Effect of relative humidity on corrosion of Q235 carbon steel under thin electrolyte layer in simulated marine atmosphere
Anti-Corrosion Methods and Materials
ISSN: 0003-5599
Article publication date: 30 January 2020
Issue publication date: 11 March 2020
Abstract
Purpose
The purpose of this paper is to obtain the environmental factor, which has the greatest effect on the corrosion rate of Q235 carbon steel under thin electrolyte layer, and to analyze the effect of this factor on the corrosion morphology, corrosion products and polarization process of Q235 carbon steel.
Design/methodology/approach
An electrochemical device, which can be used under thin electrolyte layer is designed to measure the corrosion current in different environments. Response surface methodology (RSM) is introduced to analyze the effect of environmental factors on corrosion rate. Scanning electron microscope (SEM) and X-ray diffraction (XRD) technique are used to analyze the results. The Tafel slopes of anode and cathode in different humidity and solution are calculated by least square method.
Findings
The three environmental factors are ranked according to importance, namely, humidity, temperature and chloride ion deposition rate. In a high humidity environment, the relative content of α-FeOOH in the corrosion product is high and the relative content of β-FeOOH is low. The higher the humidity, the lower the degree of anodic blockage, whereas the degree of cathodic blockage is independent of humidity. The above experiments confirm the effectiveness and efficiency of the device, indicating it can be used for the screening of corrosive environmental factors.
Originality/value
In this paper, an electrochemical device under thin film is designed, which can simulate atmospheric corrosion well. Subsequent SEM and XRD confirmed the reliability of the data measured by this device. The introduction of a scientific RSM can overcome the limitations of orthogonal experiments and more specifically and intuitively analyze the effects of environmental factors on corrosion rates.
Keywords
Acknowledgements
This paper was supported by the national key R&D Program of China under grant 2017YFB0702100.
Disclosure statement: No potential conflict of interest was reported by the authors.
Citation
Song, Q., Wang, X., Pan, B. and Wan, L. (2020), "Effect of relative humidity on corrosion of Q235 carbon steel under thin electrolyte layer in simulated marine atmosphere", Anti-Corrosion Methods and Materials, Vol. 67 No. 2, pp. 187-196. https://doi.org/10.1108/ACMM-07-2019-2157
Publisher
:Emerald Publishing Limited
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