Journal of Northeastern University Natural Science ›› 2017, Vol. 38 ›› Issue (8): 1088-1092.DOI: 10.12068/j.issn.1005-3026.2017.08.006

• Materials & Metallurgy • Previous Articles     Next Articles

Corrosion Behavior of Armor Layer Steel of Flexible Pipes Exposed to Seawater Environment

LIU Zhen-guang1,2, GAO Xiu-hua1, DU Lin-xiu1, LI Jian-ping1   

  1. 1. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China; 2. School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
  • Received:2016-02-29 Revised:2016-02-29 Online:2017-08-15 Published:2017-08-12
  • Contact: GAO Xiu-hua
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Abstract: Immersion experiment was carried out to investigate the corrosion behavior of armor layer steel immersed in a simulated seawater environment. The experimental results demonstrate that the microstructure of the designed steel is made of tempered martensite. Meanwhile, Cr-rich precipitated particles are observed in the substrate of the steel. Corrosion rate decreases with prolonging corrosion time, and the final corrosion rate is 0.0689mm·a-1. The corrosion behavior can be divided into three stages: the fast decreasing stage, stable transitional stage and slow decreasing stage. The major corrosion products are α-FeOOH, γ-FeOOH, Fe3O4, and Fe2O3. With increasing corrosion time, the structure of corrosion products becomes more compact and their thickness is wider. Chromium element tends to accumulate in the corrosion products.

Key words: flexible pipe, armor layer, low-alloy steel, seawater, corrosion behavior

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