206 results about "Corrosion current density" patented technology

The invention relates to the technical field of corrosion monitoring, in particular to an intelligent pipeline corrosion monitoring and protection system which comprises a dynamic potential disturbance measurement module, a local microcell scanning module, a corrosion rate calculation module, a corrosion risk distribution analysis module and an environmental parameter compensation module. According to the invention, accurate measurement is realized, the spatial resolution is improved, and the current response change rate is calculated by measuring the reference potential of the surface of the pipeline, applying instantaneous disturbance, combining current change differential operation, dynamically tracking the corrosion process, improving the real-time response capability and arranging a microelectrode array to cover corrosion hot spots; the corrosion current density is solved by combining the electrochemical characteristics of the material, the corrosion rate is dynamically predicted, regional distribution is analyzed based on the change of the corrosion rate, the corrosion risk assessment precision is optimized, environmental factors are monitored, disturbance parameters are adjusted, interference is compensated, the monitoring accuracy under different working conditions is ensured, and data stability and protection measure optimization are guaranteed.

The invention relates to the field of radiator testing, in particular to a radiator salt spray test data intelligent processing method and system.The method comprises the steps that test data in the salt spray test process are obtained and preprocessed, and fitting curves of salt spray concentration data and corrosion current density data are generated respectively; acquiring a peak point of the fitting curve of the salt mist concentration data as a segmentation point, matching the two curves through a dynamic time warping algorithm, and calculating a matching degree to determine the segmentation point on the fitting curve of the corrosion current density data; and calculating a correlation value based on the time difference of the matching point pairs and the shortest path distance, dynamically determining weight distribution of the salt mist concentration data and the corrosion current density data in a forgetting gate formula, correcting the forgetting gate formula, and performing test data prediction by using the corrected LSTM model. According to the method, the correlation values of the corresponding segments of the two curves are calculated, and the weights of the salt mist concentration data and the corrosion current density data in the forgetting gate are dynamically adjusted, so that the adaptability of the model to complex data and the prediction accuracy are improved.

The invention provides a method, a device and equipment for predicting corrosion current and corrosion of steel bars in concrete in a low-pressure environment, and belongs to the technical field of engineering simulation modeling. The method comprises the following steps: establishing a coupling transmission model in concrete considering oxygen concentration, sulfate ion diffusion behavior and chloride ion diffusion behavior; building a reinforcement corrosion current density and corrosion depth prediction model for predicting the number of charges at different positions of the reinforcement in the concrete, and calculating the corrosion depth and the corrosion product content based on the corrosion current density; and establishing a linear elastic damage model for simulating concrete damage evolution caused by steel bar corrosion according to the corrosion product content output by the steel bar corrosion current density prediction model so as to realize accurate prediction of corrosion and damage. According to the method, oxygen concentration changes under low air pressure are considered, oxygen diffusion is described, output of a transmission model serves as a dynamic variable to be introduced into the corrosion current calculation process, and the accuracy of corrosion current and steel bar corrosion prediction is improved.

The invention belongs to the technical field of corrosion and protection simulation analysis, and particularly relates to a multi-physics coupling corrosion simulation method for a metal material in a seawater environment, which comprises the following steps: firstly, carrying out stress and deformation calculation on a structure, and then, carrying out analysis fitting on a polarization test result of the material according to the electrochemical corrosion condition of the structure in seawater, so as to obtain a simulation result; and finally, according to the mutual influence effect between stress and electrochemistry, establishing a coupling path, realizing multi-physics coupling simulation, and quickly calculating to obtain the corrosion potential and the corrosion current density on the surface of the structure and the corrosion rates at different positions, thereby determining the most sensitive position of corrosion. By establishing an independent simulation boundary module database, rapid calling and reading of simulation boundary parameters are achieved, rapid iterative calculation of long-period corrosion evolution is achieved, corrosion evaluation efficiency is greatly improved, and the problems that in the equipment service process, seawater corrosion prediction precision is low, and the test period is long are effectively solved.

The invention discloses an oil pipeline area risk monitoring method, and relates to the technical field of risk monitoring, and the method comprises the steps: calculating an electrostatic charge accumulation risk value Qst (t), and calculating an electrostatic discharge threshold value Qth through combining the equivalent capacitance Cp of an oil pipeline and the material breakdown electric field intensity Eb; and judging whether the pipeline has the electrostatic discharge risk or not through preliminary comparison and evaluation of the electrostatic charge accumulation risk value Qst (t) and the electrostatic discharge threshold value Qth. And when the current exceeds the safety range, triggering a lightning stroke analysis mechanism, and further calculating the transient corrosion current density Icorr (t) through a transient current corrosion algorithm. And meanwhile, the surface metal corrosion rate CR of the pipeline is calculated in combination with the static charge accumulation risk value Qst (t) and external environment disturbance parameters such as a sine periodic term. And for a lightning stroke high-incidence area, calculating a cumulative effect index Lacc through a lightning stroke cumulative effect algorithm, and comprehensively evaluating the influence of lightning stroke on long-term corrosion of the pipeline.

The invention relates to the technical field of conductive corrosion-resistant coatings for metal bipolar plates of hydrogen fuel cells, and discloses a conductive corrosion-resistant silver-doped titanium nitride coating for a metal bipolar plate as well as preparation and application of the conductive corrosion-resistant silver-doped titanium nitride coating. The conductive corrosion-resistant silver-doped titanium nitride coating for the metal bipolar plate is formed by sequentially stacking a pure Ti transition layer, a silver-doped titanium nitride coating and a pure titanium nitride covering layer. According to the conductive corrosion-resistant silver-doped titanium nitride coating for the metal bipolar plate, silver can be stably and uniformly distributed in the titanium nitride coating, a conductive path is formed, the contact resistance of the coating is reduced, the titanium nitride coating forms a compact structure, the corrosion resistance and the surface hydrophobicity of the titanium nitride coating are enhanced, and the service life of the coating is prolonged. The surface contact resistance can reach 4.18 m omega.cm < 2 >, the corrosion current density can reach 0.59 mu A.cm < 2 >, the corrosion potential can reach 0.08 V, and the water contact angle can reach 106.70 degrees.

The invention relates to the technical field of processing, testing or inspection of aircraft parts, and provides a method for detecting surface defects of an aluminum alloy plate with an epoxy coating. The method comprises the following steps: applying an epoxy coating doped with a zinc yellow pigment to an anodic oxide film to construct a coating test piece with a color difference indication function, and placing the coating test piece in a coastal atmospheric environment for exposure sampling. In the detection process, the gloss loss rate, the chromatic aberration, the contact angle, the defect area proportion and the corrosion current density are collected, a dynamic correction coefficient is calculated according to the hydrolysis degree of the zinc yellow pigment, all parameter thresholds are adjusted in a self-adaptive mode, and a threshold set is constructed. And in combination with scanning electron microscope image segmentation and Tafel extrapolation analysis, multi-source indexes are fused to judge whether the coating is invalid. According to the method, the hydrolysis behavior of the zinc yellow pigment can be tracked in real time, the judgment standards of optical, morphology and electrochemical indexes are automatically corrected, and the accuracy and reliability of failure detection of the epoxy coating aluminum alloy plate under the coastal service condition are improved.

The invention belongs to the technical field of metal material surface modification, and particularly relates to a magnesium alloy surface conductive corrosion-resistant coating and a preparation method, the conductive corrosion-resistant coating comprises a three-layer structure, the total coating thickness is 33-50 microns, the bottom coating is a low-porosity MAO coating prepared through a micro-arc oxidation method, and the thickness is 20-35 microns; the middle coating is a conductive nano-particle layer prepared by adopting a negative pressure mode; and the top coating is a zinc aluminum oxide conductive layer prepared by adopting a vapor-phase hydrothermal deposition method, and the thickness of the top coating is 13-15 microns. In addition, the invention provides the modified magnesium alloy with the conductive corrosion-resistant coating prepared on the surface, the self-corrosion current density of the modified magnesium alloy is 0.18-1.8 * 10 <-7 > A / cm < 2 >, and the volume resistivity of the modified magnesium alloy is 1.30-5.21 * 10 < 4 > omega.m.

The invention belongs to the technical field of surface engineering protective coatings, and discloses a nitrogen heterocyclic compound modified corrosion-resistant high-entropy alloy coating as well as a preparation method and application thereof. The preparation method comprises the following steps that firstly, a magnetron sputtering technology is adopted, a CoCrFeMnNi target serves as a cathode target material, and a corrosion-resistant high-entropy alloy coating is obtained through deposition on the surface of a base body; and then, in a three-electrode system, the corrosion-resistant high-entropy alloy coating is placed in an electrolyte containing a nitrogen heterocyclic onium salt compound to be subjected to electro-deposition, and the nitrogen heterocyclic compound modified corrosion-resistant high-entropy alloy coating is prepared. The corrosion-resistant inorganic-organic hybrid coating prepared by the invention has excellent corrosion resistance, can keep high stability and durability in a complex corrosion environment, and has relatively high corrosion potential and relatively low corrosion current density. The coating can remarkably prolong the service life of a structural base material, is suitable for various harsh working conditions, and provides an efficient and reliable protection solution for industrial application.

The invention relates to a metal contact corrosion evaluation method and system based on a Tafel polarization curve, and the method comprises the steps: installing a to-be-evaluated sample in an electrochemical testing device, and simulating the corrosion condition of a working environment; carrying out linear polarization scanning on the to-be-evaluated sample by adopting an electrochemical workstation, recording changes of electrode potential and current density, and generating a Tafel polarization curve; a strong polarization interval is selected according to the measured Tafel polarization curve data, and Tafel curves of the anode and the cathode are obtained through mathematical fitting; and calculating the corrosion potential and the corrosion current density based on the Tafel curves of the anode and the cathode obtained by fitting. Compared with the prior art, through accurate mathematical fitting and calculation, the accuracy and reliability of corrosion parameters are ensured, and the corrosion tendency and corrosion rate of the metal material can be accurately evaluated. And an effective technical means is provided for evaluating the corrosion performance of the metal material.

The invention discloses an aging treatment optimization method for inhibiting precipitation of a gamma2 phase in solid-solution-state duplex stainless steel. Aiming at the problems of excessive precipitation of a gamma2 phase and poor stability of a passivation film caused by the existing process (700 DEG C, 8-32 hours), the precipitation amount of the low-chromium gamma2 phase at the alpha / gamma phase boundary is reduced by shortening the aging time to 0.5-4 hours. The method comprises a solution treatment stage (1100 DEG C heat preservation for 2 hours and air cooling), an aging treatment stage (700 DEG C heat preservation for 0.5-4 hours) and furnace cooling. The pitting potential of the optimized material is remarkably improved, the corrosion current density is reduced, the pitting corrosion resistance is improved by 30% or above, meanwhile, complex equipment or alloy addition is avoided, and the method is suitable for industrial production. Experiments show that gamma 2 phase precipitation can be effectively inhibited within 4 hours of aging, the stability and chloride ion erosion resistance of a passive film are enhanced, formation of corrosion holes is reduced, and the service life of the material in nuclear energy, ocean and other environments is remarkably prolonged.

The invention discloses an alloy structure optimization design manufacturing method and device, and the method comprises the steps: regulating and controlling an alloy microstructure, surface free energy parameters, a corrosion environment and stress boundary conditions through a numerical simulation method, and calculating the corrosion potential, corrosion current density and charge transfer resistance of an alloy under different conditions; establishing a quantitative relationship among the alloy microstructure, the surface free energy and the corrosion resistance; according to the target microstructure parameters, an alloy with a target microstructure is constructed through 3D printing; the super-hydrophobic alloy is prepared by utilizing a pretreatment condition and a fluorosilane modification condition; analyzing the influence rules of 3D printing conditions, pretreatment conditions and fluorosilane modification conditions on the microstructure, surface free energy and hydrophobicity of the alloy; and alloy preparation conditions are optimized according to the influence rule. Theoretical simulation and experiments are combined to clarify the internal relation among the construction method-microstructure and surface free energy-hydrophobicity-corrosion resistance of the corrosion-resistant alloy, and the corrosion resistance of the alloy structure is improved.

The invention discloses an iron-based amorphous alloy suitable for a marine environment and a method for preparing a coating based on the iron-based amorphous alloy. The chemical formula of the iron-based amorphous alloy is Fe < 35 > Ni < 20-x > Cr < 20 > Mo < 5 > B < 4 > C < 4 > P < 12 > Ce < x >, wherein the value of x ranges from 0.5 to 1.5. On the basis of the iron-based amorphous alloy, a coating formed by adopting a high velocity oxy-fuel spraying mode not only has good seawater corrosion resistance, but also has good microbial corrosion resistance; after the coating is soaked in a culture medium solution inoculated with pseudomonas aeruginosa for 14 days, the self-corrosion potential is-314 mV, the self-corrosion current density is 5.9 [mu] A cm <-2 >, the passivation interval exceeds 1200 mV, and the passivation current density is 5.1 [mu] A cm <-2 >.

The invention relates to the technical field of coatings, in particular to a nano anticorrosive coating. The invention provides a nano anticorrosive coating which comprises a component A and a component B. The component A comprises 40-100 parts by weight of bisphenol A epoxy resin, 0.3-5 parts by weight of cerium dioxide modified hexagonal boron nitride nanosheets and 60-85 parts by weight of lamellar structure zinc-aluminum alloy powder. And the component B comprises 20-40 parts of a polyamide curing agent. The zinc-aluminum alloy particles can enhance the toughness of the coating, and the cerium dioxide and hexagonal boron nitride are added to improve the hardness and wear resistance of the coating. And cerium dioxide and hexagonal boron nitride are added, so that the impedance modulus value of the coating is remarkably improved, the corrosion current density is reduced, and the corrosion resistance of the coating is enhanced. In a salt spray test, the modified coating shows better salt spray resistance, and a coating stripping area is not expanded.

The invention discloses a preparation method of a fuel cell metal bipolar plate composite coating. The preparation method comprises the following steps: carrying out pretreatment and plasma cleaning on a substrate; sequentially depositing a metal base layer and a transition layer on the surface of the substrate; the amorphous carbon surface layer is deposited on the surface of the transition layer through multi-arc ion plating, the multi-arc ion plating technology is used, the high-density and high-strength amorphous carbon surface layer is formed on the surface of the metal bipolar plate, the corrosion resistance of the bipolar plate is remarkably improved, the machining parameters of multi-arc ion plating are accurately controlled, and the corrosion resistance of the bipolar plate is improved. A carbon surface layer with fine grains and few defects can be prepared on the surface of the bipolar plate, the corrosion current density is effectively reduced, and the service life of a fuel cell is prolonged.

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 an L450 grade pipeline steel hot-rolled plate coil for ground gathering and transportation and a production method thereof. The chemical composition of the steel is C: 0.061%-0.070%, Si: 0.15%-0.25%, Mn: 0.39%-0.48%, P≤0.012%, S: 0.0028%-0.003%, Als: 0.030%-0.045%, Nb: 0.032%-0.038%, Ti: 0.020%-0.023%, Cu: 0.34%-0.42%, Cr: 0.32%-0.39%, N≤0.004%, and the remainder is iron and impurities. The yield strength of the hot-rolled coil product is 465-478 MPa, the tensile strength is 572-588 MPa, the elongation after fracture is ≥36.5%; the Charpy impact energy Akv at -40°C is ≥308 J; the corrosion rate is 0.0234-0.0270 mm / a, the corrosion potential is ≥-0.452 V, and the corrosion current density is ≤1.06×10 ‑5 A.cm ‑2 .

The invention discloses a high-strength corrosion-resistant Al-Zn-Mg-Cu-Sc-Zr alloy plate and a preparation method thereof, and belongs to the technical field of aluminum alloy materials. The alloy comprises the following components in percentage by mass: 7.0%-8.0% of Zn, 1.5%-2.0% of Mg, 1.4%-1.8% of Cu, 0.05%-0.15% of Sc, 0.05%-0.15% of Zr, less than or equal to 0.05% of Si, less than or equal to 0.1% of Fe, less than or equal to 0.01% of Mn, less than or equal to 0.01% of Cr, less than or equal to 0.01% of Ti and the balance of Al. The preparation method comprises the steps of smelting and pouring, homogenizing annealing, hot rolling, cold rolling and solid solution aging treatment. By synergistically adding Sc and Zr, a nanoscale Al3 (Sc, Zr) dispersed phase is formed, recrystallization is inhibited, grains are refined, meanwhile, grain boundary precipitated phase distribution is optimized, and the mechanical property and corrosion resistance of the alloy are improved. The tensile strength of the obtained alloy plate reaches 590 MPa or above, the yield strength reaches 540 MPa or above, the intergranular corrosion depth is smaller than or equal to 23 micrometers, the exfoliation corrosion depth is smaller than or equal to 117 micrometers, the corrosion current density is smaller than or equal to 0.53 microamperes / cm < 2 >, and the comprehensive performance is obviously superior to that of a traditional Al-Zn-Mg-Cu alloy.

The invention provides a method and equipment for calculating the flexural capacity of a steel pipe pile and a storage medium, and relates to the technical field of flexural capacity calculation, and the surface strain distribution and corrosion state of the steel pipe pile are monitored in real time through distributed optical fibers and a three-electrode system. Firstly, a spatial gradient analysis method is adopted to identify a strain mutation area as a potential damage area, corrosion current density is measured through a polarization resistance method, correction is performed in combination with a strain threshold value, and the accumulated corrosion depth is calculated. And secondly, converting the strain distribution into an amplitude sequence by using a rain flow counting method, calculating the fatigue damage degree by combining a material S-N curve, and constructing a multi-damage coupling model by combining stress amplitude, chloride ion concentration and temperature difference data to obtain the corrosion damage degree. And finally, a yield strength degradation model is established based on the service duration, factors such as strength attenuation, fatigue damage, corrosion damage and section loss are comprehensively considered, the current bearing capacity of the structure is evaluated by calculating the flexural capacity of the steel pipe column, and a grading early warning mechanism is set.

The embodiment of the invention discloses a diamond-based composite wave-absorbing material. The method comprises the following steps: S1, carrying out graphitization treatment on the surfaces of nano-diamond particles to obtain graphitized diamond composite particles; s2, carrying out compression molding on the graphitized diamond composite particles to obtain a diamond-based composite wave-absorbing material green body; s3, the diamond-based composite wave-absorbing material green body is subjected to high-temperature and high-pressure treatment, and the diamond-based composite wave-absorbing material is obtained; the minimum reflection loss value of the diamond-based composite wave-absorbing material reaches-61.47 dB when the thickness is 5.5 mm, the maximum effective absorption bandwidth can reach 4.0 GHz when the thickness is 2.7 mm, the Vickers hardness ranges from 40 GPa to 60 GPa, the diamond-based composite wave-absorbing material belongs to a superhard material, the normal-temperature heat conductivity ranges from 3.4 W / m.K to 3.7 W / m.K, the initial oxidation temperature ranges from 1100 DEG C to 1250 DEG C, the corrosion current density ranges from 10 <-6 > A / cm < 2 > to 10 <-7 > A / cm < 2 >, the self-corrosion potential ranges from-200 mV to 0 mV, and the corrosion rate ranges from 0.001 mm / a to 0.005 mm / a. The material belongs to a corrosion-resistant material.

The invention belongs to the field of aluminum alloy processing, and provides a method for evaluating the corrosion resistance of an anodic oxide film and the corrosion capacity of a semi-synthetic cutting fluid, which comprises the following steps of: respectively taking a corrosive liquid or the semi-synthetic cutting fluid as an electrolyte and simulating a corrosive environment, and then taking an aluminum alloy sample as a working electrode to evaluate the corrosion resistance of the anodic oxide film and the corrosion capacity of the semi-synthetic cutting fluid; performing an electrochemical test in a corrosion environment to obtain charge transfer resistance Rct and corrosion current density Icorr, and then calculating a corrosion resistance index CI; the higher the obtained corrosion resistance index CI value is, the higher the corrosion resistance of the anodic oxide film of the aluminum alloy sample is, or the lower the corrosion capacity of the semi-synthetic cutting fluid is. And the corrosion resistance of the anodic oxide film or the corrosivity of the semi-synthetic cutting fluid can be rapidly and accurately evaluated.

The invention relates to the technical field of functional coatings and composite materials thereof, in particular to a nano CeO2-PDMS composite anti-corrosion wave-absorbing coating and a preparation method thereof. According to the invention, PDMS is used as a hydrophobic agent, the density of PDMS is smaller than that of epoxy resin, and a small amount of added PDMS can be gathered above the whole coating in a fusion gradual change manner in a curing process, so that first-level anti-corrosion protection is formed; pDMS can also provide better flexibility and elasticity, and the durability and stability of the coating are enhanced. And the green and environment-friendly corrosion inhibitor CeO2 is supplemented, so that not only is the corrosion inhibited, but also the compactness of the coating is improved, the cost is low, and second-level anti-corrosion protection is formed. Through combination of the two, the corrosion current density of the coating is reduced by two orders of magnitude, and good performance can be kept for a long time under severe environmental conditions. The raw materials used in the invention have low requirements on reaction equipment and conditions, and have high adaptability to the wave-absorbing agent; the coating can be prepared by adopting a spraying method, is low in cost and simple and convenient to operate, is not influenced by a base material, and is suitable for large-scale production.

The invention provides a ship lock metal structure safety detection and evaluation standardization system and method, and relates to the technical field of ship lock engineering safety detection. A distributed intelligent sensing module is obtained, and multi-dimensional dynamic parameters of a ship lock metal structure are collected through the distributed intelligent sensing module; the computer sends a starting instruction to the distributed intelligent sensing module through a preset sensor control program, receives and stores dynamic parameters returned by each sensor in real time, and establishes a timestamp index. Compared with the prior art, the method has the following beneficial effects: by integrating multi-dimensional dynamic parameters such as vibration acceleration, temperature gradient, corrosion current density and the like, the state change of the ship lock metal structure under dynamic load and severe environment can be comprehensively captured, and the sampling frequency is automatically adjusted in combination with a trigger type sampling mechanism; therefore, the transient response under the sudden load is effectively captured, early damage missed judgment caused by only monitoring static parameters is avoided, and the actual safety condition of the structure is reflected more truly.

The invention discloses silicon dioxide modified carbonyl iron powder as well as a preparation method and application thereof. According to the modified material, micron-sized carbonyl iron powder serves as a core, the surface of the modified material is coated with a nano-sized silicon dioxide layer through an improved Stober method, a core-shell structure is formed, the thermal stability and corrosion resistance of the carbonyl iron powder are remarkably improved, and the initial oxidation temperature of the carbonyl iron powder is not lower than 300 DEG C and is increased by at least 50 DEG C compared with an unmodified product. The preparation method comprises the steps of dispersion, mixed catalysis, coating reaction and post-treatment, and is simple in process and high in controllability. The invention further provides application of the modified carbonyl iron powder in an epoxy resin-based anticorrosive coating, when the filling amount is 0.1-2.0% (preferably 1.00%), the coating shows excellent anticorrosive performance in a 3.5 wt% NaCl solution, the low-frequency impedance modulus value is not lower than 7.0 * 10 < 5 > omega.cm < 2 >, and the corrosion current density is not higher than 2.15 * 10 <-8 > A / cm < 2 >. The method effectively solves the problems that the carbonyl iron powder is easy to oxidize and agglomerate and poor in corrosion resistance, and is suitable for the high-performance anti-corrosion and wave-absorbing integrated coating.

The present invention discloses a zinc-aluminum-magnesium coated steel sheet based on hot-dip plating and hot-forming technology, and its preparation method and application. The steel sheet is obtained by hot-dip plating and austenitizing and stamping under high-temperature conditions. The dipping solution for hot-dip plating is a Zn-Al-Mg dipping solution, and its composition is located in the zinc-rich corner of the Zn-Al-Mg ternary phase diagram, and the mass percentage meets the following requirements: the Zn content is 85-95 wt.%, the Al content is 4.5-8.5 wt.%, and the Mg content is 1-4.5 wt.%. After hot-dip plating, the steel sheet becomes a zinc-aluminum-magnesium coated steel sheet, which is composed of a steel sheet, a zinc-aluminum-magnesium coating-2, and an intermediate compound layer. Among them, the zinc-aluminum-magnesium coating contains Zn, Al, and MgZn2 phases; the zinc-aluminum-magnesium coating contains a Zn-Al two-phase eutectic and a Zn-Al-MgZn2 three-phase eutectic; the intermediate compound layer is an Fe-Al or Fe-Al-Zn intermetallic compound. After austenitizing, the zinc-aluminum-magnesium coated steel sheet becomes a steel sheet to be stamped, which is composed of a steel sheet and a zinc-aluminum-magnesium coating-3. The zinc-aluminum-magnesium coating-3 contains an α-Fe(Zn,Al) phase. As a corrosion-resistant material, the corrosion current density I corr is (1.20-1.68)×10 ‑5 A / cm 2 ; as a high-temperature mechanical material, the elongation is 38-54%.

The invention discloses a preparation method for improving the corrosion resistance of a spray-formed aluminum alloy component, and belongs to the field of preparation of high-performance metal materials. According to the method, a high-frequency alternating magnetic field with specific parameters (such as the strength of 0.2 T-0. 8T and the frequency of 5kHz-50kHz) is synchronously applied in the deposition stage of spray forming, so that the magnetic field force acts on molten drops which are being solidified and a semi-solid layer. According to the method, nucleation, growth and spatial distribution of a nano precipitated phase and a nano dispersed phase are actively intervened in situ through magnetic field induced micro-area convection and interface energy regulation and control, so that the microscopic heterogeneity which is easy to cause corrosion is fundamentally optimized; compared with a conventional spray forming process without a magnetic field, according to the method, the corrosion current density of the 7075 aluminum alloy in a 3.5% NaCl solution can be reduced by about 60%, the pitting potential positive shift exceeds 80 mV, the service life of a component in a severe environment is remarkably prolonged, and the reliability of the component in the severe environment is remarkably improved.

The invention discloses a method for preparing a magnetic corrosion-resistant ceramic coating on a titanium alloy surface, and relates to a method for preparing a ceramic coating. The invention aims to solve the problem that a ceramic coating prepared on the surface of a titanium alloy by the existing micro-arc oxidation technology is non-magnetic, so that the application of the titanium alloy in the fields of clinical medical treatment, information storage, sensing and the like is limited. The method comprises the steps of 1, titanium alloy pretreatment; 2, ultrasonic oil removal; 3, preparing an iron oxalate precursor solution; 4, micro-arc oxidation I; and 5, micro-arc oxidation II. The corrosion-resistant current density of the prepared magnetic ceramic coating is reduced to 6.8 * 10 <-8 > A / cm < 2 >, and the corrosion potential is 0.02 V, while the corrosion current density of the matrix titanium alloy is 2.9 * 10 <-6 > A / cm < 2 >, and the corrosion potential is-0.68 V. Compared with the corrosion current density of the titanium alloy matrix, the corrosion current density of the magnetic ceramic coating prepared through micro-arc oxidation segmented treatment is reduced by nearly 2 orders of magnitude, the potential is positively shifted by 0.70 V, and the corrosion resistance of the magnetic ceramic coating is greatly improved. And the corrosion resistance of the titanium alloy is obviously improved.

The application belongs to the technical field of surface engineering protection, and discloses a transition metal compound composite coating, a preparation method and application thereof; wherein the transition metal compound composite coating is a composite multilayer structure, and comprises n same periodic structures deposited in sequence, and n is greater than or equal to 2; wherein each periodic structure comprises a titanium nitride coating and a niobium nitride coating. The application specifically discloses a high-conductivity strong-corrosion-resistance transition metal compound composite coating, and can solve the technical problems of high cost, high corrosion current density, low corrosion overpotential and poor conductivity in the prior art.

The invention relates to a method for preparing an anti-corrosion coating for a metal hook by adopting an in-situ loading method, and belongs to the technical field of metal anti-corrosion coatings. The preparation method comprises the following steps: slowly adding 3-glycidyl ether oxypropyl trimethoxy silane, bis-(2-methylallyl) cyclooctyl-1, 5-diene ruthenium, diamino titanium tetrachloride and ethanediamine into DMF (Dimethyl Formamide), heating and stirring for reaction, evaporating to remove DMF, adding acetyl ethyl acetate, and uniformly stirring to obtain a product 1; mixing and stirring acetyl ethyl acetate, tetraethyl silicate and glacial acetic acid at room temperature to obtain a product 2; dropwise adding the product 2 into the product 1, mixing and stirring at room temperature, standing and aging at room temperature, and drying to obtain the anticorrosive paint. And a dip-coating method is adopted for film coating, the metal hook is evenly coated with the anticorrosive paint, and drying is conducted. The corrosion-resistant coating prepared by the method disclosed by the invention is small in corrosion current density, low in corrosion rate and excellent in corrosion resistance in a 3.5 wt% NaCl solution through testing of an electrochemical workstation.

The invention discloses a metro steel fiber concrete structure corrosion current density time sequence prediction method fused with polarization potential monitoring signals, and the method comprises the steps: measuring corrosion current density time sequence data in a small period, taking the time sequence data in the small period as training data, constructing a corrosion current density time sequence prediction method based on a long short-term memory network (LSTM), and predicting the corrosion current density time sequence of a metro steel fiber concrete structure. According to the method, the development condition of the stray current corrosion of the steel fiber reinforced concrete structure can be accurately mastered through the corrosion current density time sequence prediction, so that the stray current corrosion early warning is realized, and the early warning of the stray current corrosion of the steel fiber reinforced concrete structure is realized. And an accurate basis is provided for carrying out stray current corrosion protection in time.