Acta Metallurgica Sinica (English Letters) ›› 2013, Vol. 26 ›› Issue (3): 257-264.DOI: 10.1007/s40195-012-0231-0

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

Feilong SUN1), Xiaogang LI1,2), Fan ZHANG1), Xuequn CHENG1,2), Cheng ZHOU3),Nianchun WU4), Yuqun YIN4),Jinbin ZHAO4)   

  1. 1) Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China
    2) Key Laboratory of Corrosion and Protection, Ministry of Education, Beijing 100083, China
    3) School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China
    4) Research Institute, Nanjing Iron & Steel Co., LTD., Nanjing 210035, China
  • Received:2012-11-30 Revised:2013-02-04 Online:2013-06-25 Published:2013-05-06
  • Contact: Xuequn CHENG
  • Supported by:

    Fundamental Research Funds for the Central Universities (No.FRF-PT-12-144A) and the National Natural Science Foundation of China (Nos.51171025 and 51271023) and National network of Field Observation & Scientific Research on Material Environmental Corrosion.

Abstract:

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 wascomposed 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.

Key words: Alloying elements, Corrosion, Low alloy steel, Raman spectroscopy, SEM