The study proposes a new method that uses the fractal characteristic of the risk curve to evaluate corrosion risk. The objective of the research is to investigate the relationship between the risk curve and corrosion distribution to evaluate the corrosion characteristics of bottom floors of oil storage tanks accurately with discrete thickness data. The method to analyze the corrosion risk with the risk curve is little affected by sample size because the fractal characteristic is used in the method with a large metal loss region. Thus, it is possible to evaluate corrosion risk accurately with discrete thickness data (small number of samples).
International Journal of Pressure Vessels and Piping, Volume 141, 2016, Pages 19–25.
Naoya Kasai1 , Takuma Maeda1 , Koichi Tamura2 , Shigeo Kitsukawa3 , Kazuyoshi Sekine3 .[expand title=”Show Affiliations”]
1 Graduate School of Environment and Information Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
2 Maintenance Institute Plant Life Service, Div. Asahi-Kasei Engineering Corporation, 1-14 Nisshincho, Kawasaki-ku, Kawasaki 210-0024, Japan
3 Center for Risk Management and Safety Sciences, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan [/expand]
Overall thickness profile data for backside corrosion of the bottom floors of 17 oil storage tanks were collected, and a risk curve from the overall thickness profile and discrete thickness data was derived to evaluate the corrosion risk of the bottom floors. The slope of the risk curve in the large corrosion region was found to indicate the local corrosion condition. Parameters for evaluating localized corrosion derived from the corrosion distributions were also investigated to evaluate the corrosion risk of the bottom floors.
Compared with the parameters obtained using the overall thickness profile and discrete thickness data, the slope of the risk curve is an excellent evaluation parameter using discrete thickness data. Thus, it is possible to accurately evaluate the corrosion characteristics of the bottom floors of oil storage tanks with the parameters obtained from discrete thickness data.Go To International Journal of Pressure Vessels and Piping