Exploring the dynamic mechanism of water wetting induced corrosion on differently pre-wetted surfaces in oil-water flows.

ABSTRACT

Water wetting induced corrosion is the core issue for uncovering the corrosion mechanism in multiphase flow environments, relevant to many industrial applications. Here, we experimentally investigated the dynamic failure of an oil film attached on the pre-wetted model surfaces by the electrochemical current detection using an "Alternate Wetting Cell" and the direct visualization of near-wall fluid states. The oil pre-wetted surface performed a superior corrosion mitigation efficiency, exhibiting a protective oil film with a duration time at least 5 times longer than the water pre-wetted surface. It confirms that the oil film rupture is a combined process of the local penetration and pinning of micro-droplets and the phase redistribution of the near-wall fluids. Corrosion finally initiates and propagates on the surface once the droplets pin there or damage the oil film. The result suggests new control strategies for materials corrosion in complex systems by surface modification and fluid management.