Corrosion behavior of low alloy steel for cargo oil tank under upper deck conditions
A simulated corrosion test apparatus was used to investigate the corrosion behavior of a low alloy steel under simulated upper deck conditions in a cargo oil tank. The estimated corrosion loss of conventional E36 class ship plate steel is 4.27 mm, which is clearly inadequate compared with the standard adopted by International Maritime Organization. Outer rust layer of specimens starts to peel off after 77 days and becomes fragmented after 98 days. X-ray diffraction, scanning electron microscopy, and Raman spectroscopy revealed that the resulting rust is composed of σ-FeOOH (the main protective phase), Fe2O3, FeS, elemental S, and FeSO4. FeSO4 in the interface of the base and rust layer leads to localized corrosion. Elemental sulfur forms on the surface of σ-FeOOH, and the quantity and size thereof increase with increasing corrosion time. Furthermore, layered elemental sulfur promotes fracture and peels off the rust layer.
KeywordsLow alloy steel Cargo oil tank Upper deck Corrosion film Elemental sulfur
- P. Tscheliesnig, in: WCNDT 2004, Proceeding of 16th World Conference on Nondestructive Testing, WCNDT 2004, Montreal, 2004, pp. 111–119.Google Scholar
- K. Kashima, Y. Tanino, S. Kubo, A. Inami, H. Miyuki, in: JASNAOE-RINA (Eds.), Shipbuilding Technology ISST, NMRI(Japan)-LLOYD’S REGISTER ASIA, Osaka, 2007, pp. 5–10.Google Scholar
- A. Zayed, Y. Garbatov, C.G. Soares, in: ASME 2007, Proceedings of OMAE2007 26th International Conference on Offshore Mechanics and Arctic Engineering, American Society of Mechanical Engineers, San Diego, 2007, pp. 567–578.Google Scholar
- P. Wang, J. Wang, S. Zheng, Y. Qi, M. Xiong, Y. Zheng, Int. J. Hydrogen Energy 40 (2015) 11925–11930.Google Scholar
- D. Abayarathna, A.R. Naraghi, S. Wang, in: Corrosion 2005, NACE International, Houston, USA, 2005, pp. 05624.Google Scholar