JP2009112946A - Repairing method of corrosion prevention coating layer, member, and rotary machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repairing method of corrosion prevention coating layer which enhances corrosion resistance, and reliability and efficiency of repair. <P>SOLUTION: The repairing method of the corrosion prevention coating layer comprises a first washing step S11 to wash the defect portion of an electroless plating Ni-P plating layer, a grinding step S12 to abrade and smooth the defect portion, the second washing step S13 to wash the defect portion and its periphery of the abraded electroless plating Ni-P plating layer, the coating step S14 to apply a solvent in which SiC particle containing polyimide resin raw material composition is dissolved to the defect portion, the drying step S15 to evaporate and dry the applied solvent to the defect portion and the calcining step S16 to calcine and cure the SiC particle containing polyimide resin raw material composition after the drying step S15 to form the SiC particle containing polyimide resin layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for repairing an anticorrosion coating layer using a SiC particle-containing polyimide resin raw material composition at a defective portion of a hard anticorrosion coating layer applied to a member in contact with a flowing gas.

Since members such as rotor blades and impellers of conventional rotating machines come into contact with the circulating steam and gas, in addition to the components of these gases, such as CO ₂ , H ₂ S, and H ₂ O, Cl contained in the steam and gas , Exposed to a corrosive environment due to corrosive components such as NaCl, NaOH, etc., members that come into contact with gas are susceptible to corrosion.

  For example, in a compressor that compresses gas as a rotary machine, the gas to be compressed often contains a corrosive component, and the components of the compressor such as an impeller and a diaphragm that directly contact the circulating gas are corrosive environment. Exposed to corrosive action with load.

  Also, in a steam turbine driven by gas, for example, as a rotating machine, high-temperature and high-pressure steam, which is a working fluid, acts on the rotor blades to generate rotational power. And the blade surface is exposed to a corrosive environment. Therefore, the surface of the steam circulation part such as the moving blade is affected by impurities such as chlorine Cl, NaCl, NaOH contained in the steam as the working fluid, and is subjected to a corrosive action.

  As described above, it is required that the surface of the member in contact with the gas of the rotating machine is provided with an anticorrosion coating that improves the corrosion resistance of the member and has strength against a load.

Therefore, as an example of anticorrosion coating to be applied at the time of manufacturing members that come into contact with steam, gas, etc. containing corrosive components such as CO ₂ compressor parts of rotating machinery, passenger compartments, raw material compositions such as polyimide resin are anticorrosive, for example. Methods have been proposed in which a resin coating is applied as a coating to repair metal plating for corrosion protection (Patent Documents 1 and 2).

  In addition, for example, electroless Ni plating is applied as an anticorrosion coating to be applied at the time of manufacturing a member in contact with steam, gas, or the like containing a corrosive component. Ni-P plating is performed by electroless plating (chemical plating) when a corrosion-resistant coating is applied to a base material such as carbon steel or carbon steel cast steel that comes into contact with a corrosive component gas with a highly corrosion-resistant plating such as Ni. It is. In addition, in electroless plating, Ni—P plating is used instead of Ni single plating because of its properties, and in addition to the corrosion resistance of Ni, it becomes amorphous plating by the action of P and improves the corrosion resistance ( Patent Document 3).

JP 2003-193216 A Japanese Patent Laid-Open No. 2007-211600 JP 2007-197766 A

  Here, in the method using electroless Ni—P plating, when surface defects, dirt, etc. remain on the surface of the substrate, the deposition of the Ni—P plating layer is inhibited and the electroless Ni—P plating layer Therefore, when repairing the electroless Ni-P plating, the so-called brush plating is used to repair the electroless Ni-P plating.

  The principle of this brush plating will be described with reference to FIGS. As shown in FIG. 3, a base material 101 to be plated is connected to a lead wire 102a on the cathode side of a power source (not shown), and a brush 103 for plating is connected to a lead wire 102b on the anode side of a power source (not shown). The tip of the tool 103 is covered with absorbent cotton 104, for example. Then, the absorbent cotton 104 is immersed in, for example, a plating solution to be plated, and the plating solution is immersed in the absorbent cotton 104. Then, as shown in FIG. 4, by contacting the absorbent cotton 104 infiltrated with the plating solution with the base material 101 with the brush 103, electricity flows to the place where the absorbent cotton 104 is in contact with the base material 101, A plating 105 is applied to the substrate 101.

  As a result, as shown in FIG. 5, Ni plating having a film thickness of, for example, about 10 μm is performed by brush plating on the defective portion 107 of the electroless Ni—P plating layer (film thickness: 50 to 60 μm) 106 on the surface of the substrate 101. Layer 108 can be formed.

  However, when a raw material composition such as a polyimide resin is used as an anticorrosive coating and the resin coating is applied, the raw material composition such as a polyimide resin is suddenly evaporated and dried at about 350 ° C. on the base material. Since the solvent dissolving the composition evaporates at a time, there is a problem that a uniform polyimide resin layer is not formed and the corrosion resistance is lowered.

  In addition, when the Ni plating layer 108 is applied on the substrate 101 by brush plating, the Ni plating film forming speed is low, and for example, it takes about 2 hours to form a film about 10 μm per 100 mm square. Therefore, there is a problem that the processing area per time is small.

  Further, the thickness of the Ni plating layer 108 to be repaired by brush plating is about 10 μm, and the thickness of the Ni plating layer 108 cannot be increased. Therefore, there is a problem that the reliability as the repair plating is low.

  Moreover, the defect part repaired by brush plating is nickel, and the part which is not repaired other than that is a Ni-P alloy, and the composition of the plating is different between the defective part and the other part which is not repaired. There is a problem that the corrosion resistance is inferior.

  Furthermore, when different metals are in contact with each other, galvanic corrosion occurs, which is not preferable from the viewpoint of corrosion prevention.

  In view of the above problems, an object of the present invention is to provide a method for repairing an anticorrosion coating layer that improves corrosion resistance and improves the reliability and efficiency of repair.

  The first invention of the present invention for solving the above-described problem is that when repairing the anticorrosion coating layer applied to the member through which the gas flows and contacts the gas, the defective portion of the anticorrosion coating layer contains ceramic particles. There exists in the repair method of the anti-corrosion coating layer characterized by repairing using a polyimide resin.

  According to a second invention, in the first invention, (a) a first cleaning step in which the defect portion of the anticorrosion coating layer is cleaned using an organic solvent, and (b) the defect portion is ground and smoothed. And (c) a second cleaning step in which the defective portion of the ground anticorrosion coating layer and its periphery are cleaned again using an organic solvent after the grinding step, and (d) ceramic particles A coating step of applying a solvent in which the contained polyimide resin raw material composition is dissolved to the defective portion; (e) a drying step of evaporating and drying the solvent applied to the defective portion after the coating step; and (f). After the drying step, the ceramic particle-containing polyimide resin raw material composition is baked and cured to form a ceramic particle-containing polyimide resin layer; In repairing method of anticorrosive coating layer, which comprises a.

  According to a third aspect of the anticorrosive coating layer according to the second aspect, after the solvent is dried, the coating step and the drying step are repeated at least twice, and then the firing step is performed. It is in the repair method.

  4th invention exists in the repairing method of the anticorrosion coating layer characterized by the drying temperature of the said drying process of (e) being 80-120 degreeC in 2nd or 3rd invention.

  According to a fifth aspect of the present invention, there is provided the method for repairing an anticorrosion coating layer according to any one of the second to fourth aspects, wherein the firing temperature in the firing step of (f) is 280 to 350 ° C.

  A sixth invention is the repair method for an anticorrosion coating layer according to any one of the first to fifth inventions, wherein the ceramic particles are SiC particles.

  The seventh invention is characterized in that the ceramic particle-containing polyimide resin layer is formed at the defective portion of the anticorrosion coating layer by using the method for repairing the anticorrosion coating layer according to any one of the second to sixth inventions. It is in the member.

  An eighth invention is the rotary machine including the member according to the seventh invention, wherein the member is any one of an impeller of a compressor, a diaphragm, a moving blade of a steam turbine, and a turbine disk supporting the same. The rotating machine is characterized by being.

  According to the present invention, after the step of applying the solvent in which the ceramic particle-containing polyimide resin raw material composition is dissolved to the repaired portion of the anticorrosion coating layer and evaporating and drying the solvent is performed at least once, the ceramics Since the particle-containing polyimide resin raw material composition is fired and cured to form a ceramic particle-containing polyimide resin layer, the corrosion resistance can be improved and the repair efficiency can be improved as compared with the conventional method.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

A method for repairing an anticorrosion coating layer according to an embodiment of the present invention will be described with reference to the drawings.
First, the state which repaired the defect location of the anticorrosion coating layer of the base material using the repair method of the anticorrosion coating layer which concerns on the Example by this invention is demonstrated.
FIG. 1 is a conceptual diagram showing a cross section of an anticorrosion coating layer and a base material repaired using the anticorrosion coating layer repair method according to an embodiment of the present invention.
As shown in FIG. 1, the base material 11 repaired by using the repair method of the anticorrosion coating layer according to the embodiment of the present invention includes an electroless Ni-P as an anticorrosion coating layer applied to the surface 11a of the base material 11. A plated layer 12 is formed, and a polyimide resin layer 14 is formed at a defective portion 13 of the electroless Ni-P plated layer 12 and a silicon carbide (SiC) particle 15 is uniformly dispersed inside the polyimide resin layer 14. An SiC particle-containing composite polyimide coating layer 16 having a structure is formed.

The base material 11 repaired by using the method for repairing the anticorrosion coating layer according to the embodiment of the present invention includes, for example, an impeller and a diaphragm that are in direct contact with a gas flowing through a rotary machine such as a compressor, a moving blade of a steam turbine, and the like. It is a base material. The substrate 11 is made of carbon steel (for example, SS400), carbon steel cast steel (for example, SC480), stainless steel (for example, SUS410J1), an aluminum plate, or the like. The electroless Ni—P plating layer 12 side of the surface 11a of the substrate 11 is a part that directly contacts a gas containing a corrosive component such as CO ₂ , H ₂ S, and H ₂ O gas in a rotating machine.

After the surface 11a of the substrate 11 is smoothed, washed, etc., and pretreated, an electroless Ni-P plating layer 12 is applied as an anticorrosive coating by electroless plating. The base material 11 has a thickness t _{1 of the} electroless Ni—P plating layer 12 of, for example, about 50 to 60 μm.

  Further, when the anticorrosion coating is applied by plating having high anticorrosion properties such as Ni as the anticorrosion coating layer, Ni-P plating is performed by electroless plating (chemical plating). This is because when Ni plating or the like is performed by electroplating, a large and complicated impeller such as a compressor, a moving blade of a steam turbine, etc., the plating film is biased to a place where electricity is easily applied as an electrode in the electrolytic solution. This is because it is difficult to form a sufficient plating film in a recessed portion that is formed and is less energized.

  In this embodiment, the electroless Ni—P plating layer 12 is used as the anticorrosion coating layer, but the present invention is not limited to this, and may be an anticorrosion coating layer using nickel, copper, or the like.

  In the present embodiment, as shown in FIG. 1, the polyimide resin layer 14 and SiC particles 15 are uniformly dispersed in the defect portion 13 of the electroless Ni—P plating layer 12. A SiC particle-containing composite polyimide coating layer 16 is formed.

  The polyimide resin layer 14 constituting the SiC particle-containing composite polyimide coating layer 16 itself is excellent in corrosion resistance as a single resin, relatively high in hardness, and particularly excellent in heat resistance.

  Moreover, since the SiC particle 15 is excellent in corrosion resistance, the polyimide resin layer 14 containing a large amount of the SiC particle 15 as described later exhibits corrosion resistance as the SiC particle-containing composite polyimide coating layer 16.

  Further, the SiC particles 15 are contained in the polyimide resin layer 14 in the proportions described later, and the SiC particles 15 are also dispersed on the surface of the polyimide resin layer 14. For this reason, the SiC particle 15 increases the effective hardness on the surface of the SiC particle-containing composite polyimide coating layer 16. For this reason, the SiC particle-containing composite polyimide coating layer 16 has dramatically improved strength and durability against the shearing force and impact force on the support surface as compared with the case where the polyimide resin layer 14 is a single body.

  Therefore, the SiC particle-containing composite polyimide coating layer 16 of this example has high hardness, excellent heat resistance such as about 350 ° C., and a shearing force due to the load, impact, and mechanical contact applied to the substrate 11. In addition to exhibiting high strength against the above, it can have particle erosion resistance and high adhesion.

  Therefore, by forming the SiC particle-containing composite polyimide coating layer 16 at the defective portion 13 of the electroless Ni—P plating layer 12, the corrosion resistance can be improved and the reliability of repair can be improved.

In the present embodiment, the thickness t ₂ of the SiC particle-containing composite polyimide coating layer 16 is preferably 30 to 80 μm. This is because when the film thickness t ₂ of the SiC particle-containing composite polyimide coating layer 16 is 30 μm or less, sufficient corrosion resistance cannot be ensured due to the presence of through defects. This is because when the film thickness t ₂ is 80 μm or more, defects due to blistering of the film are likely to occur, and it is difficult to perform a sound coating.

  In the present embodiment, the SiC particle-containing composite polyimide coating layer 16 includes the first SiC particle-containing composite polyimide coating layer 16-1 and the second SiC particles at the defect portion 13 of the electroless Ni—P plating layer 12. Although two layers of the composite polyimide coating layer 16-2 are formed, the present invention is not limited to this, and any number of layers may be formed according to the film thickness of the electroless Ni-P plating layer 12. Good.

  The SiC particles 15 to be contained in the polyimide resin layer 14 are preferably in the range of 10 to 30 wt%, and more preferably about 20 wt% on average. This is because if the SiC particles 15 are 10 wt% or less, the effect of hardening the SiC particle-containing composite polyimide coating layer 16 by the SiC particles 15 is difficult to obtain, and if the SiC particles 15 exceed 30 wt%, the SiC particle-containing composite polyimide coating This is because the layer 16 becomes brittle.

  The particle diameter of the SiC particles 15 contained in the polyimide resin layer 14 is in the range of 0.5 to 10 μm, preferably 1.0 to 5.0 μm, and more preferably 1.0 to 3.0 μm. This is because if the particle diameter is 0.5 to 10 μm, the SiC particles 15 are stably dispersed uniformly in the polyimide resin layer 14, and the SiC particles have a sufficient fixing force because the space between the SiC particles is appropriate. This is because the particle erosion resistance is excellent. Further, when the particle size of the SiC particles 15 is 10 μm or more, the distance between the SiC particles 15 in the coating increases, and the SiC particle fixing force of the matrix is weakened, so that the average particle size is about 1.2 μm. preferable.

  The SiC particles 15 have been described as the ceramic particles to be contained in the polyimide resin layer 14, but the present invention is not limited to this. For example, the metal particles other than SiN and SiC particles 15 may be used as the ceramic particles. , Metal oxides, metal borides and the like, but the present invention is not particularly limited to these, and is preferably high in hardness.

<Repair method of anticorrosion coating layer>
Here, the repair method of the anticorrosion coating layer according to the present embodiment will be specifically described.
FIG. 2 is a process diagram illustrating a process of a method for repairing an anticorrosion coating layer according to an embodiment of the present invention.
In the present embodiment, the electroless Ni—P plating layer 12 is used as the anticorrosion coating layer, and the SiC particles 15 are used as the ceramic particles.
As shown in FIG. 2, the repair method of the anticorrosion coating layer according to the present embodiment is performed by repairing the electroless Ni—P plating layer 12 applied to the member through which the gas flows and contacts. The defect portion 13 of the -P plating layer 12 is repaired using a composite polyimide resin containing SiC particles 15.
That is, the anticorrosion coating layer repair method according to the present embodiment includes the following steps (a) to (f).
(A) A first cleaning step (S11) in which the defective portion 13 of the electroless Ni—P plating layer 12 is cleaned using an organic solvent.
(B) A grinding step (S12) in which the defective portion 13 is ground and smoothed.
(C) A second cleaning step (S13) in which after the grinding step S12, the defective portion 13 of the ground electroless Ni-P plating layer 12 and its periphery are cleaned again using an organic solvent.
(D) The coating process (S14) which apply | coats the solvent by which the SiC particle containing SiC particle containing polyimide resin raw material composition was melt | dissolved to the defect location 13. FIG.
(E) A drying step (S15) for evaporating and drying the solvent applied to the defective portion 13 after the coating step S14.
(F) The process including the baking process (S16) which bakes and hardens the said SiC particle containing polyimide resin raw material composition after drying process S15, and forms the SiC particle containing polyimide resin layer 16. FIG.

  In the first cleaning step S11, the defective portion 13 of the electroless Ni—P plating layer 12 is cleaned using an organic solvent such as alcohol. This is to remove dust, oil, etc. remaining in the defective portion 13.

  And in grinding process S12, the defective part 13 of the electroless Ni-P plating layer 12 is ground, for example using a grinder etc., and the defective part 13 and its periphery are made smooth. Even if the defect part 13 after grinding of the defect part 13 and its periphery are not smoothed, a solvent in which the SiC particle-containing polyimide resin raw material composition is dissolved is applied to form the polyimide resin layer 14. This is because the polyimide resin layer 14 is peeled off.

  In the second cleaning step S13, after the defect portion 13 and its periphery are smoothed, the defect portion 13 and its periphery are again cleaned using an organic solvent. This is because if dust or the like generated by grinding remains in the defective portion 13 and its periphery, it causes peeling of the electroless Ni—P plating layer 12 and the SiC particle-containing composite polyimide coating layer 16. is there.

  And in coating process S14, the solvent which the polyimide resin raw material composition containing the SiC particle 15 melt | dissolves is apply | coated to the defect location 13 of the electroless Ni-P plating layer 12, and its periphery. At this time, the solvent in which the polyimide resin raw material composition containing the SiC particles 15 is dissolved is applied using a spatula and a brush.

  In this example, the brush coating method is used as a method of coating the solvent in which the polyimide resin raw material composition is dissolved, but the present invention is not limited to this, and a spray gun is used. Alternatively, a coating method suitable for the member 11 may be used, such as a spraying method for uniformly coating and a dipping pull-up method.

  As the solvent in which the polyimide resin raw material composition used in this example is dissolved, for example, U-varnish (trade name: manufactured by Ube Industries) can be used, but the present invention is limited to this. is not.

  In the drying step S15, the solvent in which the polyimide resin raw material composition containing the SiC particles 15 applied to the defect portions 13 is dissolved is heated to about 80 to 120 ° C. using a heater or the like and evaporated for about 30 minutes. Let dry. This is because when the solvent in which the raw material composition such as the polyimide resin is dissolved is suddenly heated to about 350 ° C. on the substrate 11, the solvent in which the raw material composition such as the polyimide resin is dissolved evaporates all at once. This is because the polyimide resin layer 14 having many defects penetrating to the material is formed and the corrosion resistance is lowered. As a result, the corrosion resistance of the SiC particle-containing composite polyimide coating layer 16 is lowered.

  Therefore, the temperature of the solvent is raised to about 80 to 120 ° C. and evaporated for about 30 minutes, and the raw material composition such as the polyimide resin remaining in the defective portion 13 is baked and cured in a baking step S <b> 16 described below to be uniform. A polyimide resin layer 14 can be formed. Thereby, durability of the polyimide resin layer 14 can be maintained, and the corrosion resistance of the SiC particle containing composite polyimide coating layer 16 can be improved.

  Moreover, since only the raw material composition such as the polyimide resin remains in the defect portion 13 by evaporating the solvent in which the polyimide resin raw material composition is dissolved, the raw material composition such as the polyimide resin is again formed. By applying the dissolved solvent and evaporating only the solvent, the polyimide resin layer 14 having an arbitrary film thickness can be formed at the defect portion 13.

  And if it becomes 80 degrees C or less, the above-mentioned coating process S14 and drying process S15 will be repeated 2 or 3 times, for example, and the film thickness of the SiC particle containing composite polyimide coating layer 16 shall be 30-60 micrometers.

  Moreover, the frequency | count of repeating coating process S14 and drying process S15 is not specifically limited, It is arbitrary according to the film thickness of coating layers, such as the electroless Ni-P plating layer 12, and the state of the defect location 13 It can be a film thickness.

  And in baking process S16, after drying the solvent which the polyimide resin raw material composition containing a SiC particle melt | dissolves in drying process S15, the said SiC particle containing polyimide resin raw material composition is about 280-350 degreeC. The temperature is raised and the mixture is baked for about 30 minutes and cured. This is because when the SiC particle-containing polyimide resin raw material composition is baked at 280 ° C. or less, the SiC particle-containing polyimide resin raw material composition is polyimidized and the reaction does not proceed. Moreover, it is because the said SiC particle containing polyimide resin raw material composition will burn if it bakes at 350 degreeC or more.

  Therefore, by heating the polyimide resin raw material composition at about 280 to 350 ° C., the defect portion 13 of the electroless Ni—P plating layer 12 has a SiC particle-containing composite polyimide coating layer 16 as shown in FIG. Is formed. Thereby, the defective part 13 can be closed with the polyimide resin layer 14.

  Therefore, by carrying out the repairing method of the anticorrosion coating layer according to the embodiment of the present invention as shown in FIG. 2, it is possible to repair in a larger area than when repairing by conventional brush plating as shown in FIG. . Thereby, since large area construction is attained by enlarging a heater area, the repair construction time per unit area of the defect location 13 can be shortened.

  Moreover, since the corrosion resistance of the SiC particle-containing composite polyimide coating layer 16 is equivalent to the electroless Ni—P plating layer 12, the corrosion resistance of the plating itself is not inferior, and the conventional brush plating as shown in FIG. 5 is used. In addition, since galvanic corrosion due to repair by Ni plating does not occur, repair with excellent durability can be performed.

  For example, even if the test piece of the SiC particle-containing composite polyimide coating layer 16 and the test piece of the electroless Ni-P plating layer 12 are immersed in a 3% NaCl aqueous solution for about 450 hours, both test pieces are affected by corrosion. There was no damage and almost no difference. Therefore, it can be said that the SiC particle-containing composite polyimide coating layer 16 has the same corrosion resistance as the electroless Ni—P plating layer 12.

  Thus, if the anticorrosion coating layer repair method according to the present embodiment is used, the solvent in which the polyimide resin raw material composition containing SiC particles is dissolved is applied to the defective portion 13 of the electroless Ni-P plating layer 12. After the step of applying, evaporating and drying is repeated at least once or more, the polyimide resin raw material composition is baked and cured to form the SiC particle-containing composite polyimide coating layer 16, thereby electroless Ni-P plating. An SiC particle-containing composite polyimide coating layer 16 having an arbitrary film thickness is formed on the peeling portion of the layer 12 or the defect portion 13 of the electroless Ni-P plating layer 12 according to the defect condition of the defect portion 13. Can be repaired.

  In addition, since it is possible to repair a large area by increasing the heater area, even if the defect portion 13 is large, the defect can be reduced in a shorter time than when repairing by conventional brush plating as shown in FIG. Since the site 13 can be repaired on site, the repair efficiency can be improved.

  Moreover, since the SiC particle containing composite polyimide coating layer 16 which has corrosion resistance equivalent to the electrolytic Ni-P plating layer 12 can be formed in the defective part 13 of the electrolytic Ni-P plating layer 12, the reliability of repair is improved. be able to.

  Therefore, by repairing the anticorrosion coating layer having better corrosion resistance than the conventional method, reliability and maintainability as a rotating machine can be improved, and operational stability, safety, and efficiency can be improved.

  The repair method of the anticorrosive coating layer of the present invention is not limited to rotating machines such as compressors and steam turbines, but is applicable to electronic parts such as substrates and sealing materials, insulating varnishes, corrosion resistant structural materials, corrosion resistant coating films, etc. It is also useful for use.

  It can also be used for parts that come into direct contact with corrosive components in the gas circulating in rotating machinery such as compressors used in corrosive environments such as chemical plants, etc., improving the reliability and efficiency of rotating machinery be able to.

  As described above, the method for repairing the anticorrosion coating layer according to the present invention includes at least one step of applying a solvent in which the ceramic particle-containing polyimide resin raw material composition is dissolved to a defective portion of the anticorrosion coating layer, and evaporating and drying the solution. After repeating the above, by forming a ceramic particle-containing polyimide resin layer, it is possible to form a SiC particle-containing composite polyimide coating layer at the defect location of the anticorrosion coating layer, so repairing the anticorrosion coating with better corrosion resistance than before It can use suitably for performing.

It is a conceptual diagram which shows the cross section of the anticorrosion coating layer and the base material which were repaired using the repairing method of the anticorrosion coating layer. It is process drawing which shows the process of the repair method of the anti-corrosion coating layer based on the Example by this invention. It is explanatory drawing about the principle of brush plating. It is an enlarged view of a brush plating front-end | tip part. It is the cross-sectional schematic which gave Ni plating layer to the defective location of an electroless nickel plating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Base material 11a Surface 12 Electroless Ni-P plating layer 13 Defect location 14 Polyimide resin layer 15 SiC particle 16 SiC particle containing composite polyimide coating layer 16-1 1st SiC particle containing composite polyimide coating layer 16-2 2nd SiC particle-containing composite polyimide coating layer t ₁ Electroless Ni-P plating layer thickness t ₂ SiC particle-containing composite polyimide coating layer thickness

Claims (8)

In repairing the anticorrosion coating layer applied to the member in contact with the gas through which the gas flows,
A method of repairing an anticorrosion coating layer, comprising repairing a repaired portion of the anticorrosion coating layer with a polyimide resin containing ceramic particles. In claim 1,
(A) a first cleaning step of cleaning the defect portion of the anticorrosion coating layer using an organic solvent;
(B) Grinding step for grinding and smoothing the defective portion;
(C) a second cleaning step in which after the grinding step, the defective portion of the ground anticorrosion coating layer and its periphery are cleaned again using an organic solvent;
(D) a coating step of applying a solvent in which the ceramic particle-containing polyimide resin raw material composition is dissolved to the defective portion;
(E) after the coating step, a drying step of evaporating and drying the solvent applied to the defective portion;
(F) After the drying step, the ceramic particle-containing polyimide resin raw material composition is fired and cured to form a ceramic particle-containing polyimide resin layer;
A method for repairing an anticorrosion coating layer, comprising: In claim 2,
After drying the solvent, the coating step and the drying step are repeated at least twice, and then the method proceeds to the firing step, wherein the anticorrosion coating layer is repaired. In claim 2 or 3,
The drying temperature of the said drying process of (e) is 80-120 degreeC, The repair method of the anticorrosion coating layer characterized by the above-mentioned. In any one of Claims 2 thru | or 4,
(F) The baking temperature of the said baking process is 280-350 degreeC, The repair method of the anticorrosion coating layer characterized by the above-mentioned. In any one of Claims 1 thru | or 5,
The method for repairing an anticorrosion coating layer, wherein the ceramic particles are SiC particles.   7. The member, wherein the ceramic particle-containing polyimide resin layer is formed at the defective portion of the anticorrosion coating layer using the repair method for an anticorrosion coating layer according to any one of claims 2 to 6. In claim 7,
A rotary machine comprising the member,
The rotary machine characterized in that the member is any one of a compressor impeller, a diaphragm, a moving blade of a steam turbine, and a turbine disk supporting the blade.

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