Influence of thermal treatments between 650 and 850℃ on the pit-ting corrosion behaviour of 2304 duplex stainless steel

摘要

In this research the effect of thermal treatments within 650-850 ℃ on the pitting cor-rosion behaviour of a Duplex stainless steel (DSS) type 2304 was investigated.DSS 2304 was treated for 5, 10 and 60 minutes at 650, 750 and 850 ℃. The pitting resistance of the treated samples was estimated in 1 M NaCl solution by the anodic polarization curve recording and by the Critical Pitting Temperature (CPT) technique.The results showed that DSS 2304 resistance to pitting corrosion decreased by in-creasing the treatment time and by decreasing the treatment temperature. The most critical conditions were the longest treatment time (60 min) at 650 and 750 ℃.Optical and scanning electron microscopy (OM and SEM) observations were used to correlate the effects of thermal treatments on the microstructure and on the pitting resistance.