Electrochemical testing device for metal passivation film growth and decline dynamic process

Abstract

The invention provides an electrochemical testing device for a metal passivation film growth and decline dynamic process, and belongs to the field of material performance detection. According to the electrochemical testing device, through reducing and rotating mutually-overlapped abrasive sheet groups, clamping of a sample and the abrasion of a passivation film on the surface of the sample are realized, so that the test is not limited by the original size of the sample and the size change in the abrasion process within a certain range; through the design of a supporting disc with a ball bearing structure, locking and integrated rotating actions of the relative positions between abrasive sheets are achieved at the same time; the rotating abrasion frequency and duration are controlled, so that one or more abrasion tests are realized; through an internally-arranged electrochemical three-electrode system, in-situ and real-time electrochemical testing of the passivation film growth and decline dynamic process is realized; and the electrochemical testing device is simple in principle and easy and convenient to operate, and compared with an existing scratching electrode technology, the effective test area of the sample is increased, and the dynamic electrochemical behaviors of metal passivation film abrasion and self-healing in the high-pressure and caustic corrosion environment or under the frequent abrasion working condition are reflected more accurately.

Description

technical field [0001] The invention belongs to the technical field of material performance detection, and in particular relates to a material corrosion electrochemical test, especially a test device for the dynamic process of growth and decline of metal passivation films. Background technique [0002] The excellent corrosion resistance of metal materials such as stainless steel and titanium alloy comes from the passivation film on their surface. This thin passivation film can provide sufficient protection for the material in an intact state, preventing the material from being attacked by corrosive media. However, when the passivation film is damaged, the local passivation state of the material will be destroyed, and a galvanic pair will be formed between the active state of a small area and the passivation state of a large area, and the electrochemical thermodynamic balance will be broken, resulting in aggravated local corrosion. In high-pressure, low-oxygen deep-sea envir...

AI Technical Summary

Problems solved by technology

[0004] The technical task of the present invention is to solve the deficiencies of the prior art, provide an electrochemical test device for the dynamic process of the growth and decline of the metal passivation film, to solve the difficult problem of in-situ wear test of the passivation film of the material in the high-pressure solution environment, and overcome the existing plan The problem of small scratch area and low signal-to-noise ratio of the scratch electrode technology realizes the electrochemical test of the dynamic process of single or multiple wear of the passivation film

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