10 results about "Corrosion potential" patented technology

This invention discloses a numerical simulation method for the corrosion rate of high-strength steel under marine stress environments, belonging to the field of corrosion and protection technology. The method includes the following steps: establishing a geometric model for simulation and meshing the model; setting material properties, including corrosion kinetic parameters and basic mechanical property parameters; applying boundary conditions to the geometric model to simulate the actual stress state of the high-strength steel plate; formulating a kinetic expression formula for the electrochemical reaction to describe the electrochemical behavior during corrosion; and performing a corrosion kinetic-mechanical coupling analysis to calculate the distribution of corrosion current, corrosion potential, and local corrosion rate. This invention, by constructing a multiphysics model, can accurately extrapolate and predict the dynamic corrosion rate of high-strength steel under different stresses and environmental parameters. It provides crucial theoretical basis and data support for the design, life assessment, and maintenance decisions of marine engineering structures.

This invention discloses a magnetically conductive plate assembly, a sound-generating device, and an electronic device, relating to the field of acoustic technology. The magnetically conductive plate assembly includes a body and a plating layer disposed on the surface of the body. The plating layer is primarily a polycrystalline material composed of Ni and Co elements. The polycrystalline material has at least one of a face-centered cubic structure and a close-packed hexagonal crystal structure. The average grain size of the plating layer is 0.01~15 μm, and the self-corrosion potential of the plating layer in a 3.5 wt.% NaCl solution is -0.7~-0.1 V. The magnetically conductive plate assembly of this invention aims to solve the technical problem of improving the magnetic permeability of the magnetically conductive plate assembly while ensuring its corrosion resistance.

The application discloses a preparation method of high-strength corrosion-resistant copper alloy wire, which comprises the following steps: (1) preparing a composite powder; (2) preparing a pretreated powder; (3) sensitizing treatment, activation, and surface chemical copper plating of the activated powder to obtain a copper-plated powder; (4) weighing copper powder, nickel powder, silicon powder and the copper-plated powder, heating and melting, adding the copper-plated powder into the melt, casting and forming, heating and stress elimination, cooling, and drawing into copper alloy wire by using a wire drawing machine; the copper alloy wire is kept at 220 DEG C for 30 min, then heated to 300 DEG C and kept for aging for 3 h, after the keeping, the copper alloy wire is cooled to below 200 DEG C in the furnace, then taken out and cooled to room temperature, and the high-strength corrosion-resistant copper alloy wire is obtained. The copper alloy casting prepared by using the method has high tensile strength, the copper alloy wire has high self-corrosion potential, and good strength and corrosion resistance are exhibited.

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 a method for preparing a welded joint, a welding wire, and a welded joint. The preparation method includes the following steps: S1, welding the welding wire to be adjusted to the base material to prepare a welded joint to be adjusted, and determining the dilution rate of the weld in the welded joint to be adjusted; S2, formulating a composition adjustment scheme for the welding wire to be adjusted; S3, preparing a weld simulation sample according to the dilution rate of the weld in the welded joint to be adjusted and the composition adjustment scheme for the welding wire to be adjusted; S4, measuring the self-corrosion potential difference between the weld simulation sample and the base material, and determining whether the self-corrosion potential difference is within the target potential difference range: if the self-corrosion potential difference is within the target potential difference range, preparing a target welding wire according to the composition adjustment scheme for the welding wire to be adjusted, and welding the target welding wire to the base material to prepare a target welded joint; if the self-corrosion potential difference is outside the target potential difference range, returning to step S2. The above preparation method can improve the corrosion resistance of the welded joint.

A high-strength, ductile, corrosion-resistant, and antibacterial Cu-based multi-component alloy and its preparation method are disclosed, belonging to the field of high-performance corrosion-resistant copper alloys. In the Cu-based multi-component alloy, the atomic percentages of Cu and Fe are 50.00 at.% and 5 at.%, respectively, while the atomic percentages of the remaining components are: Ni: 32.50~35.00 at.%, Co: 7.50~10.00 at.%, Cr: 7.5~10 at.%, Mo: 1.25~5.00 at.%, and V: 1.25~5.00 at.%. Through precise composition design and reasonable processing technology matching, a multi-level, multi-scale heterogeneous microstructure is constructed, including a Cu-rich FCC1 phase and a Ni-rich FCC2 phase formed by segregation based on the component characteristics, nanoparticle phases precipitated in the Cu-rich FCC1 phase, and amplitude-modulated decomposition microstructure in the Ni-rich FCC2 phase. These microstructure characteristics synergistically enhance the alloy's strength, ductility, corrosion resistance, and antibacterial properties. The series of alloys exhibits good antibacterial properties. The alloys also have a hardness of 224.81~270.85 HV, an ultimate tensile strength of 680~856 MPa, a yield strength of 516~751 MPa, an elongation of 4.9~24.3%, a self-corrosion potential of -0.31V~-0.22V, and a self-corrosion current density of 4.00~13.22 μA / cm². 2 .

This invention relates to a single-phase, high-corrosion-resistant Fe-Cr-Ni medium-entropy alloy, its preparation method, and its applications. The alloy is composed of the following components by mass percentage: Fe: 31-38%, Cr: 23-31.5%, Ni: 33-40%, with the balance being unavoidable impurities, and the mass percentage content being less than 0.07%. The alloy is a single-phase face-centered cubic solid solution. After high-temperature oxidation, part of the alloy remains a single-phase FCC, while the remaining alloy precipitates a small amount of Cr-rich BCC phase. This alloy exhibits a good combination of strength and ductility from room temperature to 600 °C, and in a 3.5 wt.% NaCl solution, it has a high self-corrosion potential and a low self-corrosion current density. After isothermal oxidation at high temperature for 100 h, the weight gain does not exceed 2.5 mg·cm³. ‑2 This alloy has a simple composition, low cost, and a manufacturing process compatible with traditional stainless steel, making it suitable for load-bearing structural components in marine environments and high-temperature corrosive environments of 600~1000 ℃.

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 present invention relates to the technical field of bonding wires. Disclosed are a palladium-plated / gold-palladium-plated copper bonding wire with high corrosion resistance and high conductivity, and a production process therefor. In the present invention, in order to enhance the corrosion resistance of the bonding wire, the bonding wire is improved by modifying a core material and preparing a composite coating. Firstly, according to the present invention, a core layer is improved, wherein by means of adding graphene to the core layer, the corrosion potential of the core material is significantly increased, and a copper core has a good heat dissipation performance and high-temperature conductivity, thereby preventing heat accumulation and temperature rise in the bonding wire. On this basis, according to the present invention, the coating is also improved, wherein by means of reducing the concentration of metal ions in an electroplating solution, adding a via filling agent and using pulse current electroplating, the surface morphology of the electroplated coating is improved. Furthermore, by means of an annealing treatment, a diffusion layer is formed between a graphene-copper alloy core and different electroplated layers, thereby improving the bonding strength therebetween and improving the usage performance of the bonding wire.

The purpose of the present invention is to simply and appropriately select a metal material suitable for use in a powder deposition environment (submerged environment or dry-wet cyclic environment) in which a powder containing an electroconductive powder is deposited. For this purpose, water is supplied to the same powder as the deposited powder to prepare a water-containing powder in which corrosive ions are eluted from the powder into the water. When the water-containing powder is prepared, in a case where the powder deposition environment is the submerged environment (an environment in which the deposited powder is in a wet state), the concentration of corrosive ions in the water-containing powder is allowed to coincide with a reference concentration (concentration in a wet state), or in a case where the powder deposition environment is the dry-wet cyclic environment (an environment in which the deposited powder alternates between a wet state and a dry state), the concentration of corrosive ions in the water-containing powder is allowed to coincide with a saturation concentration higher than the reference concentration. The electric potential of the metal material is measured in a state of being brought into contact with the water-containing powder, and it is determined that a metal material having a pitting potential higher than a corrosion potential is suitable for use in the powder deposition environment.