Powder for Laser Cladding on the Outer Surface of the Plunger of a Hydraulic Support

Abstract

The present invention belongs to the technical field of laser cladding surface modification, specifically a powder for laser cladding on the outer surface of the hydraulic support piston rod. This powder is composed of three kinds of particles evenly mixed: Particle I is Er@Cu particles. Inside the Er@Cu particles is a solid Er sphere, and the outside is wrapped with a Cu layer. The particle size of the solid Er sphere is 200nm - 260nm. In the Er@Cu particles, the mass percentage of the solid Er sphere is 66%, and the mass percentage of the outside wrapped Cu layer is 34%; Particle II is FZNi-60A nickel-chromium-silicon-boron series self-fluxing alloy powder; Particle III is FHT100·25 reduced iron powder; The mass percentages of Particle I, Particle II, and Particle III are: Particle I 7% - 12%, Particle II 9% - 15%, and the balance is Particle III. The cladding layer obtained by the present invention has high hardness, and the corrosion resistance time in the AASS salt spray test is greater than 4200h, effectively extending the service life of the hydraulic support piston rod.

Description

Technical Field

[0001] The invention belongs to the technical field of laser cladding surface modification, in particular to powder for laser cladding of the outer surface of a hydraulic support plunger. Background Art

[0002] Hydraulic support is the core equipment of coal mine fully mechanized mining face. During operation, the hydraulic support live column is easily hit by splashing coal gangue and suffers surface damage. In addition, the underground environment is humid and the relative humidity is high. There are a large number of corrosive media such as SO2, H2S, Cl2, etc., which accelerates the corrosion of the outer surface of the hydraulic support live column and destroys the sealing effect of the live column. The oil cylinder matched with the hydraulic support live column suffers from pressure loss and pressure relief, resulting in a decrease in the lifting force of the hydraulic support, threatening production safety. Due to the large size of hydraulic support equipment and high procurement cost, it is of great significance to repair the hydraulic support live column that has failed due to wear and corrosion.

[0003] The traditional surface treatment technology of hydraulic support columns mainly adopts the electroplating hard chrome process. The laser cladding surface modification technology is a new metal surface modification technology that has emerged in recent years. It uses a high-energy laser beam to melt and solidify the alloy powder and the surface of the workpiece matrix to form a laser cladding layer with specific excellent properties, thereby strengthening the matrix. At present, a large number of iron-based powders are used for laser cladding on the outer surface of the hydraulic support column. However, due to improper matching of the iron-based powder composition, the cladding layer has defects such as uneven structure, non-dense, pores, cracks, and easy pitting, and the hardness is not high, resulting in poor corrosion resistance and wear resistance of the laser cladding layer, and poor laser cladding strengthening effect on the outer surface of the hydraulic support column.

[0004] Chinese patent CN113981313A provides an iron-based alloy powder for laser cladding of the outer surface of the plunger of a hydraulic support (application date is October 20, 2021), which forms Fe during the laser cladding process. 41 Co7Cr 15 Mo 14 C 15 B6Y2 (atomic percentage) iron-based amorphous / nanocrystalline technical solutions to improve hardness and corrosion resistance, the actual application process has the following technical deficiencies: due to the short existence time of the molten pool formed by laser cladding, Fe 41 Co7Cr 15 Mo 14 C 15 B6Y2 iron-based amorphous / nanocrystalline requires a large number of elements and the number of atoms cannot be matched in proportion, so the number of iron-based amorphous / nanocrystalline generated is small and unevenly distributed, resulting in a small increase in the hardness of the cladding layer and poor corrosion resistance, and cannot achieve the effect of strengthening and repairing the outer surface of the hydraulic support plunger.

[0005] How to solve the above problems is the top priority for scientific and technological personnel in this field. Summary of the Invention

[0006] The object of the present invention is to provide a powder for laser cladding on the outer surface of the piston rod of a hydraulic support, and solve the following technical problems: how to improve the hardness and corrosion resistance of the cladding layer.

[0007] The present invention adopts the following technical solutions:

[0008] The powder for laser cladding on the outer surface of the piston rod of a hydraulic support is uniformly mixed by Particle Ⅰ, Particle Ⅱ and Particle Ⅲ.

[0009] The Particle Ⅰ is Er@Cu particle. The inside of the Er@Cu particle is a solid Er sphere, and the outside is wrapped with a Cu layer. The particle size of the solid Er sphere is 200nm - 260nm. The mass percentage of the solid Er sphere in the Er@Cu particle is 66%, and the mass percentage of the outside wrapped Cu layer is 34%.

[0010] The Particle Ⅱ is FZNi-60A nickel-chromium-silicon-boron-based self-fluxing alloy powder, and the particle size of the Particle Ⅱ is 10μm - 20μm.

[0011] The Particle Ⅲ is FHT100·25 reduced iron powder, and the particle size of the Particle Ⅲ is 10μm - 20μm.

[0012] The mass percentages of the Particle Ⅰ, Particle Ⅱ and Particle Ⅲ are: Particle Ⅰ 7% - 12%, Particle Ⅱ 9% - 15%, and the balance is Particle Ⅲ.

[0013] Preferably, the composition and mass percentage of the powder are: Particle Ⅰ 9% - 10%, Particle Ⅱ 11% - 13%, and the balance is Particle Ⅲ.

[0014] Preferably, the composition and mass percentage of the powder are: Particle Ⅰ 9.5%, Particle Ⅱ 12%, and the balance is Particle Ⅲ.

[0015] The preparation method of the Er@Cu is as follows:

[0016] 1) Weigh 604mg of Cu(NO3)2·3H2O and dissolve it in a three-necked flask containing 50mL of water, and stir with a thermocouple stirrer for 30min to obtain Solution Ⅰ;

[0017] 2) Weigh 418mg of Er particles with a particle size of 200nm - 260nm;

[0018] 3) Put the Er particles in 2) into the Solution Ⅰ in 1), and continuously stir for 60min under an inert gas atmosphere to obtain Solution Ⅱ;

[0019] 4) Weigh 450 mg of oxalic acid and dissolve it in 5 mL of water to prepare Solution III.

[0020] 5) Put Solution III obtained in 4) into Solution II described in 3) to obtain Solution IV.

[0021] 6) Heat the Solution IV obtained in 5) to 190 °C (heating rate is 5 °C / min), keep it warm for 3 h and then naturally cool it to room temperature. Centrifuge and wash it with a high-speed centrifuge (rotation speed 15000 r / min), and then carry out vacuum drying at 30 °C in a vacuum drying oven to obtain Er@Cu particles.

[0022] The present invention has the following beneficial technical effects:

[0023] 1. The present invention uses nanoscale Er@Cu particles as the main strengthening phase. During the laser cladding process, a chemical reaction occurs to Er@Cu. As the temperature gradually decreases during the solidification and cooling process of the deposited metal, a part of Cu reacts with Er to in-situ generate amorphous Cu57Er43, and another part in-situ generates nanocrystalline Cu57Er43.

[0024] 2. Since the present invention uses nanoscale Er@Cu particles, the types of elements required to form Cu57Er43 amorphous / nanocrystals are fewer (only two types), and the inner solid Er sphere of the Er@Cu particles is wrapped with a Cu layer. Therefore, a larger number of Cu57Er43 amorphous / nanocrystals can be formed within the existence time of the molten pool formed by laser cladding.

[0025] 3. The amorphous and nanocrystalline Cu57Er43 are uniformly distributed, the grain boundaries are also purer, and the potential difference with the inside of the grains is small, effectively improving the corrosion resistance of the deposited metal; in addition, the amorphous and nanocrystalline Cu57Er43 can improve the hardness of the deposited metal, avoiding the problem of poor corrosion resistance caused by the exposure of the bottom due to the impact of flying coal gangue and scratches of operating tools. Since nanoscale Er@Cu particles are used, even if some do not undergo chemical reactions, they can exist as strengthening particles in the deposited layer to improve the hardness of the deposited metal.

[0026] 4. Experiments show that the laser cladding layer obtained by the present invention is metallurgically bonded to the substrate, the hardness value is 68 - 72 HRC, it has good wear resistance, and the corrosion resistance time of the AASS salt spray test is greater than 4200 h, extending the service life. Specific Embodiments

[0027] The following further explains the present invention in conjunction with embodiments, but the protection scope of the present invention is not limited to the specific embodiments.

[0028] Example 1:

[0029] The powder for laser cladding on the outer surface of the movable column of a hydraulic support is composed of uniformly mixed Particle Ⅰ, Particle Ⅱ and Particle Ⅲ.

[0030] Particle Ⅰ is Er@Cu particle. The inside of the Er@Cu particle is a solid Er sphere, and the outside is wrapped with a Cu layer. The particle size of the solid Er sphere is 200nm - 260nm. The mass percentage of the solid Er sphere in the Er@Cu particle is 66%, and the mass percentage of the outside wrapped Cu layer is 34%.

[0031] Particle Ⅱ is FZNi-60A nickel-chromium-silicon-boron series self-fluxing alloy powder, and the particle size of Particle Ⅱ is 10μm - 20μm.

[0032] Particle Ⅲ is FHT100·25 reduced iron powder, and the particle size of Particle Ⅲ is 10μm - 20μm.

[0033] The mass percentages of Particle Ⅰ, Particle Ⅱ and Particle Ⅲ are: Particle Ⅰ 7%, Particle Ⅱ 9%, and the balance is Particle Ⅲ.

[0034] The preparation method of Er@Cu is as follows:

[0035] 1) Weigh 604mg of Cu(NO3)2·3H2O and dissolve it in a three-necked flask containing 50mL of water. Stir with a thermocouple stirrer for 30min to obtain Solution Ⅰ;

[0036] 2) Weigh 418mg of Er particles with a particle size of 200nm - 260nm;

[0037] 3) Put the Er particles in 2) into Solution Ⅰ described in 1), and continuously stir for 60min under an inert gas atmosphere to obtain Solution Ⅱ;

[0038] 4) Weigh 450mg of oxalic acid and dissolve it in 5mL of water to prepare Solution Ⅲ;

[0039] 5) Put Solution Ⅲ obtained in 4) into Solution Ⅱ described in 3) to obtain Solution Ⅳ;

[0040] 6) Heat Solution Ⅳ obtained in 5) to 190℃ (heating rate is 5℃ / min), keep it warm for 3h and then cool it naturally to room temperature. Centrifuge and wash it with a high-speed centrifuge (rotation speed 15000r / min), and then carry out vacuum drying in a vacuum drying oven at 30℃ to obtain Er@Cu particles.

[0041] Example 2:

[0042] The powder for laser cladding on the outer surface of the movable column of a hydraulic support is composed of uniformly mixed Particle Ⅰ, Particle Ⅱ and Particle Ⅲ.

[0043] Particle Ⅰ is Er@Cu particle. The interior of the Er@Cu particle is a solid Er sphere, and the exterior is coated with a Cu layer. The particle size of the solid Er sphere is 200 nm - 260 nm. The mass percentage of the solid Er sphere in the Er@Cu particle is 66%, and the mass percentage of the exterior Cu coating layer is 34%.

[0044] Particle Ⅱ is FZNi-60A nickel-chromium-silicon-boron self-fluxing alloy powder, and the particle size of Particle Ⅱ is 10 μm - 20 μm.

[0045] Particle Ⅲ is FHT100·25 reduced iron powder, and the particle size of Particle Ⅲ is 10 μm - 20 μm.

[0046] The mass percentages of Particle Ⅰ, Particle Ⅱ and Particle Ⅲ are as follows: Particle Ⅰ 12%, Particle Ⅱ 15%, and the balance is Particle Ⅲ.

[0047] The preparation method of the said Er@Cu is as follows:

[0048] 1) Weigh 604 mg of Cu(NO3)2·3H2O and dissolve it in a three-necked flask containing 50 mL of water. Stir with a thermocouple stirrer for 30 min to obtain Solution Ⅰ;

[0049] 2) Weigh 418 mg of Er particles with a particle size of 200 nm - 260 nm;

[0050] 3) Put the Er particles in 2) into Solution Ⅰ described in 1), and continuously stir for 60 min under an inert gas atmosphere to obtain Solution Ⅱ;

[0051] 4) Weigh 450 mg of oxalic acid and dissolve it in 5 mL of water to prepare Solution Ⅲ;

[0052] 5) Put Solution Ⅲ obtained in 4) into Solution Ⅱ described in 3) to obtain Solution Ⅳ;

[0053] 6) Heat up Solution Ⅳ obtained in 5) to 190 °C (heating rate is 5 °C / min), keep it warm for 3 h and then cool it naturally to room temperature. Centrifuge and wash it with a high-speed centrifuge (rotation speed 15000 r / min), and then carry out vacuum drying in a vacuum drying oven at 30 °C to obtain Er@Cu particles.

[0054] Example 3:

[0055] The powder for laser cladding on the outer surface of the hydraulic support piston rod is composed of Particle Ⅰ, Particle Ⅱ and Particle Ⅲ uniformly mixed.

[0056] Particle I is an Er@Cu particle. The interior of the Er@Cu particle is a solid Er sphere, and the exterior is coated with a Cu layer. The diameter of the solid Er sphere is 200 nm - 260 nm. The mass percentage of the solid Er sphere in the Er@Cu particle is 66%, and the mass percentage of the exterior Cu coating layer is 34%.

[0057] Particle II is FZNi-60A nickel-chromium-silicon-boron self-fluxing alloy powder, and the diameter of Particle II is 10 μm - 20 μm.

[0058] Particle III is FHT100·25 reduced iron powder, and the diameter of Particle III is 10 μm - 20 μm.

[0059] The mass percentages of Particle I, Particle II, and Particle III are as follows: Particle I is 9.5%, Particle II is 12%, and the balance is Particle III.

[0060] The preparation method of the Er@Cu is as follows:

[0061] 1) Weigh 604 mg of Cu(NO3)2·3H2O and dissolve it in a three-necked flask containing 50 mL of water. Stir with a thermocouple stirrer for 30 min to obtain Solution I;

[0062] 2) Weigh 418 mg of Er particles with a diameter of 200 nm - 260 nm;

[0063] 3) Put the Er particles in step 2) into Solution I described in step 1), and continuously stir for 60 min under an inert gas atmosphere to obtain Solution II;

[0064] 4) Weigh 450 mg of oxalic acid and dissolve it in 5 mL of water to prepare Solution III;

[0065] 5) Put Solution III obtained in step 4) into Solution II described in step 3) to obtain Solution IV;

[0066] 6) Heat Solution IV obtained in step 5) to 190 °C (heating rate: 5 °C / min), keep it warm for 3 h, then cool it naturally to room temperature. Centrifuge and wash it with a high-speed centrifuge (rotation speed 15000 r / min), and then perform vacuum drying in a vacuum drying oven at 30 °C to obtain Er@Cu particles. Comparative Example 1:

[0067] It is basically the same as Example 3, except that Particle I is not present.

[0068] Comparative Example 2:

[0069] It is basically the same as Example 3, except that Particle I is replaced with two particles of Er powder and Cu powder with corresponding masses.

[0070] Comparative Example 3:

[0071] It is basically the same as Example 3, except that the particle size of Particle Ⅰ is in the micron range.

[0072] Comparative Example 4:

[0073] It is basically the same as Example 3, except that the mass percentage of solid Er spheres in Particle Ⅰ is 60%, and the mass percentage of the outer Cu layer is 40%.

[0074] Comparative Example 5:

[0075] It is basically the same as Example 3, except that the mass percentage of solid Er spheres in Particle Ⅰ is 70%, and the mass percentage of the outer Cu layer is 30%.

[0076] Comparative Example 6:

[0077] Adopt the technical solution of Patent CN113981313A to prepare alloy powder.

[0078] The powders obtained in Examples 1-3 and Comparative Examples 1-6 were used for laser cladding on the outer surface of the hydraulic support piston rod. The power of the laser was 3.5 kW - 4.0 kW, the laser cladding scanning speed was 280 mm / min - 320 mm / min, the rectangular spot size was 18 mm × 1 mm - 24 mm × 3 mm, the cladding thickness was 0.7 mm - 0.9 mm, and then rough turning was carried out and ground to a surface roughness R a ≤0.32.

[0079] For each of the examples and comparative examples, after 10 experiments, the average value of 10 results was taken, and the results are shown in Table 1.

[0080] Table 1

[0081]

[0082]

[0083] The above tests show that in Comparative Examples 1-6, some technical features of the present invention were changed. In some cases, the hardness decreased significantly, and in some cases, the AASS corrosion test time was shorter. This shows that the various technical features of the present invention support and cooperate with each other to achieve the beneficial effects of the present invention.

[0084] Based on the above ideal embodiments of the present invention as inspiration, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. Powder for laser cladding on the outer surface of the movable column of a hydraulic support, characterized in that, The powder is formed by uniformly mixing particle I, particle II and particle III; The particle I is an Er@Cu particle. The inside of the Er@Cu particle is a solid Er sphere, and the outside is wrapped with a Cu layer. The particle size of the solid Er sphere is 200 nm - 260 nm. The mass percentage of the solid Er sphere in the Er@Cu particle is 66%, and the mass percentage of the outside Cu layer is 34%; The particle II is an FZNi-60A nickel-chromium-silicon-boron series self-fluxing alloy powder; The particle III is an FHT100·25 reduced iron powder; The mass percentages of the particle I, the particle II and the particle III are: particle I 7% - 12%, particle II 9% - 15%, and the balance is particle III.

2. The powder for laser cladding on the outer surface of the movable column of a hydraulic support according to claim 1, characterized in that, The composition and mass percentage of the powder are: particle I 9% - 10%, particle II 11% - 13%, and the balance is particle III.

3. The powder for laser cladding on the outer surface of the movable column of a hydraulic support according to claim 1 or 2, characterized in that The composition and mass percentage of the powder are: particle I 9.5%, particle II 12%, and the balance is particle III.

4. The powder for laser cladding on the outer surface of the movable column of a hydraulic support according to claim 1, characterized in that, The particle size of the particle II is 10 μm - 20 μm.

5. The powder for laser cladding on the outer surface of the movable column of a hydraulic support according to claim 1, characterized in that, The particle size of the particle III is 10 μm - 20 μm.

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