160 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 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 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 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 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 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.

The invention relates to the technical field of coating material preparation, in particular to a microbead modified corrosion-resistant dry plating metal powder coating material and a preparation method thereof, and the material comprises carboxyl polyester resin, epoxy resin, a curing accelerator, a flatting agent, a degassing agent, a pigment filler, brush polymer modified microbeads, a metal pigment, a dry plating binder and a charge adjusting aid. According to the powder coating material, the corrosion resistance and durability are remarkably improved while the metal appearance and the construction stability are maintained, the coating film interface bonding is high, pore channels are few, and foaming, pitting corrosion and corrosion medium permeation along the interface in the salt mist environment can be effectively inhibited; after scratches or micro-cracks are formed, the coating film has micro-crack sealing / self-passivation capability, the corrosion rate extending along the scratches can be reduced, and the service life can be prolonged; and meanwhile, the powder is electrified uniformly, the powdering rate is high, the film thickness distribution is more uniform, the metal dry plating effect is stable, the color difference fluctuation in recycling is small, and the powder coating is suitable for metal base material protective coating with the requirements for appearance and corrosion resistance at the same time.

The invention discloses a bronze ware model casting parting design method and system based on Boolean modeling, particularly relates to the field of digital model casting modeling and simulation verification, is used for solving the problems of parting cutting error accumulation and model block seepage stability loss under the complex morphology of a bronze ware, and provides a model casting parting design method and system based on Boolean modeling by constructing a morphology noise mapping and semantic slicing linkage mechanism. Early recognition of pitting corrosion and back-off areas is achieved, Boolean segmentation is driven through curvature constraint, and a flexible buffer surface is introduced into a danger area to achieve transition; a cross-domain parameter evaluation and adjustment mechanism is formed in combination with multi-scale displacement optimization and physical simulation feedback, high-response parameter write-back is realized through local disturbance search, a full-link linkage path from modeling to casting is constructed, and parting integrity and model block stability are improved.

This invention relates to a high-temperature corrosion-resistant Fe-Cr-Mo-Ni alloy, its preparation method, and its applications. The alloy composition is 37%–40% Ni, 19%–29% Cr, and 5%–10.27% Mo, with the balance being Fe and trace impurities. X-ray diffraction of the alloy reveals a single-phase face-centered cubic structure. After holding at 800℃ for 400 hours, the area fraction of the σ phase in the microstructure does not exceed 5%. The breakdown potential in 3.5% NaCl solution is as high as 1.029 V, and its pitting corrosion resistance is superior to commercial 904L stainless steel. This alloy shows great promise for industrial application in the preparation of high-temperature resistant structural components operating under high corrosion conditions above 400–900℃, especially in service environments containing chloride ions, fluoride ions, or sulfides.

Provided is a stainless steel material having excellent general corrosion resistance and pitting corrosion resistance even in a supercritical corrosive environment. A stainless steel material according to the present disclosure has a chemical composition described in the description, results in Fn1 being at least 32.0 as defined by formula (1), and has a microstructure including, in volume fraction, 35-70% of ferrite and 0-15% of residual austenite, the balance being tempered martensite. In the stainless steel material, the total number density of coarse Mn sulfides having an equivalent circle diameter of at least 1.0 µm and coarse Ca sulfides having an equivalent circle diameter of at least 2.0 µm is 0.60 particles / mm2 or less. The total number density NDF particles / mm2 of coarse Mn sulfides and coarse Ca sulfides in ferrite and the total number density NDO particles / mm2 of coarse Mn sulfides and coarse Ca sulfides in phases other than ferrite satisfy formula (2).　(1): Fn1=Cr+3.3(Mo+0.5W)+16N+2Ni+Cu+2Co+10Sn (2): NDO / NDF<0.60

This invention discloses a metal flux-cored welding wire for wind turbines, comprising flux powder and a welding sheath. The flux powder is composed of the following components: Ni: 58%-80%, Cr: 10%-16%, Mo: 4%-12%, Nb: 1%-3%, Fe: 2%-14%, C: 0.1%-0.2%, Mn: 0.2%-0.5%, Si: 0.2%-0.5%, with the sum of the mass percentages of the above components being 100%. The welding sheath is made of Inconel 718 alloy strip. This invention also discloses a method for preparing and applying the metal flux-cored welding wire for wind turbines. This invention solves the problem of pitting corrosion and abrasive wear on the surface of high-speed gears in existing wind turbines, particularly in environments with high corrosion resistance requirements, such as offshore and desert environments with high wear resistance requirements, resulting in corrosion pits and wear microcracks.

This invention relates to the field of stainless steel materials technology, specifically to a nickel-chromium-molybdenum-containing marine splash zone-resistant and corrosion-inhibiting stainless steel material and its preparation process. The chemical composition of the stainless steel material, by mass percentage, includes: carbon ≤0.04%, silicon 0.5%-0.8%, manganese ≤0.8%, phosphorus ≤0.02%, sulfur ≤0.0015%, chromium 22%, nickel 10%-11%, molybdenum 3.0%-3.5%, copper 1.2%-1.5%, titanium 0.2%-0.25%, niobium 0.1%-0.15%, with the remainder being iron. This invention's stainless steel material, through scientific chemical composition design, constructs a stable basic corrosion-resistant system. Simultaneously, the introduction of specific elements exerts a synergistic effect, effectively enhancing the stability and density of the passivation film on the material surface. This significantly improves the material's resistance to pitting corrosion in marine splash zones, reduces the risk of chloride ion damage to the passivation film, effectively inhibits intergranular corrosion, greatly improves the material's corrosion resistance stability, and extends its service life in harsh marine environments.

This invention discloses a method and system for pitting corrosion detection and residual strength calculation using multi-arm caliper logging data. The method includes: converting multi-arm caliper logging data into a three-dimensional model, performing data cleaning and batch projection transformation to obtain a sequence of planar images; classifying and labeling pitting regions in the images according to pitting corrosion type standards; employing an improved YOLOv8 intelligent image detection model, incorporating a bottleneck attention module to enhance focus on pitting regions, using batch channel normalization to optimize training effects, and replacing the traditional CIoU loss function with the Shape-IoU method; training the labeled image sequence using the improved BBI-YOLOv8 model to obtain an intelligent pitting corrosion detection model; and calculating the residual strength based on the type of pitting region, opening length, average depth, and stress concentration factor. Compared with traditional methods, this invention improves the automation and accuracy of pitting corrosion detection, optimizes the tubing strength verification process, and provides efficient and accurate technical support for tubing safety assessment in oil and gas wells.

The invention discloses superaustenitic stainless steel based on the synergistic effect of Mo and N and a preparation method of the superaustenitic stainless steel, and belongs to the technical field of high-performance metal materials. The stainless steel comprises the following components in percentage by mass: 26.0%-26.5% of Cr, 3.48%-4.52% of Mo, 0.29%-0.51% of N, 23.0%-25.0% of Ni, less than or equal to 0.01% of C, 0.40%-0.65% of Mn and the balance of Fe and inevitable impurities. According to the method, on the premise that the PREN value is kept basically unchanged, the point corrosion resistance of the stainless steel in a chloride ion-containing medium is remarkably improved by synergistically reducing the Mo content and increasing the N content and utilizing the interaction effect of Mo and N. The synergistic effect is embodied in inhibiting pitting initiation, slowing down pitting extension, promoting repassivation and forming a more protective passive film structure. The material is especially suitable for harsh corrosive environments such as offshore oil and gas exploitation and seawater desalination.

The invention discloses a copper-graphene composite material and a preparation method thereof.The composite material comprises a copper matrix and graphene serving as a reinforcing phase, the graphene is dispersed and distributed at the grain boundary of the copper matrix and in the grain boundary, and the graphene at the grain boundary is of a three-dimensional network structure and wraps the copper matrix; in the cross section of the composite material, the sum of the lengths of the graphene horizontally oriented in the crystal boundary accounts for 60% or above of the sum of the lengths of all the graphene in the crystal boundary, and the variable coefficient of the grain size of the copper matrix is smaller than or equal to 30%. The composite material has excellent strength, corrosion resistance, high-temperature oxidation resistance and intrinsic conductivity, the tensile strength of the composite material is larger than or equal to 280 MPa, the conductivity of the composite material is larger than or equal to 95% IACS, the thickness of an oxidation layer obtained after 180 DEG C / 100 h high-temperature oxidation is smaller than or equal to 20 micrometers, and the local pitting corrosion area rate obtained after 1000 h salt spray test is smaller than 10%. The composite material is excellent in comprehensive performance and low in manufacturing cost, has a good industrialization prospect, and can meet the key requirements of the electronic and electrical industry on high-conductivity, high-temperature stability and long-life conductors.

The invention belongs to the technical field of metal material surface corrosion prevention, and discloses a pitting-resistant corrosion inhibitor coated GO-Al-based composite coating as well as a preparation method and application of the pitting-resistant corrosion inhibitor coated GO-Al-based composite coating. The method comprises the following steps: adding aluminum powder into a GO aqueous solution and a corrosion inhibitor aqueous solution for ultrasonic dispersion; carrying out static settlement, filtering, washing and vacuum drying to obtain modified aluminum powder, and mixing the modified aluminum powder with alumina powder to obtain mixed powder; under the pressure of 0.6-0.8 MPa, carrying out sand blasting treatment on the magnesium alloy matrix by adopting silicon carbide to enable the surface roughness of the magnesium alloy matrix to be 1-3 microns, so as to obtain a pretreated magnesium alloy matrix; and the mixed powder is sprayed on the surface of the pretreated magnesium alloy matrix, and the corrosion inhibitor coated GO-Al-based composite coating is prepared. The composite coating releases a corrosion inhibitor at the crack defect position, a hydrophobic adsorption film is generated, invasion of a corrosion medium and pitting corrosion of the Al coating can be effectively blocked through cooperation with graphene oxide, the corrosion resistance of the Al-based coating is enhanced, and the composite coating can be applied to the field of metal surface corrosion resistance.

The invention belongs to the technical field of metal materials, and particularly relates to rare earth-antimony synergistic alloying corrosion-resistant steel special for photovoltaic and a preparation method of the corrosion-resistant steel. The corrosion-resistant steel special for photovoltaic is prepared from, by weight, 0.04%-0.08% of C, 0.20%-0.50% of Si, 0.80%-1.50% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.003% of S, 1.50%-3.00% of Cr, 0.20%-0.50% of Mo, 0.10%-0.40% of Ni, 0.010%-0.030% of RE, 0.05%-0.20% of Sb, 0.02%-0.05% of Als, smaller than or equal to 0.0050% of N and the balance Fe and inevitable impurities. Wherein RE / S satisfies 3.5 < = RE / S < = 5.0, and Sb / Cr satisfies 0.03 < = Sb / Cr < = 0.08; and through a two-stage controlled rolling and controlled cooling process, a core-shell structure with rare earth sulfur oxide as a core and an antimony atom enrichment layer as a shell is formed on the ferrite grain boundary. By the adoption of the technical scheme, the grain boundary electrochemical stability can be improved, pitting corrosion resistance and intergranular corrosion resistance are remarkably enhanced, and meanwhile the excellent comprehensive performance of high strength and high toughness is obtained.

The invention provides a preparation method of a high-pressure-resistant corrosion-resistant titanium tube for deep sea detection equipment, which comprises the following steps: weighing raw materials containing titanium, molybdenum, nickel and aluminum-vanadium alloy, removing impurities, smelting, solidifying layer by layer to obtain a titanium alloy blank, casting into a seamless tube blank, and carrying out solid solution aging treatment to obtain an inner-layer titanium alloy tube blank; compounding carbon fibers or silicon carbide fibers with the inner-layer titanium alloy tube blank to obtain a composite titanium tube; and the outer side of the composite titanium pipe is coated with high-strength titanium alloy through a forging technology, and the high-pressure-resistant and corrosion-resistant titanium pipe is obtained. The matrix material is subjected to smelting, solidification and aging treatment, and the grain structure and element distribution are optimized, so that the matrix has high strength and corrosion resistance; the fibers and the titanium-based melt are compounded to form a reinforcing layer, high-pressure stress is dispersed, and the pipe wall is prevented from deforming and cracking; the outer layer is coated with high-strength titanium alloy and forged, the pipe body structure is strengthened, the anti-pressure capacity is improved, seawater contact is blocked, then acid pickling passivation treatment is matched, a passivation film is formed on the surface of the pipe body, and pitting corrosion is restrained.

The invention discloses high-formability 430 stainless steel for eliminating black ribs and stripes and a manufacturing method of the high-formability 430 stainless steel, the high-formability 430 stainless steel comprises the following components in percentage by mass: less than or equal to 0.050% of C, 0.20-0.65% of Si, 0.15-0.65% of Mn, less than or equal to 0.045% of P, less than or equal to 0.0040% of S, 16.0-17.5% of Cr, less than or equal to 0.20% of Ni, less than or equal to 0.15% of Mo, less than or equal to 0.10% of Cu, 0.05-0.15% of V, 0.050-0.090% of N and the balance of Fe and inevitable impurities, and the material strengthening index Fc is equal to 1.1-1.7, and Fc is equal to 28.84 * N + 2.09 * Si The pitting corrosion resistance equivalent PREN is greater than or equal to 17.0, and PREN = Cr + 3.3 Mo + 16N. According to the method, the problem of black rib and stripe defects unique to the SUS430 material is solved, and the requirement for surface attractiveness of downstream finished products is met.

The application discloses a kind of stainless steel composite plate pitting test determination method, belong to corrosion detection technical field.The application measures the weight, length, width and thickness of pretreated sample, obtains sample original weight, sample length, sample width and sample thickness;Sample is soaked in closed environment, specified temperature ferric chloride solution, and is soaked to reach test time, after sample is removed and cleaned, obtain post-test sample;Measure the weight of post-test sample, obtain sample post-test weight;Calculate weight loss rate.The application pretreats sample before test, so that it is not completely exposed in ferric chloride solution, avoids the reaction of base layer and solution caused thereby, so that measurement result is more accurate;Weight loss rate is used to reflect the pitting resistance of stainless steel composite plate material with uniform corrosion not obvious, to evaluate pitting resistance, realizes accurately evaluating the pitting performance of stainless steel composite plate.

The application relates to the technical field of alloy materials, in particular to a magnesium alloy and a preparation method and application thereof. The magnesium alloy contains, in percentage by mass, Al: 0.05%-0.12%, Zn: 0.005%-0.02%, Mn: 0.005%-0.03%, Fe: <=0.015%, Cu: <=0.005%, Ni: 0.15%-0.25%, Si: <=0.01%, Gd: 2.5%-3.2%, and the balance is magnesium and inevitable impurities. The first manganese source, the second manganese source and the pretreated manganese powder without the controlled release layer are constructed to have different controlled release layer structures, and are added in stages when the base melt is cooled to the semi-solid window, so that the manganese element is released in sequence, the obtained magnesium alloy has high compressive strength, excellent early pitting corrosion resistance and stable late dissolution rate, and is suitable for preparing the center tube or the cone of the soluble segmented fracturing bridge plug, and effectively solves the technical problem that the existing soluble magnesium alloy cannot simultaneously have stable pressure resistance in the early stage and uniform dissolution in the late stage.

This invention relates to the field of metal corrosion detection and three-dimensional morphology analysis technology, specifically disclosing a method for identifying pitting corrosion based on three-dimensional morphology reference surface correction and fusion domain segmentation. The method includes: S1: acquiring three-dimensional morphology data of the metal surface; S2: obtaining potential pitting regions based on the three-dimensional morphology data; S3: dividing the potential pitting regions into pitting and fusion pits based on their area and average area, and further subdividing fusion pits into multiple pitting pits using distance transformation and watershed algorithms to obtain a set of pitting pits; S4: calculating the geometric parameters of the pits based on the set of pitting pits; S5: generating a parameter table and a visualization annotation map based on the set of pitting pits and their geometric parameters. This invention can automatically identify all target defects, including shallow pits and fusion pits, improving detection efficiency while ensuring modeling accuracy. It is applicable to the detection of pitting defects and mechanical property analysis of metal components of different sizes and operating conditions.