NYK using new type of steel in tankers
Japanese shipping company NYK said it will use a new sort of corrosion-resistant steel being made by Nippon Steel in the construction of inner bottoms of crude-oil tanks in supertankers.
NYK explained that crude oil contains salt water with salt concentration several times higher than seawater, and over time this salt water separates from crude oil and accumulates at the bottom of tanks. The accumulated salt water makes pits on the inner surface of the tanks, and this can then lead to oil leaks.
The newly developed steel plate is designed to protect the tanks from such pits.
NYK and Nippon Steel said a feasibility test of the new alloy was conducted by using it in the tank bottom of Takamine, a supertanker built in 2004 by Mitsubishi Heavy Industries.
Two and a half years later, a regular inspection showed that the steel plate, which was free of any anticorrosion coating, was capable of preventing the occurrence of pits.
NYK has decided to use the steel plate on five supertankers on order from IHI Marine United Inc. and Imabari Shipbuilding Co. Ltd.
By using the new alloy, the companies noted they can do away with anticorrosion coatings, coating agents and volatile organic compounds, reducing expenses and making a more environmentally friendly ship.