Surfacing process for wear-resistant block of low-pressure turbine blade

Abstract

The invention relates to a surfacing welding process of a low-pressure turbine blade wear-resistant block, which belongs to the technical field of wear-resistant surfacing welding and comprises the following steps: cleaning a blade crown basin-direction meshing surface S and a blade crown back tooth-shaped meshing surface M of a blade, mounting the blade on a first clamp, placing a first wear-resistant block on the blade crown basin-direction meshing surface S, and mounting a second clamp on the blade crown back tooth-shaped meshing surface M; and the first wear-resisting block and the blade crown basin-direction meshing face S are subjected to surfacing welding, the blade is installed on the second clamp again after being turned over, the second wear-resisting block is placed on the blade crown back tooth-shaped meshing face M, and then the second wear-resisting block and the blade crown back tooth-shaped meshing face M are subjected to surfacing welding. The method has the beneficial effects that the blade is mounted on the first clamp, and the first wear-resistant block and the blade crown basin-direction meshing surface S are positioned and subjected to surfacing welding; and then the blade is overturned and then installed on the second clamp, the second wear-resisting block and the back tooth-shaped meshing face M of the blade crown are positioned and subjected to surfacing welding, the welding consistency of the blade wear-resisting block can be guaranteed, and the blade product quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of wear-resistant surfacing, and in particular to a surfacing process for wear-resistant blocks of low-pressure turbine blades. Background Art

[0002] At present, the key technologies for turbine blade manufacturing are mainly reflected in high-efficiency air cooling design and manufacturing technology, material technology and surface coating protection technology. As the engine's requirements for turbine blades become more and more stringent, the design accuracy requirements for turbine blades are also getting higher and higher. In the face of the surfacing process of low-pressure turbine blade wear blocks, argon arc welding is currently used to surfacing the wear-resistant layer through welding wire. This will result in poor consistency in the quality of the wear-resistant block surfacing, and the welding surface is prone to collapse, reducing the quality of the product.

[0003] Therefore, a surfacing process for wear-resistant blocks of low-pressure turbine blades is provided to solve the problems raised in the above-mentioned background technology. Summary of the invention

[0004] The technical problem solved by the invention is how to improve the quality of blade products.

[0005] The technical solution of the present invention to solve the above technical problem is as follows: A surfacing process for a wear-resistant block of a low-pressure turbine blade comprises the following steps: Step 1: Install the blade on the first fixture so that the back edge plate A of the blade, the tenon side B of the basin-to-front edge of the blade, and the crown side C of the basin-to-front edge of the blade are all in contact with and positioned on the first fixture; Step 2: placing the first wear-resistant block on the blade crown basin meshing surface S, and then surfacing the first wear-resistant block with the blade crown basin meshing surface S; Step 3: Remove the blade, cool the blade, and complete the wear-resistant block surfacing from the blade crown basin to the meshing surface S; Step 4: Turn the blade over and reinstall it on the second fixture, so that the basin edge plate A' of the blade, the tenon side surface B' of the blade facing away from the trailing edge, and the crown side surface C' of the blade facing away from the trailing edge are all in contact with and positioned on the second fixture; Step 5: placing a second wear-resistant block on the back-facing toothed meshing surface M of the blade crown, and then surfacing welding the second wear-resistant block to the back-facing toothed meshing surface M of the blade crown; Step 6: Remove the blade, cool the blade, and complete the wear-resistant block surfacing on the toothed meshing surface M of the blade crown.

[0006] The beneficial effects of the present invention are as follows: the blade is installed on the first fixture so that the back edge plate A of the blade, the basin-toward leading edge tenon side B of the blade and the basin-toward leading edge crown side C of the blade are all abutted and positioned with the first fixture, and then the first wear-resistant block is positioned and built-up with the basin-toward meshing surface S of the blade crown, so that the wear-resistant block build-up welding of the basin-toward meshing surface S of the blade crown is completed; then, the blade is turned over and installed on the second fixture so that the basin edge plate A´ of the blade, the back-to-trailing edge tenon side B´ of the blade and the back-to-trailing edge crown side C´ of the blade are all abutted and positioned with the second fixture, and then the second wear-resistant block is positioned and built-up with the back-to-tooth meshing surface M of the blade crown is completed, so that the wear-resistant block build-up welding of the back-to-tooth meshing surface M of the blade crown is completed, which can ensure the consistency of the welding of the blade wear-resistant blocks and improve the product quality of the blade.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, the method further comprises step seven: performing stress heat treatment on the blade.

[0009] The beneficial effect of adopting the above further scheme is that stress heat treatment is performed on the blades after surfacing, which can remove the thermal stress and phase change stress of the blades, avoid cracks in the blades due to stress in the later stage, and ensure product quality.

[0010] Furthermore, in step seven, the stress heat treatment includes: placing the blade in a tempering furnace and pre-evacuating the blade to a temperature less than or equal to 0.133 Pa, heating the blade to 760±20°C at a rate of 10±2°C / min, and keeping the temperature for 60~70 minutes, then heating the blade to 900±20°C at a rate of 5±2°C / min, and keeping the temperature for 3~4 hours. After the insulation is completed, argon is filled into the tempering furnace and the blade is cooled by gas quenching at a gas quenching pressure of 0.5~1 bar and taken out of the furnace.

[0011] Furthermore, the method also includes step eight: performing 100% fluorescent treatment on the first wear-resistant block and the second wear-resistant block.

[0012] The beneficial effect of adopting the above further solution is that the first wear-resistant block and the second wear-resistant block are subjected to fluorescent treatment to check whether the surfacing welding has defects such as holes, cracks and inclusions.

[0013] Furthermore, in the step 2, a argon arc welding machine is used to perform buildup welding on the first wear-resistant block and the blade crown basin meshing surface S, the nozzle diameter of the argon arc welding machine is 8 mm to 12 mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3 mm to 1.8 mm.

[0014] The beneficial effect of adopting the above further solution is that the first wear-resistant block and the blade crown basin of the blade can be built-up welded to the meshing surface S by an argon arc welding machine, thereby improving the building-up welding efficiency.

[0015] Further, in the step 2, the first wear-resistant block and the blade crown basin are welded to the mating surface S, specifically: pulse tungsten inert gas welding is used to weld the first wear-resistant block and the blade crown basin to the mating surface S; the parameters of the pulse tungsten inert gas welding are as follows: the pulse current is 60A~90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulse tungsten inert gas welding and the first wear-resistant block is 2~4mm, the argon gas flow rate is 7~10L / min, and the welding time is 3~5s.

[0016] The beneficial effect of adopting the above-mentioned further scheme is that the tungsten electrodes of the pulse tungsten electrode argon arc welding gun are close to the first wear-resistant block and perpendicular to the first wear-resistant block. Under the protection of argon gas, pulse current is used to start an arc between the tungsten electrode and the first wear-resistant block, and the first wear-resistant block is welded under the tungsten electrode, which can ensure the quality of the welding product and improve the welding efficiency.

[0017] Furthermore, in step five, an argon arc welding machine is used to perform build-up welding on the second wear-resistant block and the back-facing toothed meshing surface M of the blade crown, the nozzle diameter of the argon arc welding machine is 8 mm to 12 mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3 mm to 1.8 mm.

[0018] The beneficial effect of adopting the above further solution is that the second wear-resistant block can be built-up welded to the back-facing tooth-shaped meshing surface M of the blade crown by an argon arc welding machine, thereby improving the build-up welding efficiency.

[0019] Further, in the step five, the second wear-resistant block and the back-facing tooth-shaped meshing surface M of the blade crown are welded, specifically: the second wear-resistant block and the blade crown basin-facing meshing surface S are welded by pulse tungsten inert gas welding; the parameters of the pulse tungsten inert gas welding are as follows: the pulse current is 60A~90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulse tungsten inert gas welding and the second wear-resistant block 4 is 2~4mm, the argon gas flow rate is 7~10L / min, and the welding time is 3~5s.

[0020] The beneficial effect of adopting the above-mentioned further scheme is that the tungsten electrodes of the pulse tungsten electrode argon arc welding gun are close to the second wear-resistant block and perpendicular to the second wear-resistant block. Under the protection of argon gas, pulse current is used to start an arc between the tungsten electrode and the second wear-resistant block, and the second wear-resistant block is welded under the tungsten electrode, which can ensure the quality of the welding product and improve the welding efficiency.

[0021] Further, in step one, the first clamp includes a first base, a first fixing block and a second fixing block, the first fixing block and the second fixing block are fixed at two ends of the first base, one side of the first fixing block has a first positioning surface, the other side of the first fixing block has a second positioning surface, and one side of the second fixing block has a third positioning surface, the first positioning surface abuts and positions the back edge plate A of the blade, the second positioning surface abuts and positions the tenon side B of the basin-to-front edge of the blade, and the third positioning surface abuts and positions the crown side C of the basin-to-front edge of the blade.

[0022] The beneficial effect of adopting the above further scheme is: the blade is placed in the first clamp so that the back edge plate A of the blade abuts and is pressed against the first positioning surface, the basin-to-front edge tenon side B of the blade abuts and is pressed against the second positioning surface, and the basin-to-front edge crown side C of the blade abuts and is pressed against the third positioning surface, thereby increasing the stability of the blade positioning.

[0023] Further, the second clamp includes a second base, a third fixing block and a fourth fixing block, the third fixing block and the fourth fixing block are fixed to both ends of the second base respectively, one side of the third fixing block has a fourth positioning surface, the other side of the third fixing block has a fifth positioning surface, and one side of the fourth fixing block has a sixth positioning surface, the fourth positioning surface abuts and positions the basin edge plate A´ of the blade, the fifth positioning surface abuts and positions the side surface B´ of the tenon of the blade facing away from the trailing edge, and the sixth positioning surface abuts and positions the side surface C´ of the blade crown facing away from the trailing edge.

[0024] The beneficial effect of adopting the above further scheme is: the blade is placed in the second clamp so that the basin edge plate A' of the blade abuts and is pressed against the fourth positioning surface, the tenon side B' of the blade facing away from the trailing edge abuts and is pressed against the fifth positioning surface, and the crown side C' of the blade facing away from the trailing edge abuts and is pressed against the sixth positioning surface, thereby increasing the stability of the blade positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the blade basin of the present invention; Figure 2 A side view of the blade basin of the present invention; Figure 3 This is a schematic diagram of the structure of the blade of the present invention facing backward; Figure 4 A side view of the blade of the present invention facing away from the ground; Figure 5 is a schematic structural diagram of a first clamp of the present invention; Figure 6 It is a schematic diagram of the partial structure of the first clamp of the present invention; Figure 7It is a side view of the first fixing block and the partial blade after being assembled in the present invention; Figure 8 is a schematic structural diagram of a second clamp of the present invention; Fig. 9 is a partial structural schematic diagram of the second clamp of the present invention; Fig.10 It is a side view of the third fixing block and the partial blade after being assembled according to the present invention.

[0026] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Blade; 2. First fixture; 201. First base; 202. First fixing block; 203. Second fixing block; 204. First positioning surface; 205. Second positioning surface; 206. Third positioning surface; 207. First baffle; 3. First wear-resistant block; 4. Second wear-resistant block; 5. Second fixture; 501. Second base; 502. Third fixing block; 503. Fourth fixing block; 504. Fourth positioning surface; 505. Fifth positioning surface; 506. Six positioning surfaces; 507, second baffle; 6, tenon; 7, tenon extension; 8, leading edge; 9, trailing edge; 10, blade basin; 11, blade back; 12, blade crown; 13, back edge plate A; 14, basin to leading edge tenon side B; 15, basin to leading edge blade crown side C; 16, blade crown basin to meshing surface S; 17, basin to edge plate A´; 18, back trailing edge tenon side B´; 19, back trailing edge blade crown side C´; 20, blade crown back toothed meshing surface M. DETAILED DESCRIPTION

[0027] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0028] like Figure 1-Figure 3 , which is a schematic diagram of the blade parts, including the tenon 6, the tenon extension section 7, the leading edge 8, the trailing edge 9, the blade basin 10, the blade back 11 and the blade crown 12.

[0029] like Figure 1-Figure 10 As shown, this embodiment provides a surfacing process for a low-pressure turbine blade wear block, comprising the following steps: Step 1: Install the blade 1 on the first fixture 2, so that the back edge plate A of the blade 1, the tenon side B of the basin-to-front edge of the blade 1, and the crown side C of the basin-to-front edge of the blade 1 are all in contact with and positioned on the first fixture 2; Step 2: placing the first wear-resistant block 3 on the blade crown basin meshing surface S, and then surfacing welding the first wear-resistant block 3 and the blade crown basin meshing surface S; Step 3: remove the blade 1, cool the blade 1, and complete the wear-resistant block surfacing from the blade crown basin to the meshing surface S; Step 4: Turn over the blade 1 and reinstall it on the second fixture 5, so that the basin edge plate A' of the blade 1, the tenon side surface B' of the blade 1 facing away from the trailing edge, and the crown side surface C' of the blade 1 facing away from the trailing edge are all in contact with and positioned on the second fixture 5; Step 5: placing the second wear-resistant block 4 on the back-facing toothed meshing surface M of the blade crown, and then surfacing the second wear-resistant block 4 with the back-facing toothed meshing surface M of the blade crown; Step 6: Remove the blade 1, cool the blade 1, and complete the wear-resistant block surfacing on the toothed meshing surface M of the blade crown.

[0030] The blade 1 is installed on the first fixture 2, so that the back edge plate A of the blade 1, the basin-toward leading edge tenon side B of the blade 1 and the basin-toward leading edge crown side C of the blade 1 are all abutted and positioned with the first fixture 2, and then the first wear-resistant block 3 is positioned and built-up with the basin-toward meshing surface S of the blade crown to complete the wear-resistant block build-up of the basin-toward meshing surface S of the blade crown; then, the blade 1 is turned over and installed on the second fixture 5, so that the basin edge plate A´ of the blade 1, the back-to-trailing edge tenon side B´ of the blade 1 and the back-to-trailing edge crown side C´ of the blade 1 are all abutted and positioned with the second fixture 5, and then the second wear-resistant block 4 is positioned and built-up with the back-to-tooth meshing surface M of the blade crown to complete the wear-resistant block build-up of the back-to-tooth meshing surface M of the blade crown, which can ensure the consistency of the wear-resistant block welding of the blade 1 and improve the product quality of the blade.

[0031] Specifically, before step 1, the blade crown basin meshing surface S and the blade crown back toothed meshing surface M of the blade 1 are cleaned to ensure that the blade crown basin meshing surface S and the blade crown back toothed meshing surface M are clean and have no missed parts, and to avoid rust spots and mechanical damage on the blade crown basin meshing surface S and the blade crown back toothed meshing surface M; Subsequently, the oxide film on the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M is first removed, and then the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M are cleaned with gasoline, alcohol or acetone; Finally, after the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M are cleaned, use the naked eye to check the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M to ensure that their surfaces are clean and there are no missed areas, to ensure the welding quality and avoid defects such as inclusions or pores during the welding process.

[0032] Among them, the oxide film on the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M can be removed by creep-feed grinding.

[0033] Specifically, the blade 1 can be quickly inserted into quartz sand for cooling, and the mesh number of the quartz sand is 100 meshes. After the surfacing welding of the wear-resistant block of the blade basin toward the meshing surface or the surfacing welding of the wear-resistant block of the blade back toward the meshing surface is completed, the blade 1 needs to be placed in quartz sand to allow the blade 1 to cool slowly to avoid microcracks and improve product quality.

[0034] Specifically, the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M have the same size.

[0035] When the wear-resistant block on the blade meshing surface facing away from the first clamp 2 is welded, the blade 1 is placed on the first clamp 2, and the blade 1 faces away from the first clamp 2; when the wear-resistant block on the blade meshing surface facing away from the second clamp 5 is welded, the blade 1 is placed on the second clamp 5, and the blade faces away from the second clamp 5.

[0036] Based on the above solution, step seven is also included: performing stress heat treatment on the blade 1.

[0037] Performing stress heat treatment on the blade 1 after surfacing welding can remove the thermal stress and phase change stress of the blade 1, avoid cracks in the blade 1 due to stress in the later stage, and ensure product quality.

[0038] On the basis of the above scheme, in step seven, the stress heat treatment includes: the blade 1 is placed in a tempering furnace and pre-evacuated to less than or equal to 0.133 Pa, the temperature is raised to 760±20°C at a rate of 10±2°C / min, and kept warm for 60~70 minutes, and then the temperature is raised to 900±20°C at a rate of 5±2°C / min, and kept warm for 3~4 hours. After the insulation is completed, argon is filled into the tempering furnace and gas quenched at a gas quenching pressure of 0.5~1 bar and taken out of the furnace.

[0039] On the basis of the above scheme, step eight is also included: performing 100% fluorescent treatment on the first wear-resistant block 3 and the second wear-resistant block 4.

[0040] The first wear-resistant block 3 and the second wear-resistant block 4 are subjected to fluorescent treatment to check whether the surfacing welding has defects such as holes, cracks and inclusions.

[0041] Specifically, ‌100% fluorescence processing‌ means that when performing fluorescence detection, all samples or target areas emit fluorescence, which means that all test objects successfully absorb the excitation light and produce fluorescence signals. This processing method is usually used to ensure the integrity and accuracy of the test.

[0042] The first wear-resistant block 3 and the second wear-resistant block 4 are both rectangular.

[0043] The sizes of the first wear-resistant block 3 and the second wear-resistant block 4 correspond one-to-one to the blade crown basin-facing meshing surface S and the blade crown back-facing tooth-shaped meshing surface M, respectively, which can improve the consistency of the blade wear-resistant block surfacing and ensure the uniform thickness of the first wear-resistant block 3 and the second wear-resistant block 4 surfacing, thereby improving product quality.

[0044] Specifically, the thickness of the first wear-resistant block 3 and the second wear-resistant block 4 may be 1.2-01.8 mm. Preferably, the thickness of the first wear-resistant block 3 and the second wear-resistant block 4 is 1.5 mm, the length is 5 mm, and the width is 6 mm.

[0045] In addition, the first wear-resistant block 3 and the second wear-resistant block 4 have the same length, and the first wear-resistant block 3 and the second wear-resistant block 4 have the same width.

[0046] The first wear-resistant block 3 and the second wear-resistant block 4 of the same size can ensure the consistency of the surfacing of the blade wear-resistant blocks.

[0047] On the basis of the above scheme, in the step 2, an argon arc welding machine is used to perform surfacing welding on the first wear-resistant block 3 and the blade crown basin meshing surface S, the nozzle diameter of the argon arc welding machine is 8mm~12mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3mm~1.8mm.

[0048] The first wear-resistant block 3 and the blade crown basin of the blade 1 can be built-up welded to the meshing surface S by using an argon arc welding machine, thereby improving the building-up welding efficiency.

[0049] Specifically, during the cladding process, the purity of argon gas for argon arc welding is greater than or equal to 99.99%. Ensuring the purity of argon gas can avoid low quality of cladding welding.

[0050] On the basis of the above scheme, in the step 2, the first wear-resistant block 3 and the blade crown basin are welded to the mating surface S, specifically: the first wear-resistant block 3 and the blade crown basin are welded to the mating surface S by pulse tungsten inert gas welding; the parameters of the pulse tungsten inert gas welding are as follows: the pulse current is 60A~90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulse tungsten inert gas welding and the first wear-resistant block 3 is 2~4mm, the argon gas flow rate is 7~10L / min, and the welding time is 3~5s.

[0051] The tungsten electrodes of the pulse tungsten inert gas welding gun are close to the first wear-resistant block 3 and perpendicular to the first wear-resistant block 3. Under the protection of argon gas, pulse current is used to start an arc between the tungsten electrode and the first wear-resistant block 3, and the first wear-resistant block 3 is welded under the tungsten electrode, which can ensure the quality of the welding product and improve the welding efficiency.

[0052] On the basis of the above scheme, in step five, an argon arc welding machine is used to perform buildup welding on the second wear-resistant block 4 and the back-facing toothed meshing surface M of the blade crown. The nozzle diameter of the argon arc welding machine is 8 mm to 12 mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3 mm to 1.8 mm.

[0053] The second wear-resistant block 4 and the blade crown back-facing tooth-shaped meshing surface M of the blade 1 can be built-up welded by an argon arc welding machine to improve the welding efficiency.

[0054] On the basis of the above scheme, in the step five, the second wear-resistant block 4 and the back-facing tooth-shaped meshing surface M of the blade crown are welded, specifically: the second wear-resistant block 4 and the blade crown basin-facing meshing surface S are welded by pulse tungsten inert gas welding; the parameters of the pulse tungsten inert gas welding are as follows: the pulse current is 60A~90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulse tungsten inert gas welding and the second wear-resistant block 4 is 2~4mm, the argon gas flow rate is 7~10L / min, and the welding time is 3~5s.

[0055] The tungsten electrodes of the pulse tungsten electrode argon arc welding gun are close to the second wear-resistant block 4 and perpendicular to the second wear-resistant block 4. Under the protection of argon gas, pulse current is used to start an arc between the tungsten electrode and the second wear-resistant block 4, and the second wear-resistant block 4 is welded under the tungsten electrode, which can ensure the quality of the welding product and improve the welding efficiency.

[0056] On the basis of the above scheme, in step one, the first clamp 2 includes a first base 201, a first fixed block 202 and a second fixed block 203, the first base 201 has the first fixed block 202 and the second fixed block 203 fixed at both ends, one side of the first fixed block 202 has a first positioning surface 204, the other side of the first fixed block 202 has a second positioning surface 205, and one side of the second fixed block 203 has a third positioning surface 206, the first positioning surface 204 abuts and positions the back edge plate A of the blade 1, the second positioning surface 205 abuts and positions the tenon side B of the basin-to-front edge of the blade 1, and the third positioning surface 206 abuts and positions the crown side C of the basin-to-front edge of the blade 1.

[0057] Place the blade 1 in the first fixture 2 so that the back edge plate A of the blade 1 abuts and presses against the first positioning surface 204, the basin-to-front edge tenon side B of the blade 1 abuts and presses against the second positioning surface 205, and the basin-to-front edge crown side C of the blade 1 abuts and presses against the third positioning surface 206, thereby increasing the stability of the positioning of the blade 1.

[0058] Specifically, it also includes a first baffle 207 , which is fixed on the second fixing block 203 and can be used to position the blade 1 to increase the stability of the positioning of the blade 1 .

[0059] On the basis of the above scheme, in step four, the second clamp 5 includes a second base 501, a third fixing block 502 and a fourth fixing block 503, the third fixing block 502 and the fourth fixing block 503 are fixed to the two ends of the second base 501 respectively, one side of the third fixing block 502 has a fourth positioning surface 504, the other side of the third fixing block 502 has a fifth positioning surface 505, and one side of the fourth fixing block 503 has a sixth positioning surface 506, the fourth positioning surface 504 is abutted and positioned with the basin edge plate A´ of the blade 1, the fifth positioning surface 505 is abutted and positioned with the side surface B´ of the tenon of the blade 1 facing away from the trailing edge, and the sixth positioning surface 506 is abutted and positioned with the side surface C´ of the blade crown of the blade 1 facing away from the trailing edge.

[0060] Place the blade 1 in the second fixture 5 so that the basin edge plate A' of the blade 1 abuts and presses against the fourth positioning surface 504, the tenon side B' of the blade 1 facing away from the trailing edge abuts and presses against the fifth positioning surface 505, and the crown side C' of the blade 1 facing away from the trailing edge abuts and presses against the sixth positioning surface 506, thereby increasing the stability of the positioning of the blade 1.

[0061] Specifically, it also includes a second baffle 507 , which is fixed on the fourth fixing block 503 and can be used to position the blade 1 to increase the stability of the positioning of the blade 1 .

[0062] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0067] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A surfacing process for wear-resistant blocks of low-pressure turbine blades, characterized in that: The following steps are involved: Step 1: Mount the blade (1) on the first fixture (2) so that the back edge plate A (13) of the blade (1), the tenon side surface B (14) of the basin-front edge of the blade (1), and the crown side surface C (15) of the basin-front edge of the blade (1) are all in contact with and positioned on the first fixture (2); Step 2: placing the first wear-resistant block (3) on the blade crown basin meshing surface S (16), and then surfacing the first wear-resistant block (3) and the blade crown basin meshing surface S (16); Step 3: removing the blade (1), cooling the blade (1), and completing the wear-resistant block surfacing of the blade crown basin to the meshing surface S (16); Step 4: Turning over the blade (1) and reinstalling it on the second fixture (5) so that the basin edge plate A' (17) of the blade (1), the tenon side surface B' (18) of the blade (1) facing away from the trailing edge, and the crown side surface C' (19) of the blade (1) facing away from the trailing edge are all in contact with and positioned on the second fixture (5); Step 5: placing the second wear-resistant block (4) on the back-facing toothed meshing surface M (20) of the blade crown, and then surfacing-welding the second wear-resistant block (4) and the back-facing toothed meshing surface M (20) of the blade crown; Step six: remove the blade (1), cool the blade (1), and complete the wear-resistant block surfacing of the toothed meshing surface M (20) of the blade crown.

2. A surfacing process for low-pressure turbine blade wear blocks according to claim 1, characterized in that: The method further comprises step seven: performing stress heat treatment on the blade (1).

3. A surfacing process for low-pressure turbine blade wear blocks according to claim 2, characterized in that: In step seven, the stress heat treatment comprises: placing the blade (1) in a tempering furnace and pre-evacuating the temperature to less than or equal to 0.133 Pa, heating the blade (1) to 760±20°C at a rate of 10±2°C / min and keeping the temperature for 60-70 min, then heating the blade (1) to 900±20°C at a rate of 5±2°C / min and keeping the temperature for 3-4 h, and after the temperature is kept, filling the tempering furnace with argon gas at a gas quenching pressure of 0.5-1 bar and cooling the blade by gas quenching before taking the blade out of the furnace.

4. The surfacing process of the wear-resistant block of a low-pressure turbine blade according to claim 2 is characterized in that: The method further comprises step eight: performing 100% fluorescent treatment on the first wear-resistant block (3) and the second wear-resistant block (4).

5. The surfacing process of the wear-resistant block of a low-pressure turbine blade according to claim 1 is characterized in that: In the step 2, a argon arc welding machine is used to perform build-up welding on the first wear-resistant block (3) and the blade crown basin meshing surface S (16), wherein the nozzle diameter of the argon arc welding machine is 8 mm to 12 mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3 mm to 1.8 mm.

6. The surfacing process of the wear-resistant block of a low-pressure turbine blade according to claim 1 is characterized in that: In the step 2, the first wear-resistant block (3) and the blade crown basin meshing surface S (16) are welded, specifically: the first wear-resistant block (3) and the blade crown basin meshing surface S (16) are welded by pulse tungsten inert gas arc welding; the parameters of the pulse tungsten inert gas arc welding are as follows: the pulse current is 60A~90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulse tungsten inert gas arc welding and the first wear-resistant block (3) is 2~4mm, the argon gas flow rate is 7~10L / min, and the welding time is 3~5s.

7. The surfacing process for low-pressure turbine blade wear blocks according to claim 1 is characterized in that: In the step five, a argon arc welding machine is used to perform build-up welding on the second wear-resistant block (4) and the back-facing toothed meshing surface M (20) of the blade crown. The nozzle diameter of the argon arc welding machine is 8 mm to 12 mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3 mm to 1.8 mm.

8. The surfacing process for low-pressure turbine blade wear blocks according to claim 1 is characterized in that: In the step five, the second wear-resistant block (4) is welded to the back-facing toothed meshing surface M (20) of the blade crown, specifically, the second wear-resistant block (4) and the blade crown basin-facing meshing surface S (16) are welded by pulse tungsten inert gas arc welding; the parameters of the pulse tungsten inert gas arc welding are as follows: the pulse current is 60A~90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulse tungsten inert gas arc welding and the second wear-resistant block (4) is 2~4mm, the argon gas flow rate is 7~10L / min, and the welding time is 3~5s.

9. The surfacing process for low-pressure turbine blade wear blocks according to claim 1, characterized in that: In the step 1, the first clamp (2) comprises a first base (201), a first fixing block (202) and a second fixing block (203); the first fixing block (202) and the second fixing block (203) are fixed to two ends of the first base (201), respectively; one side of the first fixing block (202) has a first positioning surface (204); the other side of the first fixing block (202) has a second positioning surface (205); one side of the second fixing block (203) has a third positioning surface (206); the first positioning surface (204) abuts against and positions the back edge plate A (13) of the blade (1); the second positioning surface (205) abuts against and positions the tenon side B (14) of the basin-to-front edge of the blade (1); and the third positioning surface (206) abuts against and positions the crown side C (15) of the basin-to-front edge of the blade (1).

10. The surfacing process of the wear-resistant block of a low-pressure turbine blade according to claim 1, characterized in that: In the step 4, the second clamp (5) comprises a second base (501), a third fixing block (502) and a fourth fixing block (503); the third fixing block (502) and the fourth fixing block (503) are fixed to two ends of the second base (501) respectively; one side of the third fixing block (502) has a fourth positioning surface (504); the other side of the third fixing block (502) has a fifth positioning surface (505); one side of the fourth fixing block (503) has a sixth positioning surface (506); the fourth positioning surface (504) abuts against and is positioned on the basin edge plate A´ (17) of the blade (1); the fifth positioning surface (505) abuts against and is positioned on the tenon side B´ (18) of the blade (1) facing away from the trailing edge; and the sixth positioning surface (506) abuts against and is positioned on the crown side C´ (19) of the blade (1) facing away from the trailing edge.

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