26 results about "Galvanic corrosion" patented technology

This invention provides an engine valve and a method for manufacturing the same, which can suppress galvanic corrosion even when dissimilar metals are joined, and which exhibits excellent wear resistance and corrosion resistance, for use in engines that use CNG, LPG, or alcohol as fuel. [Solution] The engine valve 10 of the present invention is a joint member in which a shaft portion 14 made of martensitic heat-resistant steel SUH11 and a umbrella portion 12 made of austenitic heat-resistant steel SUH35 are joined. A nitride layer is formed only on the surface of the base material on the shaft portion 14 side from the joint portion 13 between the shaft portion 14 and the umbrella portion 12, leaving the surface of the base material exposed on the umbrella portion 12 side from the joint portion 13.

The application relates to the technical field of electrical connection equipment, and discloses a high-current small bus plug-in box rotary plug, which is used to solve the problems that the structure of key conductive components is single, the setting space is cramped, the conductive temperature rises fast, and the components are prone to aging in the prior art. The application is characterized in that the space of the regular octagonal flame-retardant PC shell and the insulating partition plate is optimized, the T2 oxygen-free copper Z-shaped large-section pin array is symmetrically arranged, the uniform contact pressure guaranteed by the spring assembly is matched, the conductive cross-sectional area is 2-3 times higher than that of the traditional reed structure, the galvanic corrosion of dissimilar metals is effectively avoided, the current-carrying capacity and the current transmission stability are greatly improved, the multidirectional heat exchange channels formed by the regular octagonal included angle, the pin array bending gap and the internal cavity are combined, the separation and heat dissipation of the insulating partition plate are combined, the cold and hot air efficient convection is realized, and the temperature rise of the key components is significantly reduced.

This invention relates to the field of zinc alloy surface modification technology, and particularly to a corrosion-resistant medical zinc alloy, its preparation method, and its applications. The preparation method includes the following steps: weighing raw materials according to the chemical composition of the zinc alloy; cleaning the surface of the raw materials; smelting, refining, and casting to obtain an ingot; subjecting the ingot to equal-channel angular extrusion deformation to obtain an extruded zinc alloy; performing high-energy ion implantation on the zinc alloy to obtain a nitrogen-ion-implanted zinc alloy; and preparing a coating on the surface of the nitrogen-ion-implanted zinc alloy to obtain the final product. This invention achieves a high-adhesion, dense, and uniform deposition effect on the alloy surface through the synergistic control of "equal-channel angular extrusion + high-energy nitrogen ion implantation + biomimetic coating deposition," solving the problem of severe galvanic corrosion at localized sites in existing zinc alloys under corrosive environments. Simultaneously, the dense deposition layer helps inhibit rapid dissolution of the zinc alloy surface, significantly reducing the corrosion rate of the zinc alloy in corrosive environments.

The invention relates to an aluminothermy welding flux for a zinc-clad steel grounding material and a welding method of the aluminothermy welding flux, and belongs to the technical field of metal material welding. In order to solve the core technical problem that joint potential matching and welding firmness compatibility are difficult to realize by an existing aluminothermy welding flux for the zinc-clad steel grounding material, the invention provides the aluminothermy welding flux for the zinc-clad steel grounding material. The aluminothermy welding flux comprises iron oxide powder, aluminum powder, tin powder and nickel powder. According to the invention, the iron-based welding flux is compounded with tin and nickel, and the tin and the nickel have a synergistic effect, so that the technical prejudice that the iron-based welding flux is difficult to adapt to zinc-clad steel welding in the field is overcome, and the unexpected technical effect is realized. The tensile strength of the connector is larger than or equal to 620 MPa, the corrosion rate is smaller than 0.05 mm / year, the conductivity loss is smaller than 5%, and the performance is obviously superior to that of a copper-based connector. The problem of compatibility of potential matching and welding firmness is fundamentally solved, galvanic corrosion is eliminated, the process is simple and convenient, the cost is controllable, and corrosion prevention and engineering reliability are greatly improved.

The application discloses an antibacterial composite metal coating based on protective area etching and galvanic corrosion and a preparation method and equipment thereof, and the method comprises the following steps: 1) forming a composite coating by vapor depositing a metal transition layer with a standard electrode potential higher than silver, a silver island intermediate layer and electrochemically depositing a silver layer on the surface of a pretreated titanium-based equipment; 2) performing isolation line etching on the outside of the coating area boundary of the equipment surface by laser; 3) preparing a hydrophobic protective coating on the surface of the reserved coating area; 4) filling paraffin in the isolation line groove to form a temporary hole sealing layer; 5) immersing the equipment in an acidic electrolyte to selectively dissolve the coating in the to-be-stripped area in a sectional stripping mode; 6) removing the paraffin in the isolation line groove and performing trimming by laser; and 7) obtaining the coating material after mechanical polishing, cleaning, drying, vacuum packaging and radiation sterilization. The high-strength coating can realize efficient sterilization through the galvanic corrosion effect and prevent coating abrasion during use.

The objective of this invention is to provide a battery pack fixing structure that can suppress battery module swaying and inhibit galvanic corrosion. The battery pack fixing structure comprises: a support member disposed between adjacent battery modules in the vehicle's height direction, supporting the adjacent battery modules, the battery modules being enclosed in a housing formed of carbon fiber reinforced material and mounted on the vehicle's frame; a bracket that fixes the support member to the frame; a fastening member inserted into the bracket, housing, and support member when the housing is located between the support member and the bracket, connecting the bracket to the support member; and a cylindrical collar penetrating the housing and located between the support member and the bracket, contacting the support member and bracket when they are not in contact with the housing, and having the fastening member penetrating its center; the collar's surface being covered with a hard anodized layer.

This utility model discloses a cathode conductive rod, relating to the field of cathode rods. The key technical features are: a rod body and two lugs; two insulating posts are fixedly connected to the rod body; mounting grooves are formed on the side of the two insulating posts facing away from the rod body; through holes are formed on the lugs; fixing pins for passing through the through holes are provided on the insulating posts; and several contact posts are also provided on the rod body. The lugs and the rod body are insulated by an insulator, preventing current from flowing to the lugs. Since the metal lugs directly contact the rod body, they are prone to galvanic corrosion due to potential differences. The insulating posts, however, block this corrosion path, stabilizing the overall lifespan of the lugs. The lugs can be detached from the rod body and replaced via the fixing pin structure, allowing for replacement after corrosion.

This invention discloses a wear-resistant clothing fabric and its preparation method, belonging to the field of textile technology. It comprises, from the outside in, a wear-resistant surface layer, a microcapsule self-healing layer, a main functional film layer, a salt-retaining buffer layer, and a moisture-wicking inner layer, sequentially connected by dotted hot-pressing composite bonding. The wear-resistant surface layer is a double-layer asymmetric fabric woven from gradient functional core-spun yarns of copolymerized modified nylon 66, island-type composite fibers, and carbon nanotube composite nylon 66 fibers. The microcapsule self-healing layer is a polyurethane film with microcapsules capable of dynamic covalent bond exchange and self-healing. This invention achieves long-term UV resistance through copolymerized modified fibers, utilizes hydrogel microspheres to retain and release chloride ions, actively repairs damage with the microcapsule self-healing layer and dynamic covalent bond materials, and eliminates galvanic corrosion using all-plastic accessories and a conductive network, effectively slowing down the performance degradation of the fabric in high-salt-spray environments.

This technology provides a way to suppress the deterioration of sealing performance. [Solution] The fuel cell cell comprises an anode separator and a cathode separator having a coating on their surface, and each of the anode separator and cathode separator comprises a main body, a coolant manifold which is an opening formed in the main body and through which coolant flows, an internal cell seal portion which seals the space between the anode separator and the cathode separator inside the fuel cell by the main body being bonded to an insulating sheet so as to surround the coolant manifold, and a sacrificial galvanic corrosion portion which is disposed between the coolant manifold and the internal cell seal portion and has a plurality of exposed portions in which the substrate is exposed without being covered by a coating, and the sacrificial galvanic corrosion portion has at least one exposed portion on a straight line connecting the coolant manifold and the internal cell seal portion.

The application provides a kind of corrosion-resistant magnesium alloy for marine atmospheric environment and a preparation method thereof, and belongs to the field of magnesium alloy material preparation.The chemical composition of the magnesium alloy is as follows in terms of mass percentage: 6.0-6.5% of Al, 1.3-1.5% of Y, 0.3-0.5% of Zn, 0.05-0.1% of Mn, 0.1-0.12% of Sr, and the balance of magnesium and inevitable impurities.The application alloys the magnesium-aluminum alloy by the combined addition of Y, Zn, Mn and Sr elements, suppresses the micro-galvanic corrosion of the magnesium alloy, improves the protection ability of the surface film, and increases the corrosion resistance of the magnesium-aluminum alloy in the marine atmospheric environment.The preparation of the above magnesium alloy adopts semi-solid forming, the process is simple, suitable for industrial production, and the prepared product has a compact structure, reduced defects and excellent service performance.

The application discloses a water treatment agent special for water machines, air conditioners and ground heating circulating water, and a preparation method and application thereof. The water treatment agent is composed of the following components in parts by weight: polyepoxysuccinic acid 25-35 parts, hydrolyzed polymaleic anhydride 15-25 parts, phosphonocarboxylic acid copolymer 10-20 parts, sodium gluconate 8-12 parts, acetic acid ester starch 3-6 parts, zinc salt 1-3 parts and deionized water 15-38 parts. The ternary compound system of "sodium gluconate+methyl benzotriazole+organic zinc salt" solves the problem of galvanic corrosion of copper and iron dissimilar metals in the system. Meanwhile, the synergistic dispersion effect of polyepoxysuccinic acid and phosphonocarboxylic acid copolymer exhibits super strong scale inhibition capacity under high-hardness water quality, and the total phosphorus content is lower than 2.5%. The application has the characteristics of environmental protection, low phosphorus, excellent corrosion and scale inhibition performance and balanced protection for double metals, and is especially suitable for heat pump units and ground heating closed circulating systems.

The application discloses a kind of based on galvanic critical dimension of multi-metal system galvanic effect evaluation method and device, and it is related to electrochemical corrosion evaluation technical field.Multi-metal system galvanic effect evaluation method includes steps: obtaining the polarization curve and self-corrosion potential of each metal in multi-metal system, determine galvanic anode and galvanic cathode on each lap surface;Calculate the galvanic critical dimension of any two groups of metals in multi-metal system;Compare the size of actual interface distance and combined critical distance, determine the galvanic corrosion form of multi-metal system;If the galvanic of two lap surfaces has no mutual influence, then carry out independent galvanic analysis, if the galvanic of two lap surfaces exists potential competition, then carry out coupling analysis to the galvanic of two lap surfaces.The application fully considers the complex potential coupling, interface interference and mutual influence effect between multi-metals, and improves the accuracy, applicability and scientificity of multi-metal lap joint structure galvanic corrosion evaluation.

This application relates to the field of materials testing technology, and in particular to a test fixture and testing device for metal corrosion testing. The test fixture includes a first clamping plate and a second clamping plate. The first clamping plate has a first opening, and a second clamping plate has a second opening. The second clamping plate is mounted on the first clamping plate. The first and second clamping plates are capable of clamping a metal specimen. Along the thickness direction of the test fixture, the metal specimen is located between the first and second openings, allowing a solution to pass through the first and second openings to contact the metal specimen. The first and second clamping plates are made of insulating material. The first and second clamping plates of this application are capable of clamping the metal specimen, thereby fixing the metal specimen relatively to the test fixture. The insulating material of the first and second clamping plates can effectively reduce galvanic corrosion between the test fixture and the metal specimen, resulting in higher accuracy in the simulated test.

To obtain a battery pack fixing structure that can suppress the oscillation of the battery module while suppressing the occurrence of galvanic corrosion. [Solution] The battery pack fixing structure comprises a support member provided between adjacent battery modules in the vehicle's height direction and supporting the adjacent battery modules, among a plurality of battery modules enclosed in a cover made of carbon fiber reinforced material and installed on the vehicle's frame; a bracket that fixes the support member to the frame; a fastening member inserted into the bracket, cover, and support member with the cover positioned between the support member and the bracket, and connecting the bracket to the support member; and a cylindrical collar that penetrates the cover and is interposed between the support member and the bracket, with the support member and bracket in contact with the support member and bracket in a non-contact state with the cover, and through which the fastening member passes in the center, the surface of which is covered with a hard anodized layer.

The application discloses a kind of Mg-Li-Gd-Ni alloy based on LPSO / matrix potential difference accurate regulation and control degradation rate and preparation method and application;Belong to metal material technical field.The present application solves the problem that the degradation rate of existing magnesium-lithium alloy is difficult to accurately control in degradable application.The alloy composition of the present application is as follows, by mass percentage:Li:8%, Gd:1-5%, Ni:0.25-1.25%, the balance is Mg.The stable electrochemical potential difference exists between the LPSO phase and the magnesium-lithium matrix of the present application, the potential difference is maintained in the range of 750-850 mV, and does not change with the change of LPSO content.The volume fraction and distribution of LPSO phase can be changed by controlling the content of Gd and Ni, and the degradation rate can be accurately controlled by increasing the area of cathode phase without changing the unit galvanic corrosion intensity.The degradation rate of the alloy of the present application can be continuously adjustable in the range of 0.09-0.23 mg / cm 2 ·min, and the degradation behavior has excellent temperature response characteristics, especially suitable for oil and gas well fracturing operation with accurate requirement for degradation time.

The application provides a method for inhibiting galvanic corrosion of a magnesium alloy part and a dissimilar fastener, comprising magnesium alloy substrate and galvanized steel bolt nut or rivet connection, at least one of the magnesium alloy substrate or the galvanized steel bolt nut is coated with an organic layer. In the embodiments of the application, the galvanized steel bolt nut is coated with a polyamide coating and the magnesium substrate is electrostatically sprayed with an organic layer. Compared with other solutions for inhibiting galvanic corrosion of a magnesium alloy part, such as using aluminum bolts, the comprehensive performance of the solution is excellent, the cost is low, the operation is simple, and the solution has good industrial application value.

The application provides a kind of in-situ synchronous measurement device and method of dissimilar metal galvanic corrosion micro area, the device includes: environment simulation unit, sample clamping mechanism, electrochemical signal acquisition unit and real-time observation unit;Sample clamping mechanism is set in environment simulation unit, realizes the coplanar clamping of two or more dissimilar metal samples;Electrochemical signal acquisition unit, realize the real-time measurement and monitoring of the electrochemical parameters of sample;Real-time observation unit, realize time synchronization with electrochemical signal acquisition unit, high-resolution dynamic image acquisition of space same visual field.This application realizes real contact interface, and has micro area electrochemical quantitative analysis and topography visualization ability.

The application relates to a heterogeneous material mixed structure corrosion risk judgment method. A plurality of sample structures are subjected to detection tests to obtain a test database; then, a corrosion model and a risk model are established according to the test database, and a standard risk value is obtained; then, actual measured data of an actual piece are obtained, and the actual piece is judged whether to need protection treatment in combination with the corrosion model and the risk model. In the above steps, data obtained by traditional electrochemical tests and neutral salt spray tests are associated to obtain a relationship formula, so that when it is needed to judge whether the actual piece needs protection treatment, the corrosion potential difference and the corrosion current ratio obtained by galvanic corrosion risk simulation operation can be used to judge the corrosion risk, the corrosion risk of the actual piece of the heterogeneous material is quickly and effectively judged, and accurate machining standards are provided in a vehicle development process.

The utility model discloses corrosion monitoring equipment, including corrosion monitoring device and first connecting piece, corrosion monitoring equipment includes insulating shell, at least one for monitoring corrosion's sample to be measured, first fixed structure and the second fixed structure of setting corresponding each sample to be measured, the shell is the hollow structure of two end portions closed, and the upper side is equipped with a plurality of intercommunication holes, the sample to be measured is located the inside of shell and is fixed through the second fixed structure, and the intercommunication hole is connected with the outside in the inside of shell, the lateral surface of shell is equipped with the accommodation groove, and the first connecting piece part is located in the accommodation groove and is fixed through the first fixed structure. The porous insulating shell of the corrosion monitoring device can form flowing bin, can guarantee sample to be measured and outside fluid full contact, can prevent sample to be measured and shell contact and take place galvanic corrosion simultaneously, and corrosion monitoring effect is reliable. And, the corrosion monitoring equipment is integral type detachable structure, can be used repeatedly, saves manual and material cost.

This invention relates to the field of metallographic sample preparation technology, and discloses a method for metallographic sample preparation with low-damage oxidation prevention at the interface of nickel-plated magnesium alloy layers. The method includes: using a nickel-plated magnesium alloy sample as a working electrode in contact with a non-aqueous electrolyte containing a magnesium corrosion inhibitor, a nickel corrosion inhibitor, and a conductive salt; periodically collecting response current density and open-circuit potential during initial electrochemical mechanical polishing, and establishing an interface exposure criterion based on continuous sampling data before interface exposure; determining interface exposure based on the current response current density and the rate of negative shift of the open-circuit potential during continued polishing; switching to dual-potential pulse control after interface exposure, sequentially applying a magnesium protection potential and a nickel passivation potential, and determining the polishing endpoint based on the change in interface response current density at the end of the same phase. This invention reduces interfacial galvanic corrosion and excessive polishing damage through time-division detection and dual-potential pulse control, solving the problem of interface artifacts affecting accurate observation.

This invention relates to the field of metal composite materials technology, and more particularly to a steel-aluminum composite material and its preparation method. The invention discloses a steel-aluminum composite material comprising: a steel base layer and a coating layer covering at least a portion of the surface of the steel base layer. The coating layer, from near to far from the steel base layer, comprises: a deposition layer, an intermediate layer, and a sealing layer; wherein the chemical formula of the deposition layer is Al2O3; the intermediate layer is a rare-earth-doped ZrO2-SiC gradient ceramic coating; and the sealing layer is a graphene-corrosion inhibitor composite layer. The steel-aluminum composite material and its preparation method of this invention, by constructing a three-layer coating structure of a deposition layer, an intermediate layer, and a sealing layer on the surface of the steel base layer, achieve triple corrosion protection of the steel-aluminum composite interface, effectively solving the problem of galvanic corrosion in steel-aluminum composite materials, improving the interfacial bonding strength and long-term corrosion resistance of the material, and is environmentally friendly.

A rapid passivation method for the inner surface of BFe30-1-1 copper-nickel alloy heat exchanger tubes is disclosed. This method solves the severe corrosion problem caused by local defects in the protective film on the inner surface of the tubes in existing technologies. The method includes: whole-machine sandblasting, degreasing, water washing, and seawater film formation, simultaneously with film formation on a sample tube. Key parameters include sandblasting pressure of 0.6~0.8MPa, sand material of F24 mesh brown corundum, seawater flow velocity of 1.5~1.7m / s, and film formation period ≥30 days. The passivation film formed by this invention has a strong corrosion inhibition effect, exhibiting excellent corrosion resistance and stability. It achieves comprehensive and long-term protection for the inner surface of the heat exchanger tube, eliminates the "large cathode-small anode" galvanic corrosion cell caused by local defects in the film layer, effectively suppresses local corrosion tendency and pitting sensitivity, and ultimately significantly improves the corrosion resistance of the heat exchanger tube, extends its service life, and ensures the long-term operational safety and reliability of the entire heat exchanger.

The application provides a magnesium alloy and a preparation method thereof, a magnesium product and a preparation method thereof. According to the mass percentage of the magnesium alloy, the magnesium alloy comprises the following components: 4-5% of Al, 1-4% of Ca, 1-4% of Y, 0.1-0.3% of Nd, 0.1-0.3% of Mn, and the balance of inevitable impurities and Mg elements. The magnesium alloy satisfies the following condition: 0.70A+1.18D>0.50E+0.01G+0.07I. The magnesium alloy provided by the application is designed by multi-element alloying and the proportion of each element is controlled, so that the micro-galvanic effect in the alloy and the macro-galvanic corrosion tendency when the alloy contacts with dissimilar metals are significantly reduced, and meanwhile, good die casting process performance is maintained.

This invention relates to the field of aluminum alloy technology, and discloses a high-strength aluminum alloy for metal molds and its preparation process; including the following steps: Step 1: Cleaning and drying the aluminum alloy to obtain an aluminum alloy substrate; sequentially magnetron sputtering an AlTiN layer, a TiN layer, and a Ti layer onto the surface of the aluminum alloy substrate to obtain a pre-formed aluminum alloy substrate; Step 2: Placing the pre-formed aluminum alloy substrate in an electrolyte for anodic oxidation to form a porous titanium-based composite oxide layer, cleaning and drying, magnetron sputtering a TiB2 layer, and heat treatment to obtain a high-strength aluminum alloy. To form a TiB2 layer on the surface of the aluminum alloy to improve hardness; since the electrode potential difference between aluminum alloy and TiB2 is large, direct contact between the two will cause galvanic corrosion; therefore, in this solution, an AlTiN layer, a TiN layer, and a Ti layer are sequentially magnetron sputtered on the surface of the aluminum alloy; direct contact between the aluminum alloy substrate and the TiB2 layer is isolated, protecting the aluminum alloy substrate from damage.

The present application belongs to the technical field of magnesium alloy galvanic corrosion protection, and discloses a comprehensive protection method for preventing magnesium alloy galvanic corrosion. Since magnesium alloy and metal bolt fasteners are connected as dissimilar metals, magnesium alloy is accelerated to corrode. The method comprises the following steps: 1. reducing the potential difference between dissimilar metals; 2. coating the surface of the cathode and anode metals with an insulating coating to prevent direct contact between dissimilar metals. For magnesium alloy, first, phosphate conversion film treatment is performed, and then organic epoxy zinc phosphate primer coating is performed. For metal screws and gaskets, surface electrophoretic coating is performed. 3. using a larger gasket for assembly, increasing the contact area of the gasket and the magnesium alloy surface coating, reducing the pressure of the gasket on the coating when the screw is tightened, thereby avoiding damage to the magnesium alloy surface coating. The present application greatly reduces galvanic corrosion through the above method, and the process is simple and reliable.