Method and device for enhancing performance of inner wall of hydraulic support oil cylinder based on CMT ultrasonic coating

Abstract

The method comprises the following steps: S1: removing the oxide layer on the inner wall of the hydraulic support oil cylinder; S2: processing dislocation channels on the inner wall of the hydraulic support oil cylinder; S3: CMT welding is performed on the inner wall of the hydraulic support oil cylinder from inside to outside, the welding process is accompanied by ultrasonic assistance, the ultrasonic assistance is stopped when the welding gun completes one stroke, the hydraulic support oil cylinder is rotated by 9-15 degrees after 10-30 seconds, the brazing is continued, and all coating operations on the inner wall of the hydraulic support oil cylinder are completed; the present application utilizes the dislocation channel to enhance the interface reaction behavior and the bonding strength of the base body and the coating, and prepares a wear-resistant coating with uniform coating structure, simple process and low cost.

Description

Technical Field

[0001] This invention relates to the field of welding processes and equipment, specifically to a CMT ultrasonic brazing method and apparatus for enhancing the performance of the inner wall of a hydraulic support cylinder. Background Technology

[0002] Currently, coal remains my country's primary energy source and holds a vital strategic position in national economic development. Hydraulic supports play a crucial role in coal mining. The harsh working environment in coal mines means that hard particles such as coal dust easily accumulate on the inner wall of the hydraulic cylinder and the mating surface of the piston, leading to scratches. Furthermore, the hydraulic oil used in hydraulic supports is susceptible to contamination with corrosive media such as moisture and H2S. Therefore, improving the wear resistance and corrosion resistance of the hydraulic cylinder's inner wall is particularly critical.

[0003] Creating high-performance wear-resistant coatings is a method to improve the wear resistance and corrosion resistance of the inner wall of hydraulic cylinders in a way that maximizes economy and timeliness.

[0004] Cold metal transfer (CMT) technology is a welding process with alternating "cold-hot" transfer modes. This method has the following advantages: (1) The wire feeding motion is controlled by digital signals. The waveforms of welding current and voltage are matched with the waveform changes of wire feeding speed to achieve precise control and uniform weld. (2) When the welding heat input is low and the molten droplet is short-circuited, the control system adjusts the loop current to almost zero to reduce welding deformation and alleviate residual stress. (3) No spatter transfer. When the loop current is reduced to almost zero, the welding wire will be retracted to cause the molten droplet to fall off, completing the cold transfer of the molten droplet. In this way, spatter will not occur during welding.

[0005] Chinese Patent 201810464169.0 discloses "A CMT-ultrasonic vibration composite additive manufacturing method," which improves the mechanical properties of components and belongs to the field of solid-state bonding. Chinese Patent 202010223671.X, "Dual ultrasonic-assisted laser-CMT composite welding system and welding method," reduces porosity and brittle compounds at the fusion weld interface, improving the fluidity of the molten pool and belonging to the field of fusion welding. Patent 202011629497.5, "A method for preparing dissimilar metal composite structures using high-deformation assisted vacuum diffusion welding," utilizes deformation strengthening and diffusion welding processes to achieve effective bonding of dissimilar materials. To improve the wear resistance and corrosion resistance of the inner wall of hydraulic cylinders, combining the advantages of CMT technology, ultrasonic-assisted welding, and brazing, and utilizing dislocation channels to enhance the interfacial reaction behavior and bonding strength between the substrate and coating, a wear-resistant coating with uniform structure, simple process, and low cost is prepared. There is an urgent need to develop a highly automated, easy-to-operate, and environmentally friendly coating device for the inner surface of hydraulic support cylinders. Summary of the Invention

[0006] The present invention aims to provide a CMT ultrasonic brazing method and apparatus for enhancing the performance of the inner wall of hydraulic support cylinder, so as to utilize dislocation channels to enhance the interfacial reaction behavior and bonding strength between the substrate and the coating, and to prepare a wear-resistant coating with uniform coating structure, simple process and low cost.

[0007] To solve the above technical problems, the specific solution adopted by the present invention is as follows: a method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing, comprising the following steps.

[0008] S1: Remove the oxide layer from the inner wall of the hydraulic support cylinder;

[0009] S2: Machining dislocation channels on the inner wall of the hydraulic support cylinder;

[0010] S3: Perform CMT welding from the inside to the outside on the inner wall of the hydraulic support cylinder. The welding process is accompanied by ultrasonic assistance. Stop ultrasonic assistance when the welding gun completes one stroke. After 10 to 30 seconds, rotate the hydraulic support cylinder 9 to 15 degrees and continue brazing until all coating operations on the inner wall of the hydraulic support cylinder are completed.

[0011] S4: Milling and polishing the inner wall of the hydraulic support cylinder to enhance its performance.

[0012] As a further optimization of the above technical solution: in step S2, the inner wall of the hydraulic support cylinder is processed into a precision weldment with dislocation channels using ultrasonic, laser, plasma or micro-electrolysis processing methods.

[0013] As a further optimization of the above technical solution: In step S3, ultrasonic assistance is provided by an ultrasonic generator, which includes an ultrasonic generator, a cooling system and a titanium alloy working head. The vibration frequency is 20±0.05kHz, the output amplitude of the working head is 3~10μm, and the output power of the ultrasonic power supply is 0.2~1kW.

[0014] As a further optimization of the above technical solution: in step S3, the CMT welding current is 12-18A, the welding voltage is 122-202V, the wire feeding speed is 3-6m / min, and the welding speed is 150-200mm / min.

[0015] As a further optimization of the above technical solution: during CMT welding in step S3, the horizontal angle α of the welding torch is 60-70°, and the distance d between the end of the welding wire and the inner wall of the hydraulic support cylinder is 10-12mm.

[0016] As a further optimization of the above technical solution: In step S3, one stroke of the welding torch refers to one welding operation from the bottom of the inner wall of the hydraulic support cylinder to the top of the inner wall of the hydraulic support cylinder, and the rotation of the hydraulic support cylinder by 9 to 15 degrees refers to controlling the hydraulic support cylinder to rotate by 9 to 15 degrees.

[0017] As a further optimization of the above technical solution: the welding wire used in CMT welding in step S3 is a self-made drug-cored copper-based welding wire or a self-made drug-cored nickel-based welding wire.

[0018] As a further optimization of the above technical solution: The self-made flux-cored copper-based welding wire includes a flux core and a coating. The flux core is a mixture of the following weight components: copper: nickel-manganese alloy: calcium oxide: potassium fluoride: calcium difluoride: manganese oxide: nano-nickel formate = 9:4:3.5:3:0.02:0.09:0.002. The coating is T2 pure copper welding strip with a filler ratio of 20.5-23.5%, and the wire diameter is 1.05-1.15 mm. The self-made flux-cored nickel-based welding wire also includes a flux core and a coating. The flux core is a mixture of the following weight components: nickel: copper-manganese alloy: calcium oxide: potassium fluoride: calcium difluoride: manganese oxide: nano-amorphous nickel = 9:4:3.5:3:0.02:0.09:0.001. The coating is N6 pure nickel welding strip with a filler ratio of 22.1-23.1%, and the wire diameter is 1.05-1.15 mm.

[0019] As a further optimization of the above technical solution: In step S4, the milling and polishing processes process the coating to 2-5 mm, with a surface roughness Ra of 0.4-0.8 and a brazing efficiency of 0.49-0.65 μm. 2 .

[0020] A device for enhancing the inner wall performance of a hydraulic support cylinder based on CMT ultrasonic brazing is disclosed. This device, based on the aforementioned CMT ultrasonic brazing method, includes a control panel, a controller, a welding machine, a wire feeder, a wire buffer, a robotic arm, a welding torch, an ultrasonic generator, and a dedicated clamp for the hydraulic support cylinder. The control panel is used to input process parameters to the controller. The controller controls the brazing current and voltage of the welding machine, the wire feeding speed of the wire feeder, the brazing speed of the robotic arm, the ultrasonic frequency and duration of the ultrasonic generator, and the rotation of the dedicated clamp for the hydraulic support cylinder. The welding torch is fixed to the robotic arm. The robotic arm is a two-axis robotic arm with two degrees of freedom: horizontal and vertical movement. The dedicated clamp for the hydraulic support cylinder includes a three-jaw chuck and a servo system.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. In the preparation of the coating, this invention combines CMT technology and ultrasonic-assisted technology, resulting in low welding heat input, low residual stress, rapid interfacial metallurgical reaction, and high bonding strength between the coating and the inner surface of the hydraulic cylinder substrate. The ultrasonic acoustic flow effect makes the coating structure more uniform, and by utilizing dislocation channels, the liquid solder spreads well on the substrate surface, further improving wear resistance and corrosion resistance. The acoustic cavitation effect of ultrasonic-assisted welding can generate instantaneous high temperature and high pressure, which can change the physicochemical state of the liquid and accelerate the interfacial metallurgical reaction during welding. The stirring and dispersing effect brought about by the acoustic flow effect can achieve macroscopic and microscopic homogenization of the weld structure. The stress-strain effect caused by the acoustic plasticity effect can reduce the solid solution's resistance to deformation.

[0023] 2. Before brazing, this invention utilizes precision special processing methods such as ultrasonic waves, lasers, plasma, and micro-electrolysis to process dislocation channels on the inner wall of the hydraulic cylinder substrate to be brazed. By utilizing the dislocation channels and the alloying of the brazing wire through melting-diffusion reaction, the internal stress between the coating and the substrate is reduced or avoided, resulting in a coating with excellent mechanical properties, especially bonding strength.

[0024] This invention applies the processing of dislocation structures (mainly causing different types of dislocation reactions within the dislocations) to the modification of the inner surface of the brazed hydraulic cylinder substrate. By cleverly utilizing the dislocation defect structure, it provides an "effective channel for the interfacial reaction between the liquid brazing filler metal and the inner surface of the hydraulic cylinder substrate." This dislocation channel can effectively enhance the interfacial diffusion reaction behavior and bonding strength between the substrate and the coating.

[0025] 3. The present invention transforms the dislocations (a defect structure) processed on the inner surface of the hydraulic cylinder substrate into a "skeleton" (beneficial structure) that improves the interfacial reaction and interfacial bonding strength between the brazing filler metal and the inner surface of the hydraulic cylinder substrate, thereby improving and enhancing the performance of the inner surface of the hydraulic cylinder substrate and extending the service life of the hydraulic cylinder.

[0026] 4. This invention organically combines dislocation machining with ultrasonic assistance. Ultrasonic assistance removes gas (gap) from dislocation channels, reducing or preventing the generation of internal porosity or inclusion defects. Meanwhile, the dislocations provide wetted filling for the brazing filler metal, allowing for sufficient diffusion with the hydraulic cylinder substrate, further enhancing the bonding force between the brazing filler metal and the hydraulic cylinder's inner wall substrate. The machined dislocation channels are designed to ensure sufficient filling by the brazing filler metal, while ultrasonic assistance removes gas generated during filling or gas remaining inside the channels after machining. In short, the channels improve the bonding between the brazing filler metal and the hydraulic cylinder's inner wall, while ultrasonic assistance removes gas or porosity defects, reduces brazing defects, improves brazing coating quality, and extends the service life of the hydraulic cylinder.

[0027] 5. The CMT ultrasonic brazing device of the present invention adopts intermittent current welding, which results in a gentle transition of molten brazing wire, no spatter, less pollution to the working environment, saving welding wire, and low cost; in addition, the device has a high degree of automation, convenient process adjustment, and process parameters only need to be input on the control panel and transmitted to each component by the controller, which requires low operator skills. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the present invention;

[0029] Figure 2 This is a schematic diagram of the working process of the welding torch of the present invention;

[0030] Reference numerals: 1. Control panel, 2. Controller, 3. Welding machine, 4. Wire feeder, 5. Welding wire buffer, 6. Robotic arm, 7. Welding torch, 8. Ultrasonic generator, 9. Hydraulic support cylinder clamp, 901. Three-jaw chuck, 902. Servo system, 10. Protective gas cover, 11. Electrode, 12. Welding wire, 13. Hydraulic support cylinder. Detailed Implementation

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Parts not described or disclosed in detail in the following embodiments of the present invention should be understood as prior art known or should be known by those skilled in the art.

[0032] This invention discloses a method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing, comprising the following steps:

[0033] S1: Remove the oxide layer from the inner wall of the hydraulic support cylinder;

[0034] Pretreatment is performed on the inner wall of the hydraulic support cylinder by grinding and ultrasonic cleaning to remove the oxide layer. The specific grinding and ultrasonic cleaning methods can refer to the existing methods for removing oxide layers, and will not be elaborated here.

[0035] S2: Machining dislocation channels on the inner wall of the hydraulic support cylinder;

[0036] Hydraulic support cylinder inner walls are machined into precision weldable parts with dislocation channels using ultrasonic, laser, plasma, or micro-electrolysis processing methods. It should be noted that the method of creating dislocation channels through work hardening is existing technology. Work hardening involves activating dislocation sources through dislocation movement, increasing dislocation density, and thus increasing the pinning ability between dislocations, resulting in a hardening effect.

[0037] S3: CMT welding is performed on the inner wall of the hydraulic support cylinder from the inside out. The welding process is accompanied by ultrasonic assistance, which is provided by an ultrasonic generator. The ultrasonic generator includes an ultrasonic generator, a cooling system and a titanium alloy working head. The vibration frequency is 20±0.05kHz, the output amplitude of the working head is 3~10μm, and the output power of the ultrasonic power supply is 0.2~1kW.

[0038] During CMT welding, ultrasonic assistance is stopped when the welding torch completes one stroke. After 10–30 seconds, the hydraulic support cylinder is rotated 9–15° to continue brazing until all coating work is completed on the inner wall of the hydraulic support cylinder. The instantaneous high temperature and pressure generated by the acoustic cavitation effect of ultrasonic assistance can accelerate the metallurgical reaction during welding; the stirring and dispersing effect brought about by the acoustic flow effect can make the coating more uniform both macroscopically and microscopically; the stress-strain effect caused by the acoustic plasticity effect can reduce the solid's resistance to deformation.

[0039] During welding, the hydraulic support cylinder must be kept horizontal, with the cylinder opening facing the welding torch. The welding torch extends into the cylinder body to perform CMT welding on the inner wall of the hydraulic support cylinder. The distance d between the welding torch and the inner surface of the hydraulic support cylinder is 10–12 mm, and the horizontal angle α of the welding torch is 60–70°. The CMT welding current is 12–18 A, the welding voltage is 122–202 V, the wire feed speed is 3–6 m / min, and the welding speed is 150–200 mm / min. The shielding gas is nitrogen or helium.

[0040] One stroke of the welding torch refers to one welding operation from the bottom of the inner wall of the hydraulic support cylinder to the top of the inner wall of the hydraulic support cylinder. The rotation of the hydraulic support cylinder by 9 to 15 degrees refers to controlling the hydraulic support cylinder to rotate by 9 to 15 degrees.

[0041] The welding wire used in CMT welding is a self-made flux-cored copper-based welding wire. This wire consists of a flux core and a coating. The flux core is a mixture of the following components in 100% by weight: copper: nickel-manganese alloy: calcium oxide: potassium fluoride: calcium difluoride: manganese oxide: nano-nickel formate = 9:4:3.5:3:0.02:0.09:0.002. The coating is T2 pure copper welding strip with a filler content of 20.5–23.5%. The wire diameter is 1.05–1.15 mm.

[0042] CMT welding wire can also be a self-made flux-cored nickel-based welding wire. The self-made flux-cored nickel-based welding wire includes a flux core and a coating. The flux core is mixed in 100% of the following weight components: nickel: copper-manganese alloy: calcium oxide: potassium fluoride: calcium difluoride: manganese oxide: nano amorphous nickel = 9:4:3.5:3:0.02:0.09:0.001. The coating is N6 pure nickel welding strip with a filler ratio of 22.1-23.1% and a wire diameter of 1.05-1.15 mm.

[0043] S4: Milling and polishing the inner wall of the hydraulic support cylinder to enhance its performance.

[0044] Specifically, milling, rough polishing, and fine polishing processes are used to process the coating to a thickness of 2–5 mm, with a surface roughness Ra of 0.4–0.8 and a soldering efficiency of 0.49–0.65 μm. 2 This involves enhancing the performance of the inner wall of the hydraulic support cylinder. The brazing efficiency refers to the ratio of the coated area to the time taken, which is the efficiency.

[0045] The present invention also discloses a hydraulic support cylinder inner wall performance enhancement device based on CMT ultrasonic brazing, including a control panel 1, a controller 2, a welding machine 3, a wire feeder 4, a welding wire buffer 5, a robotic arm 6, a welding torch 7, an ultrasonic generator 8, and a hydraulic support cylinder special fixture 9.

[0046] The control panel 1 is used to input process parameters to the controller 2;

[0047] The controller 2 controls the brazing current and voltage of the welding machine 3, the wire feeding speed of the wire feeder 4, the brazing speed of the robotic arm 6, the ultrasonic frequency and action time of the ultrasonic generator 8, and the rotation of the hydraulic support cylinder special clamp 9.

[0048] The welding torch 7 is fixed on the robotic arm 6; the robotic arm 6 is a two-axis robotic arm with two degrees of freedom: horizontal and vertical movement; the robotic arm 6 can drive the welding torch 7 to move in the horizontal and vertical directions.

[0049] The hydraulic support cylinder special clamp 9 includes a three-jaw chuck 901 and a servo system 902. In use, the hydraulic support cylinder 13 is fixed by the three-jaw chuck 901, so that the hydraulic support cylinder 13 is horizontally arranged and the cylinder port faces the welding torch 7. The servo system 902 controls the rotation of the three-jaw chuck 901, so that the hydraulic support cylinder 13 rotates with the rotation of the three-jaw chuck 901.

[0050] The specific structure of the welding torch 7 is existing technology. For ease of understanding, the end structure of the welding torch 7 is briefly described as follows: An electrode 11 is provided at the end of the welding torch 7. The welding wire is located in the middle of the electrode 11 and extends beyond the electrode 11. A protective gas cover 10 is provided outside the electrode 11. During welding, the horizontal angle α of the welding wire is 70°, and the distance d between the end of the welding wire and the inner wall of the hydraulic support cylinder 13 is 12mm. Since the welding torch 7 and the welding wire are aligned, the horizontal angle α of the welding torch 7 is 70°.

[0051] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0052] Example 1

[0053] This embodiment uses the aforementioned hydraulic support cylinder inner wall performance enhancement device, and the specific steps are as follows:

[0054] Step 1: Pre-treat the inner wall of the hydraulic cylinder to be brazed by grinding and ultrasonic cleaning to remove the oxide layer on the inner wall of the hydraulic cylinder.

[0055] Step 2: Use ultrasonic processing to process the inner wall of the hydraulic support cylinder into a precision weldable part with dislocation channels.

[0056] Step 3: Set the process parameters on the control panel and install the brazing wire.

[0057] The brazing wire is a self-made cotton-based welding wire with a core and a diameter of 1.05mm.

[0058] The CMT welding current is 18A, the welding voltage is 180V, the wire feed speed is 5m / min, and the welding speed is 200mm / min.

[0059] The distance d between the end of the welding wire of the welding torch and the inner surface of the hydraulic support cylinder is 12mm, the horizontal angle α of the welding torch is 70°, and the shielding gas is helium.

[0060] The ultrasonic generator includes an ultrasonic generator, a cooling system, and a titanium alloy working head. The vibration frequency is 20kHz, the tool head output amplitude is 10μm, and the ultrasonic power supply output power is 500W.

[0061] Step 4: Start the controller to begin coating preparation. At the same time, the ultrasonic generator will start the coating operation from the inside out. The welding gun is operated by the robotic arm. When the welding gun completes one stroke, the ultrasonic generator stops working. After 10 seconds, the special fixture rotates by 9° and a new round of brazing begins until all coating operations on the inner wall of the hydraulic support cylinder are completed.

[0062] Step 5: The inner wall of the hydraulic support cylinder after the brazing is completed is milled, rough polished, and fine polished. The milling, rough polishing, and fine polishing processes will process the coating to 2mm and the surface roughness Ra0.4.

[0063] The performance of the inner wall of the hydraulic support cylinder after treatment was tested. The wear resistance loss was 81.3 mg and the corrosion resistance was 0.762 mm / a.

[0064] Example 2

[0065] This embodiment uses the aforementioned hydraulic support cylinder inner wall performance enhancement device, and the specific steps are as follows:

[0066] Step 1: Pre-treat the inner wall of the hydraulic cylinder to be brazed by grinding and ultrasonic cleaning to remove the oxide layer on the inner wall of the hydraulic cylinder.

[0067] Step 2: Using laser processing methods, the inner wall of the hydraulic support cylinder is processed into a precision weldable part with dislocation channels.

[0068] Step 3: Set the process parameters on the control panel and install the brazing wire.

[0069] The brazing wire is a self-made ball-cored nickel-based welding wire with a diameter of 1.15mm.

[0070] The CMT welding current is 12A, the welding voltage is 122V, the wire feed speed is 3m / min, and the welding speed is 150mm / min. The distance d between the end of the welding wire and the inner surface of the hydraulic support cylinder is 11mm, the horizontal angle α of the welding torch is 65°, and the shielding gas is helium.

[0071] The ultrasonic generator includes an ultrasonic generator, a cooling system, and a titanium alloy working head. The vibration frequency is 19.05kHz, the tool head output amplitude is 3μm, and the ultrasonic power supply output power is 200W.

[0072] Step 4: Start the controller to begin coating preparation. At the same time, the ultrasonic generator will start the coating operation from the inside out. The welding gun is operated by the robotic arm. When the welding gun completes one stroke, the ultrasonic generator stops working. After 15 seconds, the special fixture rotates by 13° and a new round of brazing begins until all coating operations on the inner wall of the hydraulic support cylinder are completed.

[0073] Step 5: The inner wall of the hydraulic support cylinder after the brazing is completed is milled, rough polished, and fine polished. The milling, rough polishing, and fine polishing processes will process the coating to 5mm and the surface roughness Ra0.8.

[0074] The performance of the inner wall of the hydraulic support cylinder after treatment was tested. The wear resistance loss was 89.5 mg and the corrosion resistance was 0.857 mm / a.

[0075] Example 3

[0076] This embodiment uses the aforementioned hydraulic support cylinder inner wall performance enhancement device, and the specific steps are as follows:

[0077] Step 1: Pre-treat the inner wall of the hydraulic cylinder to be brazed by grinding and ultrasonic cleaning to remove the oxide layer on the inner wall of the hydraulic cylinder.

[0078] Step 2: Use ultrasonic processing to process the inner wall of the hydraulic support cylinder into a precision weldable part with dislocation channels.

[0079] Step 3: Set the process parameters on the control panel and install the brazing wire.

[0080] The brazing wire is a self-made ball-cored copper-based welding wire with a diameter of 1.10mm.

[0081] The CMT welding current is 16A, the welding voltage is 202V, the wire feed speed is 6m / min, and the welding speed is 180mm / min. The distance d between the end of the welding wire and the inner surface of the hydraulic support cylinder is 10mm, the horizontal angle α of the welding torch is 60°, and the shielding gas is nitrogen.

[0082] The ultrasonic generator includes an ultrasonic generator, a cooling system, and a titanium alloy working head. The vibration frequency is 20.05kHz, the tool head output amplitude is 7μm, and the ultrasonic power supply output power is 1000W.

[0083] Step 4: Start the controller to begin coating preparation. At the same time, the ultrasonic generator will start the coating operation from the inside out. The welding gun is operated by the robotic arm. When the welding gun completes one stroke, the ultrasonic generator stops working. After 10 seconds, the special fixture rotates by 15° and a new round of brazing begins until all coating operations on the inner wall of the hydraulic support cylinder are completed.

[0084] Step 5: The inner wall of the hydraulic support cylinder after the brazing is completed is milled, rough polished, and fine polished. The milling, rough polishing, and fine polishing processes will process the coating to 2mm and the surface roughness Ra0.4.

[0085] The performance of the inner wall of the hydraulic support cylinder after treatment was tested. The wear resistance loss was 93.2 mg and the corrosion resistance was 0.894 mm / a.

[0086] Comparative Example 1

[0087] This comparative example is a hydraulic support cylinder without any treatment. The performance of the inner wall of the hydraulic support cylinder was tested, and its wear resistance loss was 125.8 mg and its corrosion resistance was 1.616 mm / a.

[0088] Comparative Example 2

[0089] The main steps of this comparative example are the same as those of Example 1, except that in Comparative Example 2, no dislocation channel is machined on the inner wall of the hydraulic support cylinder.

[0090] The performance of the hydraulic support cylinder inner wall was tested, and its wear resistance loss was 107.5 mg, and its corrosion resistance was 1.043 mm / a.

[0091] Comparative Example 3

[0092] The main steps of this comparative example are the same as those of Example 1, except that ultrasonic assistance is not used in Comparative Example 3.

[0093] The performance of the hydraulic support cylinder inner wall was tested, and its wear resistance loss was 118.6 mg and its corrosion resistance was 1.095 mm / a.

[0094] Results Analysis: In Example 1, the hydraulic support cylinder inner wall performance enhancement method based on CMT ultrasonic brazing of the present invention was adopted, and both wear resistance and corrosion resistance were improved.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing, characterized in that, Includes the following steps, S1: Remove the oxide layer from the inner wall of the hydraulic support cylinder; S2: Machining dislocation channels on the inner wall of the hydraulic support cylinder; S3: Perform CMT welding from the inside to the outside on the inner wall of the hydraulic support cylinder. The welding process is accompanied by ultrasonic assistance. Stop ultrasonic assistance when the welding gun completes one stroke. After 10~30 seconds, rotate the hydraulic support cylinder 9~15° and continue brazing until all coating operations on the inner wall of the hydraulic support cylinder are completed. S4: Milling and polishing the inner wall of the hydraulic support cylinder to enhance its performance. In step S3, the CMT welding current is 12~18 A, the welding voltage is 122~202 V, the wire feed speed is 3~6 m / min, and the welding speed is 150~200 mm / min. In step S3, the welding wire used for CMT welding is a self-made copper-based welding wire or a self-made nickel-based welding wire with a chemical core. The self-made flux-cored copper-based welding wire consists of a flux core and a coating. The flux core is a mixture of the following weight components: copper: nickel-manganese alloy: calcium oxide: potassium fluoride: calcium difluoride: manganese oxide: nano nickel formate = 9:4:3.5:3:0.02:0.09:0.

002. The coating is T2 pure copper welding strip with a filler content of 20.5~23.5%. The wire diameter is 1.05~1.15 mm. The self-made flux-cored nickel-based welding wire consists of a flux core and a coating. The flux core is a mixture of the following weight components: nickel: copper-manganese alloy: calcium oxide: potassium fluoride: calcium difluoride: manganese oxide: nano-amorphous nickel = 9:4:3.5:3:0.02:0.09:0.

001. The coating is N6 pure nickel welding strip with a filler ratio of 22.1~23.1%. The wire diameter is 1.05~1.15 mm.

2. The method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing according to claim 1, characterized in that: In step S2, the inner wall of the hydraulic support cylinder is processed into a precision weldment with dislocation channels using ultrasonic, laser, plasma, or micro-electrolysis processing methods.

3. The method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing according to claim 1, characterized in that: In step S3, ultrasonic assistance is provided by an ultrasonic generator, which includes an ultrasonic generator, a cooling system, and a titanium alloy working head. The vibration frequency is 20±0.05kHz, the output amplitude of the working head is 3~10µm, and the output power of the ultrasonic power supply is 0.2~1kW.

4. The method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing according to claim 1, characterized in that: In step S3, during CMT welding, the horizontal angle α of the welding torch is 60~70°, and the distance d between the end of the welding wire and the inner wall of the hydraulic support cylinder is 10~12 mm.

5. The method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing according to claim 1, characterized in that: In step S3, one stroke of the welding torch refers to one welding operation from the bottom of the inner wall of the hydraulic support cylinder to the top of the inner wall of the hydraulic support cylinder. The rotation of the hydraulic support cylinder by 9~15° refers to controlling the hydraulic support cylinder to rotate by 9~15°.

6. The method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing according to claim 1, characterized in that: In step S4, milling and polishing processes process the coating to 2~5 mm with a surface roughness Ra of 0.4~0.

8.

7. A device for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing, the device being based on the method for enhancing the performance of the inner wall of a hydraulic support cylinder based on CMT ultrasonic brazing as described in claim 1, characterized in that, Includes control panel (1), controller (2), welding machine (3), wire feeder (4), wire buffer (5), robotic arm (6), welding torch (7), ultrasonic generator (8), and hydraulic support cylinder special fixture (9). The control panel (1) is used to input process parameters to the controller (2); The controller (2) controls the brazing current and voltage of the welding machine (3), the wire feeding speed of the wire feeder (4), the brazing speed of the robotic arm (6), the ultrasonic frequency and action time of the ultrasonic generator (8), and the rotation amount of the hydraulic support cylinder special clamp (9). The welding torch (7) is fixed on the robotic arm (6); The robotic arm (6) is a two-axis robotic arm (6) with two degrees of freedom: horizontal movement and vertical movement; The hydraulic support cylinder special clamp (9) includes a three-jaw chuck and a servo system.

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