Duplex and superduplex stainless steels have been used extensively in the onshore and offshore sectors of the oil and gas industry for over a decade, during which time an extensive project reference has been established. Duplex grades have been utilised primarily for two reasons: their corrosive resistance to the various corrosive media found in onshore/offshore environments, e.g. CO2, H2S, chlorides, low pH etcetera and secondly their increased strength levels.