Monitoring method for dynamic change of pH value in interface micro-region during metal stress corrosion process

Abstract

The invention discloses a monitoring method for the dynamic change of a pH value in an interface micro-region during a metal stress corrosion process. The principle of the invention is that the tensile stress is applied to a tensile metal sample, a polarization potential E1 is applied to a first working electrode under the combined action of the tensile stress and an electrolyte solution, and themetal undergoes stress corrosion; a cathodic polarized potential E2 is applied to a second working electrode during the stress corrosion process; the H<+> reduction reaction occurs on the second working electrode, and the obtained current data is the corrosion current of the first working electrode and the reduction current generated by the second working electrode; and the dynamic change of the reduction current is the dynamic change of the H<+> concentration in the micro-region. The monitoring method can monitor the dynamic change of the pH value of the interface micro-region of the metal / electrolyte solution in real time; the monitoring method has the advantages of good stability, fast response, high precision, good reproducibility and the like. The monitoring device is easy to manufacture, low in cost, easy to operate, easy to use, and has a wide range of applications.

Description

technical field [0001] The invention relates to a monitoring method for the dynamic change of the pH value, in particular to a method for monitoring the dynamic change of the pH value of the interface micro-region in the metal stress corrosion process. Background technique [0002] Metal stress corrosion cracking (Stss Corrosion Cracking, SCC) is a relatively common localized corrosion, and it is also one of the most harmful forms of corrosion. When metal stress corrosion occurs, no obvious uniform corrosion occurs, and the corrosion products produced on its surface are very few and not obvious. Therefore, stress corrosion often occurs suddenly without any symptoms, which is a kind of catastrophic corrosion. Taking appropriate protective measures for metals to avoid the occurrence and development of stress corrosion can ensure the safety of facilities and avoid losses. It is the key to develop protection technology to find out the mechanism and influencing factors of metal...

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Problems solved by technology

But most of them have problems of one kind or another, such as poor stability, slow response, low accuracy, poor reproducibility, complicated operation, expensive price, etc.

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