Wear-resistant alloy material, preparation method thereof and offshore wind turbine yaw brake disc and yaw brake

Abstract

The application provides a wear-resistant alloy material, a preparation method thereof, and an offshore wind turbine yaw brake disc and yaw brake. The wear-resistant alloy material is composed of a NiCrTiSi alloy and a MoC alloy; wherein the NiCrTiSi alloy is composed of Ti: 10-30 wt.%, Cr: 20-26 wt.%, Si: 0.5-1 wt.%, and Ni: the balance; the MoC alloy contains 6-12 wt.% respectively, and the balance is the NiCrTiSi alloy. The application also provides an offshore wind turbine yaw brake disc and yaw brake made of the wear-resistant alloy material. The novel yaw brake disc provided by the application improves the corrosion resistance and wear resistance of the brake disc, greatly reduces the maintenance frequency and cost of the yaw brake disc, and thus improves the operation efficiency.

Description

Technical Field

[0001] This invention relates to a wear-resistant alloy material and its preparation method, as well as a yaw brake disc and yaw brake for offshore wind turbines, belonging to the field of materials surface engineering technology. Background Technology

[0002] Offshore winds are characterized by high average wind speeds and stable wind energy. To maximize wind energy utilization, offshore wind turbines require a yaw system to adjust the rotor direction, aligning it with the wind direction. During yaw, to ensure stable movement of the heavy nacelle and rotor, the yaw brake disc needs to maintain a certain level of damping. This damping, maintaining stability, causes wear on the brake pads of the caliper and the yaw brake disc. Because the brakes operate under high pressure for extended periods, this leads to rapid wear of the brake pads. If the brake pads are not replaced promptly after rapid wear, the hardened steel of the caliper and the brake disc will wear down, resulting in excessive wear on the yaw brake disc, causing pitting and furrowing on its surface. The brake disc is typically made of ductile iron with a surface hardness between 120-175 HBW, while the yaw brake caliper steel plate has a surface hardness exceeding 180 HBW. The uneven wear between these materials due to their different frictional characteristics can cause braking vibrations, significantly impacting the operation and maintenance of the wind turbine and potentially leading to safety accidents such as nacelle tilting. Excessive wear of the brake disc can cause the brake piston stroke to exceed the design value. The pressure-resistant seal at the piston end may separate from the piston, leading to hydraulic oil leakage and causing serious pollution and fire hazards inside the unit. For example, after a period of operation, the yaw brake disc of a certain offshore wind turbine experienced severe wear. Its original thickness was 30mm, but after wear, the thickness was reduced to 24-26mm, a reduction of 4-6mm. Wear of the yaw brake disc directly affects the normal operation of the yaw system, and further wear of the yaw brake pads and disc will cause the yaw system to fail, thus affecting the safe operation of the wind turbine.

[0003] Offshore wind turbines operate in a complex and highly corrosive marine environment. Yaw brake discs are constantly exposed to high humidity and high salt spray conditions, classified as a C5-M level atmospheric corrosion environment (the highest level) according to ISO 12944. Ductile iron, the base material for yaw brake discs, has poor resistance to salt spray corrosion and is subject to its corrosive effects during wear, accelerating the process. This interaction between wear and corrosion exacerbates the wear and corrosion of the yaw brake disc, leading to increased maintenance frequency and a significantly reduced service life. Furthermore, on-site repair of worn yaw brake discs presents challenges due to difficulties and high replacement costs. Currently, there are two on-site repair methods for worn yaw brake discs: a patch welding solution and a metal repair agent solution. These methods are suitable for situations where the thickness reduction of the worn brake disc surface is not yet severe. The brake disc is installed at the connection between the wind turbine nacelle and the tower flange. If the brake disc is severely damaged, the entire nacelle and blades must be lifted before replacing the brake disc, resulting in significant maintenance costs and workload. Generally, the cost of a crane is 200,000 to 300,000 yuan, and the cost of a yaw disc is 60,000 to 80,000 yuan. The replacement period takes more than a month. Since the maintenance cost and difficulty of offshore wind turbines are much higher than those of onshore wind turbines, frequent on-site maintenance of yaw brake discs is a major problem faced by offshore wind turbines in operation, and there is an urgent need to develop long-life, highly wear-resistant yaw brake disc materials. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention aims to provide a wear-resistant alloy material and its preparation method. By forming a wear-resistant layer on the surface of the yaw brake disc using the wear-resistant alloy material, the yaw brake disc can have good salt spray corrosion resistance and wear resistance.

[0005] To achieve the above objectives, the present invention provides a wear-resistant alloy material, which is composed of a NiCrTiSi alloy and a MoC alloy; wherein:

[0006] The composition of the NiCrTiSi alloy is as follows: Ti: 10-30 wt.%; Cr: 20-26 wt.%; Si: 0.5-1 wt.%; Ni: balance;

[0007] The content of the MoC alloy is 6-12 wt.%, and the balance is the NiCrTiSi alloy.

[0008] According to a specific embodiment of the present invention, preferably, the composition of the NiCrTiSi alloy is: Ti: 15-25 wt.%; Cr: 20-24 wt.%; Si: 0.5-1 wt.%; Ni: balance.

[0009] According to a specific embodiment of the present invention, preferably, the content of the MoC alloy is 8-10 wt.%.

[0010] The present invention also provides a method for preparing the above-mentioned wear-resistant alloy material, which includes the following steps:

[0011] The MoC alloy powder and the NiCrTiSi alloy powder are dried separately, and then the dried powders are mixed to obtain a mixed powder.

[0012] The mixed powder and adhesive are sprayed and granulated to obtain wear-resistant alloy material powder with a particle size of -150 to +325 mesh.

[0013] In the above-mentioned method for preparing wear-resistant alloy materials, preferably, both the NiCrTiSi alloy and the MoC alloy are powders; the particle size of the NiCrTiSi alloy powder is -140 to +400 mesh; and the particle size of the MoC alloy powder is -200 to +500 mesh.

[0014] In the above-mentioned method for preparing wear-resistant alloy materials, preferably, the purity of the NiCrTiSi alloy powder and the MoC alloy powder is ≥99.5% respectively.

[0015] In the above-mentioned method for preparing wear-resistant alloy materials, preferably, the spray granulation process includes the following steps:

[0016] 1) Add organic solvent and PVB-6 adhesive to a reaction vessel and stir. Heat to 50-80℃ and keep warm. After the PVB-6 adhesive is completely dissolved, lower the temperature inside the reaction vessel to room temperature to obtain a PVB-6 adhesive solution with a concentration of 4-8 wt.%. The organic solvent preferably includes an alcohol solvent, the alcohol solvent preferably includes ethanol, and the ethanol is preferably industrial alcohol.

[0017] 2) Mix the powder and PVB-6 adhesive in a mass ratio of 40-62:38-60 (preferably 1:1), and stir until the PVB-6 adhesive is fully dispersed in the powder to obtain a slurry;

[0018] 3) The slurry is sprayed and granulated in the atmosphere using a spray dryer, and then screened to obtain wear-resistant alloy material powder with a particle size of 150-325 mesh.

[0019] In the above-mentioned method for preparing wear-resistant alloy materials, preferably, the inlet temperature of the spray granulation is 150-200℃ and the outlet temperature is 90-100℃.

[0020] In the above-mentioned method for preparing wear-resistant alloy materials, preferably, the powder obtained by sieving with a particle size outside the range of 150-325 mesh is mixed with PVB-6 adhesive and then sprayed and granulated again.

[0021] In the above-mentioned method for preparing wear-resistant alloy materials, preferably, the NiCrTiSi alloy powder is prepared by vacuum medium-frequency melting gas atomization method, specifically including the following steps:

[0022] 1) Using 99.9% pure nickel blocks, 99.9% pure chromium blocks, 99.9% pure titanium blocks, and silicon as raw materials, place them in a medium-frequency induction furnace;

[0023] 2) Seal the furnace body, evacuate the furnace to 1-100 Pa, fill it with argon gas to 100-102 kPa, and heat it to completely melt the raw materials to obtain an alloy liquid;

[0024] 3) Under argon protection, the alloy liquid is poured into the atomization tower for atomization. The atomization temperature is 1450-1550℃ and the atomization pressure is 3.3-3.6MPa (preferably 3.5MPa). During the pouring process, high-pressure supersonic argon gas acts on the alloy liquid column to disperse, break up and cool the alloy liquid column to obtain NiCrTiSi alloy powder.

[0025] The present invention also provides a yaw brake disc for offshore wind turbines, the surface of which has a wear-resistant and corrosion-resistant cladding layer formed by the wear-resistant alloy material provided by the present invention.

[0026] According to a specific embodiment of the present invention, preferably, the wear-resistant and corrosion-resistant cladding layer is prepared by the following steps:

[0027] The underlayer is prepared using Ni-Cr-Mo based alloy powder: the underlayer is prepared by cladding in a circular motion of the workpiece and radial motion of the laser head along the X-axis of the workpiece's center. The composition of the Ni-Cr-Mo based alloy powder is: Cr: 18-25 wt.%; Mo: 8-12 wt.%; Ni: balance; preferably: Cr: 20-23 wt.%; Mo: 8-10 wt.%; Ni: balance.

[0028] The wear-resistant layer is prepared by using the wear-resistant alloy material: the wear-resistant layer is prepared by cladding the workpiece on the surface of the base layer in the form of circular motion of the workpiece and radial motion of the laser head along the X-axis of the workpiece ring center.

[0029] The wear-resistant layer is polished, and then the wear-resistant layer is prepared repeatedly until a wear-resistant and corrosion-resistant cladding layer of predetermined thickness is obtained.

[0030] According to a specific embodiment of the present invention, preferably, during the cladding process, the average thickness of the underlayer is 600-800 μm, and the average thickness of a single wear-resistant layer is 600-800 μm.

[0031] In the aforementioned yaw brake disc, preferably, the main parameters of the cladding include: laser power of 2-4kW, linear velocity of the workpiece in circular motion of 10-20cm / s, and laser head step distance of 0.4-0.8mm for each circular motion completed by the workpiece.

[0032] In the aforementioned yaw brake disc, preferably, the cladding parameters also include: cladding is performed using a synchronous powder feeding method, with argon powder feeding at a rate of 0.8-3 kg / h, and argon acting as a protective gas during the cladding process at a flow rate of 15-20 L / min.

[0033] According to a specific embodiment of the present invention, preferably, a wear-resistant and corrosion-resistant cladding layer is formed on the front and back sides of the yaw brake disc. That is, a wear-resistant and corrosion-resistant cladding layer is provided on the front and back sides of the area where the brake caliper and brake disc come into contact and wear occurs.

[0034] According to a specific embodiment of the present invention, preferably, the wear-resistant and corrosion-resistant cladding layer is located in the grooves on the front and back sides of the working area.

[0035] According to a specific embodiment of the present invention, preferably, the angle between the inclined surface at one end of the groove and the bottom surface of the groove is 135°-150°.

[0036] According to a specific embodiment of the present invention, preferably, the width w of the bottom of the groove is 110mm-130mm, and the depth h of the groove is 1.5-3.5mm.

[0037] According to a specific embodiment of the present invention, preferably, the excess height of the wear-resistant and corrosion-resistant cladding layer is less than 0.5 mm. This excess height refers to the height of the wear-resistant and corrosion-resistant cladding layer above the working area.

[0038] According to a specific embodiment of the present invention, preferably, the base material of the yaw brake disc is molybdenum-containing stainless steel, such as 316 stainless steel, 316L stainless steel, 317 stainless steel, etc. The present invention selects molybdenum-containing stainless steel as the base material for the wind turbine yaw brake disc. Molybdenum can improve the pitting corrosion resistance of stainless steel, especially in marine atmospheric environments with high chloride ion concentrations. Molybdenum can improve the stability of the passivation film, effectively preventing chloride ion corrosion and improving the salt spray corrosion resistance of the wind turbine yaw brake disc.

[0039] According to a specific embodiment of the present invention, preferably, the inner diameter ψ of the brake disc is 2200-2400mm, the outer diameter Φ is 2500-2700mm, and the thickness d of the brake disc is 30mm-40mm.

[0040] The present invention also provides a yaw brake for offshore wind turbines, wherein the yaw brake includes the yaw brake disc provided by the present invention.

[0041] According to a specific embodiment of the present invention, preferably, the single-sided clearance distance between the brake caliper of the yaw brake and the yaw brake disc is 1.5mm-3mm, such as... Figure 4 As shown.

[0042] The technical solution provided by this invention utilizes laser cladding technology to prepare a wear-resistant and corrosion-resistant cladding layer in the wear area of ​​a wind turbine yaw brake disc. The cladding areas are the upper and lower surfaces where the brake caliper contacts the brake disc. The wear-resistant and corrosion-resistant cladding layer consists of an underlayer and a wear-resistant layer. The underlayer is a corrosion-resistant Ni-Cr-Mo alloy cladding layer, which serves two purposes: first, it prevents Fe from the matrix from diffusing into the wear-resistant layer during cladding, thereby forming a brittle Ti-Fe intermetallic compound phase and reducing the wear and corrosion resistance of the cladding layer; second, it provides corrosion resistance and prevents the matrix from corroding when the wear-resistant layer has cracks or damage.

[0043] The wear-resistant layer is a Ni-Cr-Mo alloy cladding layer reinforced with TiC particles, synthesized in situ from NiCrTiSi alloy powder and MoC alloy powder. TiC has a melting point of around 3140℃; therefore, directly adding TiC powder during cladding will result in some TiC particles remaining unmelted. Furthermore, direct addition easily leads to localized agglomeration of TiC particles, causing cracks in the cladding layer and reducing wear resistance. Compared to directly adding TiC powder, this invention utilizes an in-situ synthesis method to achieve a superior wear-resistant layer. x The enhanced phase exhibits advantages such as small size, uniform distribution, thermodynamic stability, good compatibility with the matrix, clean interface, and high bonding strength. Furthermore, unlike most existing methods that use pure Ti powder and pure C powder for in-situ synthesis of TiC, the present invention employs a NiCrTiSi alloy and a MoC alloy for a C substitution reaction. This has two advantages: firstly, pure Ti powder and pure C powder are highly susceptible to oxidation during laser cladding, requiring extremely high-quality protective gas; the use of NiCrTiSi alloy and MoC alloy improves the oxidation resistance of the powder, preventing oxidation during cladding. Secondly, the C substitution reaction is exothermic, reducing the energy density required for laser input and thus improving cladding efficiency.

[0044] The NiCrTiSi alloy selected in this invention provides Ti element while possessing advantages such as high toughness and high modulus as a matrix. The nickel-based alloy exhibits good wettability and high bonding strength with TiC. Cr, as a solid solution element, plays a role in solid solution strengthening while improving corrosion resistance. A small amount of Si acts as a deoxidizer and slag-forming element, reducing spatter during cladding. As for the MoC alloy, since Mo is a weak carbide-forming element, MoC is easily decomposed during laser heating, forming free chemical elements Mo and C. The strong carbide-forming element Ti will combine with C to form fine, high-hardness, and highly wear-resistant titanium-carbon compounds TiC in situ. x(0 < x ≤ 1) particles, part of Mo and Cr form CrMo intermetallic compounds, which also play a role in enhancing the wear resistance of the cladding layer; the remaining Mo is dissolved in the matrix, playing a role in reducing the friction coefficient of the cladding layer and improving wear resistance. At the same time, the NiCrMo matrix formed by solid solution has excellent corrosion resistance. The chemical equation of this reaction is as follows:

[0045] Ti + MoC → TiC x + Mo

[0046] During the laser cladding process, the change in Gibbs free energy ΔG of this reaction is negative. Therefore, from a thermodynamic perspective, this reaction can proceed spontaneously.

[0047] TiC x has extremely high hardness and excellent thermal stability, and has good compatibility with nickel. In the cladding layer, TiC x reinforcement phase has the effects of refining grains, improving microhardness and wear resistance. The TiC generated in-situ from the micron-sized powder used in this method x particle size can reach the nanometer level. The finer TiC x particles represent better wear resistance. Compared with directly adding TiC powder, the in-situ synthesis method has the advantages of uniform distribution of TiC x reinforcement phase, thermodynamic stability, good compatibility with the matrix, less pollution, high bonding strength, etc.

[0048] The yaw brake disc provided by the present invention improves the corrosion and wear resistance life of the brake disc, greatly reduces the maintenance and repair times and costs of the yaw brake disc, thereby improving the operation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic structural diagram of a wind power yaw brake disc. Among them, 1 is the working surface, 2 is the transition connection surface, 3 is the flange surface, 21 is the chip removal hole, 31 is the flange hole, Φ is the outer diameter of the yaw brake disc, and ψ is the inner diameter of the yaw brake disc;

[0050] Figure 2 is a schematic cross-sectional view of the area to be laser clad. Among them, 10 is the front of the working surface 1, 11 is the back of the working surface 1, d is the thickness of the yaw brake disc, h is the groove depth, w is the width of the bottom of the groove, and α is the angle between the inclined surface and the bottom surface of the groove;

[0051] Figure 3 is a schematic cross-sectional view of the laser clad layer on the yaw brake disc. Among them, 12 is the front laser clad wear-resistant layer, 13 is the yaw brake disc, and 14 is the back laser clad wear-resistant layer;

[0052] Figure 4This is a schematic diagram of the cross-section of the yaw brake caliper and the yaw brake disc, where 15 is the yaw brake caliper, 16 is the upper brake pad, 17 is the lower brake pad, and 18 is the gap between the laser-clad wear-resistant layer and the brake caliper.

[0053] Figure 5 The image shows the microhardness curve of the cross-section of the cladding layer.

[0054] Figure 6 The images are scanning electron microscope (SEM) images of the cross-section of the cladding layer, where 23 is the TiC reinforcing phase, 24 is the CrMo intermetallic compound, and 25 is the NiTi phase.

[0055] Figure 7 This is an X-ray diffraction pattern of the cladding layer surface. Detailed Implementation

[0056] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0057] The representative structure of the yaw brake disc for offshore wind turbines provided by this invention is as follows: Figure 1 As shown, but not limited to.

[0058] The yaw brake disc of the offshore wind turbine includes a working surface 1, a transition connection surface 2, and a flange surface 3. The working surface 1 is the laser cladding area, the transition connection surface 2 is provided with chip removal holes 21, and the flange surface 3 is provided with flange holes 31.

[0059] The inner diameter ψ of the brake disc is 2200-2400mm, the outer diameter Φ is 2500-2700mm, and the thickness d of the brake disc is 30mm (1.5MW wind turbine) or 40mm (2MW wind turbine). Depending on the area where the brake caliper and brake disc wear, there are areas to be laser cladding on the front and back sides of the inner side of the brake disc.

[0060] The structure of the laser cladding area is as follows Figure 2 As shown: A groove is provided on the edge of the working surface 1, and one end of the groove is a slope (the side closer to the transition connection surface 2). The angle α between the slope and the bottom surface of the groove is 135°-150°. Laser cladding areas are provided on the front side 10 and the back side 11 of the working surface 1, respectively.

[0061] According to a specific embodiment of the present invention, the preparation method of the wear-resistant alloy material includes the following specific steps:

[0062] 1. Powders prepared by vacuum medium-frequency melting gas atomization have high sphericity and low oxygen content. The existing vacuum medium-frequency melting gas atomization method is used to prepare NiCrTiSi alloy powder. The preparation of NiCrTiSi alloy powder by vacuum medium-frequency melting gas atomization includes the following steps:

[0063] 1) The raw materials are nickel blocks with a purity of 99.9%, chromium blocks with a purity of 99.9%, titanium blocks with a purity of 99.9%, and silicon. After degreasing, cleaning, and drying, they are added to the medium frequency induction furnace according to the formula.

[0064] 2) Seal the furnace body, evacuate the furnace to 1-100Pa, fill it with argon gas to 100-102KPa, and heat it to completely melt the raw materials in the induction furnace;

[0065] 3) Under argon protection, the molten alloy is poured into the atomization tower at an atomization temperature of 1450℃-1550℃ and an atomization pressure of 3.5MPa. During the pouring process, high-pressure supersonic argon gas acts on the molten alloy column, dispersing, breaking up, and cooling the molten alloy column into near-spherical alloy powder.

[0066] 4) The NiCrTiSi alloy powder prepared was screened by sieving method. The optimal particle size range for laser cladding was -150 to +325 mesh.

[0067] 2. Preparation of mixed powder:

[0068] 1) Weigh the powder materials according to the following ratio: MoC powder (particle size -200+500 mesh, purity ≥99.5%; where "-200+500 mesh" means the powder particle size is in the range of 500 mesh to 200 mesh): 6-12 wt.%; NiCrTiSi alloy powder (particle size -140+400 mesh, purity ≥99.5%): balance.

[0069] 2) Place the above powder material in a drying oven and dry it at 100-120℃ for 3-5 hours. Then, use a mixing device to mix the dried powder for 3-5 hours to obtain a mixed powder.

[0070] 3. The mixed powder and adhesive are then spray-granulated to obtain wear-resistant alloy powder with a particle size of -150 to +325 mesh; wherein, the spray granulation preparation of wear-resistant alloy powder includes the following steps:

[0071] 1) Add industrial alcohol (97% purity) and PVB-6 glue to the reaction vessel and stir manually for 5-10 minutes. Heat the reaction vessel to 50-80℃ and keep it at that temperature for 30-40 minutes. After the PVB-6 glue has completely dissolved, lower the temperature inside the reaction vessel to room temperature to obtain a PVB-6 glue solution with a concentration of 4-8 wt.%.

[0072] 2) Mix the powder and PVB-6 adhesive in a mass ratio of 1:1 using a horizontal single-shaft paddle mixer until the PVB-6 adhesive is fully dispersed in the powder to obtain a slurry;

[0073] 3) The slurry is sprayed and granulated in the atmosphere using a spray dryer, and then sieved through a double-layer vibrating screen to obtain wear-resistant alloy powder with a particle size of 150-325 mesh. The powder with a particle size outside the 150-325 mesh range obtained by double-layer vibrating sieving is mixed with PVB-6 adhesive and then sprayed and granulated. The inlet temperature of the spray granulation is 150-200℃ and the outlet temperature is 90-100℃.

[0074] According to a specific embodiment of the present invention, the process of preparing a wear-resistant and corrosion-resistant cladding layer on a wind turbine yaw brake disc includes the following specific steps:

[0075] 1. Pre-treat the area of ​​the wind turbine yaw brake disc to be laser cladding. Use an electric grinding wheel to remove the oxide layer on the stainless steel surface and use compressed air to remove the residue after surface processing. Clean it with alcohol and blow it dry. Fix the surface-treated yaw brake disc on the worktable for cladding the ring workpiece.

[0076] 2. Ni-Cr-Mo based alloy powder is loaded into a pneumatic powder feeding device. For the annular workpiece of the yaw brake disc, the workpiece makes circular motion and the laser head moves radially along the X-axis of the brake disc ring to prepare the bottom layer of cladding. The main parameters of cladding are: laser power of 2-4kW, linear velocity of the workpiece making circular motion of 10-20cm / s, laser head step distance of 0.4-0.8mm for each circular motion of the workpiece, synchronous powder feeding is used for cladding, argon gas is used for powder feeding, the powder feeding amount is 0.8-3kg / h, argon gas is used as protective gas during the cladding process, the flow rate is 15-20L / min, and the average thickness of a single cladding layer is 600-800μm.

[0077] 3. The wear-resistant alloy powder is loaded into a pneumatic powder feeding device. For the annular workpiece of the yaw brake disc, the wear-resistant layer is prepared by cladding the bottom layer surface in the form of the workpiece making a circular motion and the laser head making a radial motion along the X-axis of the brake disc ring center. The main parameters of cladding are: laser power of 2-4kW, linear velocity of the workpiece making a circular motion of 10-20cm / s, laser head step distance of 0.4-0.8mm for each circular motion of the workpiece, synchronous powder feeding is adopted for cladding, argon gas is used for powder feeding, the powder feeding amount is 0.8-3kg / h, argon gas is used as protective gas during the cladding process, the flow rate is 15-20L / min, and the average thickness of a single cladding layer is 600-800μm.

[0078] 4. Repeat step 3 multiple times. Since the area to be laser cladding has a slope, after each layer is prepared, the surface is polished and half of the laser head spot is placed on the slope to start the next layer of cladding. Finally, polishing is performed to obtain a cladding layer with an average thickness of 1500-3500μm.

[0079] 5. A wear-resistant and corrosion-resistant cladding layer is prepared on the back of the yaw brake disc workpiece in the area to be laser cladding, and finally a cladding layer with an average thickness of 1500-3500μm is obtained.

[0080] 6. Grind the front and back cladding layers of the brake disc using a grinding machine. The excess height of the cladding layer should not exceed 0.5mm to complete the preparation of the wear-resistant and corrosion-resistant cladding layer. Figure 3 As shown, the front laser-clad wear-resistant layer 12 and the back laser-clad wear-resistant layer 14 are located on both sides of the yaw brake disc 13.

[0081] The assembly diagram of the brake disc and brake caliper is as follows: Figure 4 As shown, the upper brake pad 16 and the lower brake pad 17 of the yaw brake caliper 15 are positioned corresponding to the front laser-clad wear-resistant layer 12 and the back laser-clad wear-resistant layer 14, respectively, and the gap 18 between the laser-clad wear-resistant layer and the brake caliper is 1.5mm-3mm.

[0082] Example 1: Wind turbine yaw brake disc made of 316 stainless steel

[0083] I. Structural Design of Wind Turbine Yaw Brake Disc

[0084] The base material of the wind turbine yaw brake disc provided in this embodiment is 316 stainless steel. The inner diameter ψ of the brake disc is 2200mm, the outer diameter Φ is 2700mm, and the thickness d of the brake disc is 30mm. According to the area where the brake caliper and the brake disc are in contact and wear, the front and back sides of the inner side of the brake disc are provided with areas to be laser cladding. The areas to be laser cladding are grooves. The bottom width w of the groove is 120mm, the groove depth h is 2.5mm, and the angle α between the groove slope and the bottom surface of the groove is 140°. The back side design is the same as the front side design.

[0085] II. Composition and Preparation of Wear-Resistant Alloy Powder

[0086] 1. Components of wear-resistant alloy powder

[0087] The wear-resistant alloy powder is composed of NiCrTiSi alloy powder and MoC alloy powder, and the content of each component is as follows:

[0088] MoC alloy powder (particle size -200+500 mesh, purity ≥99.5%): 6 wt.%;

[0089] NiCrTiSi alloy powder (particle size -140+400 mesh, purity ≥99.5%): balance;

[0090] The composition of NiCrTiSi alloy powder is as follows: Ti: 10 wt.%; Cr: 26 wt.%; Si: 0.5 wt.%; Ni: balance.

[0091] 2. Preparation process of wear-resistant alloy powder

[0092] The preparation method of the mixed powder is as follows:

[0093] 1) Weigh the powder materials according to the proportions.

[0094] 2) Place the above powder material in a drying oven and dry it at 100°C for 4 hours. Then, mix the dried powder in a WSM horizontal ball mill for 5 hours to obtain mixed powder.

[0095] The mixed powder and adhesive were spray-granulated to obtain wear-resistant alloy powder with a particle size of -150 to +325 mesh.

[0096] The preparation of wear-resistant alloy powder by spray granulation includes the following steps:

[0097] 1) Add industrial alcohol (97% purity) and PVB-6 glue to the reaction vessel and stir manually for 6 minutes. Heat the reaction vessel to 60°C and keep it at that temperature for 40 minutes. After the PVB-6 glue is completely dissolved, lower the temperature inside the reaction vessel to room temperature to obtain a PVB-6 glue solution with a concentration of 5 wt.%.

[0098] 2) Mix the powder and PVB-6 adhesive in a mass ratio of 1:1 using a horizontal single-shaft paddle mixer until the PVB-6 adhesive is fully dispersed in the powder to obtain a slurry;

[0099] 3) The slurry is sprayed and granulated in the atmosphere using a spray dryer, and then sieved through a double-layer vibrating screen to obtain wear-resistant alloy powder with a particle size of 150-325 mesh. The powder with a particle size outside the 150-325 mesh range obtained by double-layer vibrating sieving is mixed with PVB-6 adhesive and then sprayed and granulated. The inlet temperature of the spray granulation is 150℃ and the outlet temperature is 90℃.

[0100] III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind turbine yaw brake disc

[0101] 1. Pre-treat the area to be laser cladding on the wind turbine yaw brake disc. Use an electric grinding wheel to remove the oxide layer on the stainless steel surface and use compressed air to remove the residue after surface processing. Clean with alcohol and blow dry. Fix the surface-treated workpiece to be clad on a cladding worktable specially designed for cladding circular structures.

[0102] 2. Hastelloy C22 alloy powder is loaded into a pneumatic powder feeding device. For the annular workpiece of the yaw brake disc, the workpiece makes circular motion and the laser head moves radially along the X-axis of the brake disc ring to prepare the bottom layer of cladding. The main parameters of cladding are: laser power of 2.4kW, linear velocity of the workpiece in circular motion of 12cm / s, laser head step distance of 0.6mm for each circular motion of the workpiece, synchronous powder feeding, argon powder feeding, powder feeding rate of 0.8kg / h, argon as protective gas during cladding, flow rate of 16L / min, and average thickness of single cladding layer of 600μm.

[0103] 3. The wear-resistant alloy powder is loaded into the pneumatic powder feeding device. For the yaw brake disc ring workpiece, the workpiece makes a circular motion and the laser head moves radially along the X-axis of the brake disc ring to perform cladding on the bottom layer surface. The main parameters of cladding are: laser power is 2.5kW, the linear velocity of the workpiece making a circular motion is 14cm / s, the laser head step distance is 0.6mm for each circular motion of the workpiece, the cladding is performed by synchronous powder feeding, argon gas is used for powder feeding, the powder feeding amount is 0.9kg / h, argon gas is used as protective gas during the cladding process, the flow rate is 16L / min, and the average thickness of a single cladding layer is 700μm.

[0104] 4. Repeat step "3" in "III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind turbine yaw brake disc" multiple times. Since the area to be laser cladding has a slope, after each layer is prepared, the surface is polished and half of the laser head spot is placed on the slope to start the preparation of the next layer. Finally, the polishing process yields a cladding layer with an average thickness of 2500μm.

[0105] 5. Prepare a wear-resistant and corrosion-resistant cladding layer on the back of the yaw brake disc workpiece in the area to be laser cladding. Repeat steps “2”, “3” and “4” in “III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind power yaw brake disc” to finally obtain a cladding layer with an average thickness of 2500μm.

[0106] 6. Grind the front and back cladding layers of the brake disc using a grinding machine, with an excess height of 0.2mm for the cladding layer.

[0107] The brake disc and brake caliper are assembled to form a wind turbine yaw brake, wherein the single-sided clearance distance between the brake caliper and the brake disc is 2mm.

[0108] Example 2: Wind turbine yaw brake disc made of 316L stainless steel

[0109] I. Structural Design of Wind Turbine Yaw Brake Disc

[0110] The base material of the wind turbine yaw brake disc is 316L stainless steel. The inner diameter ψ of the brake disc is 2200mm, the outer diameter Φ is 2700mm, and the thickness d of the brake disc is 40mm. According to the area where the brake caliper and brake disc come into contact and wear, there are areas to be laser cladding on the front and back sides of the inner side of the brake disc. The areas to be laser cladding are grooves. The bottom width w of the groove is 130mm, the groove depth h is 3.5mm, and the angle α between the groove slope and the bottom surface of the groove is 135°. The back design is the same as the front design.

[0111] II. Composition and Preparation of Wear-Resistant Alloy Powder

[0112] 1. Components of wear-resistant alloy powder

[0113] The wear-resistant alloy powder is composed of NiCrTiSi alloy powder and MoC alloy powder, and the content of each component is as follows:

[0114] MoC alloy powder (particle size -200+500 mesh, purity ≥99.5%): 9 wt.%;

[0115] NiCrTiSi alloy powder (particle size -140+400 mesh, purity ≥99.5%): balance;

[0116] The composition of the NiCrTiSi alloy powder is as follows: Ti: 20 wt.%; Cr: 24 wt.%; Si: 0.5 wt.%; Ni: balance.

[0117] 2. Preparation process of wear-resistant alloy powder

[0118] The preparation method of the mixed powder is as follows:

[0119] 1) Weigh the powder materials according to the proportions.

[0120] 2) Place the above powder material in a drying oven and dry it at 100°C for 4 hours; then mix the dried powder in a WSM horizontal ball mill for 5 hours to obtain mixed powder.

[0121] The mixed powder and binder are then spray-granulated to obtain wear-resistant alloy powder with a particle size of -150 to +325 mesh. The preparation of wear-resistant alloy powder by spray granulation includes the following steps:

[0122] 1) Add industrial alcohol (purity 97%) and PVB-6 glue to the reaction vessel and stir manually for 8 minutes. Heat the reaction vessel to 70°C and keep it at that temperature for 35 minutes. After the PVB-6 glue is completely dissolved, lower the temperature inside the reaction vessel to room temperature to obtain a PVB-6 glue solution with a concentration of 5 wt.%.

[0123] 2) Mix the powder and PVB-6 adhesive in a mass ratio of 1:1 using a horizontal single-shaft paddle mixer until the PVB-6 adhesive is fully dispersed in the powder to obtain a slurry;

[0124] 3) The slurry is sprayed and granulated in the atmosphere using a spray dryer, and then sieved through a double-layer vibrating screen to obtain wear-resistant alloy powder with a particle size of 150-325 mesh. The powder with a particle size outside the 150-325 mesh range obtained by double-layer vibrating sieving is mixed with PVB-6 adhesive and then sprayed and granulated. The inlet temperature of the spray granulation is 180℃ and the outlet temperature is 95℃.

[0125] III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind turbine yaw brake disc

[0126] 1. Pre-treat the area of ​​the wind turbine yaw brake disc to be laser cladding. Use an electric grinding wheel to remove the oxide layer on the stainless steel surface and use compressed air to remove the residue after surface processing. Clean it with alcohol and blow it dry. Fix the surface-treated yaw brake disc onto a worktable specially designed for cladding ring-shaped workpieces.

[0127] 2. Inconel 625 alloy powder is loaded into a pneumatic powder feeding device. For the annular workpiece of the yaw brake disc, the workpiece makes circular motion and the laser head moves radially along the X-axis of the brake disc ring to prepare the bottom layer of cladding. The main parameters of cladding are: laser power of 2.4kW, linear velocity of the workpiece in circular motion of 10cm / s, laser head step distance of 0.7mm for each circular motion of the workpiece, synchronous powder feeding, argon powder feeding, powder feeding rate of 1.0kg / h, argon as protective gas during cladding, flow rate of 15L / min, and average thickness of single cladding layer of 700μm.

[0128] 3. The wear-resistant alloy powder is loaded into the pneumatic powder feeding device. For the yaw brake disc ring workpiece, the workpiece makes a circular motion and the laser head moves radially along the X-axis of the brake disc ring to perform cladding on the bottom layer surface. The main parameters of cladding are: laser power is 2.7kW, the linear velocity of the workpiece making a circular motion is 16cm / s, the laser head step distance is 0.7mm for each circular motion of the workpiece, the cladding is performed by synchronous powder feeding, argon gas is used for powder feeding, the powder feeding amount is 1.2kg / h, argon gas is used as protective gas during the cladding process, the flow rate is 20L / min, and the average thickness of a single cladding layer is 800μm.

[0129] 4. Repeat step "3" in "III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind turbine yaw brake disc" multiple times. Since the area to be laser cladding has a slope, after each layer is prepared, the surface is polished and half of the laser head spot is placed on the slope to start the next layer of cladding. Finally, the polishing process is used to obtain a cladding layer with an average thickness of 3500μm.

[0130] 5. Prepare a wear-resistant and corrosion-resistant cladding layer on the back of the yaw brake disc workpiece in the area to be laser cladding. Repeat steps “2”, “3” and “4” in “III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind power yaw brake disc” to finally obtain a cladding layer with an average thickness of 3500μm.

[0131] 6. Grind the front and back cladding layers of the brake disc using a grinding machine, with an excess height of 0.3mm for the cladding layer.

[0132] The brake disc and brake caliper are assembled to form a wind turbine yaw brake, wherein the single-sided clearance distance between the brake caliper and the brake disc is 2.5mm.

[0133] Example 3: Wind turbine yaw brake disc made of 317 stainless steel

[0134] I. Structural Design of Wind Turbine Yaw Brake Disc

[0135] The base material of the wind turbine yaw brake disc is 317 stainless steel. The inner diameter ψ of the brake disc is 2200mm, the outer diameter Φ is 2600mm, and the thickness d of the brake disc is 30mm. According to the area where the brake caliper and the brake disc come into contact and wear, there are areas to be laser cladding on the front and back sides of the inner side of the brake disc. The areas to be laser cladding are grooves. The bottom width w of the groove is 120mm, the groove depth h is 2mm, and the angle α between the groove slope and the bottom surface of the groove is 140°. The back design is the same as the front design.

[0136] II. Composition and Preparation of Wear-Resistant Alloy Powder

[0137] 1. Components of wear-resistant alloy powder

[0138] The wear-resistant alloy powder is composed of NiCrTiSi alloy powder and MoC alloy powder, and the content of each component is as follows:

[0139] MoC alloy powder (particle size -200+500 mesh, purity ≥99.5%): 12 wt.%;

[0140] NiCrTiSi alloy powder (particle size -140+400 mesh, purity ≥99.5%): balance;

[0141] The composition of the NiCrTiSi alloy powder is as follows: Ti: 30 wt.%; Cr: 20 wt.%; Si: 1 wt.%; Ni: balance.

[0142] 2. Preparation process of wear-resistant alloy powder

[0143] The preparation method of the mixed powder is as follows:

[0144] 1) Weigh the powder materials according to the proportions.

[0145] 2) Place the above powder material in a drying oven and dry it at 100°C for 4 hours; then mix the dried powder in a WSM horizontal ball mill for 5 hours to obtain mixed powder.

[0146] The mixed powder and binder are then spray-granulated to obtain wear-resistant alloy powder with a particle size of -150 to +325 mesh. The preparation of wear-resistant alloy powder by spray granulation includes the following steps:

[0147] 1) Add industrial alcohol (97% purity) and PVB-6 glue to the reaction vessel and stir manually for 10 minutes. Heat the reaction vessel to 80°C and keep it at that temperature for 30 minutes. After the PVB-6 glue has completely dissolved, lower the temperature inside the reaction vessel to room temperature to obtain a PVB-6 glue solution with a concentration of 8 wt.%.

[0148] 2) Mix the powder and PVB-6 adhesive in a mass ratio of 1:1 using a horizontal single-shaft paddle mixer until the PVB-6 adhesive is fully dispersed in the powder to obtain a slurry;

[0149] 3) The slurry is sprayed and granulated in the atmosphere using a spray dryer, and then sieved through a double-layer vibrating screen to obtain wear-resistant alloy powder with a particle size of 150-325 mesh. The powder with a particle size outside the 150-325 mesh range obtained by double-layer vibrating sieving is mixed with PVB-6 adhesive and then sprayed and granulated. The inlet temperature of the spray granulation is 200℃ and the outlet temperature is 100℃.

[0150] III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind turbine yaw brake disc

[0151] 1. Pre-treat the area to be laser cladding on the wind turbine yaw brake disc. Use an electric grinding wheel to remove the oxide layer on the stainless steel surface and use compressed air to remove the residue after surface processing. Clean it with alcohol and blow it dry. Fix the surface-treated yaw brake disc onto a cladding worktable specifically for cladding ring-shaped workpieces.

[0152] 2. Hastelloy C276 alloy powder was loaded into a pneumatic powder feeding device. For the annular workpiece of the yaw brake disc, the workpiece made circular motion and the laser head made radial motion along the X-axis of the brake disc ring to prepare the bottom layer of cladding. The main parameters of cladding were: laser power of 2.2kW, linear velocity of the workpiece in circular motion of 10cm / s, laser head step distance of 0.6mm for each circular motion of the workpiece, synchronous powder feeding, argon powder feeding, powder feeding rate of 0.8kg / h, argon as protective gas during cladding, flow rate of 16L / min, and average thickness of single cladding layer of 600μm.

[0153] 3. The wear-resistant alloy powder is loaded into the pneumatic powder feeding device. For the yaw brake disc ring workpiece, the workpiece makes a circular motion and the laser head moves radially along the X-axis of the brake disc ring to perform cladding on the bottom layer surface. The main parameters of cladding are: laser power is 2.4kW, the linear velocity of the workpiece making a circular motion is 12cm / s, the laser head step distance is 0.4mm for each circular motion of the workpiece, the cladding is performed by synchronous powder feeding, argon gas is used for powder feeding, the powder feeding amount is 0.8kg / h, argon gas is used as protective gas during the cladding process, the flow rate is 16L / min, and the average thickness of a single cladding layer is 600μm.

[0154] 4. Repeat step "3" in "III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind turbine yaw brake disc" multiple times. Since the area to be laser cladding has a slope, after each layer is prepared, the surface is polished and half of the laser head spot is placed on the slope to start the next layer of cladding. Finally, a cladding layer with an average thickness of 1500μm is obtained.

[0155] 5. Prepare a wear-resistant and corrosion-resistant cladding layer on the back of the yaw brake disc workpiece in the area to be laser cladding. Repeat steps “2”, “3” and “4” in “III. Preparation of wear-resistant and corrosion-resistant cladding layer on wind power yaw brake disc” to finally obtain a cladding layer with an average thickness of 1500μm.

[0156] 6. Grind the front and back cladding layers of the brake disc using a grinding machine, with a single-sided cladding layer height of 0.1mm.

[0157] The brake disc and brake caliper are assembled to form a wind turbine yaw brake, wherein the single-sided clearance distance between the brake caliper and the brake disc is 1.5mm.

[0158] Figure 5 The cross-sectional microhardness curves of the prepared cladding layer were obtained using an FM-300 micro Vickers hardness tester with a load of 1000g. Figure 5 It can be seen that the hardness of the wear-resistant layer is significantly improved and stabilized at around 900 HV.

[0159] Figure 6 The microstructure of the prepared cladding layer cross-section was obtained at 5000x magnification using a Quanta 200F scanning electron microscope, revealing TiC reinforcing phase 23, CrMo intermetallic compound 24, and NiTi phase 25. From... Figure 6 As can be seen, the TiC reinforcing phase 23 particles inside the cladding layer are small, reaching the nanoscale in size, and are uniformly distributed and have a high density, which effectively improves the hardness of the cladding layer; moreover, there are no defects such as pores inside the cladding layer, indicating that the cladding layer has good quality.

[0160] Figure 7 X-ray diffraction patterns of the prepared cladding layer surface were obtained using a SmartLab SE X-ray diffractometer. Figure 7 It can be seen that the reinforcing phase inside the cladding layer is TiC, which confirms the feasibility of in-situ TiC generation using this method.

Claims

1. A wear-resistant alloy material, which is composed of NiCrTiSi alloy and MoC alloy; wherein: The composition of the NiCrTiSi alloy is as follows: Ti: 10-30 wt.%; Cr: 20-26 wt.%; Si: 0.5-1 wt.%; Ni: balance; The content of the MoC alloy is 6-12 wt.%, and the balance is the NiCrTiSi alloy; The preparation method of the wear-resistant alloy material includes the following steps: The MoC alloy powder and the NiCrTiSi alloy powder are dried separately, and then the dried powders are mixed to obtain a mixed powder. The mixed powder and adhesive were spray-granulated to obtain wear-resistant alloy material powder with a particle size of -150 to +325 mesh. The wear-resistant alloy material powder is used to form a wear-resistant layer by laser cladding.

2. The wear-resistant alloy material according to claim 1, wherein, The composition of the NiCrTiSi alloy is as follows: Ti: 15-25 wt.%; Cr: 20-24 wt.%; Si: 0.5-1 wt.%; Ni: balance.

3. The wear-resistant alloy material according to claim 1 or 2, wherein, The content of the MoC alloy is 8-10 wt.%.

4. A method for preparing the wear-resistant alloy material according to any one of claims 1-3, comprising the following steps: The MoC alloy powder and the NiCrTiSi alloy powder are dried separately, and then the dried powders are mixed to obtain a mixed powder. The mixed powder and adhesive are sprayed and granulated to obtain wear-resistant alloy material powder with a particle size of -150 to +325 mesh.

5. The preparation method according to claim 4, wherein, The NiCrTiSi alloy powder has a particle size of -140 to +400 mesh; the MoC alloy powder has a particle size of -200 to +500 mesh.

6. The preparation method according to claim 4, wherein, The purity of the NiCrTiSi alloy powder and the MoC alloy powder are both ≥99.5%.

7. The preparation method according to claim 4, wherein, The spray granulation process includes the following steps: 1) Add organic solvent and PVB-6 adhesive to the reaction vessel and stir. Heat to 50-80℃ and keep warm. After the PVB-6 adhesive is completely dissolved, lower the temperature inside the reaction vessel to room temperature to obtain a PVB-6 adhesive solution with a concentration of 4-8 wt.%. 2) Mix the powder and PVB-6 adhesive in a mass ratio of 40-62:38-60, and stir until the PVB-6 adhesive is fully dispersed in the powder to obtain a slurry; 3) The slurry is sprayed and granulated in the atmosphere using a spray dryer, and then screened to obtain wear-resistant alloy material powder with a particle size of -150 to +325 mesh.

8. The preparation method according to claim 7, wherein, The inlet temperature of the spray granulation is 150-200℃, and the outlet temperature is 90-100℃.

9. The preparation method according to claim 7, wherein, Powder with a particle size outside the range of -150 to +325 mesh obtained by sieving is mixed with PVB-6 adhesive and then spray granulated again.

10. The preparation method according to claim 4, wherein, The NiCrTiSi alloy powder is prepared by vacuum medium-frequency melting gas atomization method, specifically including the following steps: 1) Using 99.9% pure nickel blocks, 99.9% pure chromium blocks, 99.9% pure titanium blocks, and silicon as raw materials, place them in a medium-frequency induction furnace; 2) Seal the furnace body, evacuate the furnace to 1-100 Pa, fill it with argon gas to 100-102 kPa, and heat it to completely melt the raw materials to obtain an alloy liquid; 3) Under argon protection, the alloy liquid is poured into the atomization tower for atomization. The atomization temperature is 1450-1550℃ and the atomization pressure is 3.3-3.6MPa. During the pouring process, high-pressure supersonic argon gas acts on the alloy liquid column to disperse, break up and cool the alloy liquid column to obtain NiCrTiSi alloy powder.

11. The preparation method according to claim 7, wherein, The organic solvents include alcohol solvents.

12. The preparation method according to claim 11, wherein, The alcohol solvents include ethanol.

13. The preparation method according to claim 12, wherein, The ethanol mentioned is industrial alcohol.

14. A yaw brake disc for an offshore wind turbine, the surface of which has a wear-resistant and corrosion-resistant cladding layer formed of the wear-resistant alloy material as described in any one of claims 1-3.

15. The yaw brake disc according to claim 14, wherein, The wear-resistant and corrosion-resistant cladding layer is prepared through the following steps: The underlayer is prepared using Ni-Cr-Mo based alloy powder: the underlayer is prepared by cladding in a circular motion of the workpiece and radial motion of the laser head along the X-axis of the workpiece's center; the composition of the Ni-Cr-Mo based alloy powder is: Cr: 18-25 wt.%; Mo: 8-12 wt.%; Ni: balance; The wear-resistant layer is prepared by using the wear-resistant alloy material: the wear-resistant layer is prepared by cladding the workpiece on the surface of the base layer in the form of circular motion of the workpiece and radial motion of the laser head along the X-axis of the workpiece ring center. The wear-resistant layer is polished, and then the wear-resistant layer is prepared repeatedly until a wear-resistant and corrosion-resistant cladding layer of predetermined thickness is obtained.

16. The yaw brake disc according to claim 15, wherein, The composition of the Ni-Cr-Mo based alloy powder is: Cr: 20-23 wt.%; Mo: 8-10 wt.%; Ni: balance.

17. The yaw brake disc according to claim 15, wherein, During the cladding process, the average thickness of the underlayer is 600-800 μm, and the average thickness of a single wear-resistant layer is 600-800 μm.

18. The yaw brake disc according to claim 15, wherein, The main parameters of the cladding include: laser power of 2-4kW, linear velocity of the workpiece in circular motion of 10-20cm / s, and laser head step distance of 0.4-0.8mm for each circular motion of the workpiece. The parameters for cladding also include: cladding is performed using a synchronous powder feeding method, with argon powder feeding at a rate of 0.8-3 kg / h, and argon acting as a protective gas during the cladding process at a flow rate of 15-20 L / min.

19. The yaw brake disc according to claim 14, wherein, The yaw brake disc has wear-resistant and corrosion-resistant cladding layers formed on both its front and back sides.

20. The yaw brake disc according to claim 14, wherein, The wear-resistant and corrosion-resistant cladding layer is located in the grooves on the front and back of the working area of ​​the yaw brake disc.

21. The yaw brake disc according to claim 20, wherein, The angle between the inclined surface at one end of the groove and the bottom surface of the groove is 135°-150°. The width of the bottom of the groove is 110mm-130mm, and the depth of the groove is 1.5-3.5mm.

22. The yaw brake disc according to claim 20, wherein, The remaining height of the wear-resistant and corrosion-resistant cladding layer is less than 0.5 mm.

23. The yaw brake disc according to any one of claims 14-22, wherein, The base material of the yaw brake disc is molybdenum-containing stainless steel.

24. A yaw brake for an offshore wind turbine, wherein, The yaw brake comprises the yaw brake disc as described in any one of claims 14-23; The single-sided clearance distance between the brake caliper of the yaw brake and the yaw brake disc is 1.5mm-3mm.

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