Description
Atmospheric corrosion of a metal is largely facilitated by aqueous droplets residing on the surface as an electrolyte. These droplets are generally formed due to condensation of atmospheric moisture onto the metal surface. They can also be directly deposited on the metal surface due to fog, rain and melting snow. The composition and properties of the droplet vary according to the relevant environment. The size of the droplets dynamically evolves in size due to varying environmental conditions such as humidity and temperature. The dynamic variation of droplet geometry, compositions and the dependency of its contact angle and distribution on wettability of the surface makes it difficult to control the droplet dimension to investigate corrosion mechanisms. Corrosion under droplet is mainly driven by the formation of differential aeration cell. The differential aeration electrochemical cell is formed when the ambient oxygen diffuses through a shorter path along the edge of the droplet compare to the center because of its curvature. The dynamic variation of the droplet size, composition, material properties and the wettability of the surface has a significant influence on the corrosion rates. In order to understand the underlaying mechanisms of corrosion under droplet, potentiodynamic polarization curves and open-circuit-potential (OCP) are obtained using microcapillary in contact with sessile NaCl droplet on low carbon steel. There have been efforts in the recent years to experimentally investigate corrosion of steel under different droplet sizes using a microcapillary [1,2]. In this work, the focus is on understanding the effect of capillary diameter and droplet size on corrosion kinetics through OCP, cathodic and anodic polarization curves. The results from the microcapillary experiments are used as an input parameter for mechanistic modelling corrosion under droplet electrolyte.[1] S. Li, L. Hihara, Atmospheric-corrosion electrochemistry of nacl droplets on carbon steel, Journal of the Electrochemical Society.
[2] S. Li, L. Hihara, The comparison of the corrosion of ultrapure iron and low-carbon steel under nacl electrolyte droplets, Corrosion Science.
| Period | 7 Sept 2020 → 11 Sept 2020 |
|---|---|
| Event title | Eurocorr 2020 |
| Event type | Conference |
| Location | Brussels, BelgiumShow on map |
| Degree of Recognition | International |