Method for measuring most negative cathodic protection potential of steel

Abstract

The invention relates to a method for measuring the most negative cathodic protection potential of steel. The method comprises the following steps: (1) preparing a test solution; (2) electrochemical testing: measuring self-corrosion and inflection point potential; (3) a slow strain rate stress corrosion test: researching the hydrogen embrittlement sensitivity of the sample in the test solution under different cathodic polarization potentials, and calculating a hydrogen embrittlement coefficient; (4) TDS test: taking the fracture part of the sample after the test in the step (3) is finished, determining the hydrogen content in the sample after different polarization potential tests, and calculating the hydrogen permeation rate of the sample corresponding to different potentials in the stress corrosion test process in the step (3); (5) fracture morphology analysis; and (6) data analysis: drawing a hydrogen embrittlement coefficient-polarization potential curve and a hydrogen permeation rate-polarization potential curve according to results of the steps (3) and (4) in combination with the fracture morphology in the step (5) so as to determine the most negative cathodic protection potential of the sample.

Description

technical field [0001] The invention relates to a method for determining the most negative cathodic protection potential of high-strength steel, and belongs to the technical field of material corrosion resistance research. Background technique [0002] With the development of my country's marine industry and the continuous development of marine resources, the development and application of high-strength steel for marine engineering has become more and more extensive. While its strength has been continuously improved, its corrosion resistance has also attracted much attention. [0003] In the marine environment, cathodic protection is usually used to inhibit the corrosion of steel. The cathodic protection must first determine a reasonable cathodic protection potential range. If the potential is too positive, the anodic dissolution cannot be effectively suppressed, and if the potential is too negative, the steel will be "overprotected", resulting in The surface of the material...

AI Technical Summary

Problems solved by technology

[0003] In the marine environment, cathodic protection is usually used to inhibit the corrosion of steel. Cathodic protection must first determine a reasonable cathodic protection potential range. If the potential is too positive, anodic dissolution cannot be effectively suppressed, and if the potential is too negative, the steel will be "overprotected", resulting in Hydrogen evolution occurs on the surface of the material, which absorbs on the surface of the substrate and penetrates into the interior of the metal, making hydrogen embrittlement cracking more likely to occur

Anode dissolution is often accompanied by phenomena such as surface corrosion and anode slime generation, which can be directly observed or judged by ch

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