JP5112286B2 - Steam turbine blade and steam turbine - Google Patents

Description

  The present invention relates to a steam turbine blade and a steam turbine, and in particular, can improve the oxidation resistance and erosion resistance of a moving blade (blade) and a stationary blade (nozzle) constituting the steam turbine at the same time. The present invention relates to a steam turbine blade and a steam turbine that can maintain and improve performance.

  In a steam turbine, the pressure and temperature energy of high-temperature and high-pressure steam supplied from a boiler is converted into rotational energy using a cascade of stationary blades and moving blades. FIG. 3 is a conceptual diagram of a power generation system using such a steam turbine.

  As shown in FIG. 3, the steam generated in the boiler 1 is further heated by the heater 2 and guided to the steam turbine 3.

  The steam turbine 3 is configured by arranging a plurality of stages in the axial direction of the turbine rotor 4, each including a combination of moving blades (blades) implanted in the circumferential direction of the turbine rotor 4 and stationary blades (nozzles) supported by the casing. Has been. Then, the steam guided to the steam turbine 3 expands in the steam passage, whereby the high-temperature and high-pressure energy is converted to the turbine rotor 4 as rotational energy.

  The rotational energy of the turbine rotor 4 is transmitted to the generator 9 connected to the turbine rotor 4 and converted into electrical energy. On the other hand, the steam that has lost its energy is discharged from the steam turbine 3 and led to the condenser 10 where it is cooled and condensed by the cooling medium 11 such as seawater to become condensed water. This condensed water is supplied again to the boiler 1 by the feed water pump 12.

  By the way, the steam turbine 3 is divided into a high-pressure turbine, an intermediate-pressure turbine, a low-pressure turbine, and the like according to the temperature and pressure conditions of the supplied steam. In the case of the power generation system as described above, since the high pressure turbine and the intermediate pressure turbine are exposed to high temperatures, oxidation of the moving blades and stationary blade components of the steam turbine is remarkable.

  In a rotor blade, a stationary blade, etc. of a steam turbine, the surface roughness is made as small as possible by a method such as spraying fine particles on the surface when incorporating as a part. This is because when the surface roughness of the parts is large, the flow of fluid is disturbed on the surface of the blades, etc., causing aerodynamic characteristics as the blades by causing separation, which causes the efficiency of the entire turbine to be reduced. is there.

However, when these parts are used in an actual plant, they exhibit high aerodynamic performance because the surface roughness is small in the initial state, but the surface roughness gradually increases as the surface oxidation gradually proceeds. However, it has been pointed out that the aerodynamic performance of the blades gradually decreases with the passage of operating time, and the efficiency of the entire turbine also decreases. In addition to the problem of surface oxidation of the blades, in the turbine, fine solid particles such as oxide scale, whose main component is magnetite (Fe ₃ O ₄ ), fly as flying objects. In other words, so-called solid particle erosion occurs, which causes wing thinning. It has been pointed out that this also reduces the aerodynamic performance of the blades and causes a reduction in turbine efficiency. The following proposals have been made as techniques related to these problems.

  In order to improve the erosion resistance of turbine parts, at least one of chromium, aluminum, sulfur, nitrogen, and carbon is selected as a base material, combined and subjected to diffusion penetration treatment, and then borated. A method of forming a FeB film on the surface has been proposed (for example, see Patent Document 1).

  Also, there is a method for improving erosion resistance and oxidation resistance characteristics by forming a hard nitride layer formed on the surface of the substrate and one or more hard physical vapor deposition layers formed by physical vapor deposition on the hardened nitride layer. It has been proposed (see, for example, Patent Document 2).

In addition, a coating mainly composed of carbide ceramics (Cr ₃ C ₂ ) is formed on the surface of the steam passage effective part of the steam turbine blade by high-pressure, high-speed gas flame spraying to reduce erosion by solid particles, that is, erosion. (For example, refer to Patent Document 3).

  Further, it has been proposed to improve wear resistance by forming a Cr-containing titanium nitride film having a limited crystal structure and crystal orientation by a PVD (Physical Vapor Deposition) method (see, for example, Patent Document 4). .

In addition, it is proposed to form a highly wear-resistant film by so-called laser plating, in which a cobalt-based alloy whose composition is strictly controlled is placed in contact with a substrate and then melted and bonded using a laser. (For example, refer to Patent Document 5.)
JP 2006-176866 A JP 2006-37212 A JP 2004-232499 A JP 2002-47557 A JP 2004-270023 A

  However, in any of the above proposals, there is a problem that the process is complicated, expensive, and impractical. In addition, there is no effective method for simultaneously improving erosion resistance and oxidation resistance.

  The present invention has been made in response to such a conventional situation, and can improve the two characteristics of oxidation resistance and erosion resistance at the same time, and has a simple manufacturing process and low manufacturing cost. A blade and steam turbine is to be provided.

As a result of extensive research on the steam turbine blade structure for maintaining the turbine performance, the present inventors have found that the Vickers hardness (Hv) in the amorphous ceramic matrix is 800 (kg / mm ² ) in the amorphous ceramic matrix. ) It was found that a steam turbine blade satisfying two characteristics of oxidation resistance and erosion resistance at the same time can be obtained by forming a film in which hard particles made of the above crystalline material are uniformly dispersed, and the present invention has been completed. It is.

That is, one aspect of the steam turbine blade of the present invention supports a turbine rotor, a moving blade implanted in the turbine rotor, a stationary blade disposed upstream of the moving blade, and the stationary blade. And a turbine casing containing the turbine rotor, the moving blade and the stationary blade, and a pair of the moving blade and the stationary blade forms one paragraph and a plurality of paragraphs in the axial direction of the turbine rotor A steam turbine blade used as the stationary blade or the moving blade in a steam turbine in which a steam passage is formed side by side, and at least a part of the surface is made of zirconium oxide, titanium oxide, or aluminum oxide. uncoated film hard particles Vickers hardness amorphous in a ceramic matrix there are composed of 800 or more crystalline are present in dispersed form It is characterized in.

One aspect of the steam turbine of the present invention supports a turbine rotor, a moving blade implanted in the turbine rotor, a stationary blade disposed upstream of the moving blade, and the stationary blade. A turbine casing containing the turbine rotor, the moving blade and the stationary blade, and forming a single paragraph by a pair of the moving blade and the stationary blade, and a plurality of paragraphs in the axial direction of the turbine rotor. A steam turbine in which steam passages are formed side by side, wherein at least a part of the surface of the rotor blade and the surface of the stationary surface is a Vickers in an amorphous ceramic matrix made of zirconium oxide, titanium oxide, or aluminum oxide. A coating film in which hard particles made of a crystalline material having a hardness of 800 or more are dispersed is formed.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to improve two characteristics, oxidation resistance and erosion resistance simultaneously, a steam turbine blade and a steam turbine with a simple manufacturing process and low manufacturing cost can be provided.

  Hereinafter, details of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of a steam turbine and steam turbine blades according to an embodiment of the present invention. As shown in FIG. 1, the steam turbine 3 includes a turbine rotor 4, a moving blade (blade) 5 implanted in the turbine rotor 4, and a stationary blade (nozzle) 6 disposed on the upstream side of the moving blade 5. And a turbine casing 13 that supports the stationary blade 6 and encloses the turbine rotor 4, the moving blade 5, and the stationary blade 6. A pair of rotor blades 5 and stationary blades 6 forms one paragraph 7 and a plurality of paragraphs 7 are arranged in the axial direction of the turbine rotor 4 to form a steam passage 8. A coating film is formed on at least a part of the surface of the stationary blade 6 and the surface of the moving blade 5 (in this embodiment, the entire surface of the surface of the stationary blade 6 and the surface of the moving blade 5). As shown in FIG. 2, the coating film 17 has a structure in which hard particles 16 made of a crystal having a Vickers hardness (Hv) of 800 (kg / mm ² ) or more are dispersed in an amorphous ceramic matrix 15. It is formed so as to cover the surface of the steam turbine blade base material 14. The entire passage 8 including the stationary blade 6 and the moving blade 5, the end wall, and the platform is collectively referred to as a steam turbine blade. Here, FIG. 4 shows an electron micrograph of a section of the steam turbine blade according to the present embodiment.

  In the present embodiment having the above configuration, hard particles are dispersed in an amorphous ceramic matrix on at least a part of the surface of the stationary blade 6, the moving blade 5, the end wall, and the passage portion 8 including the platform. Since the dense coating film is formed, the coating film has few portions where the substrate directly comes into contact with oxygen in the air, and therefore, the oxidation resistance is improved, and the change in surface roughness when kept at a high temperature is extremely small. . In addition, since hard particles having a Vickers hardness of 800 or more are dispersed in the amorphous ceramic matrix, this exerts a protective function against erosion caused by solid particles, and the thinning and shape change of the turbine blades are prevented. It is hard to happen. Therefore, the two characteristics of oxidation resistance and erosion resistance can be satisfied at the same time, and the initial blade shape and surface roughness can be maintained for a long time even when actually operating in the plant. Also, the initial high level of the efficiency of the entire turbine can be maintained for a long time.

  Here, the reason why the matrix of the coating film is amorphous ceramic is as follows. That is, in order to uniformly cover the base material of the steam turbine blade with the coating film, it is desirable to use a solution method using a solution of a complex, a metal salt, a metal alkoxide, or the like for the formation of the coating film. In the heat treatment step, it is desirable to perform heat treatment at a low temperature that does not damage the substrate. This is because the ceramic matrix inevitably becomes amorphous when heat-treated at a low temperature.

In addition, the hard particles are crystalline because the hardness of the crystalline material is higher than that of the amorphous material when the amorphous material and the crystalline material are generally compared even if the material has the same composition. Because. Furthermore, the reason why the Vickers hardness is set to 800 or more is that the main component of the fine solid particles which are problematic in erosion of the steam turbine is magnetite (Fe ₃ O ₄ ), and the hardness of the magnetite (Fe ₃ O ₄ ) is 600 Vickers hardness. This is because when the Vickers hardness is less than 800, it is not sufficient to improve the erosion resistance.

  The hard particle content is preferably 30% by volume or more and 90% by volume or less with respect to the entire coating film. If the volume ratio of the hard particles to the entire coating film is less than 30% by volume, the effect on the erosion resistance is not sufficient, while if the volume ratio of the hard particles to the entire coating film is more than 90% by volume, the coating is performed. This is because the adhesion strength of the film to the substrate is lowered, and a phenomenon such as peeling occurs.

  Examples of the hard particles include oxide ceramics, carbide ceramics, nitride ceramics, boride ceramics, and the like. Examples of oxide ceramics include aluminum oxide, zirconium oxide, titanium oxide, hafnium oxide, chromium oxide, yttrium oxide, cerium oxide, mullite, and spinel from the viewpoint that the Vickers hardness is 800 or more. Examples of carbide ceramics include silicon carbide, chromium carbide, titanium carbide, zirconium carbide, hafnium carbide, niobium carbide, boron carbide, tungsten carbide, tantalum carbide, and vanadium carbide. Examples of nitride ceramics include silicon nitride, titanium nitride, zirconium nitride, hafnium nitride, chromium nitride, aluminum nitride, tantalum nitride, niobium nitride, and vanadium nitride. Examples of boride ceramics include titanium boride, zirconium boride, hafnium boride, tantalum boride, molybdenum boride, chromium boride, niobium boride, and tungsten boride.

  Among the materials exemplified above, aluminum oxide can be suitably used as the material for the hard particles. The crystal of aluminum oxide has a Vickers hardness of about 1700 to 2300 and belongs to hard particles among ceramics. It is also excellent in chemical stability, stability to water and moisture, thermal stability, and the like. Furthermore, since it is used in many fields, fine and high-purity powder is available at a relatively low cost. Also, many types of particle size distributions and particle shapes are available, and appropriate particles can be selected according to the situation.

  Silicon carbide can also be suitably used as a material for hard particles. Crystals of silicon carbide have a Vickers hardness of around 2500 and are extremely hard particles among ceramics. At the same time, they are chemically stable, stable to water and moisture, thermally stable, and oxidized in the air like aluminum oxide. Also excellent in characteristics and the like. In addition, since it has been used in many fields, fine and high-purity powder can be obtained at a relatively low cost. Also, many types of particle size distribution and particle shape are available, and appropriate particles can be selected.

  The hard particles preferably have an average particle size of 10 nm to 500 nm. When the average particle diameter is smaller than 10 nm, the aggregation of the particles becomes remarkable, and it becomes extremely difficult to uniformly disperse the hard particles in the matrix. On the other hand, when the average particle diameter is larger than 500 nm, This is because the surface roughness is increased, and it is difficult to achieve the object in terms of improving aerodynamic performance due to the small surface roughness that is the initial object.

  In addition, the amorphous ceramics that make up the coating film include chemical stability, stability to water and moisture, thermal stability, oxidation characteristics in the air, In consideration of stability and the like, zirconium oxide, titanium oxide, and aluminum oxide can be preferably used.

  As the amorphous ceramic precursor solution constituting the coating film, a zirconium oxide precursor solution, a titanium oxide precursor solution, a silicon oxide precursor solution, an aluminum oxide precursor solution, or the like is used. be able to. Zirconium oxide precursor solutions include zirconium oxide sol obtained by hydrolyzing zirconium alkoxide, zircon hydrofluoric acid, ammonium zirconium carbonate, zircon potassium fluoride, sodium zircon fluoride, basic zirconium carbonate, zirconium nitrate, acetic acid. Zirconium metal salts such as zirconium and chlorinated zirconium oxide, or zirconium complexes can be mentioned. Titanium oxide precursor solutions include titanium oxide sols obtained by hydrolyzing titanium alkoxides, titanium metal salts such as titanium hydrofluoric acid, titanium lactate, titanium tartrate, titanium acetate, titanium chlorinated oxide, and peroxotitanic acid. A titanium complex is mentioned. Examples of the silicon oxide precursor solution include silica sol obtained by hydrolyzing organosilicon compounds such as silane coupling agent, methyl silicate, ethyl silicate, propyl silicate, and butyl silicate, sodium silicate, and silicic acid. Examples of the silicate include potassium, magnesium silicate, calcium silicate, and barium silicate. As the precursor solution of aluminum oxide, aluminum oxide sol obtained by hydrolyzing aluminum alkoxide, or water-soluble aluminum nitrate, aluminum sulfate or the like is used as a raw material, and sodium carbonate, sodium hydroxide or the like is used as a precipitant. And a sol obtained by a known precipitation method.

  The thickness of the coating film is preferably 0.03 μm or more and 10 μm or less. When the film thickness is less than 0.03 μm, the coating film cannot uniformly cover the base material, and the base material is partially exposed, and the oxidation resistance is rapidly lowered. On the other hand, when the film thickness is thicker than 10 μm, the adhesion strength of the film to the substrate is lowered, so that the film is cracked, the oxidation resistance is lowered, and problems such as peeling from the substrate occur. It is.

  The method for forming the coating film includes a step of applying a solution containing a ceramic precursor to be an amorphous ceramic matrix and hard particles, and a step of decomposing the ceramic precursor by heat treatment. (Solution method) can be preferably used. This method is simple in process, low in cost, and extremely practical. At the same time, it is easy to disperse hard particles in a matrix and high adhesion strength is obtained. In the step of applying the solution, for example, application methods such as dipping, spraying, spin coating, roll coating, and bar coating can be used. Examples of the heating method in the heat treatment include a method of heating the entire turbine blade after being held in an electric furnace, a method of heating only the surface portion of the turbine blade with infrared rays, and the like. It is not limited. In addition, it is preferable to perform said heat processing at about 80 to 600 degreeC. When the heat treatment temperature is lower than 80 ° C., the thermal decomposition of the ceramic precursor becomes insufficient, a dense film cannot be obtained, and the film is unstable and problems such as aging and peeling occur. On the other hand, when the heat treatment temperature is higher than 600 ° C., the structure of the metal that is the base material of the steam turbine blade is changed, and characteristics such as fatigue strength and creep strength are deteriorated.

Example 1
As Example 1, high-purity silicon carbide nanoparticle powder having a particle size of 30 nm and a metal impurity amount of ppb level was added to an aqueous solution of zirconium acetate 8%. The amount added was adjusted so that the silicon carbide nanoparticles were finally 50% by volume of the entire coating film. This mixed solution was mixed for 24 hours using a resin pot mill and balls coated with iron balls, and then vacuum defoaming was performed to obtain a slurry for coating.

  This coating solution is applied to the surface of a plate-like high chromium steel of 50 mm × 50 mm × 5 mm by dipping. After coating, the coating liquid is dried at room temperature for about 1 hour and then heat-treated at 400 ° C. for 10 minutes in the atmosphere to form a coating film. Formed.

  The film thickness of the coating film at this time was about 0.5 μm, and the coating film was a film having a structure in which hard particles of silicon carbide having a particle diameter of 30 nm were dispersed in an amorphous zirconium oxide matrix.

The coating film was subjected to an oxidation resistance test and an erosion resistance test. In the oxidation resistance test, a change in weight and a change in surface roughness were measured after holding in the atmosphere at 500 ° C. for 500 hours. In addition, the erosion resistance test was performed using iron oxide (Fe ₃ O ₄ : magnetite) powder having an average particle size of 75 μm at a normal particle collision speed of 100 m / s and a collision angle of 60 degrees. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Example 2)
As Example 2, a coating film was formed in exactly the same manner as in Example 1 except that the hard particles incorporated in the slurry were aluminum oxide having an average particle size of 0.1 μm, and an oxidation resistance test was performed in the same manner as in Example 1. And an erosion resistance test was performed. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Example 3)
As Example 3, the amount of silicon carbide to be blended in the slurry was reduced, and the addition amount was adjusted so that the final amount of silicon carbide was 30% by volume of the entire coating film. A coating film was formed, and an oxidation resistance test and an erosion resistance test were performed in the same manner as in Example 1. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

Example 4
As Example 4, the amount of silicon carbide blended in the slurry was increased, and the amount added was adjusted in the same manner as in Example 1 except that the silicon carbide was finally adjusted to 90% by volume of the entire coating film. A coating film was formed, and an oxidation resistance test and an erosion resistance test were performed in the same manner as in Example 1. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Example 5)
As Example 5, a coating film was formed in exactly the same manner as in Example 1 except that the average particle size of silicon carbide blended in the slurry was 0.3 μm, and an oxidation resistance test was performed in the same manner as in Example 1. And an erosion resistance test was performed. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Example 6)
As Example 6, instead of the aqueous solution of zirconium acetate, about 7% of an aqueous solution of ammonium ammonium carbonate was blended into the slurry as a precursor solution of zirconium oxide. A coating film was formed in exactly the same manner as in Example 1, and an oxidation resistance test and an erosion resistance test were performed in the same manner as in Example 1. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Example 7)
As Example 7, instead of an aqueous solution of zirconium acetate, an aqueous solution of about 7% peroxotitanic acid was blended in the slurry as a precursor solution of titanium oxide. A coating film was formed in exactly the same manner as in Example 1, and an oxidation resistance test and an erosion resistance test were performed in the same manner as in Example 1. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Example 8 )
In Example 8 , instead of the aqueous solution of zirconium acetate, an aluminum oxide sol obtained by hydrolyzing about 7% aluminum alkoxide was blended in the slurry as a precursor solution of aluminum oxide. A coating film was formed in exactly the same manner as in Example 1, and an oxidation resistance test and an erosion resistance test were performed in the same manner as in Example 1. As a result, no increase in weight and no change in surface roughness were observed for the oxidation resistance test, and no significant weight change was observed for the erosion resistance test.

(Comparative Example 1)
As Comparative Example 1, a coating film was formed in exactly the same manner as in Example 1 except that the particles blended in the slurry were platinum powder having a Vickers hardness of about 400, and an oxidation resistance test was conducted in the same manner as in Example 1. And an erosion resistance test. As a result, the oxidation resistance test showed good oxidation resistance with no increase in weight and no change in surface roughness, whereas the erosion resistance test showed a significant weight loss.

(Comparative Example 2)
As Comparative Example 2, the amount of silicon carbide blended in the slurry was reduced, and the addition amount was adjusted in the same manner as in Example 1 except that the silicon carbide was finally adjusted to 20% by volume of the entire coating film. A film was formed, and an oxidation resistance test and an erosion resistance test were performed in the same manner as in Example 1. As a result, the oxidation resistance test showed good oxidation resistance with no increase in weight and no change in surface roughness, whereas the erosion resistance test showed a significant weight loss.

(Comparative Example 3)
As Comparative Example 3, the amount of silicon carbide blended in the slurry was increased and the amount added was exactly the same as in Example 1 except that the amount of silicon carbide was finally adjusted to 95% by volume of the entire coating film. A film was formed. As a result, the film peeled off, and the oxidation resistance test and the erosion resistance test could not be performed.

(Comparative Example 4)
As Comparative Example 4, a coating film was formed in exactly the same manner as in Example 1 except that the average particle size of silicon carbide blended in the slurry was 0.8 μm. As a result, the film peeled off, and the oxidation resistance test and the erosion resistance test could not be performed.

(Comparative Example 5)
As Comparative Example 5, a coating film was formed in exactly the same manner as in Example 1 except that the thickness of the finally formed coating film was 12 μm. As a result, the coating film peeled off, and the oxidation resistance test and the erosion resistance test could not be performed.

  As described above, the steam turbine blade according to the above embodiment can simultaneously satisfy the two characteristics of oxidation resistance and erosion resistance. Therefore, even when actually operating in the plant, the initial blade shape and surface roughness can be maintained over a long period of time, the aerodynamic characteristics of the initial blade are not deteriorated, and the efficiency of the entire turbine is It becomes possible to maintain a high level for a long time. In addition, the manufacturing process is simple and the manufacturing cost is low.

1 is a cross-sectional view schematically showing a main part configuration of a steam turbine according to an embodiment of the present invention. 1 is an enlarged cross-sectional view schematically showing a main part configuration of a steam turbine blade according to an embodiment of the present invention. The conceptual diagram of Rankine cycle in a steam turbine power generation system. The electron micrograph of the steam turbine blade section concerning one embodiment of the present invention.

Explanation of symbols

  3 ... Steam turbine, 4 ... Turbine rotor, 5 ... Rotor blade (blade), 6 ... Stator blade (nozzle), 7 ... Paragraph, 8 ... Steam passage, 13 ... Casing.

Claims (9)

A turbine rotor, a moving blade implanted in the turbine rotor, a stationary blade disposed on an upstream side of the moving blade, and supporting the stationary blade, and the turbine rotor, the moving blade, and the stationary blade A turbine casing including a turbine casing, and a pair of the moving blades and the stationary blades forming a single stage and a plurality of stages arranged in an axial direction of the turbine rotor to form a steam passage. A steam turbine blade used as a blade or the moving blade,
A coating film in which hard particles made of a crystalline material having a Vickers hardness of 800 or more are dispersed in an amorphous ceramic matrix composed of zirconium oxide, titanium oxide, or aluminum oxide on at least a part of the surface. A steam turbine blade that is formed.   The steam turbine blade according to claim 1, wherein the hard particles are contained in an amount of 30% by volume to 90% by volume with respect to the entire coating film.   3. The steam turbine blade according to claim 1, wherein the hard particles are made of oxide ceramics, carbide ceramics, nitride ceramics, or boride ceramics.   The steam turbine blade according to claim 1, wherein the hard particles are made of aluminum oxide.   The steam turbine blade according to claim 1, wherein the hard particles are made of silicon carbide.   The steam turbine blade according to any one of claims 1 to 5, wherein the hard particles have an average particle diameter of 10 nm or more and 500 nm or less. It said coating film is a steam turbine blade of any one of claims 1 to 6, characterized in that the film thickness is less than 10μm more than 0.03 .mu.m. The coating film is formed by a step of applying a solution containing a ceramic precursor to be the amorphous ceramic matrix and the hard particles, and a step of decomposing the ceramic precursor by heat treatment. The steam turbine blade according to any one of claims 1 to 7 , wherein: A turbine rotor, a moving blade implanted in the turbine rotor, a stationary blade disposed on an upstream side of the moving blade, and supporting the stationary blade, and the turbine rotor, the moving blade, and the stationary blade A steam turbine comprising a turbine casing that encloses, wherein a pair of the moving blades and the stationary blades forms a single stage and a plurality of stages are arranged in the axial direction of the turbine rotor to form a steam passage;
Hard particles made of a crystalline material having a Vickers hardness of 800 or more in an amorphous ceramic matrix made of zirconium oxide, titanium oxide, or aluminum oxide are formed on at least a part of the surface of the moving blade and the surface of the static surface. A steam turbine characterized in that a dispersed coating film is formed.