Electrochemical and Tribological Behavior of Oxide Dispersion Strengthened Duplex Stainless Steel in Mine Water Environment

This work investigates the electrochemical and aqueous tribological behavior of hot pressed 2205 duplex stainless steel (DSS). DSS sintered composites of different volume percentages (% vol) of partially stabilized zirconia (PSZ) were developed using powder metallurgy (PM) technique. Electrochemical behavior was studied at room temperature, using open circuit potential and potentiodynamic scanning in simulated mine water and 3.5% NaCl solution, while aqueous tribological test was carried out in simulated mine water. The influence of PSZ, Cr and Ni additions on the degradation mechanisms of corrosion and wear of the modified DSS was evaluated. X-Ray Microtomography (XRM) was used as experimental technique for defect analysis from the corrosion studies. The obtained results show the surface imaging capability of SEM and the internal structures imaging capability of XRM. SEM revealed important surface degradation mechanisms of the materials, while relevant information on the pitting corrosion was obtained from XRM. It was concluded that the pitting corrosion can be caused by the growth of intergranular corrosion resulting from the attack and the breakdown of passive films by chloride ions which affected both the surface and the internal parts of the samples.