Comparative corrosion studies of 2205 duplex steel after electropolishing and passivation in Ringer’s solution

In present work, the results of corrosion analysis of pitting and general corrosion of austenitic duplex 2205 (EN 1.4462) stainless steel in Ringer's solution, are presented. The corrosion rate was studied using potentiodynamic polarisation method by means of the ATLAS 98 potentiostat with POL 98 software. For these measurements the platinum EPT-101 and calomel reference EK-101P electrodes were used. For each run, the electrolytic cell made of glass was used, containing up to 500 ml of the electrolyte. The specimens used for the studies were obtained from a cold-rolled sheet of steel in three forms: as received (without any pretreatment), after abrasive polishing, and after electrochemical polishing. Some of them were passivated for 15 and 30 minutes, respectively, in 20% HNO3 by volume. The study results show clearly that the samples of duplex 2205 stainless steels after electropolishing and passivation for 15 minutes in 20% HNO3 by volume revealed the highest corrosion resistance.