Cavitation-corrosion studies on welded and nonwelded duplex stainless steel in aqueous lithium bromide solutions

The objective of this work was to study the effect of dynamic flow conditions (mechanical effect) on the cyclic potentiodynamic and potentiodynamic curves of EN 1. 4462, its filler metal (EN 1.4462F), and the welded metal (EN 1.4462W obtained by gas tungsten arc welding (GTAW. The implosion of bubbles on the surface modifies the electrochemical behavior of these different alloys. Values of open-circuit potentials (OCP), corrosion potentials, corrosion current densities, passivation current densities, pitting potentials, repassivation current densities, repassivation potentials, and anodic hysteresis loops were obtained from potentiodynamic curves at 25 degrees C in 400, 700, and 850 g/L lithium bromide (LiBr) solutions under static and dynamic conditions. It has been determined that the welding causes a deterioration of the corrosion resistance of the duplex stainless steel, and the EN 1.4462W is always the anodic element of the pair comprising welded and nonwelded stainless steel. The corrosion behavior and the repassivation behavior of the alloys are modified by cavitation. The surface of the materials was examined to evaluate the corrosion damage to the samples. The electrode surfaces of the alloys show differences when the attack takes place under static or under dynamic conditions.