corro5

 

 

Fifth CorroZoom Webinar – Sanna Virtanen

 

Respirometric Measurements of Corrosion Processes

Sanna Virtanen

Friedrich-Alexander University Erlangen-Nürnberg, Germany

 

Abstract

Recently developed respirometric techniques that allow in situ real-time monitoring of corrosion will be presented. The respirometric approach is based on real-time measurement of the rate of cathodic reactions, for instance simultaneous measurement of the cathodic kinetics of the H2 evolution reaction (HER) and the O2 reduction reaction (ORR). The non-destructive methods enable the determination of real-time corrosion rates for both atmospheric corrosion and immersion. Monitoring of H2-type corrosion can be carried out gravimetrically but also based on pressure increase in a hermetically closed chamber. For ORR, gravimetric measurements, a pressure sensor, or a fibre optic O2 sensor are employed to monitor the rate of consumption of O2 gas under immersion or atmospheric corrosion. A combination of these methods enables to monitor ORR and HER simultaneously. Mass loss measurements are carried out to validate the corrosion rates determined by respirometry. Combining these approaches with a flow cell setup expands the possible corrosion scenarios to be investigated. Switching between different exposure conditions enables following e.g. wet-dry cycles and temperature changes with a real-time response of the corrosion rate. Finally, time-lapse video observation of the corroding surfaces and integration of electrochemical control to the setups complete the information achievable. The presentation will discuss the development of the different experimental setups and show highlights of various corrosion cases where new details on mechanisms were revealed with the help of the respirometric approach. 

 

Biography

Sanna Virtanen is a professor for Corrosion and Surface Science at the Department of Materials Science and Engineering of the Friedrich-Alexander University Erlangen-Nürnberg in Germany.  She studied Materials Science at the Helsinki University of Technology, Finland (MSc) and then carried out her PhD studies in the Department of Materials at the Swiss Federal Institute of Technology, Zurich (ETH-Z). She carried out postdoctoral research at the Brookhaven National Laboratory (USA) and at McMaster University (Canada), with shorter research stays at Kyoto University (Japan) and University of Helsinki (Finland). She was assistant professor at the ETH-Zurich, before joining the department of Materials Science in Erlangen. Her research targets the elucidation of corrosion and degradation mechanisms of advanced metallic materials under various environmental loads as well as development of techniques for studying the reactive solid/liquid and solid/gas interfaces. Her research interests include microstructure/chemistry effects on passivity and its breakdown, corrosion behavior of light alloys (especially Mg alloys), and corrosion of metallic biomedical implant materials (with special focus on biodegradable Mg alloys).