Method for evaluating protective capability of weathering steel rust layers based on freezing-unfreezing treatment

Abstract

The invention provides a method for evaluating the protective capability of weathering steel rust layers based on freezing-unfreezing treatment. The method comprises the following steps of: (1) collecting various weathering steel samples to be measured and with rust layers; (2) performing freezing-unfreezing treatment on the weathering steel samples; (3) analyzing influence of the freezing-unfreezing treatment on change of fissures of the rust layer of each weathering steel sample; (4) analyzing influence of the freezing-unfreezing treatment on change of the alternating-current impedance fitting resistance value of the rust layer of each weathering steel sample; and (5) evaluating the protective capability of the rust layers of the weathering steel samples, determining that the protective capability of the weathering steel samples is high if the increment of the fissures of the rust layers and the change of the alternating-current impedance fitting resistance values of the rust layers of the weathering steel samples are low, and determining that the protective capability of the weathering steel samples is low if the increment of the fissures of the rust layers and the change of the alternating-current impedance fitting resistance values of the rust layers of the weathering steel samples are high. According to the method, destructiveness conditions of the outside are considered, particularly the capability of the rust layers resisting a frost environment in a northern cold region, the compactness of the weathering steel rust layers is judged from a brand-new angle, the protective capability of the weathering steel rust layers can be reflected really, and accordingly a judgment result is real and reliable.

Description

technical field

[0001] The invention belongs to the corrosion of iron and steel materials in the atmospheric environment, and in particular relates to the evaluation of the protection performance of the weather-resistant steel rust layer. Background technique

[0002] The corrosion performance of bare steel in the atmospheric environment is mainly achieved by the resistance of the corrosion progress to the stable and dense corrosion product layer formed on the surface. At present, the evaluation of the hindering effect of the corrosion product layer mainly includes weight loss method, corrosion product analysis and electrochemical method.

[0003] The weight loss method is to measure the corrosion progress of steel in a certain environment by using the weight loss per unit area or thinning per unit area of ​​steel after removing surface corrosion products. This is the simplest and most effective macro-analysis method for evaluating the atmospheric corrosion of metals, which...

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