Combinations of system glasses can be employed.

As the PbO-based glass, for example, PbO 10 to 90%, ZnO 0 to 50%, B ₂ O ₃ 0.5 to 40%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na ₂ O + K ₂ O 0 to 20% by mass percentage. A glass containing 0 to 50% of SiO _{2 and} 0 to 30% of Al ₂ O ₃ can be selected. The reason for limiting the glass composition range as described above will be described below. In the following description, “%” means “% by mass” unless otherwise specified.

PbO is a component that contributes to glass formation as an intermediate oxide, and is a component for lowering the viscosity of the glass and achieving a low softening point. Therefore, the content of PbO contained in the glass composition is preferably 10 to 90%, 20 to 85%, particularly 40 to 80%. In addition, when there is too much content of PbO, fluidity | liquidity will become high too much and a sealing agent will fall from a film, or the reactivity with a film will become high too much. When there is too little content of PbO, viscosity will become high and fluidity | liquidity will fall.

ZnO is a component contributing to glass formation as an intermediate oxide. The content of ZnO is preferably 0 to 50%, 0.5 to 40%, particularly 1 to 20%. If the content of ZnO is too large, devitrification is likely to occur, and if the content is too small, the melting temperature becomes high and it becomes difficult to melt, or the glass becomes unstable.

B ₂ O ₃ is a glass network-forming oxide. B ₂ When the content of O ₃ is too large will water resistance is low, the handling of a normal humidity becomes difficult. B ₂ When the content of O ₃ is too small glass tends to be devitrified and becomes unstable. The content of B ₂ O ₃ is preferably 0.5 to 40%, 1 to 30%, particularly 2 to 20%.

MgO, CaO, SrO and BaO are all components that lower the melting temperature of the glass. However, if there is too much MgO + CaO + SrO + BaO, devitrification tends to occur. The content of MgO + CaO + SrO + BaO is preferably 0 to 80%, particularly preferably 0 to 25%. The MgO content is preferably 0 to 40%, 0 to 25%, particularly preferably 0 to 10%. The CaO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%. The SrO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%. The BaO content is preferably 0 to 50%, 0 to 40%, 0 to 30%, particularly preferably 0 to 25%.

Li ₂ O, Na ₂ O and K ₂ O are all components for lowering the viscosity of the glass to lower the temperature at which it softens and flows. However, if there is too much Li ₂ O + Na ₂ O + K ₂ O, it will cause high temperature corrosion. The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0 to 20%, 0 to 15%, 0.1 to 13%, particularly 1 to 12%. The content of Li ₂ O is preferably 0 to 20%, 0 to 15%, 0 to 13%, particularly preferably 0.1 to 12%. The content of Na ₂ O is 0-20%, 0-15% 0.01 to 13% particularly preferably 0.1 to 12%. The content of K ₂ O is preferably 0 to 20%, 0.01 to 10%, particularly preferably 0.1 to 12%.

SiO ₂ is a network-forming oxide of glass, and is a component that contributes to glass formation and simultaneously increases water resistance. When the content of SiO ₂ is too large it tends to be devitrified. If the content of SiO ₂ is too small, the water resistance becomes low and the glass becomes unstable. The content of SiO ₂ is preferably 0 to 50%, 0.5 to 40%, particularly 1 to 35%.

Al ₂ O ₃ is a component to increase the water resistance. When the content of Al ₂ O ₃ is too large watermarks easily lost, the viscosity of the glass becomes high. Al ₂ When the content of O ₃ is too small becomes water resistance is low, the handling of a normal humidity becomes difficult. The content of Al ₂ O ₃ is preferably 0 to 30%, 0.1 to 20%, particularly preferably 0.5 to 10%.

In addition to the above components, P ₂ O ₅ , TiO ₂ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO, CuO, Y ₂ O ₃ , ZrO ₂ , SnO ₂ , and La ₂ are within a range that does not impair the desired characteristics. O ₃ , CeO ₂ , Bi ₂ O _{3 and the} like may be included up to 10% each.

Examples of the ZnO—B ₂ O ₃ glass include ZnO 1 to 75% by mass percentage, B ₂ O ₃ 5 to 40%, PbO 0 to 60%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na ₂ O + K ₂ O 0. Glasses containing ˜20%, SiO ₂ 0-50%, Al ₂ O ₃ 0-30% can be selected. The reason for limiting the glass composition range as described above will be described below.

ZnO is a component contributing to glass formation as an intermediate oxide. If the content of ZnO is too large, devitrification is likely to occur, and if the content is too small, the melting temperature becomes high and it becomes difficult to melt, or the glass becomes unstable. The content of ZnO is preferably 1 to 75%, 5 to 70%, particularly 10 to 45%.

B ₂ O ₃ is a glass network-forming oxide. B ₂ When the content of O ₃ is too large will water resistance is low, the handling of a normal humidity becomes difficult. B ₂ When the content of O ₃ is too small glass tends to be devitrified and becomes unstable. The content of B ₂ O ₃ is preferably 5 to 40%, 10 to 35%, particularly preferably 15 to 30%.

MgO, CaO, SrO and BaO are all components that lower the melting temperature of the glass. However, if there is too much MgO + CaO + SrO + BaO, devitrification tends to occur. The content of MgO + CaO + SrO + BaO is preferably 0 to 80%, particularly preferably 0 to 25%. The MgO content is preferably 0 to 40%, 0 to 25%, particularly preferably 0 to 10%. The CaO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%. The SrO content is preferably 0 to 40%, 0 to 30%, particularly preferably 0 to 20%. The BaO content is preferably 0 to 50%, 0 to 40%, 0 to 30%, particularly preferably 0 to 25%.

Li ₂ O, Na ₂ O and K ₂ O are all components for lowering the viscosity of the glass to lower the temperature at which it softens and flows. However, if there is too much Li ₂ O + Na ₂ O + K ₂ O, it will cause high temperature corrosion. The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0 to 20%, 0 to 15%, 0.1 to 13%, particularly 1 to 12%. The content of Li ₂ O is preferably 0 to 20%, 0 to 15%, 0 to 13%, particularly preferably 0.1 to 12%. The content of Na ₂ O is preferably 0 to 20%, 0 to 15%, 0.01 to 13%, particularly preferably 0.1 to 12%. The content of K ₂ O is preferably 0 to 20%, 0.01 to 10%, particularly preferably 0.1 to 12%.

SiO ₂ is a network-forming oxide of glass, and is a component that contributes to glass formation and simultaneously increases water resistance. When the content of SiO ₂ is too large it tends to be devitrified. If the content of SiO ₂ is too small, the water resistance becomes low and the glass becomes unstable. The content of SiO ₂ is preferably 0 to 50%, 0.5 to 40%, particularly 1 to 35%.

Al ₂ O ₃ is a component that increases water resistance. When the content of Al ₂ O ₃ is too large watermarks easily lost, the viscosity of the glass becomes high. Al ₂ When the content of O ₃ is too small becomes water resistance is low, the handling of a normal humidity becomes difficult. The content of Al ₂ O ₃ 0 ~ 30% is from 0.1 to 20%, it is preferable in particular from 0.5 to 10%.

In addition to the above components, PbO, P ₂ O ₅ , TiO ₂ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO, CuO, Y ₂ O ₃ , ZrO ₂ , SnO ₂ , as long as desired properties are not impaired. La ₂ O ₃ , CeO ₂ , Bi ₂ O _{3 and the} like may be included up to 10% each.

The sealant is composed of a mixture such as PbO-based glass and ZnO—B ₂ O ₃ -based glass. When the entire mixture is represented by an oxide composition, PbO 2 to 60% by mass percentage, ZnO 0.5 70%, B ₂ O ₃ 1-40%, MgO + CaO + SrO + BaO 0-80%, Li ₂ O + Na ₂ O + K ₂ O 0-20%, SiO ₂ 0-50%, Al ₂ O ₃ 0-30% preferable.

When a combination of PbO glass and ZnO—B ₂ O ₃ glass is used as the sealing agent, the mixing ratio of the _two is 10:90 to 80: PbO glass: ZnO—B ₂ O ₃ glass in mass ratio. : 20 to 20:80 to 70:30 is preferable.

The softening point of the glass constituting the sealant is preferably 350 to 850 ° C., 370 to 750 ° C., particularly 400 to 650 ° C. for the low softening point glass. The glass having a high softening point is preferably 450 to 900 ° C, 500 to 800 ° C, particularly 550 to 700 ° C. When the softening point of each glass is too high, it becomes difficult for the glass to be in a molten state in the operating temperature range, and it becomes difficult to enclose the pores. If the softening point of each glass is too low, the viscosity of the glass in the operating temperature range becomes too low, and there is a possibility that the glass will be washed away from the surface of the corrosion-resistant coating.

Each glass constituting the sealant is preferably a glass powder having an average particle diameter of 10 nm to 500 μm, particularly 1 to 100 μm.
Next, the sealing agent coating solution of the present invention will be described.

The sealant coating liquid of the present invention refers to a paste or slurry obtained by mixing the above-mentioned sealant with various resins, paints, organic solvents, sol-gel liquids, water and other inorganic solvents. By making it into a paste or slurry, it becomes easy to apply uniformly on the corrosion-resistant coating. Resins, paints, and sol-gel solutions have a function of fixing the sealing agent on the coating until the sealing agent is softened and does not fall off from the corrosion-resistant coating. Examples of such resins and paints, sol-gel solutions, and water glasses include vinyl resins such as unsaturated polyester resins, epoxy resins, polyvinyl butyral, polyvinyl alcohol, polybutyl methacrylate, polymethyl methacrylate, and polyethyl methacrylate. Cellulose resins such as acrylic resins, ethyl cellulose and nitrocellulose, amide resins, silicone resins, polytitanocarboxylsilane solutions, solutions of metal alkoxides such as tetraethoxysilane and their partial condensates, sodium silicate as defined in JIS K1408 No. 1, No. 2, No. 3, etc. can be used.

Further, in order to promote the permeability when the sealing agent is in a molten state and penetrates into the corrosion-resistant film, boric acid powder or boron oxide powder may be added to the sealing agent coating solution.

Next, the corrosion resistant coating of the present invention will be described.

In the corrosion-resistant coating of the present invention, the powder comprising any of the above-mentioned sealing agents is attached to the surface, or part or all of the pores existing on the surface are filled with any of the above-mentioned sealing agents. Yes.

The corrosion-resistant film is a corrosion-resistant film containing 50% by mass or more of one or more selected from ZrO ₂ , Al ₂ O ₃ and SiO ₂ . This type of corrosion-resistant coating can have corrosion resistance against corrosive and oxidizing combustion gas atmospheres of oxygen, sulfur oxides, hydrogen sulfide, etc. at 500 to 1000 ° C., for example.

Examples of the corrosion resistant coating include a corrosion resistant coating having stabilized ZrO ₂ as a main constituent (hereinafter referred to as a stabilized ZrO ₂ -based corrosion resistant coating). Stabilized ZrO ₂ is mainly composed of ZrO ₂ , and one or more kinds of stable selected from Y ₂ O ₃ , MgO, CaO, SiO ₂ , CeO ₂ , Yb ₂ O ₃ , Dy ₂ O ₃ , HfO _{2 and the} like. An agent is added. Specifically, the ZrO ₂ content is 85% by mass or more, preferably 85 to 95% by mass, and the stabilizer content is 15% by mass or less, preferably 5 to 15% by mass. If the ZrO ₂ content is 85% by mass or more, the corrosion resistance of the coating can be ensured, and the phase from the tetragonal or cubic to monoclinic phase of ZrO ₂ generated near 1000 ° C. in the cooling process after plasma spraying. Metastasis can also be suppressed. Incidentally the content of ZrO ₂ is less than 85 wt%, the corrosion resistance of the coating is reduced.

The porosity of the corrosion-resistant film is preferably 5% or less, particularly 4% or less. By densifying the corrosion-resistant film, it becomes possible to further prevent the corrosion of the base material caused by the acidic gas permeating the film. When the porosity of the corrosion-resistant coating is too high, it becomes difficult to completely seal the pores with the sealing agent, and it becomes difficult to suppress permeation of acid gas. Here, “porosity is 5% or less” means that when the cross section of the corrosion-resistant coating is observed with a scanning electron microscope at a magnification of 1000 times, the ratio of the total area of cracks and voids to the surface of the observation screen is 5%. It means the following.

The thickness of the corrosion-resistant film is preferably 10 to 1000 μm, 10 to 500 μm, 50 to 400 μm, particularly preferably 70 to 300 μm. If the thickness of the corrosion-resistant film is too small, it is difficult to suppress permeation of acidic gas. On the other hand, when the film thickness of the corrosion-resistant film is too large, the thermal stress generated by the thermal cycle increases, and the corrosion-resistant film easily peels off. The porosity of the corrosion-resistant coating can be adjusted by changing the particle size of the sprayed powder (stabilized ZrO ₂ powder or inorganic glass powder).

Next, the high temperature member of the present invention will be described.

The high temperature member of the present invention preferably has the above-mentioned corrosion-resistant film formed thereon. In addition, as a material of a high temperature member main body (base material), the metal material which has at least one of Fe, Ni, Co, and Cr as a main component is preferable. The corrosion-resistant coating is preferably formed directly on the substrate, but for the purpose of improving adhesion and the like, one or more underlayers may be provided between the substrate and the corrosion-resistant coating.

For example, when the above-described stabilized ZrO ₂ -based corrosion-resistant film is formed on a substrate made of SUS, a layer made of, for example, an M—Cr—Al—Y alloy (M = Ni, Co, Fe) is used as the underlayer. It is preferable to provide it. The M-Cr-Al-Y alloy is an alloy containing Ni or Co, which has excellent properties of high temperature oxidation resistance and high temperature corrosion resistance, with Cr, Al and Y added. This type of alloy is characterized in that it easily adheres to both SUS and the stabilized ZrO ₂ -based corrosion resistant coating.

The porosity of the underlayer is preferably 1% or less. From the viewpoint of suppressing permeation of acid gas, the lower the porosity of the underlayer, the more advantageous.

The film thickness of the underlayer is preferably 10 to 500 μm, particularly 50 to 400 μm, more preferably 70 to 350 μm. From the viewpoint of suppressing permeation of acid gas, the thicker the base layer, the more advantageous. In addition, the underlayer generally has an effect of relieving thermal stress due to the difference in thermal expansion characteristics generated at the interface between the base material and the corrosion-resistant film, but it is difficult to obtain a thermal stress mitigating effect if the underlayer is too thin. Become. On the other hand, if the film thickness of the underlayer is too large, thermal stress generated by a heat cycle or the like inside the power generation facility increases, and the underlayer is easily peeled off. The porosity of the underlayer can be adjusted by changing the particle size of the M-Cr-Al-Y alloy powder to be sprayed.

It is preferable that the high-temperature member is a thermal power generation turbine or a heat transfer tube that generates power by collecting kinetic energy or heat energy via a fluid such as steam or air. However, it is not limited to these. For example, it can be suitably applied to various engines.

Next, a method for producing a high-temperature member using the sealing agent of the present invention is a stabilized ZrO ₂ -based corrosion-resistant coating film on a base material made of SUS and through an underlayer made of an M—Cr—Al—Y-based alloy. An example of forming the case will be described. In the following description, if a metal tube is used as the substrate, a heat transfer tube with a corrosion-resistant coating can be produced. The production method of the present invention is not limited to the following description. Of course, it goes without saying that the formation of the underlayer is not an essential requirement.

First, an underlayer made of an M—Cr—Al—Y alloy is formed on a base material made of SUS.

The formation of the underlayer is not particularly limited, but is preferably formed by gas spraying such as high-speed flame spraying (HVOF). By using high-speed flame spraying, it becomes easy to obtain a base layer having good adhesion to SUS as a base material and low porosity. Further, it is preferable to use a powder made of an M—Cr—Al—Y alloy as the thermal spraying powder used at this time. The M—Cr—Al—Y alloy is as described above, and the description thereof is omitted here. The average particle size of the sprayed powder is preferably 10 to 75 μm, 10 to 53 μm, and particularly preferably 10 to 45 μm. When the particle size of the thermal spray powder is large, the porosity of the base layer formed by gas spraying is increased. In addition, if the particle size of the thermal spray powder is small, clogging of the jet port (port) for supplying the thermal spray powder to gas or plasma is likely to occur, and it takes time to form the thermal spray coating of any film thickness, resulting in thermal spraying. Cost is likely to increase.

Next, a stabilized ZrO ₂ -based corrosion resistant coating is formed on the underlayer made of the M—Cr—Al—Y alloy.

The stabilized ZrO ₂ -based corrosion resistant coating can be formed by a plasma spraying method. As the plasma spraying method, various methods such as an atmospheric pressure plasma spraying method and a vacuum plasma spraying method can be used. It is preferable to use stabilized ZrO ₂ powder as the thermal spraying powder used at this time. The corrosion resistant coating can be formed by a spraying technique other than plasma spraying (for example, gas spraying), a cold spray, an aerosol deposition method, or the like.

The average particle size of the stabilized ZrO ₂ powder is preferably 10 to 75 μm, 10 to 53 μm, particularly 10 to 45 μm. When the average particle size of the stabilized ZrO ₂ powder is large, the porosity of the corrosion-resistant coating formed by plasma spraying is increased. Also the average particle size of the stabilized ZrO ₂ powder is smaller, become clogged jets supplying spray powder into the plasma (port) is likely to occur, it takes time for the formation of any film thickness of the spray coating, resulting The thermal spraying cost tends to be high.

Subsequently, a sealing agent layer is formed on the stabilized ZrO ₂ -based corrosion resistant coating.

For forming the sealant layer, for example, a paste or slurry containing the above-mentioned sealant is applied onto the corrosion-resistant film by a method such as brushing or spraying, and further dried as necessary. In this way, a sealant layer can be formed. It should be noted that other methods may be employed as long as the sealing agent powder does not fall off the corrosion-resistant coating, such as sputtering and thermal spraying.

Moreover, when using the sealing agent C which mixed 2 or more types of glass, after mixing 2 or more types of glass, the paste-form or slurry-form sealing agent coating liquid is produced by the said method, and the method of apply | coating this Is simple, but is not limited to this method. For example, in order to reinforce the penetration promoting action of the low softening point glass, the first sealing agent coating solution with a high mixing ratio of the low softening point glass alone or the low softening point glass is applied to the corrosion resistant coating and dried. After producing the first sealing agent layer, a method of applying a second sealing agent coating liquid having a low mixing ratio of the low softening point glass and drying to form the second sealing agent layer may be employed. . In this case, the entire glass mixture contained in the two layers is regarded as a single glass, and the proportion of the components contained therein is an oxide composition, PbO 2 to 60% by mass percentage, ZnO 0.5 to 70 %, B ₂ O ₃ 1-40%, MgO + CaO + SrO + BaO 0-80%, Li ₂ O + Na ₂ O + K ₂ O 0-20%, SiO ₂ 0-50%, Al ₂ O ₃ 0-30% Is preferred.

The sealant layer of the high temperature member thus produced is in a state where the sealant powder is adhered to the surface of the corrosion-resistant coating, and is not yet in a state of completely closing the pores, Can be installed. That is, when the use is started, it is exposed to a high temperature atmosphere, and the heat causes the sealing agent to soften and flow to fill pores existing on the surface of the corrosion-resistant coating.

In producing the high-temperature member of the present invention, firing may be performed after the sealing agent layer is dried (and before actual use). As firing conditions, for example, 300 to 1000 ° C. and 10 minutes to 2 hours are preferable. By firing in advance before actual use, it is possible to prevent the sealant layer from falling off or being damaged during transfer or installation at the place of use.

Hereinafter, the present invention will be described in detail based on examples.

Example 1
[Preparation of sealant]
Table 1 shows examples of the sealing agent of the present invention (sealing agent samples Nos. 1 to 9).

Each sample was prepared as follows. First, a glass batch prepared to have the composition in the table was melted at 1000 ° C. for 1 hour. Next, after forming this into a film, it was pulverized and classified to obtain a sealing agent made of glass powder having an average particle size of 50 μm.

The softening point was measured using a differential thermal analyzer according to the method described by Masayuki Yamane, “For the first person who makes glass”. The thermal expansion coefficient was calculated as an average linear thermal expansion coefficient of 30 to 380 ° C. from a thermal expansion curve obtained by pressing a sample into a rod shape and firing at 600 to 800 ° C. for 20 minutes and then using a dilatometer.

[Production of high-temperature components]
Next, sealant sample No. A high-temperature member (Sample No. 1) was produced using the glass No. 1.

High temperature member sample No. 1 was produced as follows. First, the SUS310S base material is degreased, washed, and then subjected to blasting, and an alloy powder having an average particle size of 10 to 45 μm made of a Co—Ni—Cr—Al—Y alloy is sprayed at high speed to provide high temperature oxidation resistance and resistance. An underlayer (Co—Ni—Cr—Al—Y alloy layer) excellent in high temperature corrosion resistance was formed. The thickness of the underlayer was uniform and was 200 to 400 μm. The film thickness of the underlayer was measured with a micrometer. The film thickness can be adjusted by first moving the thermal spraying device parallel to the substrate and spraying it, and measuring with a micrometer how much film thickness can be obtained with a single spray. This was done by adjusting the number of times.

Next, 8% Y ₂ O ₃ —ZrO ₂ powder having an average particle size of 10 to 45 μm was sprayed at atmospheric pressure on the underlayer to form a corrosion-resistant coating. The film thickness of the corrosion-resistant film was uniform and was 50 to 200 μm. The adjustment and measurement of the thickness of the corrosion-resistant coating were performed in the same manner as when the Co—Ni—Cr—Al—Y alloy was sprayed.

Subsequently, a sealant layer was formed on the corrosion-resistant film by the following method. First, polyvinyl butyral resin, thinner and sealant sample No. 1 was mixed to prepare a sealant paste. Next, a sealant paste was applied onto the corrosion-resistant film by brushing and then baked at 550 ° C. for 4 days. In this way, the high temperature member sample No. 1 was obtained.

For comparison, the high temperature member sample No. 10 were prepared.

High temperature member sample No. 10 is a high temperature member sample No. 10 except that no sealant layer is formed. 1 was prepared.

The high temperature member sample No. obtained in this way. 1 and no. About 10, the permeability to the film was evaluated. The results are shown in FIGS. 1 and 2 show the high-temperature member sample No. FIG. 3 shows the observation and analysis results of the high-temperature member sample No. 10.

As is clear from FIG. 1 and FIG. No. 1 high-temperature member sample No. In No. 1, the glass melt penetrated into the corrosion-resistant film (FIG. 1), only a small number of pores were present (FIG. 2), and the pore permeability was excellent. On the other hand, the high temperature member sample No. As is clear from FIG. 3, it was confirmed that a large number of pores 10 existed. These facts indicate that the sealing agent A has high sealing properties and is excellent in long-term stability.

For permeability, the cut sample was embedded in a resin, the cut surface was polished, and then the cut surface was subjected to SEM (scanning electron microscope) observation and EDS (energy dispersive X-ray analysis) analysis. Note that not all pores in the corrosion-resistant coating penetrate through the outside. Therefore, there is no problem even if independent pores exist.

(Example 2)
[Preparation of sealant]
Table 2 shows examples of the present invention (sample Nos. 11 to 14).

The sealant sample was prepared as follows. First, a glass batch prepared to have the composition in the table was melted at 1000 ° C. for 1 hour. Next, this was formed into a film, and then pulverized and classified to obtain a sealing agent (sealing agent samples No. 11 to 14) made of glass powder having an average particle diameter of 50 μm.

[Production of high-temperature components]
The high temperature member was produced as follows. First, the SUS310S base material is degreased, washed, and then subjected to blasting, and an alloy powder having an average particle size of 10 to 45 μm made of a Co—Ni—Cr—Al—Y alloy is sprayed at high speed to provide high temperature oxidation resistance and resistance. An underlayer (Co—Ni—Cr—Al—Y alloy layer) excellent in high temperature corrosion resistance was formed. The thickness of the underlayer was uniform and was 200 to 400 μm. The film thickness of the underlayer was measured with a micrometer. The film thickness can be adjusted by first moving the thermal spraying device parallel to the substrate and spraying it, and measuring with a micrometer how much film thickness can be obtained with a single spray. This was done by adjusting the number of times.

Next, 8% Y ₂ O ₃ —ZrO ₂ powder having an average particle size of 10 to 45 μm was sprayed at atmospheric pressure on the underlayer to form a corrosion-resistant coating. The film thickness of the corrosion-resistant film was uniform and was 50 to 200 μm. The adjustment and measurement of the thickness of the corrosion-resistant coating were performed in the same manner as when the Co—Ni—Cr—Al—Y alloy was sprayed.

Subsequently, a sealant layer was formed on the corrosion-resistant film by the following method. First, polyvinyl butyral resin, thinner, and sealant sample No. Any of 11 to 14 was mixed to prepare a sealant paste. Next, a sealant paste was applied onto the corrosion-resistant film by brushing and then baked at 550 ° C. for 4 days. Thus, high-temperature members (high-temperature member samples No. 11 to 14) in which the corrosion-resistant film was sealed with the sealing agent were obtained.

Also, the anticorrosion film is not sealed with a sealant, and other processes are performed at high temperature member sample No. The high temperature member sample No. 15 was prepared and used as a comparison target.

For the obtained high-temperature member samples No. 11 to 14, the permeability of the sealing agent into the coating film was evaluated. The results are shown in Table 1. The results of SEM and EDS are shown in FIGS. 4 and 5 are high-temperature member sample Nos. 13 is a result of observation and analysis of No. 13, and FIG. 15 observation and analysis results.

In addition, the permeability to the coating was obtained by embedding the cut sample in a resin and polishing the cut surface, and then performing SEM (scanning electron microscope) observation and EDS (energy dispersive X-ray analysis) analysis on the cut surface. . When the element contained in the sealant was detected in the corrosion-resistant film, the permeability was evaluated as “◯”, and when the element was not detected as “X”.

As a result, the high temperature member sample no. No. 15 shows from FIG. 6 that a large number of pores exist in the corrosion-resistant film. On the other hand, high temperature member sample No. which is an embodiment of the present invention. As is clear from Table 2, in Nos. 11 to 14, the sealing agent penetrated into the corrosion-resistant coating. Moreover, it can be seen from FIG. 4 that the sealing agent penetrates into the corrosion-resistant film, and FIG. 5 that only a small number of pores are present in the corrosion-resistant film. In addition, since the pore which exists in a corrosion-resistant film is thought not to communicate with the outside, it is considered that there is no practical problem.

These facts indicate that the sealing agent B has a high sealing property.

(Example 3)
[Preparation of sealant]
Table 3 shows examples of glass constituting the sealing agent (glass samples A to C). Table 4 shows examples (samples Nos. 16 and 17) of the present invention.

Glass samples A to C were prepared as follows. First, a glass batch prepared to have the composition shown in Table 3 was melted at 1000 ° C. for 1 hour. Next, this was formed into a film, and then pulverized and classified to obtain a glass sample made of glass powder having an average particle size of 50 μm.

Subsequently, glass samples were mixed at the ratios shown in Table 4 to obtain sealant samples (sealing agent samples No. 16 and 17).

[Production of high-temperature components]
The high temperature member was produced as follows. First, the SUS310S base material is degreased, washed, and then subjected to blasting, and an alloy powder having an average particle size of 10 to 45 μm made of a Co—Ni—Cr—Al—Y alloy is sprayed at high speed to provide high temperature oxidation resistance and resistance. An underlayer (Co—Ni—Cr—Al—Y alloy layer) excellent in high temperature corrosion resistance was formed. The thickness of the underlayer was uniform and was 200 to 400 μm. The film thickness of the underlayer was measured with a micrometer. The film thickness can be adjusted by first moving the thermal spraying device parallel to the substrate and spraying it, and measuring with a micrometer how much film thickness can be obtained with a single spray. This was done by adjusting the number of times.

Next, 8% Y ₂ O ₃ —ZrO ₂ powder having an average particle size of 10 to 45 μm was sprayed at atmospheric pressure on the underlayer to form a corrosion-resistant coating. The film thickness of the corrosion-resistant film was uniform and was 50 to 200 μm. The adjustment and measurement of the thickness of the corrosion-resistant coating were performed in the same manner as when the Co—Ni—Cr—Al—Y alloy was sprayed.

Subsequently, a sealant layer was formed on the corrosion-resistant film by the following method. First, polyvinyl butyral resin, thinner, and a sealing agent sample were mixed to prepare a sealing agent paste. Next, a sealant paste was applied onto the corrosion-resistant film by brushing and then baked at 550 ° C. for 4 days. Thus, the high temperature member (high temperature member sample No. 16, 17) by which the corrosion-resistant film was sealed with the sealing agent was obtained.

Also, the high temperature member sample No. prepared in Example 2 was used. 15 was used as a comparison target.

For the obtained high-temperature member samples No. 16 and 17, the permeability of the sealing agent into the coating film was evaluated. The results are shown in Table 4. The high temperature member sample No. The results of 16 SEMs and EDSs are shown in FIGS. High temperature member sample No. For 15 observations and analysis results, refer to FIG.

For the permeability to the coating, the cut sample was embedded in a resin, the cut surface was polished, and then the cut surface was subjected to SEM (scanning electron microscope) observation and EDS (energy dispersive X-ray analysis) analysis. When the element contained in the sealant was detected in the corrosion-resistant film, the permeability was evaluated as “◯”, and when the element was not detected as “X”.

As a result, the high temperature member sample no. No. 15 shows from FIG. 6 that a large number of pores exist in the corrosion-resistant film. On the other hand, high temperature member sample No. which is an embodiment of the present invention. As is apparent from Table 4, in Nos. 16 and 17, the sealing agent penetrated into the corrosion-resistant coating. Further, it can be seen from FIG. 7 that the sealing agent penetrates the corrosion-resistant film, and FIG. 8 that only a small number of pores are present in the corrosion-resistant film. In addition, since the pore which exists in a corrosion-resistant film is thought not to communicate with the outside, it is considered that there is no practical problem.

These facts indicate that the sealing agent C has a high sealing property.

The corrosion-resistant coating using the sealant of the present invention is a protective film for a thermal power generation turbine or heat transfer tube that recovers kinetic energy or thermal energy from a high-temperature combustion gas via a fluid such as steam or air. It is preferable to use it. Specifically, it is suitable as a protective film for turbines and heat transfer tubes of gas turbine power generation, coal thermal power generation, coal gasification combined power generation, oil thermal power generation, waste power generation, geothermal power generation, and the like. However, the present invention is not limited to these, and is also suitable as a protective film for various engines. The high-temperature member of the present invention is suitable as a turbine or heat transfer tube for various types of engines such as gas turbine power generation, coal-fired power generation, coal gasification combined power generation, oil-fired power generation, waste power generation, and geothermal power generation.

DESCRIPTION OF SYMBOLS 1 Sealing agent 2 Corrosion-resistant film 3 Underlayer 4 Resin

Claims (20)

1. A sealing agent for sealing pores of a corrosion-resistant film, characterized by comprising a glass having a proportion of alkali metal oxide in the composition of 20% by mass or less and a proportion of lead oxide of 2% by mass or more. Sealing agent.
2. A sealing agent for sealing pores of a corrosion-resistant film, characterized by comprising a glass having an alkali metal oxide ratio of 20% by mass or less and a lead oxide ratio of 10% by mass or more in the composition. The sealing agent according to claim 1.
3. Glass has a glass composition of PbO 10 to 90% by mass, ZnO 0 to 50%, B ₂ O ₃ 0 to 50%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na ₂ O + K ₂ O 0 to 20%, SiO _{2 0-50%,} sealing agent according to claim 2, characterized in _{that Al} 2 O 3 0 containing 30%.
4. A sealing agent for sealing pores of a corrosion-resistant coating, comprising glass containing PbO 5 to 50%, ZnO + B ₂ O ₃ 25 to 60%, Li ₂ O + Na ₂ O + K ₂ O 0 to 20% by mass percentage The sealing agent according to claim 1, wherein
5. Glass has a glass composition of PbO 5-50% by mass, ZnO + B ₂ O ₃ 25-60%, ZnO 0-40%, B ₂ O ₃ 0-40%, MgO + CaO + SrO + BaO 0-40%, Li ₂ O + Na _2. 5. The sealing agent according to claim 4, comprising 0 to 20% of O + K ₂ O, 0 to 40% of SiO _{2 and} 0 to 30% of Al ₂ O ₃ .
6. The sealing agent according to claim 1, wherein the sealing agent is a sealing agent for sealing pores of the corrosion-resistant film, and is composed of a mixture of two or more kinds of glasses having different softening points.
7. The sealing agent according to claim 6, wherein the difference in softening point of the glass is 50 ° C or more.
8. The sealing agent according to claim 6 or 7, comprising PbO-based glass and ZnO-B ₂ O _3- based glass.
9. PbO-based glass is PbO 10 to 90% by mass, ZnO 0 to 50%, B ₂ O ₃ 0.5 to 40%, MgO + CaO + SrO + BaO 0 to 80%, Li ₂ O + Na ₂ O + K ₂ O 0 to 20%, SiO _{2 0-50%,} sealing agent according to claim 8, characterized in _{that Al} 2 O 3 0 containing 30%.
10. _ZnO-B 2 _{O 3} based glass, _ZnO 1 _~ 75% by mass percentage, B 2 O 3 5 ~ 40 %, PbO 0 ~ 60%, MgO + CaO + SrO + BaO 0 ~ 80%, Li 2 O + Na 2 O + K 2 O 0 ~ 20 %, SiO ₂ 0 to 50%, Al ₂ O ₃ 0 to 30%.
11. Oxide composition of the glass mixture, PbO ₂ ~ _60% in percent by mass, ZnO 0.5 ~ 70%, B 2 O 3 1 ~ 40%, MgO + CaO + SrO + BaO 0 ~ 80%, Li 2 O + Na 2 O + K 2 O 0 ~ 20 %, SiO ₂ 0 to 50%, and Al ₂ O ₃ 0 to 30%.
12. A sealing agent coating liquid comprising the sealing agent according to any one of claims 1 to 11.
13. A corrosion-resistant film containing 50% by mass or more of one or more selected from ZrO ₂ , Al ₂ O ₃ and SiO _{2, wherein the} powder comprising the sealing agent according to any one of claims 1 to 11 adheres to the surface. A corrosion-resistant film characterized by
14. 12. A corrosion-resistant film containing 50% by mass or more of one or more selected from ZrO ₂ , Al ₂ O ₃ and SiO ₂ , wherein part or all of the pores existing on the surface are according to any one of claims 1 to 11. A corrosion-resistant film characterized by being filled with a sealing agent.
15. 13. Production of a corrosion-resistant coating film characterized by applying the sealing agent coating liquid according to claim 12 on a corrosion-resistant coating film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO _2. Method.
16. The method for producing a corrosion-resistant coating film according to claim 15, further comprising a step of baking after applying the sealant coating solution.
17. A powder comprising a sealing agent according to any one of claims 1 to 11, having a corrosion-resistant film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO _{2 on} the surface of the substrate. A high-temperature member attached to the surface of the corrosion-resistant coating.
18. The surface of the substrate has a corrosion-resistant coating containing 50% by mass or more of one or more selected from ZrO ₂ , Al ₂ O ₃ and SiO _2, and some or all of the pores present on the surface of the corrosion-resistant coating are claimed Item 12. A high temperature member filled with a sealing agent according to any one of Items 1 to 11.
19. The step of forming a corrosion-resistant film containing 50% by mass or more of at least one selected from ZrO ₂ , Al ₂ O ₃ and SiO ₂ on a substrate, and the sealing agent coating liquid according to claim 12 on the corrosion-resistant film. A method for producing a high-temperature member.
20. The method for producing a high-temperature member according to claim 19, further comprising a step of firing after application of the sealant coating solution.
    
    
    

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