The mechanism of erosion-corrosion of API X65 steel under turbulent slurry flow: Effect of nominal flow velocity and oxygen content

Abstract

Erosion-corrosion (E-C) of carbon steel API 5L X65 by mineral quartz and alumina slurry is studied to understandthe mechanism of corrosion-accelerated material’s degradation. A rotating cylinder electrode is employedto simulate the E-C damage and for electrochemical characterization, observed at different flow velocities andcontents of dissolved oxygen (DO). Microstructural inspection using SEM and EBSD reveals the extension of thework-hardened layer and other features of the sub-surface. The effect of nominal flow velocity is shown to beassociated with an increment in average particles’ impact angle and frequency of impacts at the faster flow. Theincrease in DO availability is shown to promote localized-type corrosion different from pitting, demonstrating themechanism of erosion-enhanced corrosion.