In 1995 our company has cooperatively developed 09CrCuSb (enterprise code ND) seamless steel tubes with Shanghai Material Research Institute, which was selected in standard GB150-1998 in 1997, and have widely used in the service of high sulfur in flue gas economizer, air preheater, evaporator and heat exchanger and etc. Due to the gradual increase in imports of high sulfur crude oil, the ND materials could not meet the actual needs of the most refineries, power plants and other enterprises. By the end of 2015, in the technical support of the relevant research institutes, our company optimized the material composition, and added other trace elements, the finished pipes were detected by the third party of Hefei General Machinery Research Institute, which concluded that the uniform corrosion rate was less than 4mg/cm2.h.
Depend on the optimization of the alloy ratio and the addition of rare alloy, thefinished pipes had uniform excellent corrosion resistance to sulfuric acid. According to the third-party inspection reportof Hefei General Machinery Research institute, corrosion resistance of the ND steel has increased two times than the original steel;
Controlling the content of five harmful elementslike As, Sn andPband the gas content of hydrogen, oxygen, nitrogen made the purity of the billet became much higher. According to many analyses, the grain size of the material was not more than level 8;
This kind of material has great economic benefit which improvesthe
corrosion resistance of the equipment, extends the maintenance cycle of refinery and power plantrelatively.