Integrated machining process for special valve sealing element

Abstract

The invention relates to the technical field of mechanical engineering, and discloses a special valve sealing element integrated machining process which comprises the following steps: S1, carrying out ultrasonic cleaning on a high-performance stainless steel or titanium alloy base material to remove oil stains and impurities on the surface; s2, performing one-time rough machining on the outer circle, the inner hole and the end face of the base material by using a five-axis numerical control lathe; s3, the multiple sealing elements are connected into a whole through TIG welding or high-strength epoxy resin bonding; s4, a numerical control grinding machine is adopted for conducting finish machining on the sealing face, and polishing liquid is matched with an automatic polishing machine to enable the surface roughness to meet the design requirement; an anti-corrosion coating is sprayed on the sealing surface according to use requirements; and S5, ultrapure water in a dust-free room environment is adopted for cleaning and drying, and then a pressure sealing test, a temperature resistance test and a corrosion resistance test are conducted. Through TIG welding, hot press molding and X-ray nondestructive testing, connection of multiple parts on the molecular level is achieved through the technology, and defects at joints are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical engineering, and specifically to an integrated processing technology for special valve seals. Background Art

[0002] The existing processing technology for special valve seals is mainly based on traditional machining and assembly techniques. CNC lathes, milling machines, and grinders are widely used to machine the outer diameter, inner hole, and end face of stainless steel or titanium alloy substrates, and then complex geometric shapes are formed by cold stamping. The improvement of sealing performance usually depends on surface polishing and coating treatment, such as using electroless Ni-P coating or PVD coating to enhance corrosion resistance. In addition, multiple sealing elements are often assembled by welding or mechanical fastening methods, and some processes introduce heat treatment to improve material properties. Ultrasonic or X-ray non-destructive testing methods are used for inspection to verify product quality. The above technologies are applied in industries such as oil and gas, and chemical industry, meeting the sealing requirements in some medium and low pressure environments.

[0003] However, there are several deficiencies in the existing processing technology for special valve seals. First, the traditional step-by-step processing and assembly methods result in stress concentration at the joints, and small leaks are likely to occur in the sealing performance under high pressure of 5 - 15 MPa or high temperature of 150 - 250 °C environments, and the fatigue life is limited. Second, most coating technologies are single deposition, with insufficient wear resistance and corrosion resistance. Especially in 5 - 15% salt spray or acidic solutions, the phenomenon of coating peeling is common, affecting the service life. In addition, the production efficiency is low, relying on manual inspection and parameter adjustment, with a high scrap rate, and it is difficult to meet the requirements of mass production. Finally, the existing testing methods cover limited working conditions, and it is difficult to comprehensively verify the reliability of products in extreme environments, resulting in an increased risk of failure in actual applications. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides an integrated processing technology for special valve seals, which solves the problems that the traditional step-by-step processing and assembly methods lead to stress concentration at the joints, and small leaks are likely to occur in the sealing performance under high pressure of 5 - 15 MPa or high temperature of 150 - 250 °C environments, and the fatigue life is limited.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: An integrated processing technology for special valve seals, including the following steps:

[0006] S1. Material pretreatment: Perform ultrasonic cleaning on high-performance stainless steel or titanium alloy substrates to remove surface oil and impurities, then perform annealing treatment to eliminate internal stress, and then achieve the initial surface roughness requirement through sandblasting or chemical polishing;

[0007] S2. Precision forming: Use a five-axis CNC lathe to perform one-time rough machining of the outer circle, inner hole, and end face of the base material; for complex geometric shapes, use customized molds for cold stamping forming with uniform wall thickness; and use laser cladding technology to add wear-resistant coatings in key sealing areas.

[0008] S3. Integrated integration: Connect multiple sealing elements into one by TIG welding or high-strength epoxy resin bonding; then place the prefabricated parts in a high-temperature and high-pressure mold for hot pressing forming to achieve tight bonding between material molecules; and use X-ray non-destructive testing to verify the integrity of the connection parts.

[0009] S4. Finishing and surface treatment: Use a CNC grinding machine to perform finishing on the sealing surface, and use polishing fluid in combination with an automatic polishing machine to make the surface roughness meet the design requirements; spray an anti-corrosion coating on the sealing surface according to the usage requirements.

[0010] S5. Post-treatment and testing: Clean and dry with ultrapure water in a cleanroom environment, and then perform pressure seal testing, temperature resistance testing, and corrosion resistance testing; use a coordinate measuring machine to verify the key dimensions.

[0011] Preferably, in the S1 material pretreatment step, the annealing temperature range is 600 - 700 °C, and the heat preservation time range is 1 - 3 hours; the surface roughness of the base material reaches Ra1.0 - 2.0 μm after sandblasting treatment, and is then optimized to Ra0.4 - 1.0 μm through chemical polishing.

[0012] Preferably, in the S2 precision forming step, the cutting parameters of the CNC lathe are that the spindle speed range is 600 - 1500 rpm, and the feed rate range is 0.05 - 0.15 mm / r; the laser cladding coating material is PTFE or PVD coating, the coating thickness range is 0.03 - 0.15 mm, and the cladding speed range is 3 - 12 mm / s.

[0013] Preferably, in the S3 integrated integration step, the TIG welding parameters are that the current range is 80 - 200 A, and the argon gas flow rate range is 8 - 20 L / min; the hot pressing forming pressure range is 3 - 12 MPa, the temperature range is 120 - 200 °C, and the temperature deviation in the mold is controlled within ±5 - 10 °C.

[0014] Preferably, in the S4 finishing and surface treatment step, emulsified liquid is used as the coolant, the flow rate range is 3 - 12 L / min, and the cutting area temperature is controlled at 15 - 30 °C; the thickness range of the anti-corrosion coating is 0.01 - 0.05 mm.

[0015] Preferably, in the S5 post-processing and testing step, the pressure sealing test pressure range is 5 - 15 MPa, and the duration range is 12 - 36 hours; the temperature resistance test temperature range is 150 - 250 °C, and the number of cycles range is 5 - 15 times; the corrosion resistance test environment is 5 - 15% salt spray or acidic solution, and the test time range is 24 - 96 hours; the critical dimension tolerance range is ±0.005 - 0.02 mm.

[0016] Preferably, it further includes an S6 online monitoring step, where temperature, pressure, and dimension sensors are installed in the welding and grinding processes, and the real-time data is transmitted to the control system, and the process parameters are automatically adjusted when the deviation exceeds the set range.

[0017] Preferably, the base material is 316L stainless steel or high-performance alloy, and the coating is Ni-P or anti-corrosion coating.

[0018] Preferably, the processing technology is suitable for mass production, and the single-piece processing time is optimized to 1 - 2 hours per piece through an automated production line.

[0019] Preferably, the seal has the performance of being resistant to high temperatures of 150 - 250 °C and pressures above 5 - 15 MPa.

[0020] The present invention provides an integrated processing technology for special valve seals. It has the following beneficial effects:

[0021] 1. Through TIG welding, hot pressing, and X-ray non-destructive testing, the technology of the present invention realizes the connection of multiple components at the molecular level, reducing defects at the joints. The welding uses automated equipment, the weld width is controlled at about 2 mm, the hot pressing uses a multi-stage heating program, and the X-ray detection resolution reaches 0.1 mm. Compared with the step-by-step assembly method, the joint strength is increased by 40%, and the fatigue life is extended by 35%, meeting the sealing requirements in the high-pressure environment of 5 - 15 MPa.

[0022] 2. Using a fiber laser and coaxial powder feeding technology, the present invention deposits PTFE or PVD coatings in the key sealing areas, with the coating thickness range of 0.03 - 0.15 mm and the cladding speed of 3 - 12 mm / s. The coating forms a gradient structure through multi-layer deposition, with the wear resistance increased by 30% and the corrosion resistance enhanced by 50% in the 5 - 15% salt spray environment. Compared with the traditional coating method, the risk of coating peeling is reduced, and the service life is extended by 25%.

[0023] 3. Integrating PT100 thermal resistors, piezoresistive pressure sensors, and laser displacement sensors in the welding and grinding processes, the present invention transmits the data to the PLC control system through industrial Ethernet, with the deviation controlled within 5%. The sensors monitor the welding pool temperature and feed rate in real time and adjust the equipment parameters. Compared with the manual detection method, the production efficiency is increased by 15%, the product consistency is improved by 25%, and the scrap rate is reduced.

[0024] 4. The present invention uses a CBN grinding wheel for multi-stage grinding, with a speed range of 20 - 30 m / s. Combined with the treatment of nano-level polishing powder, the surface roughness reaches below Ra 0.2 μm. The Ni-P coating is deposited by electroless plating process, with the pH value controlled at 4.5 - 5.0 and the thickness range of 0.01 - 0.05 mm. Compared with the single polishing process, the micro-cracks are reduced, the corrosion resistance is increased by 50%, and the durability in the environment of 150 - 250 °C is enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a flowchart of the integrated processing technology for the special valve seal of the present invention;

[0026] Figure 2 is a schematic diagram of the PTFE coating of the integrated processing technology for the special valve seal of the present invention;

[0027] Figure 3 is a schematic diagram of the PVD coating of the integrated processing technology for the special valve seal of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] Please refer to the attached Figure 1 - attached Figure 3 , the embodiment of the present invention provides an integrated processing technology for special valve seals, including the following steps:

[0030] S1. Material pretreatment: The high-performance stainless steel or titanium alloy substrate is ultrasonically cleaned to remove surface oil stains and impurities, then annealed to eliminate internal stress, and finally sandblasted or chemically polished to make the surface roughness meet the initial requirements;

[0031] S2. Precision forming: The outer circle, inner hole and end face of the substrate are rough machined at one time by using a five-axis CNC lathe; for complex geometric shapes, cold stamping is performed using a customized mold with uniform wall thickness; and a wear-resistant coating is added in the key sealing area by using laser cladding technology;

[0032] S3. Integrated integration: Multiple sealing elements are connected into one by TIG welding or high-strength epoxy resin bonding; then the prefabricated parts are placed in a high-temperature and high-pressure mold for hot pressing to achieve close combination between material molecules; and X-ray non-destructive testing is used to verify the integrity of the connection part;

[0033] S4, Finish Machining and Surface Treatment: Use a CNC grinding machine to perform finish machining on the sealing surface, and use a polishing liquid in combination with an automatic polishing machine to make the surface roughness meet the design requirements; Spray an anti-corrosion coating on the sealing surface according to the usage requirements.

[0034] S5, Post-treatment and Testing: Clean and dry with ultrapure water in a cleanroom environment, and then conduct pressure seal testing, temperature resistance testing, and corrosion resistance testing; Use a coordinate measuring machine to verify the key dimensions.

[0035] Specifically, for S1 material pretreatment, select 316L stainless steel as the base material, use an industrial ultrasonic cleaning device to clean for 10 minutes at a frequency of 40 kHz to thoroughly remove surface grease and particles, then place it in a vacuum annealing furnace, and gradually heat up to the annealing temperature in a uniform heating manner. During the cooling process, introduce nitrogen for protection to prevent oxidation. For sandblasting, use 80-mesh rigid abrasive, and for chemical polishing, soak in a mixed solution of diluted phosphoric acid and sulfuric acid for 5 minutes; For S2 precision forming, use a five-axis CNC lathe equipped with high-precision cutting tools, and synchronously monitor the cutting force during the processing. For laser cladding, use a 500W fiber laser, and the coating material is evenly deposited through a powder feeding system; For S3 integrated integration, use an automated TIG welding robot, control the weld width to about 2 mm, use a multi-stage heating program for hot pressing to reduce thermal stress, and the resolution of the X-ray detection equipment reaches 0.1 mm; For S4 finish machining and surface treatment, use a multi-stage grinding process, first rough grind and then finish grind, add nano-level polishing powder to the polishing liquid, and the coating is evenly deposited through an electroplating device; For S5 post-treatment and testing, conduct in a constant temperature and humidity cleanroom, use a high-pressure pump for pressure testing to simulate the actual working conditions, and the coordinate measuring machine is equipped with a laser scanning head for comprehensive scanning. The beneficial effects are as follows: This process realizes the full-process optimization of the seal from raw material to finished product through systematic steps, significantly improves the machining accuracy and product consistency, reduces the defective rate by more than 15%, and simultaneously shortens the production cycle by about 20%.

[0036] In the S1 material pretreatment step, the annealing temperature range is 600 - 700 °C, and the holding time range is 1 - 3 hours; The surface roughness of the base material reaches Ra1.0 - 2.0 μm after sandblasting treatment, and is then optimized to Ra0.4 - 1.0 μm through chemical polishing.

[0037] Specifically, in the S1 material pre-treatment, annealing is carried out using a programmable temperature control furnace. The heating rate is controlled at 5 - 10 °C / min. During the holding period, the temperature inside the furnace is monitored in real time through a thermocouple to ensure uniform temperature distribution. Cooling is carried out using a stepwise cooling method to avoid material embrittlement. For sandblasting, abrasive is transported using high-pressure air flow, and the spraying angle is adjusted to 45°. After chemical polishing, it is rinsed with deionized water and the acidic residue is neutralized. In a further implementation, the annealing time can be adjusted according to the substrate thickness. For thin parts, 1 hour is used, and for thick parts, it is extended to 3 hours. The beneficial effects are that the optimized annealing and surface treatment processes effectively eliminate the internal stress of the material, the surface roughness is reduced to the range of Ra0.4 - 1.0 μm, the stability of subsequent processing is enhanced, the service life of the seal is extended by about 25%, and the processing volume of subsequent grinding operations is reduced.

[0038] In the S2 precision forming step, the cutting parameters of the CNC lathe are that the spindle speed range is 600 - 1500 rpm and the feed rate range is 0.05 - 0.15 mm / r. The laser cladding coating material is PTFE or PVD coating, the coating thickness range is 0.03 - 0.15 mm, and the cladding speed range is 3 - 12 mm / s.

[0039] Specifically, in the S2 precision forming, the CNC lathe is equipped with a cooling system. High-pressure jet emulsified liquid is used during the cutting process, and the tool life can reach more than 500 hours. Laser cladding uses coaxial powder feeding technology. The particle size of PTFE powder is controlled at 20 - 50 μm. The PVD coating achieves gradient performance through multi-layer deposition. After cladding, an infrared thermal imager is used to detect the temperature distribution of the coating. Cold stamping forming of complex geometric shapes uses a hydraulic press, and the die surface is nitrided to improve wear resistance. In a further implementation, the spindle speed can be adjusted according to the part size. For small parts, 600 rpm is selected, and for large parts, it can be increased to 1500 rpm. The beneficial effects are that this process realizes a firm combination of the coating and the substrate, the wear resistance is increased by more than 30%, the friction coefficient is reduced by about 20%, and at the same time, it meets the processing requirements of various geometric structures and improves production flexibility.

[0040] In the S3 integrated integration step, the TIG welding parameters are that the current range is 80 - 200 A and the argon gas flow range is 8 - 20 L / min. The hot pressing forming pressure range is 3 - 12 MPa, the temperature range is 120 - 200 °C, and the temperature deviation inside the die is controlled within ±5 - 10 °C.

[0041] Specifically, in the S3 integrated integration, the TIG welding adopts a pulsed current mode. During the welding process, a filler is added to enhance the weld strength. Argon is supplied through a double protection device to ensure that the weld is free of oxidation. Heating rods and cooling channels are embedded in the hot pressing die. The PID control system is used to adjust the temperature. The pressure is applied in stages through a hydraulic system. After X-ray detection, ultrasonic flaw detection is combined to further verify internal defects. In a further implementation method, the hot pressing time can be adjusted according to the complexity of the seal. For a simple structure, it is pressed for 10 minutes, and for a complex structure, it is extended to 20 minutes. The beneficial effects are that this method realizes seamless connection between multiple components, reduces the air leakage risk at the joint by about 40%, the hot pressing process reduces internal stress, and extends the fatigue life of the product by 35%. The detection accuracy improves the overall reliability.

[0042] In the S4 finishing and surface treatment steps, emulsified liquid is used as the coolant, and the flow rate range is 3 - 12 L / min. The temperature in the cutting area is controlled at 15 - 30 °C. The thickness range of the anti-corrosion coating is 0.01 - 0.05 mm.

[0043] Specifically, in the S4 finishing and surface treatment, a CBN grinding wheel is used on the CNC grinding machine, and the grinding speed is 20 - 30 m / s. After rough grinding, a fine-grained grinding wheel is replaced for finishing. The temperature of the polishing liquid is controlled at 20 - 25 °C, and a surfactant is added to enhance the cleaning effect. The Ni-P coating is achieved through an electroless plating process. The pH value of the plating solution is adjusted to 4.5 - 5.0, and the deposition time is controlled within 1 - 2 hours. In a further implementation method, the electroplating current density can be adjusted according to the coating thickness requirement. For a thin layer, 2 A / dm 2 is selected, and for a thick layer, it is increased to 5 A / dm 2 . The beneficial effects are that the multi-stage grinding and precise coating process make the surface roughness reach below Ra0.2 μm, the corrosion resistance is increased by more than 50%, the surface micro-cracks are reduced, and the durability of the seal in a high-temperature environment is improved.

[0044] In the S5 post-treatment and testing steps, the pressure seal test pressure range is 5 - 15 MPa, and the duration range is 12 - 36 hours; the temperature resistance test temperature range is 150 - 250 °C, and the number of cycles range is 5 - 15 times; the corrosion resistance test environment is 5 - 15% salt spray or acidic solution, and the test time range is 24 - 96 hours; the critical dimension tolerance range is ±0.005 - 0.02 mm.

[0045] Specifically, in the post-processing and testing of S5, a circulating ultrapure water system with a flow rate of 5L / min is used for cleaning, and a hot air circulation oven is used for drying with a wind speed controlled at 2-3m / s; a multi-channel pressure sensor is used for pressure testing to simulate pulse loading conditions, and the temperature resistance test is carried out in a constant temperature box equipped with thermocouples to monitor the temperature at each point; a salt spray box is used for corrosion resistance testing with a spray volume of 1-2mL / h, and a stirring device is used for acid solution testing to maintain uniform concentration, and the scanning resolution of the coordinate measuring machine reaches 0.001mm. In a further implementation method, the number of test cycles can be adjusted according to the working conditions, and the high-pressure environment is increased to 15 times. The beneficial effect is that the comprehensive test covers a variety of working conditions, the detection accuracy is improved by 20%, and the product reliability verification rate is more than 98%, which meets the needs of harsh industrial environments and reduces the risk of failure during use.

[0046] It also includes the S6 online monitoring step, installing temperature, pressure and dimension sensors in the welding and grinding processes, transmitting real-time data to the control system, and automatically adjusting process parameters when deviations exceed the set range.

[0047] Specifically, in the S6 online monitoring step, the temperature sensor uses a PT100 thermal resistor, the pressure sensor is a high-precision piezoresistive type, and the size sensor uses a laser displacement sensor. The data is transmitted to the PLC control system via industrial Ethernet, the alarm threshold is set, and the equipment parameters are adjusted in conjunction; the welding pool temperature is monitored during the welding process, and the feed rate is corrected in real time during the grinding process. In further implementation, a visual inspection system can be added to identify surface defects and record data. The beneficial effect is that real-time monitoring reduces human intervention, process deviations are controlled within 5%, production efficiency is increased by 15%, product consistency is improved by 25%, scrap rate is reduced, and process parameters are optimized.

[0048] The substrate is 316L stainless steel or high performance alloy, and the coating is Ni-P or anti-corrosion coating.

[0049] Specifically, the substrate is made of 316L stainless steel, which is rolled into a plate after smelting in an electric arc furnace. The thickness ranges from 2 to 10 mm. The Ni-P coating is deposited by a chemical plating process, and the phosphorus content of the coating is controlled at 8-12%, which is suitable for the oil and gas valve environment. An anti-static workbench is used during the processing, which meets the sealing performance requirements of the API6A standard. In a further implementation method, a titanium alloy substrate can be selected according to the working conditions, and the coating can be replaced with a CrN layer to adapt to a more corrosive environment. The beneficial effect is that the material selection optimizes the corrosion resistance and pressure resistance, meets industry standards, extends the service life by 30%, and reduces maintenance costs by about 20%.

[0050] The processing technology is suitable for mass production, and the single-piece processing time is optimized to 1-2 hours / piece through automated assembly lines.

[0051] Specifically, the processing technology introduces an automated production line, equipped with multi-station CNC machine tools and robotic arms. AGV is used for transportation between processes. The single-piece processing time is achieved at 1 - 2 hours per piece through optimizing the path planning. A buffer is set up during the production process to reduce the equipment downtime, and the MES system is used to record the production data. In a further implementation, parallel processing units can be added to process multiple batches of products. The beneficial effects are that the automated production increases the production capacity by more than 40%, reduces the labor cost by 30%, reduces the product quality fluctuation, and meets the demands of large-volume orders.

[0052] The seal has the properties of being resistant to high temperatures of 150 - 250 °C and pressures of 5 - 15 MPa or more.

[0053] Specifically, in the high-temperature resistance test of the seal, ceramic fiber thermal insulation materials are used. In the pressure resistance test, a multi-stage loading method is used to gradually increase the pressure to 5 - 15 MPa, and the deformation amount is analyzed after the test. After processing, microstructure analysis is carried out to confirm that the grain size is less than 10 μm. In a further implementation, an antioxidant coating can be added to enhance the high-temperature stability. The beneficial effects are that the optimized temperature and pressure resistance properties meet the requirements of extreme working conditions, the deformation amount is controlled below 0.1%, the product reliability is increased by 35%, and the risk of thermal fatigue failure is reduced.

[0054] The following is an introduction in combination with specific embodiments:

[0055] Example 1: The highest data range

[0056] Material pretreatment

[0057] The base material is selected as 316L stainless steel. The ultrasonic cleaning frequency is 40 kHz and lasts for 15 minutes; the annealing temperature is 700 °C, and the heat preservation is for 3 hours. The cooling is carried out under nitrogen protection; the abrasive used for sandblasting is 100 mesh, and the chemical polishing is carried out by soaking in a mixed solution of phosphoric acid and sulfuric acid for 10 minutes, and the surface roughness reaches Ra1.0 μm.

[0058] Precision forming

[0059] The spindle speed of the five-axis CNC lathe is 1500 rpm, and the feed rate is 0.15 mm / r; for cold stamping forming, a Cr12MoV die is used, and the pressure of the hydraulic press is 12 MPa; for laser cladding, a 500W fiber laser is used, the thickness of the PTFE coating is 0.15 mm, and the cladding speed is 12 mm / s.

[0060] Integrated integration

[0061] The TIG welding current is 200 A, the argon gas flow rate is 20 L / min, and the weld width is 2.5 mm; the hot pressing forming pressure is 12 MPa, the temperature is 200 °C, and the die temperature deviation is ±10 °C; the X-ray detection resolution is 0.1 mm.

[0062] Finishing and surface treatment

[0063] The grinding speed of the CNC grinding machine is 30 m / s, nano-scale polishing powder is added to the polishing liquid, and the surface roughness reaches Ra 0.2 μm; the thickness of the Ni-P coating is 0.05 mm, the pH value of electroless plating is 5.0, and the deposition time is 2 hours.

[0064] Post-treatment and testing

[0065] The flow rate of ultra-pure water for cleaning is 5 L / min, and the drying temperature is 80 °C; the pressure seal test is 15 MPa and lasts for 36 hours; the temperature resistance test is 250 °C and cycles 15 times; the corrosion resistance test is 15% salt spray and lasts for 96 hours; the resolution of the coordinate measuring machine is 0.001 mm, and the dimensional tolerance is ±0.005 mm.

[0066] Applicable scenarios

[0067] This embodiment is applicable to extreme working conditions, such as high-pressure and high-temperature valves in the oil and gas industry, meeting the API 6A standard.

[0068] Example 2: Intermediate data range

[0069] Material pre-treatment

[0070] The base material is made of titanium alloy, the ultrasonic cleaning frequency is 40 kHz, and it lasts for 10 minutes; the annealing temperature is 650 °C, the holding time is 2 hours, and the cooling is protected by nitrogen; the abrasive used for sandblasting is 80 mesh, and the chemical polishing immersion time is 7 minutes, and the surface roughness reaches Ra 1.5 μm.

[0071] Precision forming

[0072] The spindle speed of the five-axis CNC lathe is 1000 rpm, and the feed rate is 0.1 mm / r; the pressure of the cold stamping die is 7 MPa; the laser cladding uses a 400 W fiber laser, the PVD coating thickness is 0.09 mm, and the cladding speed is 7 mm / s.

[0073] Integrated integration

[0074] The TIG welding current is 120 A, the argon gas flow rate is 12 L / min, and the weld width is 2 mm; the hot pressing forming pressure is 7 MPa, the temperature is 160 °C, and the die temperature deviation is ±7 °C; the resolution of the X-ray detection is 0.1 mm.

[0075] Finishing and surface treatment

[0076] The grinding speed of the CNC grinding machine is 25 m / s, the temperature of the polishing liquid is 22 °C, and the surface roughness reaches Ra 0.25 μm; the thickness of the Ni-P coating is 0.03 mm, the pH value of electroless plating is 4.8, and the deposition time is 1.5 hours.

[0077] Post-treatment and testing

[0078] Ultra-pure water cleaning flow rate: 4 L / min, drying temperature: 70 °C; Pressure seal test: 10 MPa, duration: 24 hours; Temperature resistance test: 200 °C, cycle: 10 times; Corrosion resistance test: 10% salt spray, duration: 48 hours; Coordinate measuring machine resolution: 0.001 mm, dimensional tolerance: ±0.01 mm.

[0079] Applicable scenarios

[0080] This embodiment is applicable to medium-pressure and medium-temperature environments, such as medium-sized valves in the chemical industry, meeting general industrial standards.

[0081] Example 3: Minimum data range

[0082] Material pretreatment

[0083] The base material is selected as 316L stainless steel, ultrasonic cleaning frequency: 40 kHz, duration: 5 minutes; Annealing temperature: 600 °C, heat preservation: 1 hour, natural cooling; Sandblasting uses 60-mesh abrasive, chemical polishing immersion: 5 minutes, surface roughness reaches Ra2.0 μm.

[0084] Precision forming

[0085] Spindle speed of five-axis CNC lathe: 600 rpm, feed rate: 0.05 mm / r; Cold stamping forming die pressure: 3 MPa; Laser cladding uses a 300W fiber laser, PTFE coating thickness: 0.03 mm, cladding speed: 3 mm / s.

[0086] Integrated integration

[0087] TIG welding current: 80 A, argon gas flow rate: 8 L / min, weld width: 1.5 mm; Hot pressing forming pressure: 3 MPa, temperature: 120 °C, die temperature deviation: ±5 °C; X-ray detection resolution: 0.1 mm.

[0088] Finishing and surface treatment

[0089] Grinding speed of CNC grinder: 20 m / s, polishing liquid temperature: 20 °C, surface roughness reaches Ra0.3 μm; Ni-P coating thickness: 0.01 mm, pH value of electroless plating: 4.5, deposition time: 1 hour.

[0090] Post-treatment and testing

[0091] Ultra-pure water cleaning flow rate: 3 L / min, drying temperature: 60 °C; Pressure seal test: 5 MPa, duration: 12 hours; Temperature resistance test: 150 °C, cycle: 5 times; Corrosion resistance test: 5% salt spray, duration: 24 hours; Coordinate measuring machine resolution: 0.001 mm, dimensional tolerance: ±0.02 mm.

[0092] Applicable scenarios

[0093] This embodiment is applicable to low - pressure and low - temperature environments, such as small valves in the water treatment industry, and meets the basic performance requirements.

[0094] Table 1: Comparison Table of Special Valve Seal Properties

[0095]

[0096] Table Explanation

[0097] Sealing Performance (Leakage Rate, %)

[0098] In Examples 1 - 3, due to seamless integration and precision coating, the leakage rate gradually decreases. The prior art has a higher leakage rate due to joint defects.

[0099] Pressure Resistance Performance (MPa)

[0100] The examples improve the pressure resistance ability according to the data range. The prior art is unstable under high pressure and is prone to micro - leakage.

[0101] Temperature Resistance Performance (°C)

[0102] The examples expand the temperature resistance range by optimizing heat treatment and coating. The prior art has local deformation at high temperatures.

[0103] Corrosion Resistance Performance (Weight Loss Rate after 48 - hour Salt Spray Test, mg / cm 2 )

[0104] The examples use laser cladding and multi - level coatings, and the corrosion resistance is better than the prior art, with a significantly reduced weight loss rate.

[0105] Service Life (years)

[0106] The examples extend the service life due to process improvement. The prior art has a shorter service life due to material and joint limitations.

[0107] Production Efficiency (pieces / day)

[0108] The examples improve the efficiency through an automated production line. The prior art has a lower efficiency due to dependence on manual labor.

[0109] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. The integrated processing technology of special valve seals is characterized by: The following steps are involved: S1. Material pretreatment: ultrasonic cleaning of high-performance stainless steel or titanium alloy substrates to remove surface oil and impurities, followed by annealing to eliminate internal stress, and then sandblasting or chemical polishing to make the surface roughness meet the initial requirements; S2, precision forming, using a five-axis CNC lathe to perform one-time rough machining of the substrate's outer circle, inner hole and end face; using customized molds to cold stamp complex geometric shapes with uniform wall thickness; and using laser cladding technology to add wear-resistant coatings in key sealing areas; S3, integrated integration, multiple sealing components are connected into one by TIG welding or high-strength epoxy resin bonding; the prefabricated parts are then placed in a high-temperature and high-pressure mold for hot pressing to achieve close bonding between material molecules; and the integrity of the connection parts is verified by X-ray non-destructive testing; S4, finishing and surface treatment, use CNC grinder to finish the sealing surface, and use polishing liquid with automatic polishing machine to make the surface roughness meet the design requirements; spray anti-corrosion coating on the sealing surface according to the use requirements; S5, post-processing and testing, using ultrapure water in a clean room environment to clean and dry, followed by pressure sealing test, temperature resistance test and corrosion resistance test; using a three-coordinate measuring machine to verify key dimensions.

2. The integrated processing technology for special valve seals according to claim 1 is characterized in that: In the S1 material pretreatment step, the annealing temperature ranges from 600 to 700° C. and the holding time ranges from 1 to 3 hours; the surface roughness of the substrate reaches Ra 1.0 to 2.0 μm after sandblasting, and is then optimized to Ra 0.4 to 1.0 μm through chemical polishing.

3. The integrated processing technology for special valve seals according to claim 1 is characterized in that: In the S2 precision forming step, the CNC lathe cutting parameters are as follows: the spindle speed range is 600-1500rpm, the feed rate range is 0.05-0.15mm / r; the laser cladding coating material is PTFE or PVD coating, the coating thickness range is 0.03-0.15mm, and the cladding speed range is 3-12mm / s.

4. The integrated processing technology for special valve seals according to claim 1 is characterized in that: In the S3 integrated integration step, the TIG welding parameters are a current range of 80-200A and an argon gas flow range of 8-20L / min; the hot pressing pressure range is 3-12MPa, the temperature range is 120-200°C, and the temperature deviation in the mold is controlled within ±5-10°C.

5. The integrated processing technology for special valve seals according to claim 1 is characterized in that: In the S4 finishing and surface treatment step, an emulsion is used as a coolant with a flow rate range of 3-12 L / min, and the temperature of the cutting zone is controlled at 15-30° C.; the thickness of the anti-corrosion coating ranges from 0.01 to 0.05 mm.

6. The integrated processing technology for special valve seals according to claim 1 is characterized in that: In the S5 post-processing and testing step, the pressure sealing test pressure range is 5-15MPa, and the duration range is 12-36 hours; the temperature resistance test temperature range is 150-250°C, and the number of cycles range is 5-15 times; the corrosion resistance test environment is 5-15% salt spray or acid solution, and the test time range is 24-96 hours; the key dimension tolerance range is ±0.005-0.02mm.

7. The integrated processing technology for special valve seals according to claim 1, characterized in that: It also includes the S6 online monitoring step, installing temperature, pressure and dimension sensors in the welding and grinding processes, transmitting real-time data to the control system, and automatically adjusting process parameters when deviations exceed the set range.

8. The integrated processing technology for special valve seals according to claim 1, characterized in that: The substrate is 316L stainless steel or a high-performance alloy, and the coating is Ni-P or an anti-corrosion coating.

9. The integrated processing technology for special valve seals according to claim 1, characterized in that: The processing technology is suitable for mass production, and the single-piece processing time is optimized to 1-2 hours / piece through an automated assembly line.

10. The integrated processing technology for special valve seals according to claim 1, characterized in that: The sealing element has the performance of high temperature resistance of 150-250°C and pressure resistance of 5-15MPa or more.

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