Electrochemical performance testing device for crevice corrosion

Abstract

The invention relates to an electrochemical performance testing device for crevice corrosion, belonging to the field of corrosion prevention of metal materials. The testing device comprises a plastic clamp, a polytetrafluoroethylene pressure head, an O-shaped seal gasket, a sample, a plastic bolt, a wire, a spring, a double cylindrical liquor pool and a three-electrode electrochemical testing system, wherein the O-shaped seal gasket is placed on a test face of the sample, and the sample and the seal gasket are compressed at the top of a threaded hole of the liquor pool to seal. The wire connected with the spring is led out from the center of a nut of the plastic screw. The polytetrafluoroethylene pressure head with a bump is placed on the surface of the sample, and crevices in different widths are manufactured by using pressure heads with different heights of bumps. By means of a keyway on the outer wall of the inner cylindrical wall of the liquor pool, the pressure head is compressed on the surface of the sample by the plastic clamp. The three-electrode electrochemical testing system is arranged in the liquor pool and is externally connected with an electrochemical workstation for collecting electrochemical information of the sample in the corrosion process in real time or electrochemically testing the electrochemical information, thereby realizing research on the crevice corrosion of various materials with special crevice width and under liquor environment.

Description

technical field [0001] The invention relates to a crevice corrosion test device for metal materials, which has a controllable test environment and can accurately measure the electrochemical information of the surface of a material with crevice corrosion under different solutions, temperatures and gap widths. Background technique [0002] Crevice corrosion is localized corrosion that occurs in the crevices of metal components. There are narrow gaps in the screw, riveting, welding and other connectors or welding joint defects of most metal components, especially gaps with a gap width of 0.025 mm to 0.1 mm, which are enough to allow the electrolyte solution to enter. With the development of corrosion, due to the difficulty of dissolving oxygen in the gap, the oxidation-reduction reaction terminates after the oxygen is consumed. The process of dissolving oxygen in the cathode depends on the outside of the gap, and the anode dissolution continues to occur inside the gap, forming ...

AI Technical Summary

Problems solved by technology

The biggest defect of the current standard is that it cannot explain the corrosion mechanism of the sample during the corrosion process.

Secondly, the corrosion rate of crevice corrosion varies greatly under different widths of crevices. The current method cannot control the crevice width and cannot evaluate the crevice corrosion performance of materials under different crevices.

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