6 results about "Crevice corrosion" patented technology

The application discloses a kind of based on the coupling of electrochemical parameter gap corrosion evaluation method and device, it is related to electrochemical corrosion evaluation technical field.Gap corrosion evaluation method includes the following steps: based on gap structure establishes oxygen concentration cell, determines anode, cathode and its surface area;In the oxygen-poor medium environment, the anodic polarization curve of target material is measured, the cathodic polarization curve of target material is measured in the oxygen-rich medium environment, obtains anode current density-potential relationship and cathode current density-potential relationship;According to the electrochemical balance formula that total cathode current is equal to total anode current, the coupling potential of oxygen concentration cell is calculated, and further the gap corrosion current density corresponding to coupling potential is obtained, and the gap corrosion rate is calculated according to gap corrosion current density.The gap corrosion evaluation method provided by the application is suitable for the rapid prediction of initial stage of gap corrosion, with the characteristics of convenient, high repeatability, the result is more accurate.

This invention relates to the field of rail vehicle technology, providing an online monitoring sensor and method for car body crevice corrosion. The online monitoring sensor includes a base, a substrate sample, a first gasket, a reference sample, a second gasket, and a cable. The substrate sample is mounted on the base. The corrosion sample is mounted on the base, with a first gap formed between the corrosion sample and the substrate sample via the first gasket. The reference sample is mounted on the base, with a second gap formed between the reference sample and the corrosion sample via the second gasket. The cable passes through the base, with one end electrically connected to the substrate sample, the corrosion sample, and the reference sample within the base. The other end of the cable exits the base and is connected to a current measuring unit. The current measuring unit measures a first current value between the corrosion sample and the reference sample, and a second current value between the corrosion sample and the substrate sample. This enables online monitoring of car body crevice corrosion.

The application discloses a processing method of a high-entropy alloy, which comprises first laser action, second laser action, electric field action and He + ion irradiation, coupling of the three means, and can realize improvement of the corrosion resistance of the high-entropy alloy, and through accurate matching and regulation of multiple process parameters, a synergistic effect is realized. Specifically, a certain amount of He + ion irradiation can improve the residual stress distribution and mechanical properties of the surface layer of the high-entropy alloy, the electric field action can improve the diffusion of the composition of the high-entropy alloy, and the laser action can optimize the microstructure, so that the pitting corrosion resistance, the crevice corrosion resistance and the stress corrosion resistance of the high-entropy alloy can be significantly improved as a whole, the comprehensive corrosion resistance of the high-entropy alloy is significantly enhanced, and the market application value of the high-entropy alloy is increased, so as to meet the demand of nuclear power plants for corrosion-resistant materials.

This invention provides a low-carbon Fe-Cr-Ni-Mo-Mn-C martensitic stainless steel, its preparation method, and its applications. The general formula of the stainless steel is Fe. a Cr b Ni c Mo d Mn e C f Where a, b, c, d, e, and f are mass fractions: 75≤a≤82; 13≤b≤14; 3≤c≤7; 1≤d≤2; 1≤e≤2; 0.005≤f≤0.02; and a+b+c+d+e+f=100. This invention also discloses a method for preparing stainless steel and its applications. Through low-carbon, high-alloy composition design, this invention synergistically optimizes the material's strength, toughness, and corrosion resistance. While achieving a high yield strength exceeding 750MPa, the elongation can reach over 15%, and it possesses excellent resistance to pitting corrosion, crevice corrosion, and intergranular corrosion, showing promising application prospects and large-scale promotion potential in marine engineering and hydropower engineering.

The application discloses an experimental device for arc-shaped gap corrosion between metal pipeline fasteners and a test method thereof, and aims to explore the influence of different arc-shaped gap widths, different ion concentrations and other factors on the arc-shaped gap corrosion through the arc-shaped gap corrosion experimental test device and the electrochemical experimental method. The application discloses a test device for arc-shaped gap corrosion between metal pipeline fasteners. The core of the device is a three-electrode test system: a working electrode (9) is clamped in two clamps, an arc-shaped gap is formed through a gasket (8), and the gap width is adjusted by replacing gaskets (8) with different thicknesses or rotating a nut for extrusion. An electrochemical reaction tank (5) contains a solution, a built-in Pt pair electrode (10), a reference electrode (6) is connected to a reference electrode hole of a top clamp through a salt bridge, and the three electrodes are connected to an electrochemical workstation. The test device provided by the application is suitable for testing corrosion tests in arc-shaped gaps.

This invention belongs to the field of anti-corrosion materials technology, and specifically relates to an anti-corrosion material, its preparation method, and its application. The anti-corrosion material of this invention includes a substrate and an anti-corrosion layer located on the surface of the substrate. The anti-corrosion layer comprises polyisobutylene, butyl rubber, petroleum resin, and a first filler. The first filler includes basic magnesium stearate-calcium complex salt and serpentine precursor. Upon contact with water, the first filler undergoes a crystallization reaction to generate hydrate crystals with anisotropic growth characteristics, producing sufficient crystallization growth stress to fill microscopic gaps, thus blocking the crevice corrosion pathway at its source and achieving excellent anti-corrosion effects. Simultaneously, the synergistic effect between the first and second protective layers solves the problem of traditional anti-corrosion methods being unable to protect irregularly shaped structural gaps, offering advantages such as convenient construction, reliable protection, and long-term self-adaptive properties, fundamentally eliminating crevice corrosion.