Duplex Stainless Steels
Pp. 52-63 (12)
Joseph Ki Leuk Lai, Kin Ho Lo and Chan Hung Shek
This chapter is devoted to duplex stainless steels (DSSs). This chapter begins with an
introduction to the different types of DSSs (ordinary, lean, superduplex and hyperduplex), their
applications and compositions of the commonly used grades. Their typical microstructures and methods
for phase prediction via different constitution diagrams are discussed. The precipitate phases that may
form in DSSs and their implications on mechanical/corrosion properties are presented (a more in-depth
discussion on these precipitates is presented in Chapter 8). The superplasticity of DSSs is discussed in
detail. Both the conventional method and a new one for producing the microduplex structure are
introduced. Recent developments in explaining the underlying mechanisms leading to the superplastic
behaviour in DSSs are discussed.
Duplex stainless steel, wrought duplex stainless steel, cast duplex stainless steel, superduplex
stainless steel, hyperduplex stainless steel, lean duplex stainless steel, microduplex microstructure,
superplasticity, phase prediction, constitution diagram, ferrite potential, ferrite factor.
City University of Hong Kong.