Modification of Corrosion Resistance of the Plain Carbon Steels by Pulsed Electric Current

Jun-Yang Gao¹，Xue-Bing Liu¹，Hai-Fei Zhou²，Xin-Fang Zhang¹

1. School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing2. Zhejiang Electric Power Corporation Research Institute

摘 要：The fracture of pipelines caused by corrosion cracks and the resulting oil and gas leakage can lead to great environmental pollution and economic losses. These negative effects are due to serious corrosion of the plain carbon steels used for armor of flexible pipe in oil and gas transmission medium. However, corrosion resistance of carbon steel armors has yet to be improved. In this study, the relationship between corrosion resistance and pearlite fraction in the plain carbon steels has been investigated through the application of pulsed electric current. Based on immersion test and electrochemical measurement, pulsed electric current increases the corrosion resistance of the plain carbon steels by reducing the fraction of pearlite phase. Pitting corrosion, which tends to initiate by galvanic corrosion of ferrite and cementite, is therefore inhibited due to the decrease in pearlite fraction(mixture of ferrite and cementite) under electropulsing.

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