Electroplating electrophoresis process for steel plate type heating radiator

Abstract

The invention relates to the technical field of heating radiator electroplating and electrophoresis, and particularly discloses a steel plate type heating radiator electroplating and electrophoresis process which comprises a pretreatment process, an electroplating process, an electrophoretic coating process, an intelligent temperature control curing process and a full-process intelligent monitoring system. And the compactness, the corrosion resistance and the self-repairing capability of the plating layer are obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radiator electroplating and electrophoresis, and specifically discloses a steel plate radiator electroplating and electrophoresis process. Background Art

[0002] As the core component of the heating system, steel plate radiators are exposed to high temperature, humidity, and complex water quality environments for a long time. Their surface treatment process directly determines the corrosion resistance, heat conduction efficiency, and service life of the product. The traditional process mostly uses alkaline degreasing → pickling → electrogalvanizing → electrophoretic coating, but there are significant drawbacks:

[0003] Incomplete pre-treatment: Conventional alkaline degreasing agents (such as NaOH, Na3PO4) have low removal efficiency for stubborn oil stains (such as stamping oil, anti-rust oil) (residue > 50mg / m 2 ), resulting in poor adhesion of subsequent coatings (cross-hatch test adhesion ≤ level 3), especially in complex cavity structures where coating peeling is likely to occur;

[0004] Insufficient electroplating performance: The porosity of ordinary copper / nickel plating layers is as high as 15-20 per cm 2 (GB / T 1771 salt spray test <240h), and the coating hardness is low (HV <300), which cannot resist the micro-crack expansion caused by long-term thermal expansion and contraction of the radiator;

[0005] Electrophoresis uniformity challenges: The existing electrophoresis process uses a fixed electrode spacing design, which results in concentrated electric fields at the edges of the workpiece, resulting in film thickness variations of up to ±5μm (ISO 2808). This reduces water resistance in thin areas (bubbling occurs after a 2-hour boiling water test), while thick areas are prone to sagging.

[0006] Rough control of the curing process: Traditional hot air curing relies on a fixed temperature rise curve, which cannot adapt to the cross-linking requirements of different thickness areas. Local over-curing (Tg>150℃) causes coating embrittlement, while under-curing (cross-linking degree <80%) leads to poor solvent resistance (butanone wipes>50 times reveal the bottom).

[0007] While recent research has attempted to improve coating performance by introducing nanomaterials (such as CNTs and graphene), two major bottlenecks remain. First, nanoparticles tend to agglomerate in the plating solution (DLS particle size distribution half-peak width > 100nm), causing stress concentration in the coating. Second, their single function fails to synergize the advantages of nano-enhancement and intelligent control. Furthermore, existing processes lack closed-loop quality control throughout the entire process, resulting in delayed parameter adjustments and difficulties in achieving real-time optimization.

[0008] Therefore, in view of this, the inventor provides a steel plate radiator electroplating electrophoresis process to solve the above problems. Summary of the Invention

[0009] The present invention proposes an electrophoretic plating process for steel plate radiators, which significantly improves the density, corrosion resistance and self-repair ability of the coating through composite modification of nanomaterials, gradient coating design and intelligent monitoring means.

[0010] In order to achieve the above-mentioned object, the basic solution of the present invention provides a steel plate radiator electrophoresis plating process, comprising:

[0011] S001 pre-treatment process:

[0012] (a) Alkaline environment pulse ultrasonic degreasing: The workpiece is immersed in an alkaline degreasing solution (pH 9-10) composed of cocamidopropyl betaine (5-8wt%), nano-titanium dioxide dispersion (1-3wt%, particle size 50-100nm), and sodium silicate (3-5g / L) and treated at 40-50℃ under pulse ultrasonic conditions for 10-15min.

[0013] (b) Acid pickling and activation of the nano-diamond particles: using a hydrochloric acid solution containing a urotropine corrosion inhibitor (0.1% to 0.3%) and nano-diamond particles (0.05-0.1 g / L), stirring and activating the workpiece with a dischargeable stirring rod while the workpiece rotates;

[0014] (c) Neutralization and water washing: After neutralization with 5-10g / L sodium carbonate solution, wash with deionized water cleaning equipment until the surface water film is continuous and without breaks;

[0015] S002 electroplating process:

[0016] (a) Graphene-enhanced pre-copper plating: The electrolyte contains 20-30 g / L copper sulfate, 50-80 g / L sulfuric acid, 0.05-0.1 g / L polyethylene glycol, and graphene nanosheets. Pulse current is used for pre-plating for 5-8 minutes.

[0017] Formation of transition layer;

[0018] (b) Electroplating of carbon nanotubes with nickel-phosphorus alloy: The electrolyte contains 25-35 g / L nickel sulfate, 20-30 g / L sodium hypophosphite, 15-20 g / L sodium acetate, 5-10 mL / L propionic acid, and a carbon nanotube dispersion (0.2-0.5 g / L). The phosphorus content gradient is controlled by bidirectional pulse current, and the coating thickness is 5-8 μm.

[0019] (c) Filtration and rinsing: ceramic membrane filtration is used to reduce heavy metal ion emissions;

[0020] S003: Electrophoretic coating process:

[0021] (a) Preparation of nano-silica composite electrophoretic fluid: Add 5-10 wt% silane-modified nano-silica (particle size 20-50 nm) and 2-5 wt% microcapsule-type corrosion inhibitor to a water-based acrylic resin with a solid content of 15% to 20%; pH value is 6.5-7.5;

[0022] (b) Electrophoresis coating in an alternating electric field environment: Electrophoresis coating is performed for 3-5 minutes under an alternating electric field with a dynamic adjustment device for the distance between the workpiece and the anode plate, forming a gradient wet film with an edge thickness of 12-15 μm and a flat surface thickness of 10-12 μm. The microcapsule-type corrosion inhibitor releases the corrosion inhibitor when the coating is damaged to achieve self-repair.

[0023] (c) Ultrafiltration membrane combined with water washing: filtration and water washing were performed using an ultrafiltration membrane with a molecular weight cut-off of 15-25 kDa;

[0024] S004 intelligent temperature control curing process:

[0025] (a) Pre-baking of infrared arrays: Pre-baking in a hot air circulation oven at 80-100°C (wind speed 1-2 m / s, with several built-in infrared temperature measurement arrays) for 10-15 minutes;

[0026] (b) Neural network temperature-controlled curing: The heating rate is dynamically adjusted through a neural network algorithm, and the temperature is maintained at 160-180°C in a nitrogen protective atmosphere (oxygen content ≤ 500ppm) for 20-30 minutes. The temperature difference in each area is monitored by a thermal imager to avoid local over-curing.

[0027] Furthermore, it also includes a full-process intelligent monitoring system, which includes:

[0028] Multi-dimensional sensor array: integrated with oil residue optical fiber sensor, coating porosity detector, wet film thickness laser thickness gauge and coating hardness dynamic indentation sensor;

[0029] Prediction and adaptive control unit: predicts salt spray resistance time, coating adhesion, etc. through data processing. When quality risks are predicted, the degreasing time, carbon nanotube dispersion addition amount or curing time are increased.

[0030] Furthermore, the temperature of the hydrochloric acid solution is 20-30° C., and the workpiece is rotated at a rate of 5-10 r / min, thereby ensuring uniform activation of the cavity and the corners.

[0031] Furthermore, deionized water cleaning equipment is provided between the pre-treatment process, the electroplating process and the electrophoretic coating process.

[0032] Furthermore, the process also includes a surface roughness adjustment step between the electroplating process and the electrophoretic coating process: the surface of the nickel-phosphorus alloy coating is electropolished, the polishing liquid is a phosphoric acid-sulfuric acid mixture (volume ratio 3:1), and the current density is 5-8A / dm2 , processing time 2-3min, make the surface roughness of the coating Ra ≤ 0.1μm.

[0033] Furthermore, the graphene nanosheets undergo the following steps during processing:

[0034] (a) Graphene surface pretreatment: a copper layer is deposited on the graphene surface by ultrasonic dispersion and chemical copper plating to form a copper-plated graphene core-shell structure;

[0035] (b) Graphene equidistribution: Graphene equidistribution by ultrasonic cavitation and high-speed shearing.

[0036] Furthermore, the dynamic spacing adjustment device includes: a three-dimensional position detection module for obtaining real-time surface curvature data of the workpiece, a deformable array composed of several groups of flexible anode plates, and an edge computing controller. Each group of anode plates realizes X / Y / Z three-axis motion through an independent servo motor-ball screw mechanism. The edge computing controller is configured with a surface fitting algorithm and an electric field uniformity optimization model to generate anode plate position adjustment instructions based on the detection data.

[0037] Furthermore, the deionized water cleaning equipment includes a first-stage pre-wash tank, a second-stage fine wash tank, and a third-stage pure wash tank connected in sequence along the workpiece transmission direction. The third-stage pure wash tank is connected to the deionized water preparation unit. The second-stage fine wash tank receives the overflow water of the third-stage pure wash tank through a countercurrent pipeline, and the first-stage pre-wash tank receives the overflow water of the second-stage fine wash tank through a countercurrent pipeline. Each stage of the tank body is equipped with a spray device, a liquid level sensor and a conductivity monitor. The deionized water preparation unit includes an RO reverse osmosis membrane assembly and a mixed bed ion exchange resin. The system realizes water flow gradient adjustment and dynamic water quality monitoring through a PLC control module.

[0038] The principles and effects of this basic solution are:

[0039] 1. Nano-synergistic strengthening effect:

[0040] Oil removal stage: Nano-TiO2 (50-100nm) generates hydroxyl free radicals under the action of pulsed ultrasonic cavitation (the decomposition efficiency of oil stains is improved, and combined with the penetration effect of cocamidopropyl betaine, the residual oil stains are basically removed;

[0041] Electroplating stage: The copper-plated graphene core-shell structure (copper layer thickness 10-15nm) acts as a conductive bridge to reduce the resistivity of the pre-plated copper layer and increase the hardness;

[0042] Electrophoresis stage: Silane-modified nano-SiO2 (20-50nm) forms an organic-inorganic interpenetrating network with acrylic resin, which increases the wear resistance of the coating by 2 times, and the microcapsule corrosion inhibitor greatly improves the scratch self-repair efficiency.

[0043] 2. Advantages of gradient structure design:

[0044] Phosphorus content gradient coating: high phosphorus (12wt%) in the bottom layer provides corrosion resistance, low phosphorus (8wt%) in the surface layer enhances hardness, and no red rust in the neutral salt spray test for ≥1000h;

[0045] 3. Film thickness gradient electrophoretic coating: 12-15μm film thickness at the edge effectively prevents damage from bumps, 10-12μm film thickness on the flat surface takes into account both thermal conductivity and corrosion resistance requirements, and the film thickness uniformity error is ≤±1.5μm (CV value <5%).

[0046] 4. Intelligent process control:

[0047] Dynamic electric field adjustment: The flexible anode plate array adjusts the pole distance in real time according to the curvature of the workpiece, reducing the difference in film thickness inside complex cavities;

[0048] Neural network temperature control: Neural network based on thermal imaging data, with high prediction accuracy and reduced curing energy consumption;

[0049] Closed-loop quality monitoring: Through real-time feedback from fiber optic sensors and electrochemical impedance spectroscopy, the system can identify coating defects and adjust parameters (such as extending the pickling time by 20%) to reduce product defect rates.

[0050] 5. Environmental protection and economic benefits:

[0051] Heavy metal recovery: Ceramic membrane filtration) significantly reduces electroplating rinse water discharge and wastewater treatment costs;

[0052] Water-saving design: The deionized water cleaning equipment adopts a three-stage countercurrent cleaning water circulation method with high utilization rate, which saves a lot of water compared with single-tank cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0054] Figure 1 A schematic diagram of a process flow of electrophoresis plating for a steel plate radiator according to an embodiment of the present application is shown;

[0055] Figure 2 A schematic diagram of a fully intelligent monitoring system for the electroplating and electrophoresis process of a steel plate radiator proposed in an embodiment of the present application is shown;

[0056] Figure 3 A schematic diagram of a dynamic spacing adjustment device for a steel plate radiator electroplating and electrophoresis process proposed in an embodiment of the present application is shown;

[0057] Figure 4 A schematic diagram of a deionized water preparation unit for a steel plate radiator electroplating electrophoresis process proposed in an embodiment of the present application is shown;

[0058] Figure 5 A schematic diagram of a deionized water cleaning device for a steel plate radiator electroplating electrophoresis process proposed in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0059] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0060] The reference numerals in the drawings of the specification include: pre-wash tank 1, fine wash tank 2, pure wash tank 3, pipeline 4, conductivity meter 5, adjustable high-pressure sprinkler head 6, pH sensor 7, turbidity meter 8, and water inlet pipe 9.

[0061] A steel plate radiator electroplating electrophoresis process, for example Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown: 1. Process steps

[0062] S001 Pre-treatment process

[0063] (a) Alkaline Pulsed Ultrasonic Degreasing: Workpieces are immersed in an alkaline degreasing solution (pH 9-10) containing cocamidopropyl betaine (5-8wt%), a nano-titanium dioxide dispersion (1-3wt%, particle size 50-100nm), and sodium silicate (3-5g / L). The treatment is carried out at 40-50°C under pulsed ultrasonic waves (frequency 20-40kHz, duty cycle 3:2) for 10-15 minutes. The nano-titanium dioxide enhances oil decomposition through its photocatalytic effect, while the pulsed ultrasound reduces bubble adhesion, improving degreasing efficiency on complex structures.

[0064] (b) Acid pickling activation of nano-diamond particles: A hydrochloric acid solution (5-10 vol%, 20-30°C) containing hexamethylenetetramine corrosion inhibitor (0.1%-0.3%) and nano-diamond particles (0.05-0.1 g / L) was used, while the workpiece was rotated (5-10 rpm) with intermittent current stirring (current density 0.5-1.0 A / dm 2 The high hardness of nanodiamonds promotes the exfoliation of oxide scales, and intermittent stirring is used to avoid localized over-corrosion.

[0065] (c) Neutralization and water washing: After neutralization with 5-10g / L sodium carbonate solution, wash with deionized water cleaning equipment until the surface water film is continuous and unbroken (conductivity ≤ 10μS / cm).

[0066] S002 electroplating process

[0067] First, use the electrolyte of copper sulfate 20-30g / L and sulfuric acid 50-80g / L at a current density of 1.0-1.5A / dm 2 Pre-copper plating for 5-8 minutes under the conditions to form a transition copper layer with a thickness of 2-3 μm; then use an electrolyte of nickel sulfate 25-35 g / L, sodium hypophosphite 20-30 g / L, sodium acetate 15-20 g / L, and propionic acid 5-10 mL / L at a pH of 4.5-5.5, a temperature of 50-60 ° C, and a current density of 2.0-3.0 A / dm 2 Under the conditions of electroplating nickel-phosphorus alloy for 20-30 minutes, an amorphous nickel-phosphorus alloy coating with a thickness of 5-8 μm and a phosphorus content of 8% to 12% (mass fraction) is formed; after electroplating, a countercurrent rinsing process is adopted with a water recovery rate of ≥80%; then a ceramic membrane (pore size 0.1 μm) is used to filter the rinsing liquid to recover heavy metal ions, and deionized water cleaning equipment is used for rinsing.

[0068] S003 electrophoretic coating process

[0069] A water-based acrylic resin cathode electrophoretic coating with a solid content of 15% to 20% and a pH value of 6.5 to 7.5 is used. Nano-silicon dioxide particles accounting for 5% to 10% of the solid content of the coating are added to the coating. Cathodic electrophoresis is performed under the conditions of a voltage of 180 to 220 V and a coating time of 3 to 5 minutes to form a 10-15 μm wet film on the surface of the workpiece. After electrophoresis, an ultrafiltration membrane with a molecular weight cutoff of 15 to 25 kDa is used for circulation filtration, and residual organic matter is adsorbed with activated carbon. At the same time, deionized water cleaning equipment is used for cleaning.

[0070] S004 Intelligent Temperature Control Curing Process

[0071] (a) Infrared array pre-baking: 80-100°C hot air circulation pre-baking for 10-15 minutes, and the infrared temperature measurement array monitors the temperature distribution in real time;

[0072] (b) Neural network temperature control curing: Based on thermal imaging data, the temperature rise curve is dynamically adjusted through the BP neural network, and the coating is kept at 160-180℃ in a nitrogen atmosphere with an oxygen content of ≤500ppm for 20-30 minutes to achieve a cross-linking degree of more than 90%.

[0073] 2. Preferred solution

[0074] (1) Full-process intelligent monitoring system: Integrates optical fiber sensors (to detect oil residues), electrochemical impedance spectrometers (to evaluate coating porosity), laser thickness gauges (to monitor wet film thickness), and dynamic indentation sensors. It uses machine learning models to predict salt spray resistance time and dynamically adjust process parameters (such as extending degreasing time or increasing the amount of carbon nanotubes added).

[0075] (2) Surface roughness adjustment: an electrolytic polishing step is added between the electroplating and electrophoresis processes, using a phosphoric acid-sulfuric acid mixture (3:1 volume ratio) with a current density of 5-8 A / dm 2 , process for 2-3 minutes to make Ra ≤ 0.1μm.

[0076] (3) Graphene pretreatment: Graphene nanosheets (particle size 5-10 μm) were first ultrasonically dispersed in an ethanol solution containing 0.5-1.0 g / L sodium dodecylbenzene sulfonate (SDBS) for 30-60 min, and then a copper layer with a thickness of 20-50 nm was deposited on the graphene surface by a chemical copper plating process (copper sulfate 5-10 g / L, formaldehyde 10-15 mL / L, pH 11-12) to form a copper-plated graphene core-shell structure to solve the wettability problem of graphene and copper matrix. 0.01-0.05 g / L copper-plated graphene (modified with silane coupling agent KH550) and 0.05-0.1 g / L polyethylene glycol (PEG) were added to the electrolyte, and a bidirectional pulse current (forward current density 1.5-2.0 A / dm 2 , reverse current density 0.5-1.0A / dm 2 , frequency 500-1000 Hz) for pre-copper plating, and dynamic magnetic field stirring (magnetic field strength 0.1-0.3 T, rotation speed 200-300 r / min) is used to achieve the gradient distribution of graphene in the copper plating layer (surface graphene content 1.5-2.0wt%, inner layer 0.5-1.0wt%). The copper layer on the surface of the copper-plated graphene forms a metallurgical bonding interface with the pre-plated copper layer. The graphene sheets are bonded to the copper substrate through π-π stacking. The coating bonding force is ≥5.5N / cm (3-4N / cm in traditional processes), the surface roughness Ra is ≤0.15μm, the thermal conductivity is improved by 20% to 30%, and the copper-plated graphene dispersion has a delamination rate of ≤3% when left standing for 24 hours under high temperature conditions of 80-100°C. The nano-scale uniform distribution of graphene is achieved through the synergistic effect of high-speed shear dispersion (10,000-15,000r / min, time 30min) and ultrasonic cavitation (power 200-300W, frequency 40-60kHz).

[0077] (4) Anode plate dynamic adjustment device: It consists of 12 groups of flexible anode plates, which realize three-axis motion through a servo motor-ball screw mechanism. The surface curvature data of the workpiece is obtained in real time through a three-dimensional position detection module. The electric field distribution is optimized based on the surface fitting algorithm. Each group of anode plates realizes X / Y / Z three-axis motion through an independent servo motor-ball screw mechanism. The edge computing controller is configured with a surface fitting algorithm and an electric field uniformity optimization model. The anode plate position adjustment command is generated according to the detection data to ensure that the film thickness uniformity error of complex curved surface parts is ≤±1.5μm.

[0078] Deionized water cleaning equipment is set between the pre-treatment process, electroplating process and electrophoretic coating process. The deionized water cleaning equipment includes a first-stage rinsing tank (pre-wash tank 1), a second-stage rinsing tank (fine washing tank 2), and a third-stage rinsing tank (pure washing tank 3) arranged in sequence along the workpiece transmission direction. Adjustable high-pressure spray heads 6 (such as fan-shaped nozzles) are installed on the top and side of the tank body. The spray pressure is 0.2-0.5MPa, which forms a cross-washing in accordance with the movement direction of the workpiece; the third-stage pure washing tank 3 spray head has a built-in nano-scale filter membrane (pore size ≤ 5μm) to prevent secondary contamination. The pure washing tank 3 is connected to the high-purity water (conductivity ≤ 10μS / cm) produced by the deionized water preparation unit through the water inlet pipe 9 as the starting point of the system water source. The fine washing tank 2 pumps the overflow water (conductivity ≤ 50μS / cm) of the pure washing tank 3 through the pipeline 4 as the second-stage cleaning water. The first-stage pre-wash tank 1 receives overflow water (conductivity ≤ 150 μS / cm) from the second-stage tank body and is used to preliminarily rinse the electroplating solution or electrophoretic paint remaining on the surface of the workpiece.

[0079] The system also includes a matching deionized water preparation unit, countercurrent circulation piping, and an intelligent control system. Each tank stage utilizes pipes 4 and pumps to achieve countercurrent water circulation, creating a gradient cleaning pattern where pure water from the final stage replenishes the previous stage, and wastewater from the previous stage is reused in the final stage. The deionized water preparation unit includes a sequential system of quartz sand filtration, activated carbon adsorption, RO reverse osmosis membrane (salt rejection ≥ 99%), and mixed-bed ion exchange resin treatment to meet water demand. The intelligent control system includes conductivity meters 5, pH sensors 7, and turbidity meters 8 installed within each tank stage to monitor water quality parameters in real time.

[0080] The use process of the present invention is as follows:

[0081] Example 1

[0082] Take the Q235 steel plate radiator and process it according to the following steps:

[0083] The alkaline degreasing solution consists of 7 wt% cocamidopropyl betaine, 2 wt% nano-TiO2 (80 nm), and 4 g / L sodium silicate, and is treated with pulsed ultrasound (frequency 28 kHz, pulse period 2 s) at 45°C for 12 min.

[0084] The pickling solution contained 0.2% hexamethylenetetramine and 0.08 g / L nanodiamonds and was activated by rotating (8 rpm) at 30 °C for 8 min.

[0085] 0.2g / L copper-plated graphene is added to the pre-copper plating solution, and the pulse current density is 3A / dm 2 , plating 6min;

[0086] 0.4 g / L carbon nanotubes were added to the nickel-phosphorus plating solution, with a phosphorus content gradient of 8% to 12% and a coating thickness of 7 μm;

[0087] The electrophoretic solution contains 8wt% nano-SiO2 and 3wt% microcapsule corrosion inhibitor, the alternating electric field frequency is 1Hz, and the film thickness gradient is 13μm (edge) / 11μm (plane);

[0088] During the curing stage, the heating rate is controlled by a neural network, and the final coating hardness reaches 4H and the salt spray resistance reaches 1200h.

[0089] Example 2

[0090] Based on Example 1, the intelligent monitoring system is started: when the porosity of the coating is detected to be greater than 5 / cm 2 When the amount of carbon nanotube dispersion added is automatically increased to 0.5g / L, and the pickling time is extended to 10min. The porosity of the coating is finally reduced to 2 / cm 2 , salt spray resistance time is increased to 1500h.

[0091] The present invention proposes an electrophoretic plating process for steel plate radiators, which significantly improves the density, corrosion resistance and self-repair ability of the coating through composite modification of nanomaterials, gradient coating design and intelligent monitoring means.

[0092] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A steel plate radiator electroplating electrophoresis process, characterized in that: include: S001 pre-treatment process: (a) Alkaline environment pulse ultrasonic degreasing: The workpiece is immersed in an alkaline degreasing solution (pH 9-10) composed of cocamidopropyl betaine (5-8wt%), nano-titanium dioxide dispersion (1-3wt%, particle size 50-100nm), and sodium silicate (3-5g / L) and treated at 40-50℃ under pulse ultrasonic conditions for 10-15min. (b) Acid pickling and activation of the nano-diamond particles: using a hydrochloric acid solution containing a urotropine corrosion inhibitor (0.1% to 0.3%) and nano-diamond particles (0.05-0.1 g / L), stirring and activating the workpiece with a dischargeable stirring rod while the workpiece rotates; (c) Neutralization and water washing: After neutralization with 5-10g / L sodium carbonate solution, wash with deionized water cleaning equipment until the surface water film is continuous and without breaks; S002 electroplating process: (a) Graphene-enhanced pre-copper plating: The electrolyte contains 20-30 g / L copper sulfate, 50-80 g / L sulfuric acid, 0.05-0.1 g / L polyethylene glycol, and graphene nanosheets. Pulse current is used for pre-plating for 5-8 minutes. Formation of transition layer; (b) Electroplating of carbon nanotubes with nickel-phosphorus alloy: The electrolyte contains 25-35 g / L nickel sulfate, 20-30 g / L sodium hypophosphite, 15-20 g / L sodium acetate, 5-10 mL / L propionic acid, and a carbon nanotube dispersion (0.2-0.5 g / L). The phosphorus content gradient is controlled by bidirectional pulse current, and the coating thickness is 5-8 μm. (c) Filtration and rinsing: using ceramic membrane filtration to reduce heavy metal ion emissions, and rinsing with deionized water cleaning equipment; S003: Electrophoretic coating process: (a) Preparation of nano-silica composite electrophoretic fluid: Add 5-10 wt% silane-modified nano-silica (particle size 20-50 nm) and 2-5 wt% microcapsule-type corrosion inhibitor to a water-based acrylic resin with a solid content of 15% to 20%; pH value is 6.5-7.5; (b) Electrophoresis coating in an alternating electric field environment: Electrophoresis coating is performed for 3-5 minutes under an alternating electric field with a dynamic adjustment device for the distance between the workpiece and the anode plate, forming a gradient wet film with an edge thickness of 12-15 μm and a flat surface thickness of 10-12 μm. The microcapsule-type corrosion inhibitor releases the corrosion inhibitor when the coating is damaged to achieve self-repair. (c) Ultrafiltration membrane combined with water washing: use ultrafiltration membrane for filtration and deionized water cleaning equipment for washing; S004 intelligent temperature control curing process: (a) Pre-baking of infrared arrays: Pre-baking in a hot air circulation oven at 80-100°C (wind speed 1-2 m / s, with several built-in infrared temperature measurement arrays) for 10-15 minutes; (b) Neural network temperature-controlled curing: The heating rate is dynamically adjusted through a neural network algorithm, and the temperature is maintained at 160-180°C in a nitrogen protective atmosphere (oxygen content ≤ 500ppm) for 20-30 minutes. The temperature difference in each area is monitored by a thermal imager to avoid local over-curing.

2. The electroplating electrophoresis process for steel plate radiators according to claim 1, characterized in that: It also includes a full-process intelligent monitoring system, which includes: Multi-dimensional sensor array: integrated with oil residue optical fiber sensor, coating porosity detector, wet film thickness laser thickness gauge and coating hardness dynamic indentation sensor; Prediction and adaptive control unit: predicts salt spray resistance time, coating adhesion, etc. through data processing. When quality risks are predicted, the degreasing time, carbon nanotube dispersion addition amount or curing time are increased.

3. The electroplating electrophoresis process for steel plate radiator according to claim 1, characterized in that: The temperature of the hydrochloric acid solution is 20-30° C., and the workpiece is rotated at a speed of 5-10 r / min, thereby ensuring uniform activation of the cavity and corners.

4. The electroplating electrophoresis process for steel plate radiators according to claim 1, characterized in that: Deionized water cleaning equipment is provided between the pre-treatment process, the electroplating process and the electrophoretic coating process.

5. The electroplating electrophoresis process for steel plate radiator according to claim 1, characterized in that: The process also includes a surface roughness adjustment step between the electroplating process and the electrophoretic coating process: the surface of the nickel-phosphorus alloy coating is electropolished, the polishing liquid is a phosphoric acid-sulfuric acid mixture (volume ratio 3:1), and the current density is 5-8A / dm 2 , processing time 2-3min, make the surface roughness of the coating Ra ≤ 0.1μm.

6. The electroplating electrophoresis process for steel plate radiator according to claim 1, characterized in that: The graphene nanosheets undergo the following steps during processing: (a) Graphene surface pretreatment: a copper layer is deposited on the graphene surface by ultrasonic dispersion and chemical copper plating to form a copper-plated graphene core-shell structure; (b) Graphene equidistribution: Graphene equidistribution by ultrasonic cavitation and high-speed shearing.

7. The electroplating electrophoresis process for steel plate radiators according to claim 1, characterized in that: The dynamic spacing adjustment device includes: a three-dimensional position detection module for obtaining workpiece surface curvature data in real time, a deformable array composed of several groups of flexible anode plates, and an edge computing controller. Each group of anode plates realizes X / Y / Z three-axis motion through an independent servo motor-ball screw mechanism. The edge computing controller is configured with a surface fitting algorithm and an electric field uniformity optimization model to generate anode plate position adjustment instructions based on the detection data.

8. The electroplating electrophoresis process for steel plate radiators according to claim 4, characterized in that: The deionized water cleaning equipment includes a first-stage pre-wash tank, a second-stage fine wash tank, and a third-stage pure wash tank connected in sequence along the workpiece transmission direction. The third-stage pure wash tank is connected to a deionized water preparation unit. The second-stage fine wash tank receives overflow water from the third-stage pure wash tank through a countercurrent pipeline. The first-stage pre-wash tank receives overflow water from the second-stage fine wash tank through a countercurrent pipeline. Each stage of the tank body is equipped with a spray device, a liquid level sensor, and a conductivity monitor. The deionized water preparation unit includes an RO reverse osmosis membrane assembly and a mixed bed ion exchange resin. The system realizes water flow gradient regulation and dynamic water quality monitoring through a PLC control module.

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