Electrochemical behaviour of stainless steel 304 alloy in erosion-corrosion conditions and synergism effect

摘要

A study has been made of the erosion-corrosion behaviour of stainless steel (SS) 304 in tap water in the presence and the absence of solid particles. Water at ambient temperature impinged in various angles (15-90°) on specimen surfaces at different velocities (7-85-14 m s~(-1)) and sand concentrations (0.43-2%). In this research, potentiodynamic, electrochemical impedance spectroscopy and weight loss measurements were used to study the damage mechanism and to estimate corrosion rate. The SEM micrographs and optical microscopy images were used to study the corrosion morphology. Under test conditions, protective passive film and non-protective film formations formed on SS 304 surface. It was found that maximum corrosion-erosion rate happened at the impact angles between 60 and 75°. The synergism effect was positive in all conditions and it was greater for the lower angles, the higher velocities and the higher solid contents.