Super duplex stainless steels present excellent corrosion resistance of austenite steel and a high mechanical behaviour of ferrite steel. However, performance presented by super duplex stainless steels can be drastically reduced if undesirable phases, such as sigma phase, chi phase, secondary austenite and a lot of rich chromium and carbides precipitate. The purpose of this work was to ascertain how 30-minutes isothermal heat treatments at 530°C and corrosion time effect the relative mass loss and profile roughness parameters of the X2CrNiMoN25-7-4 super duplex stainless steel. The influence of boiling nitric acid on the steel corrosion resistance was investigated using weight loss and roughness parameters.

Super duplex stainless steels present excellent corrosion resistance of austenite steel and a high mechanical behaviour of ferrite steel. However, performance presented by super duplex stainless steels can be drastically reduced if undesirable phases, such as sigma phase, chi phase, secondary austenite and a lot of rich chromium and carbides precipitate. The purpose of this work was to ascertain how 30-minutes isothermal heat treatments at 530°C and corrosion time effect the relative mass loss and profile roughness parameters of the X2CrNiMoN25-7-4 super duplex stainless steel. The influence of boiling nitric acid on the steel corrosion resistance was investigated using weight loss and roughness parameters.