A Method for Evaluation of Galvanic Corrosion Under Thin Liquid Film

Abstract

The invention discloses a method for evaluating galvanic corrosion under a thin liquid film, which comprises the following steps: (1) preparing a lap joint sample; (2) preparing a control sample; (3) salt spray test; (4) evaluating corrosion , the test sample A, the test sample B, and the control sample A were determined. 0 , control sample B 0 The respective average corrosion depths, respectively Z tst‑A ,Z tst‑B ,Z ref‑A ,Z ref‑B , according to the statistical t test to judge Z tst‑A Is it significantly different from Z ref‑A ,Z tst‑B Is it significantly different from Z ref‑B , if Z tst‑A Significantly different from Z ref‑A And Z tst‑B Significantly different from Z ref‑B , then calculate the respective galvanic effect values ​​of material A and material B. The invention uses the corrosion depth data to quantify the description of the corrosion degree, can more accurately evaluate the galvanic effect between different metals, and is convenient for objective comparison.

Description

A method for evaluating galvanic corrosion under thin liquid films technical field [0001] The present invention relates to metal materials, and specifically refers to a method for evaluating galvanic corrosion under a thin liquid film. Background technique [0002] With the tightening of energy saving and emission reduction requirements, the application ratio of lightweight materials in industrial products is increasing day by day. brought by this The galvanic corrosion problem between different materials has also attracted the attention of many engineers. Therefore, how to evaluate economically and effectively The level of the galvanic effect between the galvanic combination in the atmospheric environment has become one of the concerns of the industry, especially the automotive industry. one. [0003] Chinese invention patent CN111141661A discloses a kind of dissimilar metal sheet mechanical connection structure galvanic couple in automobile Corrosion evaluation met...

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Problems solved by technology

[0004] The above-mentioned patents have the following defects: 1. The processing procedure of the sample to be corroded is complicated. First, the polarity of the two materials must be distinguished, and then an anodic plate with holes is made according to the polarity, and cathodic bolts and nuts are made, and then a connection test is formed. 2. The accuracy is poor, galvanic corrosion only occurs in a limited area, and the weight loss caused by galvanic corrosion before and after the test is very small, and the weight loss by corrosion is used for evaluation. The level of galvanic corrosion cannot be accurately evaluated; 3. The risk level of galvanic corrosion between mechanical structures can only be qualitatively obtained, and the degree of galvanic corrosion at the same risk level cannot be compared

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