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

This work investigated the electrochemical and aqueous tribological behavior of hot pressed 2205 duplex stainless steel (DSS). DSS sintered composites of different volume percent (% vol) of partially stabilized zirconia (PSZ) was developed using powder metallurgy (PM) technique. Electrochemical behaviour 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 were evaluated. X-Ray Microtomography (XRM) was used as experimental technique for defect analysis from the corrosion studies. 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 whilst relevant information on pitting corrosion was obtained from XRM. It was deduced that, 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.