JP6253098B2 - Thermal spraying method - Google Patents

Description

  The present invention relates to a thermal spraying method.

  High temperature members such as moving blades, stationary blades, and combustors used in gas turbines and the like are required to have high heat resistance because they are exposed to high temperature gas. Therefore, not only a material having excellent heat resistance is used for the base material such as a high-temperature member, but also a coating for improving the heat resistance is applied.

  Such coatings and substrates are exposed to hot working fluids during gas turbine operation. And with the operation of the gas turbine for a long time, a part of the coating may be peeled off, or the surface of the base material may be lost and thinning may occur, which may reduce the heat resistance. A repair method for a damaged portion such as a region where the coating has been peeled off or a region where thinning has occurred is performed by applying a repair material to the damaged portion by brazing or spraying. In such a repair method, it is necessary to improve the bondability so that the applied repair material does not peel off from the surface of the damaged base material.

  For example, Patent Document 1 discloses a method in which a heat treatment is performed after a plurality of materials are coated on a missing region on the surface of a base material where a crack has occurred. Specifically, in the method of Patent Document 1, the first material, which is a mixture of a low melting point alloy, which is a brazing material, and a base material that is compatible with a nickel-based material, is deficient in the region. After the deposition, a second material having a different mixing ratio of the low melting point alloy and the base material is deposited on the first material. Thereafter, the base material on which the first material and the second material are laminated is heated at a predetermined temperature for a predetermined time. By performing such heat treatment, the bondability of the first material and secondly the repair material such as the material to the surface of the substrate is ensured.

Japanese Patent No. 5226184

  However, in the method as disclosed in Patent Document 1, it is necessary to perform heat treatment as a separate step after laminating the first material and the second material to be coated on the base material. For this reason, if the target component is large, the component does not fit in the apparatus for performing the heat treatment, and it becomes difficult to perform the heat treatment as a separate process. In addition, if the heat treatment process is performed separately, the number of work processes increases and additional costs and the like occur and become a burden.

  The present invention has been made in order to solve the above-described problems, and provides a thermal spraying construction method capable of easily improving the bondability to a base material.

In order to solve the above problems, the present invention proposes the following means.
A thermal spraying method according to an aspect of the present invention is a thermal spraying method for forming a laminate composed of a plurality of materials on the surface of a base material using a solvent , the brazing material on the surface of the base material Molten metal by twin wire arc spraying using a power supply device for supplying a large current of 1000 A or more so as to give a heat amount exceeding the melting point of the brazing material to the surface of the brazing material. by spraying, including, a spray process to form the laminate without performing heat treatment.

  According to such a configuration, in the thermal spraying process, a high temperature molten metal exceeding the melting point of the brazing material is sprayed, so that the temperature rises and the brazing material is melted. As a result, components such as boron contained in the brazing material diffuse into the molten metal or the base material, and the brazing material can be firmly bonded to the base material or the molten metal. Thereby, a base material and a molten metal can be firmly joined via the melt | dissolved brazing material, and the joining property of a laminated body and a base material can be improved.

In the thermal spraying method according to another aspect of the present invention, the brazing material is a nickel brazing material, and the thermal spraying process uses twin wire arc thermal spraying using a power supply device that supplies a large current of 1000 A or more. The molten metal may be sprayed so as to contact the brazing material at a temperature exceeding the melting point of the brazing material.

  According to such a configuration, by using a nickel brazing material as a brazing material, not only firmly joining a base material and a molten metal, but also a component that requires high heat resistance used in a high temperature environment. On the other hand, it can suppress that the heat resistance of the part in which the laminated body after thermal spraying was formed falls.

  Moreover, in the thermal spraying construction method according to another aspect of the present invention, the base material may be a turbine member.

  According to such a configuration, even when the turbine member is damaged over a wide range due to long-term use, highly reliable repair and processing can be performed in a short time.

  According to the thermal spraying construction method of the present invention, it is possible to easily improve the bondability to the base material without performing heat treatment as a separate process by spraying the molten metal so as to give a heat amount exceeding the melting point of the brazing material. Can do.

It is a flowchart explaining the process of the thermal spraying construction method in embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram explaining the process of the thermal spraying construction method in embodiment of this invention, Comprising: The same figure (a) is a figure explaining the base material before implementing the thermal spraying construction method in embodiment, The same figure (b) is FIG. The figure explaining a brazing material lamination process and the figure (c) are figures explaining a thermal spraying process. It is a figure explaining the twin wire arc spraying apparatus 5 used when implementing the thermal spraying process of embodiment of this invention. It is a schematic diagram explaining the process of the thermal spraying construction method in the modification of this invention, Comprising: The figure (a) is a figure explaining the base material before implementing the thermal spraying construction method in a modification, The figure (b) is The figure explaining a brazing material lamination process and the figure (c) are figures explaining a thermal spraying process.

Embodiments according to the present invention will be described below with reference to FIGS. 1 to 3.
The thermal spraying method S1 is performed using a turbine member such as a turbine stationary blade, a turbine rotor blade, a split ring, and a combustor component as a base material 1. Thermal spray construction method S1 forms the laminated body 4 comprised with a some material with respect to the surface of the base material 1 using thermal spraying. In the thermal spraying method S1 of this embodiment, the brazing material 2 and the molten metal 3 are repaired by repairing the damaged portion 11 on the surface of the base material 1 where the thinning has occurred. Specifically, as shown in FIGS. 1 and 2, the thermal spraying method S <b> 1 of the present embodiment includes a brazing material laminating step S <b> 10 for laminating a brazing material 2 on the surface of the base material 1, and a brazing material 2 that has been laminated. And a thermal spraying step S20 for spraying the molten metal 3 so as to give the surface a heat amount exceeding the melting point of the brazing filler metal 2. For example, a Ni-based alloy used for a turbine member is used as the material of the base material 1 in the present embodiment.

  In the brazing material laminating step S10, as shown in FIG. 2A, the brazing material 2 is laminated on the damaged portion 11 where the surface of the base material 1 has been thinned. Specifically, in the brazing material laminating step S10 of the present embodiment, as shown in FIG. 2B, the paste-like brazing material 2 is applied to the damaged portion 11 and laminated. In the present embodiment, a nickel brazing material 21 as shown in Table 1 is used as the brazing material 2. The nickel brazing material 21 is configured based on a nickel-based alloy. The nickel brazing filler metal 21 is a brazing filler metal 2 that is often used for stainless steel, nickel base, cobalt base alloy, and the like because it has high corrosion resistance and heat resistance and good wettability to an iron base material. As described in Table 1, the nickel brazing material 21 has a melting temperature (a brazing temperature in Table 1) of about 1000 ° C. to 1200 ° C.

  In the thermal spraying step S <b> 20, the molten metal 3 is sprayed on the surface of the brazing material 2 laminated on the surface of the substrate 1, and the laminate 4 is formed on the damaged portion 11 on the surface of the substrate 1. In the thermal spraying step S <b> 20 of the present embodiment, the molten metal 3 is sprayed on the surface of the brazing material 2 so as to give an amount of heat exceeding the melting point of the brazing material 2 as shown in FIG. As the molten metal 3 used in the present embodiment, for example, the same Ni-based alloy as the material used for the turbine member is used. Specifically, in the spraying step S20 of the present embodiment, as shown in FIG. 3, the molten metal 3 is sprayed using a twin wire arc spraying device 5 using a power supply device that supplies a large current of 1000 A or more. . In the twin wire arc spraying device 5, an arc discharge is generated between two wire-like molten metals 3, and the wire-like molten metal 3 is melted and compressed by this discharge energy so as to be inert such as argon or nitrogen. Send gas. As a result, in the thermal spraying step S20, the molten molten metal 3 is sprayed onto the nickel brazing filler metal 21 on the substrate 1 while being atomized from the nozzle 51 to continuously form a film. In the present embodiment, by supplying a large current, a large amount of molten metal 3 of 100 [g / min] or more is melted, and the tip of the nozzle 51 for injecting the molten metal 3 to the nickel brazing filler metal 21 is 100 mm to Thermal spray near 300mm. Thus, in the thermal spraying step S <b> 20, while maintaining the temperature of the molten metal 3 at the time of contact with the nickel brazing material 21 at 1000 ° C. or higher, which is close to the melting temperature of the nickel brazing material 21, 3 is sprayed.

  According to the thermal spraying method S1 as described above, in the thermal spraying step S20, the nickel brazing filler metal 21 is contacted with the nickel brazing filler metal 21 laminated on the damaged portion 11 where the thinning of the surface of the substrate 1 has occurred. By performing thermal spraying so that the temperature of the molten metal 3 at the time is maintained at 1000 ° C. or more which is the melting temperature of the nickel brazing filler metal 21, the nickel brazing filler metal 21 can be given a heat amount exceeding the melting point. That is, when the high temperature molten metal 3 exceeding the melting point of the nickel brazing material 21 is sprayed, the temperature rises and the nickel brazing material 21 is melted. As a result, the components such as boron contained in the nickel brazing material 21 diffuse into the molten metal 3 and the base material 1, whereby the nickel brazing material 21 can be firmly bonded to the base material 1 and the molten metal 3. Thereby, the base material 1 and the molten metal 3 can be firmly joined via the molten nickel brazing material 21, and the joining property between the laminate 4 and the base material 1 can be improved. Therefore, by spraying the molten metal 3 so as to give an amount of heat exceeding the melting point of the nickel brazing material 21, it is possible to easily improve the bondability of the laminate 4 to the base material 1 without performing heat treatment as a separate process. Can do.

  In addition, since the time required for the brazing filler metal 2 to melt and sufficiently diffuse into the base material 1 and the molten metal 3 is about several minutes, while the molten metal 3 is continuously sprayed in the spraying step S20, The molten metal 3 continues to be firmly joined by the brazing material 2. Therefore, the molten metal 3 can be highly stacked on the base material 1, and the thick laminate 4 can be formed firmly.

  Further, in a method in which the amount of heat exceeding the melting point cannot be applied to the brazing material 2 when the temperature of the molten metal 3 contacts the brazing material 2 as in conventional arc welding, the temperature of the molten metal 3 is only several hundred degrees. Since it does not rise, the brazing filler metal 2 cannot be melted. On the other hand, in the thermal spraying step S20 of the present embodiment, a nozzle 51 that melts a large amount of molten metal 3 by twin wire arc spraying using a power supply device that supplies a large current and injects the molten metal 3 onto the substrate 1. By carrying out thermal spraying on the brazing material 2 with the tip of the solder close, the temperature of the molten metal 3 can be maintained at 1000 ° C. or higher when it contacts the brazing material 2, and the amount of heat exceeding the melting point of the brazing material 2 Can be easily given.

  Further, by using the nickel brazing material 21 as the brazing material 2, not only the base material 1 and the molten metal 3 are firmly joined, but also high heat resistance used in a high temperature environment such as a gas turbine is required. It can suppress that the heat resistance of the part in which the laminated body 4 after thermal spraying was formed with respect to the components to be reduced.

  Furthermore, by using the turbine member as a base material, even when the turbine member is damaged over a wide range due to long-term use, highly reliable repair can be performed in a short time. Therefore, a turbine member that can be used for a long period of time can be obtained.

  In addition, this invention is not limited to said embodiment, A various deformation | transformation is accept | permitted in the range which does not deviate from the summary. That is, the thermal spraying method S1 is not limited to being performed on the damaged portion 11 on the surface of the base material 1 where the thinning has occurred as in the above embodiment. For example, as a modification, you may use when forming a large convex part by the laminated body 4 on the surface of the base material 1 which has not thinned.

  That is, in the modified example, as shown in FIG. 4A, the brazing filler metal laminating step S10 is performed on the smooth surface of the base material 1 where no thinning occurs, and the brazing filler metal 2 is laminated. As shown in FIG. 4B, the brazing material lamination step S10 of the modified example is a paste-like material, similar to the brazing material lamination step S10 of the embodiment, for the position where the convex shape of the surface of the substrate 1 is desired. The nickel brazing material 21 is applied and laminated.

  As shown in FIG. 4C, the modified spraying step S <b> 20 is melted on the surface of the brazing filler metal 2 so as to give a heat amount exceeding the melting point of the brazing filler metal 2 as in the thermal spraying step S <b> 20 of the embodiment. Metal 3 is sprayed.

  According to the modified thermal spraying method S1 as described above, since the bonding property with the base material 1 can be improved without performing heat treatment in a separate process, a large-scale heat treatment apparatus is used even for large parts. Can be easily formed on the surface of the base material 1 without providing the protrusions such as protrusions.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible. Further, the present invention is not limited by the embodiments, and is limited only by the scope of the claims.

  The method for laminating the brazing material 2 in the brazing material laminating step S10 is not limited to the method for laminating the paste-like brazing material 2 as described above. What is necessary is just to be able to laminate. For example, in the brazing material laminating step S10, the sheet-like brazing material 2 may be laminated on the surface of the base material 1 by bonding with a binder material.

  Further, the brazing material 2 is not limited to the nickel brazing material 21 as in the present embodiment, and may be a low melting point alloy having a melting point lower than that of the material used for the base material 1. Any material that can join the molten metal 3 without melting may be used. That is, as the brazing material 2, various brazing materials 2 corresponding to the base material 1 material such as a silver brazing material, a brass brazing material, and an aluminum brazing material may be used in addition to the nickel brazing material 21.

DESCRIPTION OF SYMBOLS S1 ... Thermal spraying construction method S10 ... Brazing material lamination process S20 ... Thermal spraying process 1 ... Base material 2 ... Brazing material 3 ... Molten metal 4 ... Laminate

Claims (3)

A thermal spraying method for forming a laminate composed of a plurality of materials on the surface of a substrate using a solvent,
And the brazing material lamination step of laminating a brazing material on a surface of the substrate,
Heat treatment is performed by spraying molten metal by twin wire arc spraying using a power supply device that supplies a large current of 1000 A or more so that the amount of heat exceeding the melting point of the brazing material is applied to the surface of the brazing material. a spray process to form the laminate without,
Thermal spraying method including The brazing material is a nickel brazing material;
In the thermal spraying process, the molten metal is sprayed so as to be in contact with the brazing material at a temperature exceeding the melting point of the brazing material by using twin wire arc thermal spraying using a power supply device that supplies a large current of 1000 A or more. Item 2. The thermal spraying method according to Item 1.   The thermal spraying method according to claim 1, wherein the base material is a turbine member.

Images