NKK Corporation announced today that it has developed a new steel pipe containing 1% chromium, which features excellent corrosion and wear resistance and weldability, for cargo oil piping use onboard oil tankers. The company has begun marketing the new product called "NK-MARINE COP."

   Cargo oil pipes used onboard oil tankers for unloading crude oil and seawater require a high resistance to the saline environment, to corrosion and to wear in order to endure the transport of sludge-containing crude oil. Good weldability is also required to facilitate piping installation and reduce construction time. To meet such requirements, it is common to use 400 megapascal-class coated steel pipe (STPY400) or chromium-containing cast iron tube.

   STPY400 coated steel pipe excels in weldability but incurs such problems as high coating cost and shorter service life. On the other hand, cast iron tube has weldability problems despite its high corrosion and wear resistance.

   To overcome these hurdles, NKK successfully developed a high-performance steel pipe for oil tanker piping use, by adding special alloy elements and applying controlled rolling and accelerated cooling processes. The steel features both good weldability and high resistance to corrosion and wear. NKK has confirmed the new product's positive effects in a three-year demonstration test by using it for cargo oil pipes onboard the NKK-built tanker "Benetia" during its commercial service.

   Features of NK-MARINE COP include the following:

• High corrosion resistance even without coating
• Easy installation allowing shorter construction periods
• Allows easy onsite welding without pre-heat treatment, due to low carbon base steel
• Excellent corrosion resistance against crude oil, seawater and wear
• Applicable for broad size requirements, ranging from small-diameter (65A--350A) seamless pipes to large-diameter (400A--1000A) UOE welded pipes.

   NKK expects that applications for the new steel pipe will increase due to the many benefits it offers to shipbuilders in reducing construction and maintenance costs of oil tankers and to chemical manufacturers in improving the performance of steel piping systems.