0000000000850563
AUTHOR
Robert Akid
Numerical modelling of the electrochemical behaviour of 316L stainless steel based upon static and dynamic experimental microcapillary-based techniques
Microcapillary-based techniques allow the selection and interrogation of single metallurgical sites and are therefore becoming increasingly popular to investigate the electrochemical behaviour of metallic phases and non-metallic heterogeneities in alloys. This study has been carried out to assess the differences between current measurements made using a 'closed' microcapillary system (the electrochemical microcell technique) with current measurements derived from a flowing 'open' microcapillary droplet cell (the scanning droplet cell). The experimental results were compared with calculations derived from a model system adopting a finite element approach. The corrosion system consists of fou…
Numerical modelling of the electrochemical behaviour of 316 stainless steel based upon static and dynamic experimental microcapillary-based techniques: effect of electrolyte flow and capillary size
objective of this work was to determine the parameters that affect the mass transport and the distribution of species in microcapillaries close to the specimen surface. Local experiments were carried out under static and flow conditions on type 316L stainless steel in 1.7 M NaCl, pH = 3, by means of the electrochemical microcell and the scanning droplet cell technique. The polarisation behaviour of pure iron (used as a model system) in an aqueous environment was calculated adopting a finite element approach and was compared to the experimental results. The corrosion system consists of three parallel electrochemical reactions: the oxygen reduction reaction (ORR), the hydrogen evolution react…
Galvanic Corrosion Following Local Breakdown of a Scale Formed on X-65 in CO2 Saturated Solutions
Under some conditions in sweet environments, the precipitation of corrosion products (primarily FeCO3) on the surface of X-65 pipeline steel can decrease the corrosion rate of the metal, this precipitated film acting like a protective scale. However, when these scales are damaged due to effects such as solidparticle erosion or mechanical stress, a galvanic pair can form between the bare steel (anode) and the surrounding undamaged scale (cathode). The aim of this work is to evaluate the magnitude of galvanic coupling that arises when the protective scale is broken and a corrosion cell is established between the defect and the surrounding scale. This study has been conducted in two stages: fi…