Effects of Cl- Ions on the Corrosion Behaviour of Low Alloy Steel in Deaerated Bicarbonate Solutions
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2016年第4期
论文作者：Yunfei Lu Junhua Dong Wei Ke
文章页码：341 - 348
摘 要：The effect of Cl-ions on corrosion evolution of Ni Cu low alloy steel during immersion tests（up to 70days） in deaerated 0.05 mol/L bicarbonate solutions was investigated by in-situ electrochemical measurements combined with X-ray diffraction（XRD）, scanning electron microscopy（SEM） and electron probe microanalysis（EPMA） characterisations. The results showed that due to the acceleration of substrate dissolution in the presence of Cl-, corrosion of Ni Cu low alloy steel underwent only two stages, i.e., a quick oxidation process followed by a final metastable passive state, without the initial slow anodic dissolution as observed in the Cl--free bicarbonate solution. The main components of the formed rust layer in the Cl--free bicarbonate solution were α-Fe OOH and Fe)3O4 , while apart from α-Fe OOH, （Fe）6（OH）12（CO）3 was found evident instead of （Fe）3O4 in the Cl--containing solution. Metastable pits were only found in the Cl--containing solution where Cl-accumulated after the immersion test, confirming the attack of Cl-on the substrate after penetrating the formed corrosion product layer.
Yunfei Lu1,2，Junhua Dong1，Wei Ke1
1. Institute of Metal Research, Chinese Academy of Sciences2. Wuhan the Second Ship Design and Research Institute
摘 要：The effect of Cl-ions on corrosion evolution of Ni Cu low alloy steel during immersion tests（up to 70days） in deaerated 0.05 mol/L bicarbonate solutions was investigated by in-situ electrochemical measurements combined with X-ray diffraction（XRD）, scanning electron microscopy（SEM） and electron probe microanalysis（EPMA） characterisations. The results showed that due to the acceleration of substrate dissolution in the presence of Cl-, corrosion of Ni Cu low alloy steel underwent only two stages, i.e., a quick oxidation process followed by a final metastable passive state, without the initial slow anodic dissolution as observed in the Cl--free bicarbonate solution. The main components of the formed rust layer in the Cl--free bicarbonate solution were α-Fe OOH and Fe)3O4 , while apart from α-Fe OOH, （Fe）6（OH）12（CO）3 was found evident instead of （Fe）3O4 in the Cl--containing solution. Metastable pits were only found in the Cl--containing solution where Cl-accumulated after the immersion test, confirming the attack of Cl-on the substrate after penetrating the formed corrosion product layer.
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