A double-layer powder high-speed laser cladding method for hydraulic support rod parts

Abstract

The present invention discloses a double-layer powder high-speed laser cladding method for hydraulic support rod parts. The workpiece surface is treated before high-speed double-layer powder laser cladding. The alloy powder for cladding is prepared by selecting and preparing two layers of powder respectively: the first layer uses powder with lower hardness and higher corrosion resistance for priming, and the powder needs to have a strong bonding ability with the substrate; the second layer uses powder with higher hardness and lower corrosion resistance for surface treatment to cope with the impact of bumps and scratches caused by coal blocks and falling rocks underground; the two layers of powder are used to perform two layers of high-speed laser cladding in sequence through high-speed laser cladding equipment. Iron-based alloy powders with different compositions and properties are used as raw materials, and laser cladding is used to prepare a laser cladding coating that meets the thickness requirements and takes into account the hardness and corrosion resistance of the cladding layer.

Description

Technical Field

[0001] The invention relates to a repair technology for hydraulic support rod parts, and in particular to a double-layer powder high-speed laser cladding method for hydraulic support rod parts. Background Art

[0002] At present, the main process methods for corrosion-resistant and wear-resistant coatings on the metal surfaces of equipment in the coal mine mechanical hydraulic support manufacturing industry and their repair are through hard chrome electroplating, thermal spraying, surfacing and laser cladding technology. The electroplating process has a thin coating and poor anti-corrosion performance, and the industry causes serious waste of resources and environmental pollution. It is an industry that the government urgently needs to relieve. The thermal spraying process has low material utilization, weak bonding between the coating and the substrate, and easy to produce pores. Surfacing is often used for the repair of parts. The coating is thick, the heat input is large and the efficiency is low. Although conventional laser cladding technology can produce high-quality and thin coatings, its low efficiency and high cost also limit its industrial promotion. The current bottleneck restricting the large-scale industrial application of laser cladding technology also lies in materials and processing efficiency.

[0003] For the hydraulic support columns of coal mining machinery, the preparation process of the corrosion-resistant coating on the surface mainly adopts the electroplating process, but the electroplating coating is thin, weak in bonding, and has poor anti-corrosion performance. Especially in the harsh and complex working environment underground, the splashing of coal slag can easily cause the coating to bump and peel off, thus rendering its anti-corrosion function ineffective. In addition, the electroplating process consumes a huge amount of non-ferrous metals such as copper, zinc, and nickel, as well as chemical raw materials such as acids and alkalis, and emits a large amount of pollutants. The pollution situation is worrying, and it is an industry that the government urgently requires to be relieved. Under pressure from environmental protection, many companies are facing the crisis of bankruptcy due to the ban on electroplating production. Many countries have completely banned electroplating production, which has also imposed certain restrictions on product exports.

[0004] At present, more and more users tend to use laser cladding technology instead of electroplating. Although traditional laser cladding technology can produce coatings with good corrosion resistance, its processing efficiency is low, and the surface finish of the coating obtained is poor. Subsequent machining is required to obtain the final product, which also causes its production cost to remain high, which also limits its large-scale industrial application.

[0005] In the prior art:

[0006] In order to solve the bottleneck problem of low efficiency of traditional laser cladding, high-rate laser cladding technology was developed.

[0007] High-speed laser cladding technology was first invented by the Fraunhofer Institute for Laser Technology (Fraunhofer ILT) in Germany. Based on years of experience in developing cladding heads, the institute has developed a high-precision, high-stability, and long-life high-speed laser cladding dedicated powder feeding cladding head, which solves the bottleneck problem of low laser cladding efficiency. In 2016, IHC VremacCylinder BV, a Dutch offshore platform pipe manufacturer, adopted high-speed laser cladding technology to replace traditional electroplating processes, effectively extending the product life cycle and improving the product's industry competitiveness. Its corrosion resistance has passed ISO 15614-7 verification and has achieved industrial production.

[0008] After Fraunhofer released this technology, Germany's Trump also started research on high-speed laser cladding equipment and has produced a prototype, but has not yet started industrial production verification.

[0009] In recent years, although high-speed laser cladding technology has developed rapidly at home and abroad, the following problems still exist:

[0010] The thickness of the cladding layer in a single high-speed laser cladding process is low, making subsequent processing difficult; it is impossible to take into account both hardness and corrosion resistance.

[0011] In view of this, the present invention is proposed. Summary of the invention

[0012] The purpose of the present invention is to provide a double-layer powder high-speed laser cladding method for hydraulic support rod parts to solve the above-mentioned technical problems existing in the prior art.

[0013] The objective of the present invention is achieved through the following technical solutions:

[0014] The double-layer powder high-speed laser cladding method for hydraulic support rod parts of the present invention comprises:

[0015] Step 1: surface treatment of workpiece before high-speed double-layer powder laser cladding;

[0016] Step 2: Preparation of cladding alloy powder, selection and preparation of two layers of powder respectively:

[0017] The first layer is made of powder with lower hardness and higher corrosion resistance, and the powder needs to have strong bonding ability with the substrate;

[0018] The second layer is treated with powder with higher hardness and lower corrosion resistance to cope with the impact of bumps and scratches caused by coal blocks and falling rocks underground;

[0019] Step 3: Use high-speed laser cladding equipment to sequentially perform two layers of high-speed laser cladding using the above two layers of powder.

[0020] Compared with the prior art, the double-layer powder high-speed laser cladding method for hydraulic support rod parts provided by the present invention uses iron-based alloy powders with different compositions and properties as raw materials, and prepares a laser cladding coating that meets the thickness requirements and takes into account the hardness and corrosion resistance of the cladding layer through laser cladding. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A design drawing of double-layer powder high-speed laser cladding for hydraulic support rod parts provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0023] First, the terms that may be used in this article are explained as follows:

[0024] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0025] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0026] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0027] Unless otherwise specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0028] The orientation or position relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the drawings and are only for the convenience and simplification of description, and do not explicitly or implicitly indicate 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 understood as a limitation of this document.

[0029] The contents not described in detail in the examples of the present invention belong to the prior art known to professionals in the field. If no specific conditions are specified in the examples of the present invention, the conditions are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used in the examples of the present invention, they are all conventional products that can be purchased commercially.

[0030] The double-layer powder high-speed laser cladding method for hydraulic support rod parts of the present invention comprises:

[0031] Step 1: surface treatment of workpiece before high-speed double-layer powder laser cladding;

[0032] Step 2: Preparation of cladding alloy powder, selection and preparation of two layers of powder respectively:

[0033] The first layer is made of powder with lower hardness and higher corrosion resistance, and the powder needs to have strong bonding ability with the substrate;

[0034] The second layer is treated with powder with higher hardness and lower corrosion resistance to cope with the impact of bumps and scratches caused by coal blocks and falling rocks underground;

[0035] Step 3: Use high-speed laser cladding equipment to sequentially perform two layers of high-speed laser cladding using the above two layers of powder.

[0036] In step 2, the first layer uses 316L stainless steel metal powder; the second layer uses Fe55 stainless steel metal powder.

[0037] In step 1, the requirements for workpiece surface treatment before cladding are:

[0038] There shall be no cracks or pores on the surface to be clad;

[0039] Maintain complete traceable process benchmarks;

[0040] After processing, the surface of the clad workpiece meets the requirements of process size, tolerance and surface roughness.

[0041] In step 2, the storage requirements of the cladding alloy powder are: moisture-proof, sealed packaging, opened as needed, and used within the warranty period;

[0042] Before using the powder, it should be dried and stirred evenly to avoid lumps and ensure that it is free of moisture.

[0043] In step 3, the powder feeder of the high-speed laser cladding equipment uses argon as a carrier gas.

[0044] In step 3, the cladding process technical requirements are:

[0045] 1) The surface to be clad must not have any defects that affect the cladding quality, including oil stains, rust, and dust, and the completed processing surface must be protected;

[0046] 2) Observe the cladding condition at any time, ensure smooth and stable powder feeding, and do not allow slag inclusion, cracking, or peeling defects;

[0047] 3) The actual output power shall not exceed 4000W to prevent the workpiece from discoloring;

[0048] 4) The overlap rate of the cladding surface shall not be less than 45%, and the excess height shall not exceed 0.3 mm;

[0049] 5) After the first layer of cladding, the workpiece should be slowly cooled to room temperature before the second layer of cladding is performed;

[0050] 6) After the second layer is clad, the workpiece should be slowly cooled to room temperature before machining is allowed.

[0051] After step 3, the machining technical requirements for the cladding layer are:

[0052] 1) The empty groove and chamfer should comply with the drawings and process requirements to ensure the thickness of the cladding layer at this location;

[0053] 2) Maintain complete traceability of the process benchmark to ensure uniform thickness of the cladding layer on the molding surface.

[0054] The high-rate laser cladding layer technical requirements:

[0055] 1) Cladding layer quality: It should be fine and uniform, without spiral lines, cracks, local unfused, dense pits, pores, slag inclusions, looseness, and hard spot defects;

[0056] 2) The minimum thickness of the cladding layer on one side shall meet the technical requirements of the drawing or the requirements of the technical agreement;

[0057] 3) Surface roughness of cladding layer: ≤Ra 0.4;

[0058] 4) Hardness of cladding layer: 40-60HRC;

[0059] 5) Porosity of cladding layer: visual inspection, the number of pores shall not exceed 5 / dm2, and the pore diameter shall not exceed 0.2mm;

[0060] 6) Corrosion resistance of cladding layer: neutral salt spray test for 3300 hours, surface corrosion level is not less than Rp9;

[0061] 7) Wear resistance of cladding layer: Wet sand rubber wheel wear test, weight loss every 3000 revolutions is not more than 0.45g.

[0062] In summary, the double-layer powder high-speed laser cladding method for hydraulic support rod parts in the embodiment of the present invention uses iron-based alloy powders of different compositions and properties as raw materials, and through laser cladding, prepares a laser cladding coating that meets the thickness requirements and takes into account the hardness and corrosion resistance of the cladding layer.

[0063] High-speed laser cladding technology uses a synchronous powder feeding method to use a high-energy density beam to melt the added material and the surface of the high-speed moving base material at the same time, and after rapid solidification, it forms a cladding layer with extremely low dilution rate and metallurgical bonding with the base material, which greatly improves the cladding rate and significantly improves the wear resistance, corrosion resistance, heat resistance, oxidation resistance and other process characteristics of the base material surface, thereby achieving the purpose of surface modification or repair, meeting the requirements for specific performance of the material surface, and greatly improving the work efficiency, solving the bottleneck problem of the current traditional laser cladding technology that limits its application and development due to low efficiency and high cost. Compared with traditional processes such as electroplating and thermal spraying, high-speed laser cladding has obvious characteristics such as high bonding strength and superior coating performance, and the product life is relatively long. As one of the effective technologies to replace electroplating, the efficiency of high-speed laser cladding is also greatly improved compared with traditional cladding.

[0064] The principle of high-precision laser cladding process is to rely on high-precision and long-life laser cladding powder feeding nozzles. By reshaping the matching relationship between powder particles, matrix materials, and laser beams, the spatial action position of the laser beam and powder flow is accurately controlled, and the laser energy is optimized. The powder particles converge above the matrix and absorb most of the laser energy to melt into liquid and enter the matrix micro-molten pool, which greatly shortens the time required for the powder particles to melt and combine with the matrix and solidify, and significantly improves the laser cladding efficiency.

[0065] The double-layer powder high-speed laser cladding method for hydraulic support rod parts of the present invention solves the following technical problems:

[0066] 1. Solved the problem of low thickness of cladding layer in a single high-speed laser cladding process and difficulty in subsequent processing:

[0067] Although high-speed laser cladding solves the problem of low efficiency of traditional cladding, since high-speed laser cladding enables powder particles to converge above the substrate and absorb most of the laser energy to melt into a liquid state, it requires the laser to produce a small-diameter, high-precision laser beam and optimize the distribution of laser energy. As a result, the molten pool must not be too large, and the obtained cladding thickness is limited. The limited cladding layer thickness is difficult to meet the needs of underground work and subsequent processing procedures.

[0068] However, if the laser power and powder feeding rate are forcibly increased, resulting in a molten pool that is too large or too deep, it will cause excessive stress release during cooling, which can easily cause cracking and stratification of the cladding layer, leading to processing failure.

[0069] 2. Solve the problem of not being able to take into account both hardness and corrosion resistance:

[0070] The laser cladding layer has fine and uniform structure and narrow heat-affected zone. Due to the high laser power and short scanning time, the coating and substrate surface melt quickly after heating, and the supercooling degree is large during rapid cooling. The alloy elements in the molten pool can quickly form a variety of compounds to increase the number of non-spontaneous crystal nuclei, greatly improve the nucleation rate, and form a fine and uniform microstructure. Fine structure can improve the grain boundary bonding force and enhance the strength and toughness of the material. Fine structure not only reduces the impurity content on the unit grain boundary, but also reduces the degree of component segregation during rapid cooling, thereby reducing the impact of accelerated corrosion due to the formation of the galvanic cell effect.

[0071] Among them, chromium can significantly improve the corrosion resistance of the laser cladding layer, but the affinity between carbon and chromium can easily generate chromium carbide. The higher the carbon content in the base steel, the lower the chromium content in the molten layer, and the corrosion resistance of the molten layer will be reduced. However, the sliding sealing surface of the column and jack of the general hydraulic support and the exposed surface underground require a certain hardness and strength, and the higher the carbon content, the higher the strength and hardness of the laser cladding layer. Therefore, the role of carbon and chromium in the cladding powder is contradictory, and it is impossible to guarantee the corrosion resistance and hardness of the laser cladding layer at the same time.

[0072] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the embodiments of the present invention are described in detail with specific embodiments below.

[0073] Example 1

[0074] like Figure 1 As shown:

[0075] 1 Technical requirements for workpiece before high-speed double-layer powder laser cladding

[0076] 1.1 The surface to be clad shall not have any defects such as cracks, pores, etc. that may affect the cladding quality.

[0077] 1.2 Maintain complete traceable process benchmarks.

[0078] 1.3 After the surface of the cladding workpiece is processed, it should meet the requirements of process size, tolerance and surface roughness.

[0079] 2 Technical requirements for cladding alloy powder

[0080] 2.1 Powder selection:

[0081] The first layer is made of powder with lower hardness and higher corrosion resistance, and the powder needs to have a strong bonding ability with the substrate; (316L stainless steel metal powder is used in the test)

[0082] The second layer is treated with a powder with higher hardness and lower corrosion resistance to deal with the impact of bumps and scratches caused by coal blocks and falling rocks underground. (Fe55 stainless steel metal powder was used in the test)

[0083] 2.2 Storage requirements: Moisture-proof, sealed packaging, open before use, and use within the warranty period.

[0084] 2.3 Before using the powder, it should be dried and stirred evenly to avoid caking and ensure that there is no moisture.

[0085] 3. High-speed laser cladding equipment operation process

[0086] 3.1 Turn on the main power switch.

[0087] 3.2 Turn on the power of each device, open the gas cylinder, and adjust the pressure reducing valve to the appropriate pressure. Turn on the "external device" button on the laser console and wait for the laser to be preheated.

[0088] 3.3 Clean the workpiece to remove oil and rust, clamp it on the machine tool, measure the diameter of the workpiece and record it.

[0089] 3.4 Set the powder feeder "carrier gas" to argon, set the "operating state" to production, and set the parameters of carrier gas flow, powder feeder plate speed and agitator speed.

[0090] 3.5 Turn the laser control key to the "2" position, log in as "Local Admin" on the touch screen, the password is "0123", and select the "EXT" mode for the light program.

[0091] 3.6 In the "manual" mode of the machine tool console, use the controller to move the laser cladding head to locate the starting point and the end point, and record the coordinates of the two points in "OFS SET". Light up the "shielding gas" and "powder feeder" buttons respectively to check whether the shielding gas and powder feeder are normal.

[0092] 3.7 In the "Automatic" mode of the machine tool console, light up the "EDIT" button, write the cladding operation program in "PROG", enter the laser power, coordinates of each point and process parameters, press the "Check" soft key at the bottom of the screen to save, and press the "RESET" button to put the program in the initial position; light up the "AUTO" button, when the indicator lights of all devices are green, press "CYCLE STRAT" to start cladding.

[0093] 3.8 After cladding is completed, disassemble the workpiece and clean the powder in the machine tool and powder feeder.

[0094] 3.9 Turn off the gas cylinder and pressure reducing valve, turn the laser control key to the "0" position, turn off the power of each device, and finally turn off the main power switch.

[0095] 4 Technical requirements for cladding process

[0096] 4.1 The surface to be clad must not have any defects such as oil, rust, dust, etc. that may affect the quality of cladding, and the completed processed surface must be protected.

[0097] 4.2 Observe the cladding condition at any time, and ensure that the powder feeding is smooth and stable; defects such as slag inclusion, cracking, and peeling are not allowed.

[0098] 4.3 The actual output power shall not exceed 4000W to prevent the workpiece from discoloring.

[0099] 4.4 The overlap rate of the cladding surface shall not be less than 45%, and the excess height shall not exceed 0.3 mm.

[0100] 4.5 After the first layer of cladding, the workpiece should be slowly cooled to room temperature before the second layer of cladding can be performed.

[0101] 4.6 After the second layer of cladding, the workpiece should be slowly cooled to room temperature before machining is allowed.

[0102] 5. Technical requirements for machining of cladding layer

[0103] 5.1 Empty tool grooves, chamfers, etc. should comply with the drawings and process requirements to ensure the thickness of the cladding layer in this area.

[0104] 5.2 Maintain complete traceability of the process benchmark to ensure uniform thickness of the cladding layer on the molding surface.

[0105] 6 Technical requirements for high-rate laser cladding

[0106] 6.1 Cladding layer quality: It should be fine and uniform, and no defects such as spiral lines, cracks, local unfusion, dense pitting, pores, slag inclusions, looseness, hard spots, etc. are allowed.

[0107] 6.2 The minimum thickness of a single side of the cladding layer shall meet the technical requirements of the drawing or the requirements of the technical agreement.

[0108] 6.3 Surface roughness of cladding layer: ≤Ra 0.4.

[0109] 6.4 Hardness of cladding layer: 40-60HRC.

[0110] 6.5 Porosity of cladding layer: Visual inspection, no more than 5 pores / dm2, and the pore diameter does not exceed 0.2mm. If there are special requirements in the technical agreement, the requirements of the agreement shall be implemented.

[0111] 6.6 Corrosion resistance of cladding layer: In principle, the surface corrosion level shall not be lower than Rp9 after 3300 hours of neutral salt spray test. If there are special requirements in the technical agreement, the requirements of the agreement shall be implemented.

[0112] 6.7 Wear resistance of cladding layer: wet sand rubber wheel wear test, weight loss every 3000 revolutions is not more than 0.45g.

[0113] 7 High-rate laser cladding layer inspection items and methods

[0114] 7.1 Appearance

[0115] Visually inspect the effective surface, which should have uniform color and a relatively smooth cladding surface layer. No cracks, bumps, pits, weak bonding, foreign matter adhesion or other defects are allowed.

[0116] 7.2 Thickness

[0117] Use a micrometer to directly measure the dimensions before and after cladding, calculate the thickness, and the thickness of the laser cladding layer shall be implemented according to the requirements; the thickness of the laser cladding sample block can be measured by metallographic method to measure the thickness of the cross section of the cladding layer, in accordance with GB / T6462.

[0118] 7.3 Bonding strength

[0119] When tested according to GB / T 8642 standard, it shall comply with the requirements of Clause 4 of this standard.

[0120] 7.4 Hardness

[0121] Use ultrasonic hardness tester to test according to GB 9790 or JB / T 6050, and divide into three sections, and measure the hardness uniformity at four points on each section. The result should meet the requirements of clause 4 of this standard.

[0122] 7.5 Porosity

[0123] Use visual inspection or color flaw detection method to detect.

[0124] 7.6 Others

[0125] Mechanical properties, metallographic structure, non-destructive testing, cladding welding quality and fatigue test (life) shall comply with relevant standards.

[0126] 8 Factory inspection rules for high-speed laser cladding products

[0127] 8.1 Appearance, pores and dimensions inspection

[0128] 100% inspection.

[0129] 8.2 Hardness and porosity testing

[0130] Each batch (up to 100 pieces) shall be inspected at 5%, with no less than 5 pieces; if the inspection fails, a full inspection shall be carried out at 100%.

[0131] 8.3 Factory corrosion resistance test

[0132] Each batch (up to 100 pieces) is inspected at 2%, with no less than 2 pieces; if the inspection fails, double sampling is conducted; if double sampling fails, all inspections are conducted. The cladding layer is subjected to a neutral salt water corrosion test for 168 hours, and no rust is observed visually.

[0133] 9Safety operating procedures for high-speed laser cladding equipment

[0134] 9.1 Before cladding begins, check whether the three pipelines of the laser cladding head protection gas circuit, cooling water circuit and powder delivery circuit are blocked or leaking, check whether the powder outlet is unobstructed, and check whether the laser protection lens is contaminated by dust.

[0135] 9.2 Except for the operator, other personnel are prohibited from standing in the working area to prevent injury or affect normal operation.

[0136] 9.3 High-speed laser cladding uses high-energy laser beams. During the working process, there is high temperature and strong light exposure. Protective covers and protective glasses can reduce the high temperature and strong light exposure, but cannot completely shield them. It is recommended not to look directly at the laser spot for a long time to avoid retinal burns, and avoid any part of the body contacting the protective cover and the running machine tool to prevent collision, pinching or burns.

[0137] 9.4 Operators must wear work clothes, protective masks, and protective gloves and protective glasses when necessary in the work area.

[0138] 9.5 Pay attention to personal safety when loading and unloading workpieces to avoid bumps or injuries.

[0139] 9.6 After cladding, the surface temperature of the workpiece is very high. It is forbidden to have any part of the body directly contact the workpiece to avoid burns. Workers must wear protective gloves when disassembling the workpiece and use necessary tools to assist in disassembly and transportation.

[0140] 9.7 When cleaning the powder delivery barrel, you must wear a protective mask to avoid inhaling metal powder and causing damage to the respiratory tract and lungs. If you accidentally inhale the powder, you should immediately move to a ventilated place. If the condition is serious, seek medical attention in time.

[0141] 10 High-speed laser cladding equipment maintenance instructions

[0142] 10.1 Laser

[0143] 10.1.1 The laser internal water tank needs to be filled with about 45L of deionized water (distilled water), and the conductivity is required to be ≤3μs / cm.

[0144] 10.1.2 The laser must be supplied with dry compressed air during operation.

[0145] 10.1.3 The laser water cooler must be running during laser operation.

[0146] 10.1.4 The laser must not be shut down when the temperature is below 5°C. If it needs to be shut down, the internal water tank must be emptied.

[0147] 10.1.5 The laser maintenance cycle is one year. When a prompt appears, it is recommended to contact the manufacturer for necessary maintenance and care.

[0148] 10.1.6 It is strictly forbidden to touch or even plug or unplug the optical fiber connector when the laser is emitting light.

[0149] 10.2 Powder Feeder

[0150] 10.2.1 The carrier gas for the powder feeder is only allowed to be 99.99% ordinary argon or 99.999% high-purity argon, and the carrier gas pressure range is 0.5~0.9MPa.

[0151] 10.2.2 To prevent the powder from being affected by moisture and affecting its fluidity, the powder in the powder delivery barrel should be ready for use in summer and stored for 24 hours in winter. If there are special requirements for the powder, they should be implemented accordingly.

[0152] 10.3 Laser Water Cooler

[0153] 10.3.1 It is recommended to add deionized water or drinking water with low ionization degree to the water tank inside the laser water cooler, and it is recommended to replace it every six months.

[0154] 10.3.2 The recommended setting temperature of the low-temperature water of the laser water cooler is 17℃~20℃ in summer and 20℃~21℃ in winter.

[0155] 10.3.3 The laser water cooler is prohibited from shutting down when the temperature is below 5°C. If shutdown is required, the internal water tank must be emptied.

[0156] 10.3.4 It is recommended to clean the air inlet filter of the laser water cooler every 7 days.

[0157] 10.4 Cladding head water cooling machine

[0158] 10.4.1 The internal water tank of the cladding head water cooler is only allowed to use deionized water (distilled water) that meets the standards as the circulating medium. It is recommended to replace it every six months.

[0159] 10.4.2 The recommended setting temperature for the cladding head water cooler is 20℃~30℃ in summer and 25℃~30℃ in winter.

[0160] 10.4.3 The cladding head water cooler is prohibited from shutting down when the temperature is below 5°C. If shutdown is required, the internal water tank must be emptied.

[0161] 10.4.4 It is recommended to clean the air inlet filter of the cladding head water cooler every 7 days.

[0162] 10.5 Laser Cladding Head

[0163] 10.5.1 Before starting the laser cladding head each time, the integrity and air tightness of the powder circuit, cooling water circuit and protective gas circuit must be checked.

[0164] 10.5.2 Regularly check whether the optical path of the laser cladding head is offset.

[0165] 10.5.3 The cleanliness of protective lenses should be checked once a day.

[0166] 10.5.4 After the water tank of the cladding head water cooler is emptied, the water inside the laser cladding head and in the cooling water circuit must be drained at the same time, and the moisture must be completely drained with dry compressed air.

[0167] 10.5.5 It is strictly forbidden to touch any part of the laser cladding head during the cladding process, and it is forbidden to touch the powder feeding nozzle within 5 minutes after the completion of cladding.

[0168] 10.5.6 For long-term cladding processing (single cladding time is not less than 4 hours), it is recommended to use tin foil to completely wrap the powder delivery pipeline and protective gas line to avoid damage to the powder delivery pipeline and protective gas line due to continuous high temperature during the cladding process.

[0169] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A double-layer powder high-speed laser cladding method for hydraulic support rod parts, characterized in that: include: Step 1: surface treatment of workpiece before high-speed double-layer powder laser cladding; Step 2: Preparation of cladding alloy powder, selection and preparation of two layers of powder respectively: The first layer uses powder with lower hardness and higher corrosion resistance for primer, and the powder needs to have strong bonding ability with the substrate. The first layer uses 316L stainless steel metal powder; The second layer is treated with powder with higher hardness and lower corrosion resistance to cope with the impact of bumps and scratches caused by coal blocks and falling rocks underground. The second layer uses Fe55 stainless steel metal powder; Step 3: Using a high-speed laser cladding device, the two layers of powder are used to perform two layers of high-speed laser cladding in sequence; Surface roughness of cladding layer: ≤Ra 0.4; Cladding layer hardness: 40-60HRC; Corrosion resistance of cladding layer: neutral salt spray test for 3300 hours, surface corrosion level is not less than Rp9; Wear resistance of cladding layer: wet sand rubber wheel wear test, weight loss is no more than 0.45g per 3000 revolutions; In step 3, the cladding process technical requirements are: 1) The surface to be clad must not have any defects that affect the cladding quality, including oil stains, rust, and dust, and the completed processing surface must be protected; 2) Observe the cladding condition at any time, ensure smooth and stable powder feeding, and do not allow slag inclusion, cracking, or peeling defects; 3) The actual output power shall not exceed 4000W to prevent the workpiece from discoloring; 4) The overlap rate of the cladding surface shall not be less than 45%, and the excess height shall not exceed 0.3 mm; 5) After the first layer of cladding, the workpiece should be slowly cooled to room temperature before the second layer of cladding is performed; 6) After the second layer of cladding, the workpiece should be slowly cooled to room temperature before machining is allowed; After step 3, the machining technical requirements for the cladding layer are: 1) The empty groove and chamfer should comply with the drawings and process requirements to ensure the thickness of the cladding layer at this location; 2) Maintain complete traceability of the process benchmark to ensure uniform thickness of the cladding layer on the molding surface; High-speed laser cladding equipment includes a laser, a powder feeder and a laser water cooler; the laser internal water tank is filled with 45L of deionized water with a conductivity of ≤3μs / cm; dry compressed air is connected during the operation of the laser; the laser water cooler is operated simultaneously during the operation of the laser; the powder feeder carrier gas uses 99.99% ordinary argon or 99.999% high-purity argon, and the carrier gas pressure range is 0.5-0.9MPa.

2. The double-layer powder high-speed laser cladding method for hydraulic support rod parts according to claim 1 is characterized in that: In step 1, the requirements for workpiece surface treatment before cladding are: There shall be no cracks or pores on the surface to be clad; a complete and traceable process benchmark shall be retained; After the surface of the clad workpiece is processed, it meets the requirements of process size, tolerance and surface roughness.

3. The double-layer powder high-speed laser cladding method for hydraulic support rod parts according to claim 1 is characterized in that: In step 2, the storage requirements of the cladding alloy powder are: moisture-proof, sealed packaging, opened as needed, and used within the warranty period; Before using the powder, it should be dried and stirred evenly to avoid lumps and ensure that it is free of moisture.

4. The double-layer powder high-speed laser cladding method for hydraulic support rod parts according to claim 1 is characterized in that: High-speed laser cladding layer technical requirements: 1) Cladding layer quality: It should be fine and uniform, without spiral lines, cracks, local unfused, dense pits, pores, slag inclusions, looseness, and hard spot defects; 2) The minimum thickness of the cladding layer on one side shall meet the technical requirements of the drawing or the requirements of the technical agreement; 3) Porosity of cladding layer: visual inspection, no more than 5 pores / dm 2 , and the pore diameter does not exceed 0.2mm.

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