Automatic sand blasting method for steam turbine blade

Abstract

The application relates to a steam turbine blade automatic sand blasting method, which comprises the following steps: non-sand blasting area protection, preventing sand blasting of the non-sand blasting area of the blade; sand blasting area cleaning, cleaning oil stains and dust on the surface of the sand blasting area; selecting sand blasting process parameters, selecting different sand blasting process parameters according to different basic materials of the blade; automatic sand blasting, fixing the cleaned blade, and automatically sand blasting according to the selected sand blasting process parameters; and sand cleaning treatment, cleaning the sand blasted blade. The steam turbine blade automatic sand blasting method provided by the application can obtain higher surface roughness and lower sand inclusion rate after the surface sand blasting treatment of the blade through the optimal selection of the steam turbine blade sand blasting process, so that the interface bonding strength between the surface coating and the base material of the blade after the thermal spraying is strengthened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of blade manufacturing, in particular to an automatic sand blasting method for steam turbine blades. BACKGROUND

[0002] The working environment of steam turbine blades has the characteristics of high temperature, high pressure and hot corrosion, and the thermal barrier coating can significantly improve the high temperature resistance and oxidation resistance of the steam turbine blades. The sand blasting process is a key process to ensure the performance of the thermal barrier coating, which can roughen the surface of the substrate alloy and improve the interfacial bonding strength between the coating and the high-temperature alloy substrate. However, during the sand blasting process, some sand will inevitably remain on the surface of the workpiece substrate, and effective detection of the sand inclusion rate is an important technical guarantee for the high reliability of the blade in service.

[0003] High roughness and low sand inclusion rate are ideal technical targets for sand blasting process, but the existing sand blasting process is mainly manual, which cannot accurately control the sand blasting surface, and the research on sand blasting process is not systematic, which cannot achieve the purpose of high roughness and low sand inclusion rate, resulting in low bonding strength between the coating and the substrate. SUMMARY

[0004] To solve the above technical problems, the purpose of the present application is to provide an automatic sand blasting method for steam turbine blades, which selects the optimal sand blasting process for steam turbine blades, and at the same time obtains a higher surface roughness and a lower sand inclusion rate after sand blasting treatment of the blade surface, thereby strengthening the interfacial bonding strength between the coating and the substrate after thermal spraying of the blade surface.

[0005] The technical scheme of the present application is as follows:

[0006] An automatic sand blasting method for steam turbine blades, comprising:

[0007] Non-sand blasting area protection, sand blasting protection is performed on the non-sand blasting area of the blade;

[0008] Sand blasting area cleaning, cleaning oil stains and dust on the surface of the sand blasting area;

[0009] Selecting sand blasting process parameters, selecting different sand blasting process parameters according to different blade base materials;

[0010] Automatic sand blasting, fixing the cleaned blade, and automatically sand blasting according to the selected sand blasting process parameters;

[0011] Sand cleaning treatment, cleaning the sand blasted blade.

[0012] Preferably, the automatic sand blasting process parameters include: using 20-40 mesh white corundum sand, sand blasting pressure 0.2-0.6 MPa, sand blasting angle 30°-75°, sand blasting flow rate 2-6 kg / min, sand blasting distance 100-300 mm, and moving speed of the sand blasting gun 0.1-0.8 m / s.

[0013] Preferably, in the process of automatic sand blasting, double-channel sand blasting is adopted, and the sand blasting coverage of the blade surface is between 100% and 200%.

[0014] Preferably, in the process of automatic sand blasting, when the blade substrate is new ferrite heat-resistant steel CB2, the automatic sand blasting process parameters are selected as follows: sand blasting pressure 0.5-0.6 MPa, sand blasting distance 200-250 mm, sand blasting flow rate 2.5-3 kg / min, and sand blasting angle 50-60°.

[0015] Preferably, in the process of automatic sand blasting, when the blade substrate is directional solidification columnar crystal high-temperature alloy Mar247, the automatic sand blasting process parameters are selected as follows: sand blasting pressure 0.4-0.6 MPa, sand blasting distance 100-150 mm, sand blasting flow rate 3-4 kg / min, and sand blasting angle 40-45°.

[0016] Preferably, in the process of automatic sand blasting, when the blade substrate is equiaxed crystal cast high-temperature alloy In738, the automatic sand blasting process parameters are selected as follows: sand blasting pressure 0.4-0.5 MPa, sand blasting distance 200-250 mm, sand blasting flow rate 4-5 kg / min, and sand blasting angle 60-75°.

[0017] Preferably, the non-sand blasting area protection comprises using sand blasting protection tape to prevent sand blasting on the non-sand blasting area of the blade.

[0018] Preferably, when the sand blasting protection tape is used to prevent sand blasting on the non-sand blasting area of the blade, a special fixture is used to clamp the blade.

[0019] Preferably, the sand blasting area cleaning comprises using acetone solution to clean oil stains and dust on the surface of the sand blasting area.

[0020] Preferably, the fixing of the cleaned blade comprises fixing the cleaned blade on a sand blasting platform.

[0021] An automatic sand blasting method for a steam turbine blade, the method comprising: non-sand blasting area protection, preventing sand blasting on the non-sand blasting area of the blade; sand blasting area cleaning, cleaning oil stains and dust on the surface of the sand blasting area; selecting sand blasting process parameters, selecting different sand blasting process parameters according to different blade substrates; automatic sand blasting, fixing the cleaned blade and automatically sand blasting according to the selected sand blasting process parameters; and sand cleaning treatment, cleaning the sand blasted blade. Compared with the prior art, the automatic sand blasting method for the steam turbine blade provided in the application can obtain higher surface roughness and lower sand inclusion rate after the surface sand blasting of the blade, thereby strengthening the interface bonding strength between the surface coating and the substrate after the thermal spraying of the blade. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Fig. 1 A flowchart of an automatic sandblasting method for turbine blades provided in an embodiment of the present invention;

[0024] Fig. 2 This is a schematic diagram of the sandblasting area in the automatic sandblasting method for turbine blades provided in an embodiment of the present invention;

[0025] Fig. 3 This is a schematic diagram of the sandblasting area in the automatic sandblasting method for turbine blades provided in an embodiment of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0027] In the description of this invention, it should be understood that the terms "upper" and "lower" indicate orientation or positional relationship only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0028] Please Figs. 1 to 3As shown, the application provides a steam turbine blade automatic sand blasting method, which comprises: non-sand blasting area protection, preventing sand blasting on the non-sand blasting area of the blade; sand blasting area cleaning, cleaning the oil stains and dust on the surface of the sand blasting area; selecting sand blasting process parameters, selecting different sand blasting process parameters according to the different basic materials of the blade; automatic sand blasting, fixing the cleaned blade, and automatically sand blasting according to the selected sand blasting process parameters; and sand cleaning treatment, cleaning the sand blasted blade. Compared with the prior art, the steam turbine blade automatic sand blasting method provided by the application can obtain higher surface roughness and lower sand inclusion rate after the surface sand blasting treatment of the blade by optimizing the selection of the steam turbine blade sand blasting process, thereby strengthening the interface bonding strength between the blade surface coating and the substrate after thermal spraying.

[0029] The specific steps are as follows:

[0030] S10, non-sand blasting area protection, preventing sand blasting on the non-sand blasting area of the blade;

[0031] S20, sand blasting area cleaning, cleaning the oil stains and dust on the surface of the sand blasting area;

[0032] S30, selecting sand blasting process parameters, selecting different sand blasting process parameters according to the different basic materials of the blade;

[0033] S40, automatic sand blasting, fixing the cleaned blade, and automatically sand blasting according to the selected sand blasting process parameters;

[0034] S50, sand cleaning treatment, cleaning the sand blasted blade.

[0035] Specifically, the automatic sand blasting process parameters include: using 20-40 mesh white corundum sand, sand blasting pressure of 0.2-0.6 MPa, sand blasting angle of 30°-75°, sand blasting flow rate of 2-6 kg / min, sand blasting distance of 100-300 mm, and moving speed of the spray gun of 0.1-0.8 m / s. Based on the selection of these process parameters, the content of residual sand and gravel in the blade surface is effectively controlled on the basis of roughening the surface of the steam turbine blade to the maximum extent.

[0036] Further, in the process of automatic sand blasting, double-channel sand blasting is used, and the sand blasting coverage of the blade surface sand blasting area reaches 100%-200%. The use of double-channel sand blasting has high sand blasting efficiency and ensures that the overall sand blasting coverage reaches 100%-200%.

[0037] In the process of automatic sandblasting, when the blade substrate is new ferrite heat-resistant steel CB2, the automatic sandblasting process parameters are selected as follows: sandblasting pressure 0.5-0.6 MPa, sandblasting distance 200-250 mm, sandblasting flow rate 2.5-3 kg / min, and sandblasting angle 50-60°. Preferably, sandblasting protective tape is used to protect the non-sandblasting area of the blade, acetone is used to wipe and clean the surface of the sandblasting area of the blade, the sandblasting process parameters of the automatic sandblasting equipment are adjusted, then the blade is clamped on the sandblasting table to sandblast the sandblasting area, 24-mesh white corundum powder is selected as the sandblasting material, the blade substrate is new ferrite heat-resistant steel CB2, and the parameters of the automatic sandblasting equipment are set as follows: sandblasting pressure 0.6 MPa, sandblasting distance 200 mm, sandblasting flow rate 3 kg / min, and sandblasting angle 60°. After sandblasting, the surface roughness of the sandblasting area of the blade is 10.78 μm, and the sand inclusion rate is 19%.

[0038] In the process of automatic sandblasting, when the blade substrate is directional solidification columnar grain high-temperature alloy Mar247, the automatic sandblasting process parameters are selected as follows: sandblasting pressure 0.4-0.6 MPa, sandblasting distance 100-150 mm, sandblasting flow rate 3-4 kg / min, and sandblasting angle 40-45°. Preferably, sandblasting protective tape is used to protect the non-sandblasting area of the blade, acetone is used to wipe and clean the surface of the sandblasting area of the blade, the sandblasting process parameters of the automatic sandblasting equipment are adjusted, then the blade is clamped on the sandblasting table to sandblast the sandblasting area, 24-mesh white corundum powder is selected as the sandblasting material, the blade substrate is directional solidification columnar grain high-temperature alloy Mar247, and the parameters of the automatic sandblasting equipment are set as follows: sandblasting pressure 0.4 MPa, sandblasting distance 150 mm, sandblasting flow rate 4 kg / min, and sandblasting angle 45°. After sandblasting, the surface roughness of the sandblasting area of the blade is 8.54 μm, and the sand inclusion rate is 17%.

[0039] In the process of automatic sandblasting, when the blade substrate is equiaxed crystal cast high-temperature alloy In738, the automatic sandblasting process parameters are selected as follows: sandblasting pressure 0.4-0.5 MPa, sandblasting distance 200-250 mm, sandblasting flow rate 4-5 kg / min, and sandblasting angle 60-75°. Preferably, sandblasting protective tape is used to protect the non-sandblasting area of the blade, acetone is used to wipe and clean the surface of the sandblasting area of the blade, the sandblasting process parameters of the automatic sandblasting equipment are adjusted, then the blade is clamped on the sandblasting table to sandblast the sandblasting area, 24-mesh white corundum powder is selected as the sandblasting material, the blade substrate is equiaxed crystal cast high-temperature alloy In738, and the parameters of the automatic sandblasting equipment are set as follows: sandblasting pressure 0.5 MPa, sandblasting distance 250 mm, sandblasting flow rate 5 kg / min, and sandblasting angle 75°. After sandblasting, the surface roughness of the sandblasting area of the blade is 9.77 μm, and the sand inclusion rate is 18%.

[0040] Therefore, the three specific embodiments of the turbine blade manufactured by different materials need to select different sandblasting parameters to achieve the best sandblasting effect. Such setting is because the blades manufactured by different materials have different hardness and crystal structures, and the same sandblasting parameters cause different sandblasting effects, so that appropriate sandblasting parameters need to be selected for blades made of different materials.

[0041] The non-sandblasting area protection includes using sandblasting protection tape to prevent sandblasting on the non-sandblasting area of the blade. When the sandblasting protection tape is used to prevent sandblasting on the non-sandblasting area of the blade, a special clamp is used to hold the blade. The sandblasting protection tape is attached to the non-sandblasting area of the blade, exposing the sandblasting area, and a special clamp is used to hold it. Such setting is to protect the non-sandblasting area of the blade and avoid damage to the surface of the non-sandblasting area.

[0042] Further, the sandblasting area cleaning includes using acetone solution to clean oil stains and dust on the surface of the sandblasting area. Such setting is to make the surface of the blade after sandblasting free of oil stains and dust, and to ensure that the exposed new surface after sandblasting is free of oil stains.

[0043] Preferably, the fixed cleaned blade includes fixing the cleaned blade on the sandblasting platform.

[0044] In addition, in the implementation, high-pressure gas is used to clean the surface of the blade after sandblasting, which can remove the sand particles embedded in the surface of the blade substrate. Such setting is because the sand particles remaining on the surface of the blade substrate, especially the sand particles embedded in the substrate and easily falling off, will seriously affect the coating quality of the thermal spraying process.

[0045] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between the embodiments can be referred to each other.

[0046] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of automatic sandblasting of steam turbine blades, characterized in that, The method comprises: Non-sandblasting area protection, sandblasting protection is prevented to the blade non-sandblasting area; Sandblasting area cleaning, using acetone solution to clean the oil dirt and dust on the surface of the sandblasting area; Selecting sandblasting process parameters, selecting different sandblasting process parameters according to the different blade basic materials; Automatic sandblasting, fixing the cleaned blade, and automatically sandblasting according to the selected sandblasting process parameters;During the automatic sandblasting process, when the blade substrate is directional solidification columnar crystal high-temperature alloy Mar247, the automatic sandblasting process parameters are selected as sandblasting pressure 0.4-0.6MPa, sandblasting distance 100-150mm, sandblasting flow rate 3-4kg / min, and sandblasting angle 40-45°;During the automatic sandblasting process, when the blade substrate is equiaxed crystal cast high-temperature alloy In738, the automatic sandblasting process parameters are selected as sandblasting pressure 0.4-0.5MPa, sandblasting distance 200-250mm, sandblasting flow rate 4-5kg / min, and sandblasting angle 60-75°;During the automatic sandblasting process, double-channel sandblasting is adopted, and the sandblasting coverage rate of the blade package surface sandblasting area reaches between 100%-200%. Sand cleaning treatment, cleaning the blade after sandblasting.

2. The automatic sandblasting method for the steam turbine blade according to claim 1, characterized in that, The non-sandblasting area protection comprises sandblasting protection tape for preventing sandblasting to the blade non-sandblasting area.

3. A steam turbine blade automatic sandblasting method according to claim 2, characterized by, When the sandblasting protection tape is used to prevent sandblasting to the blade non-sandblasting area, a special fixture is used to clamp the blade.

4. The method of claim 2, wherein, The fixed cleaned blade comprises fixing the cleaned blade on the sandblasting platform.

Images