Tribocorrosion Behavior of Overlay Welded Super Duplex Stainless Steel in Chloride Medium

The tribocorrosion behavior of super duplex stainless steel overlay weldment, sliding against alumina counterpart in a pin-on-disk tribometer in 1 M NaCl solution, was investigated under open circuit potential and potentiostatic conditions. The results demonstrated the significant effect of applied potential on the tribocorrosion behavior; by shifting the potentiostatic potential from cathodic to anodic range, the material degradation increased due to the introduction of synergistic wear-accelerated corrosion. Moreover, by shifting from cathodic to anodic potentiostatic polarization, the wear track became smoother and the coefficient of friction decreased. Although some evidences of corrosion-accelerated wear, such as occasional corrosion pits as well as reduction of work hardening inside the wear track, were observed, based on the synergistic approach followed, it was inferred that the dominant degradation components of the overlay welded specimen were sequentially wear and wear-accelerated corrosion.