228 results about "Pitting corrosion" patented technology

The invention discloses an intelligent steel pipe surface defect recognition system based on deep learning, and particularly relates to the technical field of pipe surface defect analysis. An annular polarization light source array and a high-frame-rate CMOS sensor are adopted to synchronously collect visible light and near-infrared multi-polarization images; a surface normal is calculated based on Stokes parameters, mirror surface suppression and diffuse reflection enhancement are realized, a defect candidate area is generated by fusing multi-scale Laplacian pyramid residual error and Renyi entropy segmentation threshold positioning, multi-physical quantity registration is completed through white light interference and infrared thermal imaging, a six-channel feature cube is constructed, and a three-dimensional image is obtained. According to the method, space, spectrum and thermal characteristics are jointly extracted in the multi-head attention convolutional neural network, the confidence coefficient is evaluated in combination with Jensen-Shannon divergence, and the polarization angle and the focal length are dynamically adjusted according to the confidence coefficient, so that closed-loop parameter self-optimization is realized, and the micro-scale pitting corrosion and millimeter-scale crack detection precision is remarkably improved.

The invention belongs to the field of prediction of fatigue failure caused by surface defects under rolling contact loads, and particularly relates to a rolling contact fatigue pitting corrosion prediction method considering crystal plasticity, a corresponding computer readable storage medium and electronic equipment. The method comprises the following steps: S1, constructing a crystal plastic constitutive model of a coupling damage accumulation theory; s2, developing the model in the step 1 into a UMAT subprogram by using Fortran, and embedding ABAQUS into the UMAT subprogram; s3, establishing a representative volume element crystal plastic finite element model; s4, applying a periodic boundary condition and a shear load, obtaining a shear stress-strain curve, carrying out a torsional fatigue test, obtaining fatigue damage parameters of the material, and determining constitutive model parameters of the material; s5, establishing a crystal plastic finite element model of the roller and raceway contact pair; s6, applying boundary conditions in two steps; and S7, observing a damage evolution path to the surface, and obtaining the rolling contact fatigue pitting corrosion life. The method can fill the blank of rolling contact fatigue pitting corrosion prediction methods at present.

The invention discloses a corrosion-resistant aluminum alloy profile and a preparation method thereof, and belongs to the technical field of aluminum alloy profiles. By optimizing the components of the corrosion-resistant aluminum alloy, the strength of the aluminum alloy profile can be guaranteed, and the corrosion resistance of the aluminum alloy profile is positively influenced. Besides, the corrosion-resistant coating is formed on the surface of the corrosion-resistant aluminum alloy base material in a laser cladding mode, the corrosion resistance of the aluminum alloy profile can be remarkably improved while the application performance of the aluminum alloy profile is guaranteed, and in the corrosion-resistant coating, nickel powder can enhance pitting corrosion resistance and intergranular corrosion resistance, so that the corrosion resistance of the aluminum alloy profile is improved. The adhesive force with an aluminum alloy base material is improved; the boron nitride can improve the acid resistance and wear resistance of the surface of the aluminum alloy profile and block a corrosion channel; the lanthanum oxide and the cerium dioxide have a synergistic effect, so that surface grains can be refined, air holes generated in the cladding process are reduced, the compactness of the coating is improved, the compatibility with an aluminum alloy base material is promoted, and the apparent quality of the aluminum alloy profile is guaranteed.

The invention relates to the technical field of lamps, in particular to a plating forming process of a lamp. The problems that the interface bonding force of the coating and the matrix is insufficient and the corrosion resistance of the coating is poor are solved. According to the method, micro-arc oxidation is carried out in the pretreatment stage, a compact Al-Si-O ceramic layer is generated on the surface of a high-aluminum matrix in situ, and in combination with deep diffusion of plasma siliconizing, a transition area with gradient Si distribution is constructed; the pitting corrosion resistance of the coating is optimized through the component gradient design of the inner-layer coating, the middle-layer coating and the outer-layer coating; the surface of the coating lamp is subjected to checkerboard scanning by using short pulse laser, so that the porosity and microdefects of the surface of the coating are improved, and the corrosion resistance of the coating is enhanced; a uniform oxynitride passivation film is generated on the surface of the coating in situ through low-temperature plasma post-oxidation-nitridation treatment, the defect that a film layer is easy to strip in a traditional passivation process is avoided, and the corrosion resistance of the material in long-term service can be stably maintained.

The invention belongs to the technical field of wind turbine generators, and particularly relates to a wind turbine generator fault early warning and abnormal parameter inspection method comprising the following steps: collecting historical operation data of a wind turbine generator, analyzing the data, and establishing a data model; the historical data comprises operation data of a generator, a gear box, a main bearing, a variable pitch system and an electrical system; vibration spectrums of a gearbox and a generator rotating part are monitored through an acceleration sensor to identify whether bearing pitting corrosion, gear tooth breakage mechanical faults and frequency are abnormal or not; an on-line monitoring device is installed in an oil way of the wind turbine generator to monitor the oil state in real time. The temperature of the gearbox and the bearing is detected through the thermal infrared imager, and whether the temperature is abnormal or not is monitored; abnormal sound signals of blade cracks or bearing early damage are captured through an ultrasonic sensor, and the blade is judged.

The invention discloses a material tensile strength testing device suitable for a high-humidity and high-salt environment, the material tensile strength testing device comprises a box body, two connecting plates are fixedly connected to the rear side, close to the top, of an inner cavity of the box body, the two connecting plates are arranged in a bilateral symmetry mode, and two concentric-square-shaped frames are jointly and fixedly connected between the two connecting plates; through mutual cooperation of a driving gear, a concave mounting plate, an A-shaped mounting plate, a driving motor, a cleaning gear, an inner gear ring and the like, the outer surface of a reinforcing steel bar can be pretreated, and the situation that a test result is affected by corrosion of the surface of the reinforcing steel bar is prevented; through mutual cooperation of a component moving motor, a connecting plate, a double-thread lead screw, a moving block, a salt spray test box, a linkage rod, absorption cotton and other components, when a steel bar is tested in a continuous salt spray environment, salt spray liquid drops are attached to the outer surface of the steel bar, so that the surface of a sample is condensed; a local electrolyte membrane can be prevented from being formed on the surface of the steel bar to accelerate pitting corrosion or galvanic corrosion.

The invention relates to economical corrosion-resistant 5Cr80 rare earth oil well pipe steel and a preparation method thereof, belongs to the technical field of corrosion-resistant oil well pipe steel for petroleum engineering, and aims to solve the problems that the cost is high due to addition of precious metals such as Mo and Ni in existing medium Cr steel, pitting corrosion is induced by inclusion of MnS, and a rare earth treatment process is unstable. The oil well pipe steel is prepared from the following chemical components in percentage by mass: 0.05 percent to 0.08 percent of C, 0.3 percent to 0.50 percent of Si, 0.80 percent to 1.5 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.0020 percent of S, less than or equal to 0.0020 percent of O, 0.0050 percent to 0.0350 percent of Ce, 4.5 percent to 5.5 percent of Cr, less than or equal to 0.035 percent of Al, 0.020 percent to 0.030 percent of V and the balance of Fe and inevitable impurities. The yield strength of the oil well pipe steel is larger than or equal to 580 MPa. The economical corrosion-resistant 5Cr80 rare earth oil well pipe steel which is low in cost and free of a Mo-Ni component system is used for replacing a traditional high-alloy pipe in a harsh oil and gas well environment containing high Cl <-> and CO2, and the economical corrosion-resistant 5Cr80 rare earth oil well pipe steel is suitable for batch production of corrosion-resistant oil well pipes of deep wells, ultra-deep wells and sulfur-containing and CO2-containing complex working conditions.

The invention relates to the technical field of alloy processing, and discloses a high-performance corrosion-resistant nickel-based alloy plate and a preparation method thereof, and the method comprises the following steps: raw material preparation, smelting treatment, casting treatment, hot rolling treatment, solution treatment, aging treatment and surface passivation treatment. According to the invention, when a composite acid system is adopted for passivation treatment, the concentration of chromium / molybdenum atoms in a passivation film is optimized and balanced due to the specific ratio of nitric acid to chromic acid, a chromium oxide provides a compact passivation barrier, and a molybdenum oxide endows the film layer with a self-repairing characteristic to synergistically inhibit pitting nucleation; meanwhile, nano titanium dioxide particles pretreated by silane are embedded into the passivation film in situ under the action of ultrasonic oscillation, organic pollutants adsorbed on a film layer can be decomposed by the photocatalytic characteristic of the nano titanium dioxide particles, the local corrosion effect of a battery caused by dirt coverage is avoided, and the performance of the battery is improved through double upgrading of components and the structure of the passivation film. And the alloy plate has excellent pitting corrosion resistance and fouling resistance in a chloride ion-containing medium.

The invention discloses a corrosion-induced stress full-coupling characterization method. The method comprises the following steps: characterizing an electrochemical corrosion degree based on a corrosion dynamics principle; representing a three-dimensional stress field of the metal structure based on a mechanical constitutive relation; the interaction of corrosion and stress is considered based on a corrosion expansion theory and a mechanical chemistry theory; a corrosion-induced stress full coupling model considering the interaction of corrosion and stress; and the influence of the corrosion induced stress on the corrosion process is quantified. According to the method, a corrosion expansion theory and a mechanical chemical effect are introduced into a mechanical constitutive equation and a current density equation respectively, and the corrosion-induced stress full-coupling characterization method is constructed. According to the method, collaborative characterization of force and electrochemical information in the corrosion dynamic evolution process is realized, stress evolution information induced by the corrosion process is characterized, the influence of corrosion induced stress on the corrosion process is considered, and time nonlinear characteristics and spatial heterogeneity of mechanical and electrochemical parameters in the pitting evolution process are disclosed.

The invention belongs to the technical field of stainless steel composite plates, and particularly relates to an iron-nickel stainless steel composite plate production process which comprises the following steps: performing plasma sputtering cleaning on a carbon steel base layer; the iron-nickel-stainless steel composite layer is subjected to laser micro-cladding treatment to form a micro-groove array, and a nano nickel-titanium alloy transition layer is preset in the micro-groove array; explosive cladding is carried out in a helium and argon mixed gas environment with the oxygen content smaller than or equal to 10 ppm, so that the carbon steel base layer and the iron-nickel-stainless steel cladding layer are subjected to interface metallurgical bonding to form a composite plate blank; the composite plate blank is hot-rolled and water-cooled to 500 DEG C or below after being heated and subjected to heat preservation; and the rolled composite plate blank is placed in mixed gas of nitrogen and hydrogen for isolation annealing, the bonding strength and the shearing strength are improved through an interface gradient diffusion layer composite structure constructed through the nanoscale, and interface oxidation and stress concentration in the rolling process are inhibited through asymmetrical rolling and a nanometer heat insulation coating; and multi-stage controlled cooling and diffusion barrier annealing are cooperatively regulated and controlled, so that the pitting corrosion resistance potential of the iron-nickel stainless steel clad layer is improved.

The invention discloses a high-robustness multi-scale defect detection method for a metal matrix surface, and relates to the technical field of machine vision and surface defect detection. In order to solve the problems of large scale difference of metal matrix surface defects, strong background noise and easy missing detection of tiny targets in a complex service environment, an EMA-YOLO deep network proposed by the invention is characterized in that an efficient multi-scale attention (EMA) mechanism is introduced into a YOLOv8 backbone network, and the influence of background interferences such as surface water stains and oil stains on defect identification is inhibited through a cross-space learning strategy; a P2 layer-based high-resolution tiny target detection head is constructed, and shallow geometric details are reserved to accurately capture early pitting corrosion and microcracks; a Shape-IoU loss function is introduced, and through shape perception and adaptive weight adjustment, the positioning precision of cracks and irregular spalling defects with extreme length-width ratios is optimized. The EMA-YOLO deep network provided by the invention can effectively improve the accuracy, stability and robustness of multi-scale defect detection under a complex texture background.

The invention provides a method for evaluating the corrosion behavior of a small hole of an anticorrosive coating under the action of current. The method comprises the following steps: (1) acquiring corrosion kinetic parameters of a metal material; (2) constructing a parameterized multi-physical field model; (3) simulating a corrosion evolution process; (4) verifying the reliability of the model through experiments; and (5) constructing a comprehensive evaluation index. Obtaining corrosion kinetic parameters (corrosion potential, corrosion current density, Tafel slope and exchange current density) of the metal material through a potentiodynamic polarization curve test; the method comprises the following steps: preparing an anticorrosive coating metal sample with artificial pores, constructing a parameterized multi-physical field model by combining finite element software, and simulating local current density distribution and corrosion evolution under different pore diameters (greater than or equal to 2 mm), spacing (greater than or equal to 0 mm) and current density (greater than or equal to 0 A / m < 2 >); the reliability (corrosion potential error lt, 20%) of the model is verified through experiments, a comprehensive evaluation index is constructed based on multi-parameter sensitivity analysis, and rapid evaluation of the corrosion risk of the small hole of the anticorrosive coating and protection scheme optimization are achieved.

The invention relates to the technical field of image recognition, in particular to an agricultural machinery gear pitting measurement method based on KANs, which comprises the following steps: acquiring a gear pitting image through image acquisition equipment; unifying the resolutions of the gear pitting images and preprocessing the gear pitting images; making a segmentation label of the processed gear pitting image and dividing a data set, wherein the data set is divided into a training set and a verification set; the P-KAN module and the D-KAN module are combined with the convolution block, and a U-KAN + network is constructed; inputting the training set into the U-KAN + network, and performing iterative updating training on the U-KAN + network by using a cross entropy loss function considering category weight; and inputting the verification set into the trained U-KAN + network, segmenting an effective tooth surface and a pitting corrosion area of the gear, and detecting the gear through a segmentation index. According to the method, the segmentation precision of the gear pitting corrosion image can be effectively improved, so that the problem of efficiently and accurately detecting the gear failure in the gear contact fatigue test is solved.

The invention relates to the technical field of circuit board electroplating, in particular to a floating ball linkage type PCB electroplating bath liquid level mechanical adjusting device which comprises an electroplating bath, a switch button, a connecting rod mechanism and a guide rail and further comprises a floating ball, a driving assembly, an annular plate assembly and a protection assembly. The floating ball is driven to rotate through the driving assembly, pitting corrosion caused by the fact that the bottom of the floating ball is still below the liquid level for a long time is avoided, meanwhile, the situation that the weight of the floating ball is affected after electroplating liquid attached to the upper side of the floating ball is condensed into solid is avoided, and therefore the accuracy of liquid level measurement and control of the floating ball is guaranteed; meanwhile, the floating ball is separated from the fluctuating liquid level through the annular plate assembly, so that the influence of liquid level fluctuation on the floating ball is reduced to a certain extent; in addition, protection airflow is formed on the surface, close to the liquid level, of the connecting rod mechanism through the protection assembly, so that the surface, close to the liquid level, of the connecting rod mechanism is dry and clean, and the situation that the liquid level control accuracy of the floating ball is affected due to the weight change caused by condensation of by-products is avoided.

The present invention belongs to the technical field of metal materials, and particularly relates to a high-corrosion-resistant magnesium alloy sheet having filiform corrosion characteristics and a preparation method thereof. Based on the total amount of the magnesium alloy sheet, in terms of mass percentage, the magnesium alloy sheet contains the following elements: Al: 6-9%, Sc: 0.05-0.15%, Y: 0.05-0.15%, Mn: 0.05-0.15%, and the balance is Mg and inevitable impurity elements; the alloy preparation method includes: alloy ingot melting, ingot solution treatment, extrusion into sheets, and then multi-pass rolling treatment and aging heat treatment regulation. Among them, the magnesium alloy sheet has a phase structure of dispersed Mg 17 Al 12 phase, and its corrosion behavior is typical filiform corrosion characteristics, which has the advantages of shallow corrosion depth and small destructiveness compared with traditional pitting corrosion. The magnesium alloy sheet in the present invention has excellent mechanical properties and corrosion resistance.

The invention belongs to the technical field of anti-freezing solutions, particularly relates to an anti-freezing cooling liquid and a preparation method and application thereof, and provides an all-organic heat transfer system anti-freezing cooling liquid which contains efficient all-organic adsorption acid and an anti-corrosion inhibition additive, has better anti-corrosion and anti-rust capabilities on various metals, and has a good anti-freezing effect. And the anti-corrosion agent has excellent anti-rust function for soldering tin, cast aluminum, cast iron, steel, brass, red copper and the like, especially the anti-corrosion performance of a wet cylinder sleeve of a heavy-duty vehicle. The lubricating oil has excellent cavitation erosion resistance and pitting corrosion resistance, and has an excellent protection effect on an engine cooling system. The anti-freezing cooling liquid product is free of precipitates, stable in performance, safe, non-toxic, green and environment-friendly.

The invention discloses an aluminum pipe, a heat exchanger and application thereof, and belongs to the technical field of heat exchange materials. The aluminum pipe comprises an aluminum pipe base material layer and a zinc impregnation layer arranged on the surface of the aluminum pipe base material layer. The zinc impregnation layer has a zinc concentration gradient which is gradually reduced from outside to inside; the maximum zinc concentration of the zinc impregnation layer is 0.01 to 10 weight percent; the thickness of the zinc impregnation layer is larger than 0 and smaller than or equal to 400 micrometers. The zinc impregnation layer is formed on the surface of the aluminum pipe base material layer, corrosion can be limited from expanding to the inner layer, longitudinal expansion of corrosion is avoided, pitting corrosion is inhibited, the zinc content distribution of the zinc impregnation layer at different zinc impregnation depths can be controlled by controlling the maximum zinc concentration and thickness of the zinc impregnation layer, and the corrosion resistance of the aluminum pipe is improved. The zinc impregnation layer has a good anodic protection effect on the aluminum pipe, pitting corrosion extension is effectively inhibited, the corrosion resistance of the aluminum pipe is improved, and the service life of the aluminum pipe is prolonged.

The invention relates to the technical field of medical instruments, in particular to a medical magnesium alloy anchor and a preparation method thereof.The technical scheme includes that the medical magnesium alloy anchor comprises an anchor material, and the anchor material is a magnesium alloy anchor outer structure support formed by at least one of zirconium dioxide prepared through 3D printing, polycaprolactone and PLGA; the composite amorphous alloy prepared from the other three kinds of magnesium, zinc and calcium alloy powder is filled in pores of the support, and finally surface treatment is carried out on the surface of the anchor. Compared with a traditional magnesium alloy anchor nail, a stable supporting structure is provided for the anchor nail by means of the 3D-printed outer structure support and the internal high-strength amorphous composite magnesium alloy, the structural stability after implantation can be effectively maintained through the structural design, and the stability of the anchor nail is improved. The instant loss of mechanical properties caused by pitting corrosion cannot occur after corrosion, and the problems of structural integrity damage, deformation, displacement and the like possibly caused by early corrosion of a traditional anchor in a bone are solved.

The invention relates to the technical field of detection, in particular to a valve quality detection method and system. According to the method, a valve is divided into sub-blocks, ultrasonic thickness, eddy current pitting corrosion signals, temperature, pH value, Cl <-> concentration and other environmental parameters are synchronously collected, a comprehensive corrosion coefficient is generated through a formula, a laser displacement meter is used for conducting three-dimensional scanning on a valve rod to obtain crack point cloud data, the volume density is calculated, and a health index is generated through fusion for decision making. The system comprises a multi-mode sensor, an active scanning module, a data analysis module and a decision output module, and the detection precision is improved through an anti-shake mechanism and a transfer learning model. According to the method, the problems of insufficient local corrosion capture, crack depth deficiency, complex structure shielding leak detection and the like in traditional detection are solved, accurate evaluation of the health state of the valve is realized, a scientific basis is provided for predictive maintenance of valves in petrochemical engineering, electric power and other industries, and the risks of production shutdown and equipment damage are effectively reduced.

The invention relates to the technical field of corrosion monitoring, and provides a titanium equipment pitting early warning method and system based on electrochemical impedance spectroscopy analysis, and the method comprises the steps: collecting an electrochemical impedance spectroscopy original response signal, and carrying out the spectroscopic normalization of the electrochemical impedance spectroscopy original response signal to obtain an effective characteristic segment; performing decoupling analysis on the real part and the imaginary part of the effective feature segment to obtain decoupling component data, and performing phase correction on the decoupling component data to obtain a calibrated component; constructing an impedance characteristic spectrum by taking the capacitive reactance characteristic in the calibrated component as a center and the impedance characteristic in the calibrated component as an edge; performing precursor targeted identification on the impedance characteristic spectrum to obtain pitting precursor characteristics; performing development gradient deduction on the pitting precursor features to obtain pitting evolution data; performing hierarchy judgment on the pitting evolution data to obtain a risk hierarchy, and generating early warning information according to the risk hierarchy; according to the method, the pitting early warning efficiency of the titanium equipment can be improved.

According to the anodic oxidation technology suitable for the 6061 aluminum alloy, multi-component silica sol is adopted for conducting room-temperature dipping hole sealing and low-temperature curing on a 6061 aluminum alloy anodic oxidation film, and technology energy consumption and equipment requirements are reduced. The dense silicon network seals the membrane holes, prolongs the diffusion path of a corrosive medium and prevents the corrosive medium from invading the substrate, thereby greatly improving the corrosion resistance of the membrane layer and inhibiting pitting corrosion.

The invention belongs to the technical field of metal material plating, and particularly relates to a connector surface composite coating and a preparation process thereof, and the preparation process comprises the following steps: adding modified carbon black and sodium molybdate into deionized water, stirring to obtain a corrosion inhibition material, and mixing with modified zinc oxide to obtain a mixed filler; the preparation method comprises the following steps: adding dibutyltin dilaurate and toluene diisocynate into polypropylene glycol to obtain a core material; adding hexadecyl trimethyl ammonium bromide and the mixed filler into a 93-96 wt% ethanol solution, adding the core material for emulsification, adding an isophorone diisocyanate solution, and stirring to obtain a microcapsule; nickel sulfate hexahydrate, nickel chloride hexahydrate, sodium citrate, boric acid, a surface dispersant, a sodium hydroxide solution and microcapsules are added into deionized water to be mixed, and an electroplating solution is obtained; and putting the connector into the electroplating solution for electroplating to obtain the composite coating. The expansion of pitting corrosion can be inhibited, and the long-term use reliability and stability of the connector in a marine environment are improved.

The invention provides a method for removing a low-temperature oxidation film on the surface of a titanium alloy plate strip and a regeneration method of a used solution, and relates to the technical field of metal surface cleaning. Comprising the steps that firstly, a titanium alloy plate strip is subjected to rolling deformation, cooled and then soaked in a mixed aqueous solution of oxalic acid and sodium chloride at the temperature of 60-80 DEG C, meanwhile, the titanium alloy plate is connected to a positive electrode of a direct-current power source, and the mixed aqueous solution used in the soaking process serves as an electrolyte to remove an oxidation film on the surface of the titanium alloy through electrolysis. A mixed solution of oxalic acid and sodium chloride is adopted as an electrolyte to soak and electrolyze a titanium alloy plate strip, on one hand, the complexing effect of oxalic acid on titanium ions effectively promotes chemical dissolution of an oxide layer, on the other hand, chloride ions assist in stripping the oxide layer through pitting corrosion, and the reducibility of oxalic acid can inhibit excessive corrosion of a matrix. A titanium alloy plate strip is connected to a direct-current power supply, and a dense titanium dioxide oxide layer is rapidly dissolved by means of the synergistic effect of electrolysis. And the solution regeneration method is used, so that the green recycling of the solution can be realized.

The present application relates to a heat exchanger device pitting corrosion detection method and heat exchanger device pitting corrosion detection equipment, wherein the heat exchanger device pitting corrosion detection method comprises: obtaining a target infrared thermal image of the heat exchanger device during a salt spray test on the heat exchanger device; performing target area detection on the target infrared thermal image, and when the target area exists in the target infrared thermal image, determining the temperature difference between the target area and the surrounding area and the shape of the target area, wherein the target area includes a bright area and / or a dark area; and analyzing and obtaining the target pitting corrosion result of the heat exchanger device based on the temperature difference and the shape of the target area. Through this application, in-situ monitoring of pitting corrosion and pitting corrosion failure of automotive heat exchanger devices is achieved without destroying the heat exchanger device.

The utility model discloses a cathode protection copper sulfate evaporator, which is characterized in that a plurality of anodes are arranged in the copper sulfate evaporator, the anodes are inserted in a copper sulfate solution in the copper sulfate evaporator, and the anodes, a cathode binding post and a reference electrode are all connected with a constant potential controller; the constant potential controller, the anode, the copper sulfate solution in the copper sulfate evaporator and the copper sulfate evaporator body form a current loop, the controller outputs direct current, and the protection potential of the equipment is changed by automatically controlling the magnitude of the output direct current until the potential of the equipment reaches the protection potential ranging from-0.1 V to-0.6 V; a cathode protection anti-corrosion technology is applied to the copper sulfate evaporator, uniform corrosion and pitting corrosion caused by high-temperature dilute sulphuric acid and high-concentration chloride ions of equipment materials in a copper sulfate solution are prevented, the corrosion speed is reduced, and the service life is prolonged.

The invention discloses an additive for enhancing corrosion resistance of trivalent chromium oxidation liquid and a preparation method of the additive, and belongs to the technical field of chemical oxidation treatment.The additive is prepared from chromium sulfate, rare earth salt, a complexing agent, a corrosion inhibitor, gamma-mercaptopropyltriethoxysilane, tetraethoxysilane and water. Two kinds of silane which is insoluble or slightly soluble in water are compounded into an additive for enhancing the corrosion resistance, the additive is added into a trivalent chromium aqueous solution, and after corresponding process treatment, the corrosion resistance of trivalent chromium chemical oxidation treatment can be improved from less than 96 h to more than 336 h. The additive prepared by the invention can effectively improve the pitting corrosion resistance of the trivalent chromium oxide film, and the neutral salt mist resistance of the trivalent chromium oxide film is greatly improved.

A multi-element microcouple adaptive selective corrosion dynamic expansion simulation method, belonging to the field of electro-corrosion simulation technology, is disclosed. The method includes: constructing a geometric model of compound particles and meshing the model; constructing the compound particle transport control equations and establishing the coupling relationship between potential, particle concentration, current density, boundary coverage, and reaction rate; adaptively selecting the anode and cathode among the multi-element microcouples of the compound particles and performing fixed-value processing on the geometric model; setting boundary conditions and initial values, including setting insulating boundaries, electrode surface boundaries, and initial particle concentrations; re-meshing the mesh, calculating the movement velocity of the corrosion interface, and constraining and controlling boundaries that do not corrode or undergo geometric deformation to complete the construction of the finite element model; solving the finite element model and outputting relevant physicochemical parameters during the corrosion process. This application clarifies the driving mechanism of pitting corrosion under open-circuit conditions and the existence state of corrosion products.

The invention discloses an anti-corrosion composite coating for an ammonia gas engine, relates to an anti-corrosion technology for an ammonia gas fusion engine, and solves the technical problem that the reliability, durability and commercialization process of an ammonia fuel engine are restricted by the existing engine material system and protection technology. The composite coating comprises a base material arranged on the surface of the ammonia gas engine component; the base material layer is adjacent to the base material layer, is arranged on the surface of the base material and is used for resisting ammonia-alkali corrosion; the middle transition layer is arranged on the surface of the adjacent base material layer and is used for component gradient transition and stress relief; and the outermost surface layer is arranged on the surface of the middle transition layer and is used for resisting acid corrosion and pitting corrosion. The invention further discloses an intelligent corrosion prevention system and method for the ammonia gas engine. The invention solves the problem of limited protection performance of the traditional single coating.

The invention relates to a method and a product for regenerating and repairing duplex stainless steel, the duplex stainless steel is used for a nuclear-grade main pipeline, pulse current with optimized parameters is adopted to treat the duplex stainless steel in the nuclear-grade main pipeline with pitting corrosion or intergranular corrosion generated in the service process, the corrosion resistance of the duplex stainless steel is recovered, and dynamic self-repairing of a passive film is achieved. According to the method, pulse current in-situ / near-in-situ treatment is carried out on the duplex stainless steel for the nuclear-grade main pipeline under the electric-thermal coupling condition, components do not need to be disassembled or large-volume furnace heating does not need to be carried out, and the structure and geometric accuracy of a casting are not changed; by selecting matched parameters such as pulse frequency, pulse width, current density and treatment time, an amplitude-modulated decomposed structure in a ferrite phase and a phase interface precipitated phase are promoted to be re-dissolved, the formation dynamics and stability of a passive film are improved, and the corrosion resistance and toughness of an aged material are recovered or close to an unaged state.

The invention discloses a welding and heat treatment method for improving corrosion resistance of a 2205 duplex stainless steel welded joint, and belongs to the field of heat treatment of metal materials. The problem that in the prior art, a 2205 duplex stainless steel welded joint is insufficient in corrosion resistance in a severe marine corrosion environment is solved. The method comprises the steps that the surface of a to-be-welded 2205 duplex stainless steel plate is pretreated, and assembling is conducted in a butt joint mode; then, under the protection of inert gas, direct current positive connection and pulsed argon arc welding methods are adopted for welding; and then carrying out heat treatment, and cooling in an air cooling manner. According to the method, the microstructure of the joint can be effectively optimized, so that the pitting corrosion resistance, the stress corrosion resistance and the like of the joint are remarkably improved. The method disclosed by the invention is particularly suitable for a welded component serving in a marine harsh corrosion environment.