Hardfacing Process for Wear-Resistant Block of Low-Pressure Turbine Blade

Abstract

The present invention relates to a surfacing process for wear-resistant blocks of low-pressure turbine blades, belonging to the technical field of wear-resistant surfacing. It includes cleaning the crown basin-facing meshing surface S and the crown back-facing tooth-shaped meshing surface M of the blade, installing the blade on the first fixture, placing the first wear-resistant block on the crown basin-facing meshing surface S, and then surfacing the first wear-resistant block and the crown basin-facing meshing surface S. After turning the blade over, reinstall it on the second fixture, place the second wear-resistant block on the crown back-facing tooth-shaped meshing surface M, and then surfacing the second wear-resistant block and the crown back-facing tooth-shaped meshing surface M. The beneficial effects are as follows: Install the blade on the first fixture, position and surfacing the first wear-resistant block and the crown basin-facing meshing surface S; then turn the blade over and install it on the second fixture, position and surfacing the second wear-resistant block and the crown back-facing tooth-shaped meshing surface M, which can ensure the consistency of the welding of the blade wear-resistant blocks and improve the quality of the blade products.

Description

Technical Field

[0001] The present invention relates to the technical field of wear-resistant surfacing welding, and particularly to a surfacing welding process for wear-resistant blocks of low-pressure turbine blades. Background Technique

[0002] At present, the key technologies in the manufacturing of turbine blades are mainly reflected in high-efficiency air-cooled design and manufacturing technologies, material technologies, and surface coating protection technologies. With the increasingly stringent requirements of engines for turbine blades, the design accuracy requirements for turbine blades are also getting higher and higher. In the face of the surfacing welding process for wear-resistant blocks of low-pressure turbine blades, currently, argon arc welding is used to surfacing weld the wear-resistant layer through welding wires. This will result in poor consistency in the surfacing welding quality of the wear-resistant blocks, and the welding surface is also prone to collapse, reducing the product quality.

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

[0004] The technical problem solved by the present invention is how to improve the product quality of the blades.

[0005] The technical solution for the present invention to solve the above technical problems is as follows: A surfacing welding process for wear-resistant blocks of low-pressure turbine blades includes the following steps:

[0006] Step 1: Install the blade on the first fixture so that the back flange A of the blade, the side surface B of the blade's basin forward edge tenon, and the side surface C of the blade's basin forward edge shroud are all in contact with and positioned by the first fixture;

[0007] Step 2: Place the first wear-resistant block on the crown basin engagement surface S, and then surfacing weld the first wear-resistant block and the crown basin engagement surface S;

[0008] Step 3: Remove the blade and cool the blade to complete the surfacing welding of the wear-resistant block on the crown basin engagement surface S;

[0009] Step 4: After turning the blade over, reinstall it on the second fixture so that the basin flange A' of the blade, the side surface B' of the blade's back rear edge tenon, and the side surface C' of the blade's back rear edge shroud are all in contact with and positioned by the second fixture;

[0010] Step 5: Place the second wear-resistant block on the crown back tooth-shaped engagement surface M, and then surfacing weld the second wear-resistant block and the crown back tooth-shaped engagement surface M;

[0011] Step 6: Remove the blade and cool the blade to complete the surfacing welding of the wear-resistant block on the crown back tooth-shaped engagement surface M.

[0012] The beneficial effects of the present invention are as follows: The blade is mounted on the first fixture, such that the back flange A of the blade, the side surface B of the blade's front edge tenon on the concave side, and the side surface C of the blade's front edge crown on the concave side are all in contact with and positioned by the first fixture. Then, the first wear-resistant block is positioned and surfacing welded to the crown concave meshing surface S to complete the surfacing welding of the wear-resistant block on the crown concave meshing surface S. Subsequently, after the blade is flipped and mounted on the second fixture, such that the concave flange A' of the blade, the side surface B' of the blade's rear edge tenon on the convex side, and the side surface C' of the blade's rear edge crown on the convex side are all in contact with and positioned by the second fixture, and then the second wear-resistant block is positioned and surfacing welded to the crown convex tooth-shaped meshing surface M to complete the surfacing welding of the wear-resistant block on the crown convex tooth-shaped meshing surface M, which can ensure the consistency of the blade wear-resistant block welding and improve the quality of the blade product.

[0013] Based on the above technical solution, the present invention can be further improved as follows.

[0014] Further, it further includes step seven: subjecting the blade to stress heat treatment.

[0015] The beneficial effect of adopting the above further solution is: Subjecting the blade after surfacing welding to stress heat treatment can remove the thermal stress and phase transformation stress of the blade, avoid the generation of cracks in the blade due to stress in the later stage, and ensure the product quality.

[0016] Further, in the above step seven, the stress heat treatment includes: putting the blade into a tempering furnace, pre-evacuating to less than or equal to 0.133 Pa, heating up to 760 ± 20 °C at a rate of 10 ± 2 °C / min, and holding for 60 - 70 min, then heating up to 900 ± 20 °C at a rate of 5 ± 2 °C / min, and holding for 3 - 4 h. After the holding is completed, then filling the tempering furnace with argon and performing gas quenching cooling with a gas quenching pressure of 0.5 - 1 bar and then taking out of the furnace.

[0017] Further, it further includes step eight: performing 100% fluorescence treatment on the first wear-resistant block and the second wear-resistant block.

[0018] The beneficial effect of adopting the above further solution is: Performing fluorescence treatment on the first wear-resistant block and the second wear-resistant block can check for defects such as holes, cracks, and inclusions in the surfacing welding.

[0019] Further, in the above step two, an argon arc welding machine is used to perform surfacing welding on the first wear-resistant block and the crown concave meshing surface S. The nozzle diameter of the argon arc welding machine is 8 mm - 12 mm, and the tungsten electrode diameter of the argon arc welding machine is 1.3 mm - 1.8 mm.

[0020] The beneficial effect of adopting the above further solution is: The first wear-resistant block can be surfacing welded to the crown concave meshing surface S of the blade by an argon arc welding machine, improving the surfacing welding efficiency.

[0021] Further, in the second step, surfacing the first wear-resistant block and the crown-facing engagement surface S specifically includes: performing surfacing on the first wear-resistant block and the crown-facing engagement surface S by pulsed tungsten inert gas welding; the parameters of the pulsed tungsten inert gas welding are as follows: the pulsed current is 60A - 90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulsed 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.

[0022] The beneficial effect of adopting the above further scheme is that the tungsten electrodes of the welding torch of the pulsed tungsten inert gas welding are respectively close to the first wear-resistant block and perpendicular to the first wear-resistant block. Under the protection of argon gas, an arc is generated between the tungsten electrode and the first wear-resistant block by using the pulsed current, and surfacing is performed on the first wear-resistant block below the tungsten electrode, which can ensure the quality of the welded product and improve the welding efficiency.

[0023] Further, in the fifth step, surfacing the second wear-resistant block and the crown-backward tooth-shaped engagement surface M by an argon arc welder, the nozzle diameter of the argon arc welder is 8mm - 12mm, and the tungsten electrode diameter of the argon arc welder is 1.3mm - 1.8mm.

[0024] The beneficial effect of adopting the above further scheme is that the second wear-resistant block can be surfaced with the crown-backward tooth-shaped engagement surface M of the blade by the argon arc welder, improving the surfacing efficiency.

[0025] Further, in the fifth step, surfacing the second wear-resistant block and the crown-backward tooth-shaped engagement surface M specifically includes: performing surfacing on the second wear-resistant block and the crown-facing engagement surface S by pulsed tungsten inert gas welding; the parameters of the pulsed tungsten inert gas welding are as follows: the pulsed current is 60A - 90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulsed 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.

[0026] The beneficial effect of adopting the above further scheme is that the tungsten electrodes of the welding torch of the pulsed tungsten inert gas welding are respectively close to the second wear-resistant block and perpendicular to the second wear-resistant block. Under the protection of argon gas, an arc is generated between the tungsten electrode and the second wear-resistant block by using the pulsed current, and surfacing is performed on the second wear-resistant block below the tungsten electrode, which can ensure the quality of the welded product and improve the welding efficiency.

[0027] Further, in the first step, the first fixture includes a first base, a first fixing block, and a second fixing block. The first fixing block and the second fixing block are respectively fixed at two ends of the first base. One side of the first fixing block has a first positioning surface, and the other side of the first fixing block has a second positioning surface. One side of the second fixing block has a third positioning surface. The first positioning surface abuts against and positions the back flange A of the blade, the second positioning surface abuts against and positions the side surface B of the blade's front edge tenon on the concave side, and the third positioning surface abuts against and positions the side surface C of the blade's front edge crown on the concave side.

[0028] The beneficial effect of adopting the above further solution is that when the blade is placed in the first fixture, the back flange A of the blade abuts against and is pressed by the first positioning surface, the side surface B of the blade's front edge tenon on the concave side abuts against and is pressed by the second positioning surface, and the side surface C of the blade's front edge crown on the concave side abuts against and is pressed by the third positioning surface, thereby increasing the stability of blade positioning.

[0029] Further, the second fixture includes a second base, a third fixing block, and a fourth fixing block. The third fixing block and the fourth fixing block are respectively fixed at two ends of the second base. One side of the third fixing block has a fourth positioning surface, and the other side of the third fixing block has a fifth positioning surface. One side of the fourth fixing block has a sixth positioning surface. The fourth positioning surface abuts against and positions the concave flange A' of the blade, the fifth positioning surface abuts against and positions the side surface B' of the blade's rear edge tenon on the convex side, and the sixth positioning surface abuts against and positions the side surface C' of the blade's rear edge crown on the convex side.

[0030] The beneficial effect of adopting the above further solution is that when the blade is placed in the second fixture, the concave flange A' of the blade abuts against and is pressed by the fourth positioning surface, the side surface B' of the blade's rear edge tenon on the convex side abuts against and is pressed by the fifth positioning surface, and the side surface C' of the blade's rear edge crown on the convex side abuts against and is pressed by the sixth positioning surface, thereby increasing the stability of blade positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural view of the concave side of the blade of the present invention;

[0032] Figure 2 It is a side view of the concave side of the blade of the present invention;

[0033] Figure 3 It is a schematic structural view of the convex side of the blade of the present invention;

[0034] Figure 4 It is a side view of the convex side of the blade of the present invention;

[0035] Figure 5 It is a schematic structural view of the first fixture of the present invention;

[0036] Figure 6 Schematic diagram of the partial structure of the first fixture of the present invention;

[0037] Figure 7 Side view after the first fixing block and the partial blade of the present invention are assembled;

[0038] Figure 8 Schematic diagram of the structure of the second fixture of the present invention;

[0039] Figure 9 Schematic diagram of the partial structure of the second fixture of the present invention;

[0040] Figure 10 Side view after the third fixing block and the partial blade of the present invention are assembled.

[0041] In the drawings, the list of components represented by each reference numeral is as follows:

[0042] 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, sixth positioning surface; 507, second baffle; 6, tenon; 7, tenon extension section; 8, leading edge; 9, trailing edge; 10, blade bowl side; 11, blade back side; 12, blade crown; 13, back side flange A; 14, bowl side leading edge tenon side surface B; 15, bowl side leading edge blade crown side surface C; 16, blade crown bowl side meshing surface S; 17, bowl side flange A'; 18, back side trailing edge tenon side surface B'; 19, back side trailing edge blade crown side surface C'; 20, blade crown back side tooth-shaped meshing surface M. Detailed implementation manners

[0043] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not used to limit the scope of the present invention.

[0044] As shown in Figures 1 - 3 the figure, it is a schematic diagram of the blade part, which includes a tenon 6, a tenon extension section 7, a leading edge 8, a trailing edge 9, a blade bowl side 10, a blade back side 11, and a blade crown 12.

[0045] As shown in Figures 1 - 10 the figure, this embodiment provides a surfacing process for wear-resistant blocks of a low-pressure turbine blade, including the following steps:

[0046] Step 1: Install the blade 1 on the first fixture 2 so that the back flange A of the blade 1, the side surface B of the blade 1's front edge tenon on the basin side, and the side surface C of the blade 1's front edge crown on the basin side are all in contact with and positioned on the first fixture 2;

[0047] Step 2: Place the first wear-resistant block 3 on the crown meshing surface S on the basin side, and then build-up weld the first wear-resistant block 3 and the crown meshing surface S on the basin side;

[0048] Step 3: Remove the blade 1 and cool the blade 1 to complete the build-up welding of the wear-resistant block on the crown meshing surface S on the basin side;

[0049] Step 4: After flipping the blade 1, reinstall it on the second fixture 5 so that the flange A' on the basin side of the blade 1, the side surface B' of the blade 1's rear edge tenon on the back side, and the side surface C' of the blade 1's rear edge crown on the back side are all in contact with and positioned on the second fixture 5;

[0050] Step 5: Place the second wear-resistant block 4 on the crown back-tooth-shaped meshing surface M, and then build-up weld the second wear-resistant block 4 and the crown back-tooth-shaped meshing surface M;

[0051] Step 6: Remove the blade 1 and cool the blade 1 to complete the build-up welding of the wear-resistant block on the crown back-tooth-shaped meshing surface M.

[0052] Install the blade 1 on the first fixture 2 so that the back flange A of the blade 1, the side surface B of the blade 1's front edge tenon on the basin side, and the side surface C of the blade 1's front edge crown on the basin side are all in contact with and positioned on the first fixture 2. Then, position and build-up weld the first wear-resistant block 3 and the crown meshing surface S on the basin side to complete the build-up welding of the wear-resistant block on the crown meshing surface S on the basin side. Subsequently, after flipping the blade 1, install it on the second fixture 5 so that the flange A' on the basin side of the blade 1, the side surface B' of the blade 1's rear edge tenon on the back side, and the side surface C' of the blade 1's rear edge crown on the back side are all in contact with and positioned on the second fixture 5. Then, position and build-up weld the second wear-resistant block 4 and the crown back-tooth-shaped meshing surface M to complete the build-up welding of the wear-resistant block on the crown back-tooth-shaped meshing surface M, which can ensure the consistency of the welding of the wear-resistant blocks of the blade 1 and improve the quality of the blade products.

[0053] Specifically, before Step 1, it also includes cleaning the crown meshing surface S on the basin side and the crown back-tooth-shaped meshing surface M of the blade 1 to ensure that the surfaces of the crown meshing surface S on the basin side and the crown back-tooth-shaped meshing surface M are clean and there are no missed cleaning parts, which can avoid rust spots and mechanical damages on the crown meshing surface S on the basin side and the crown back-tooth-shaped meshing surface M;

[0054] Subsequently, first remove the oxide film on the crown meshing surface S on the basin side and the crown back-tooth-shaped meshing surface M, and then clean the crown meshing surface S on the basin side and the crown back-tooth-shaped meshing surface M with gasoline, alcohol or acetone;

[0055] Finally, after the cleaning of the crown facing meshing surface S and the crown back tooth profile meshing surface M is completed, visually inspect the crown facing meshing surface S and the crown back tooth profile meshing surface M to ensure that their surfaces are clean and there are no uncleaned areas, guarantee the welding quality, and avoid defects such as inclusions or pores during the welding process.

[0056] Among them, the oxide film on the crown facing meshing surface S and the crown back tooth profile meshing surface M can be removed by creep-feed grinding.

[0057] Specifically, the blade 1 can be quickly inserted into quartz sand for cooling, and the mesh number of the quartz sand is 100. After the surfacing of the wear-resistant block on the blade facing meshing surface or the surfacing of the wear-resistant block on the blade back meshing surface is completed, the blade 1 needs to be placed in the quartz sand to cool the blade 1 slowly, avoid generating microcracks, and improve the product quality.

[0058] Specifically, the crown facing meshing surface S and the crown back tooth profile meshing surface M have the same dimensions.

[0059] Among them, when surfacing the wear-resistant block on the blade facing meshing surface, the blade 1 is placed on the first fixture 2, and the blade facing is made to be away from the first fixture 2; when surfacing the wear-resistant block on the blade back meshing surface, the blade 1 is placed on the second fixture 5, and the blade back is made to be away from the second fixture 5.

[0060] On the basis of the above scheme, it further includes step seven: performing stress heat treatment on the blade 1.

[0061] Performing stress heat treatment on the blade 1 after surfacing can remove the thermal stress and phase transformation stress of the blade 1, avoid cracks in the blade 1 due to stress in the later stage, and guarantee the product quality.

[0062] On the basis of the above scheme, in step seven, the stress heat treatment includes: putting the blade 1 into a tempering furnace, pre-evacuating to less than or equal to 0.133 Pa, heating up to 760 ± 20 °C at a rate of 10 ± 2 °C / min, and holding for 60 - 70 min, then heating up to 900 ± 20 °C at a rate of 5 ± 2 °C / min, and holding for 3 - 4 h. After the holding is completed, then fill the tempering furnace with argon and perform gas quenching cooling with a gas quenching pressure of 0.5 - 1 bar and then take out of the furnace.

[0063] On the basis of the above scheme, it further includes step eight: performing 100% fluorescent treatment on the first wear-resistant block 3 and the second wear-resistant block 4.

[0064] Performing fluorescent treatment on the first wear-resistant block 3 and the second wear-resistant block 4 can check for defects such as holes, cracks, and inclusions in the surfacing welding.

[0065] Specifically, 100% fluorescence treatment means that when performing fluorescence detection, all samples or target areas emit fluorescence, which means that all detection objects have successfully absorbed the excitation light and generated fluorescence signals. This treatment method is usually used to ensure the integrity and accuracy of detection.

[0066] Among them, both the first wear-resistant block 3 and the second wear-resistant block 4 are rectangular.

[0067] The sizes of the first wear-resistant block 3 and the second wear-resistant block 4 respectively correspond one-to-one to the crown basin meshing surface S and the crown back tooth-shaped meshing surface M of the blade, which can improve the consistency of the surfacing of the blade wear-resistant blocks and ensure the uniform thickness of the surfacing of the first wear-resistant block 3 and the second wear-resistant block 4, thereby improving the product quality.

[0068] Specifically, the thickness of the first wear-resistant block 3 and the second wear-resistant block 4 can be 1.2 - 1.8 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.

[0069] 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.

[0070] The first wear-resistant block 3 and the second wear-resistant block 4 with the same size can ensure the consistency of the surfacing of the blade wear-resistant blocks.

[0071] On the basis of the above solution, in the second step, a tungsten argon arc welding machine is used to perform surfacing on the first wear-resistant block 3 and the crown basin meshing surface S of the blade. The nozzle diameter of the tungsten argon arc welding machine is 8 mm - 12 mm, and the tungsten electrode diameter of the tungsten argon arc welding machine is 1.3 mm - 1.8 mm.

[0072] The first wear-resistant block 3 can be surfaced with the crown basin meshing surface S of the blade 1 by using a tungsten argon arc welding machine, improving the surfacing efficiency.

[0073] Specifically, during the surfacing process, the purity of the argon gas for tungsten argon arc welding is greater than or equal to 99.99%. Ensuring the purity of the argon gas can avoid low surfacing welding quality.

[0074] On the basis of the above solution, in the second step, the surfacing of the first wear-resistant block 3 and the crown basin meshing surface S is specifically: pulsed tungsten inert gas welding is used to perform surfacing on the first wear-resistant block 3 and the crown basin meshing surface S; the parameters of the pulsed tungsten inert gas welding are as follows: the pulsed current is 60 A - 90 A, the number of pulses is 2, the interval time is 0.4 s, the distance between the tungsten electrode of the pulsed tungsten inert gas welding and the first wear-resistant block 3 is 2 - 4 mm, the argon gas flow rate is 7 - 10 L / min, and the welding time is 3 - 5 s.

[0075] The tungsten electrode of the welding torch for pulsed tungsten inert gas welding approaches the first wear-resistant block 3 respectively and is perpendicular to the first wear-resistant block 3. Under the protection of argon gas, an arc is struck between the tungsten electrode and the first wear-resistant block 3 by using pulsed current, and surfacing is carried out on the first wear-resistant block 3 below the tungsten electrode, which can ensure the quality of the welded product and improve the welding efficiency.

[0076] On the basis of the above scheme, in the fifth step, an argon arc welding machine is used to carry out surfacing on the second wear-resistant block 4 and the back-tooth engagement 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.

[0077] The second wear-resistant block 4 can be surfacing welded to the back-tooth engagement surface M of the blade 1 through the argon arc welding machine, improving the surfacing efficiency.

[0078] On the basis of the above scheme, in the fifth step, surfacing the second wear-resistant block 4 and the back-tooth engagement surface M of the blade crown specifically includes: using pulsed tungsten inert gas welding to carry out surfacing on the second wear-resistant block 4 and the forward-tooth engagement surface S of the blade crown; the parameters of the pulsed tungsten inert gas welding are as follows: the pulsed current is 60 A to 90 A, the number of pulses is 2, the interval time is 0.4 s, the distance between the tungsten electrode of the pulsed tungsten inert gas welding and the second wear-resistant block 4 is 2 to 4 mm, the argon gas flow rate is 7 to 10 L / min, and the welding time is 3 to 5 s.

[0079] The tungsten electrode of the welding torch for pulsed tungsten inert gas welding approaches the second wear-resistant block 4 respectively and is perpendicular to the second wear-resistant block 4. Under the protection of argon gas, an arc is struck between the tungsten electrode and the second wear-resistant block 4 by using pulsed current, and surfacing is carried out on the second wear-resistant block 4 below the tungsten electrode, which can ensure the quality of the welded product and improve the welding efficiency.

[0080] On the basis of the above scheme, in the first step, the first fixture 2 includes 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 respectively fixed at both ends of the first base 201. 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 flange A of the blade 1, the second positioning surface 205 abuts against and positions the side surface B of the forward-edge tenon of the blade 1, and the third positioning surface 206 abuts against and positions the side surface C of the forward-edge blade crown of the blade 1.

[0081] Place the blade 1 in the first fixture 2 such that the trailing edge plate A of the blade 1 abuts and is pressed against the first positioning surface 204, the side surface B of the blade 1's dovetail forward edge tenon abuts and is pressed against the second positioning surface 205, and the side surface C of the blade 1's crown forward edge abuts and is pressed against the third positioning surface 206, thereby increasing the positioning stability of the blade 1.

[0082] Specifically, it further includes a first baffle 207 which is fixed to the second fixing block 203 and can be used to position the blade 1, thereby increasing the positioning stability of the blade 1.

[0083] Based on the above solution, in step four, the second fixture 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 respectively fixed at both ends of the second base 501. 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 and positions the dovetail forward edge plate A' of the blade 1, the fifth positioning surface 505 abuts and positions the side surface B' of the blade 1's trailing edge tenon, and the sixth positioning surface 506 abuts and positions the side surface C' of the blade 1's trailing edge crown.

[0084] Place the blade 1 in the second fixture 5 such that the dovetail forward edge plate A' of the blade 1 abuts and is pressed against the fourth positioning surface 504, the side surface B' of the blade 1's trailing edge tenon abuts and is pressed against the fifth positioning surface 505, and the side surface C' of the blade 1's trailing edge crown abuts and is pressed against the sixth positioning surface 506, thereby increasing the positioning stability of the blade 1.

[0085] Specifically, it further includes a second baffle 507 which is fixed to the fourth fixing block 503 and can be used to position the blade 1, thereby increasing the positioning stability of the blade 1.

[0086] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0087] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0088] In the present invention, unless otherwise clearly specified and defined, terms such as "mounted", "connected", "coupled", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0089] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be 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, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0090] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection 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 can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0091] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to 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, It includes the following steps: Step 1: Install the blade (1) on the first fixture (2) such that the trailing edge plate A (13) of the blade (1), the dovetail side B (14) of the leading edge of the blade (1) facing the dovetail, and the crown side C (15) of the leading edge of the blade (1) facing the crown are all in contact with and positioned against the first fixture (2); Step 2: Place the first wear-resistant block (3) on the crown dovetail meshing surface S (16), and then perform surfacing welding on the first wear-resistant block (3) and the crown dovetail meshing surface S (16); Step 3: Remove the blade (1) and cool the blade (1) to complete the surfacing welding of the wear-resistant block on the crown dovetail meshing surface S (16); Step 4: After flipping the blade (1), reinstall it on the second fixture (5) such that the dovetail edge plate A´ (17) of the blade (1), the dovetail side B´ (18) of the trailing edge of the blade (1) facing away from the dovetail, and the crown side C´ (19) of the trailing edge of the blade (1) facing away from the crown are all in contact with and positioned against the second fixture (5); Step 5: Place the second wear-resistant block (4) on the crown trailing tooth-shaped meshing surface M (20), and then perform surfacing welding on the second wear-resistant block (4) and the crown trailing tooth-shaped meshing surface M (20), wherein the sizes of the first wear-resistant block (3) and the second wear-resistant block (4) respectively correspond one-to-one to the crown dovetail meshing surface S (16) and the crown trailing tooth-shaped meshing surface M (20); Step 6: Remove the blade (1) and cool the blade (1) to complete the surfacing welding of the wear-resistant block on the crown trailing tooth-shaped meshing surface M (20); In the said Step 1, the first fixture (2) includes 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 respectively fixed at both ends of the first base (201). One side of the first fixing block (202) has a first positioning surface (204), and 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) is in contact with and positioned against the trailing edge plate A (13) of the blade (1), the second positioning surface (205) is in contact with and positioned against the dovetail side B (14) of the leading edge of the blade (1) facing the dovetail, and the third positioning surface (206) is in contact with and positioned against the crown side C (15) of the leading edge of the blade (1) facing the crown; In the fourth step, the second fixture (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 respectively fixed at two ends of the second base (501). One side of the third fixing block (502) has a fourth positioning surface (504), and 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 positions the shroud side A´ (17) of the blade (1). The fifth positioning surface (505) abuts against and positions the back trailing edge dovetail side B´ (18) of the blade (1). The sixth positioning surface (506) abuts against and positions the back trailing edge shroud side C´ (19) of the blade (1).

2. The surfacing process of a wear-resistant block for a low-pressure turbine blade according to claim 1, characterized in that, It further includes step seven: performing stress heat treatment on the blade (1).

3. The surfacing process of a wear-resistant block for a low-pressure turbine blade according to claim 2, characterized in that, In the seventh step, the stress heat treatment includes: putting the blade (1) into a tempering furnace, pre-pumping the vacuum to be less than or equal to 0.133 Pa, heating it at a rate of 10 ± 2 °C / min to 760 ± 20 °C, and holding for 60 - 70 min, then heating it at a rate of 5 ± 2 °C / min to 900 ± 20 °C, and holding for 3 - 4 h. After the holding is completed, then filling argon into the tempering furnace and performing gas quenching cooling at a gas quenching pressure of 0.5 - 1 bar and taking it out of the furnace.

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

5. The surfacing process of a wear-resistant block for a low-pressure turbine blade according to claim 1, characterized in that, In the second step, an argon arc welder is used to build up weld the first wear-resistant block (3) and the shroud side meshing surface S (16). The nozzle diameter of the argon arc welder is 8 mm - 12 mm, and the tungsten electrode diameter of the argon arc welder is 1.3 mm - 1.8 mm.

6. The surfacing process of a wear-resistant block for a low-pressure turbine blade according to claim 1, characterized in that, In the second step, building up weld the first wear-resistant block (3) and the shroud side meshing surface S (16) specifically includes: using pulsed tungsten inert gas welding to build up weld the first wear-resistant block (3) and the shroud side meshing surface S (16). The parameters of the pulsed tungsten inert gas welding are as follows: the pulsed current is 60 A - 90 A, the number of pulses is 2, the interval time is 0.4 s, the distance between the tungsten electrode of the pulsed tungsten inert gas welding and the first wear-resistant block (3) is 2 - 4 mm, the argon gas flow rate is 7 - 10 L / min, and the welding time is 3 - 5 s.

7. The surfacing process of a wear-resistant block for a low-pressure turbine blade according to claim 1, characterized in that, In the fifth step, an argon arc welder is used to build up weld the second wear-resistant block (4) and the back shroud tooth-shaped meshing surface M (20). The nozzle diameter of the argon arc welder is 8 mm - 12 mm, and the tungsten electrode diameter of the argon arc welder is 1.3 mm - 1.8 mm.

8. The surfacing process of a wear-resistant block for a low-pressure turbine blade according to claim 1, characterized in that, In the fifth step, surfacing the second wear-resistant block (4) with the tooth profile meshing surface M (20) on the back of the shroud, specifically: surfacing the second wear-resistant block (4) and the tooth profile meshing surface S (16) on the basin side of the shroud by pulsed tungsten inert gas welding; the parameters of the pulsed tungsten inert gas welding are as follows: the pulsed current is 60A - 90A, the number of pulses is 2, the interval time is 0.4S, the distance between the tungsten electrode of the pulsed 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.

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