Development of Large-sized UNS N08367 Super Austenitic Stainless Steel Seamless Pipe

Described here in the article is the manufacturing process of the large-sized UNS N08367 super austenitic stainless steel seamless pipe for the seawater system of the nuclear power plant. Also analyzed is the performance of the said pipe. The large-sized UNS N08367 super austenitic steel seamless pipe for the seawater system of the nuclear power plant is successfully developed and produced by means of a number of measures，including the combined process of rotaryrolling hot piercing + hot-rolling + reeling + cold drawing，optimizing the chemical composition and the billet heating temperature，and controlling the rolling temperature so as to avoiding the development of the α phase ferrite and the inhomogeneous carbon nitride structure， and properly designing the heat treatment scheme， controlling the heat treatment temperature，holding time and cooling rate to avoid precipitation of the harmful phase，etc. The research result shows that the above mentioned seamless pipe features homogeneous metallographic structure， consistent mechanical properties and excellent corrosion resistance，being suitable for servicing in the seawater system of the pressurized reactor nuclear power plant.