Corrosion Mechanism of Corrosion-Resistant Steel Developed for Bottom Plate of Cargo Oil Tanks

Feilong SUN¹，Xiaogang LI^1,2，Fan ZHANG¹，Xuequn CHENG^1,2，Cheng ZHOU³，Nianchun WU⁴，Yuqun YIN⁴，Jinbin ZHAO⁴

1. Corrosion and Protection Center, University of Science and Technology Beijing2. Key Laboratory of Corrosion and Protection, Ministry of Education3. School of Materials Science and Engineering, University of Science and Technology Beijing4. Research Institute, Nanjing Iron & Steel Co., LTD.

摘 要：A new type of corrosion-resistant steel consisting of ferrite and bainite phases was developed for cargo oil tanks of crude oil tankers. The corrosion rate of this new steel was 0.22 mm/a, which was equivalent to ca. 1/5 of the criterion （ ≤ 1 mm/a） for corrosion-resistant steels. The composition and element distribution of the corrosion products were investigated by micro-Raman spectrometry and energy dispersive spectrometer. The results demonstrated that the corrosion product was composed of α-FeOOH, Fe3O4 and a continuous Cu enrichment layer. This kind of corrosion product was protective to the steel matrix and accounted for the enhancement of the corrosion resistance of the new developed steel.

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