Effect of Heat Treatment on the Localized Corrosion Resistance of S32101 Duplex Stainless Steel in Chloride/Sulphate Media

摘要

2101 lean duplex steel was subjected to extreme temperature of 1200°C and subsequently cooled at rapid and slow rate before assessing its corrosion resistance in 2 M H_2SO_4/0%-I.75% NaCl. The annealed steel specimen (A2101ST) corroded at maximum corrosion rate of 11.3 mm/y (0.5% NaCl), trailed by the quenched specimen (Q2101ST). The untreated steel specimen (ASR2101ST) retained it passivity up to 1.75% NaCl. At this concentration, the passive films on Q2101ST and A2101ST collapsed in the presence of the corrosive species. Low surface deterioration occurred on ASR2101ST in comparison to severe intergranular and pitting corrosion on Q2101ST. Pseudo-corrosion pits formed on the surface of A2101 ST.