The austenite-ferrite duplex stainless steels have stable austenite phase and ferrite phase structure that have higher mechanical properties and excellent pitting

intergranular corrosion and stress corrosion resistance

therefore the steels are wide applied in manufacture of equipment for nuclear power station. In general the volume fraction of ferrite phase in casting of duplex stainless steels is ≤ 20% with service temperature less than 425 ℃

and the volume fraction of ferrite phase in forgings of duplex stainless steel is about 50% with service temperature less than 250 ℃. The chemical composition

manufacture and welding process

and structure and properties of casting and forgings o£ duplex stainless steels applied in equipment for nuclear power station are presented in this article.