Fourth CorroZoom Webinar – Gerald S. Frankel
9 April 2021 at 0800 US Eastern
A Framework for Pitting Corrosion Based on Pit Growth Stability
Gerald S. Frankel
Fontana Corrosion Center, The Ohio State University, USA
This talk will describe a unifying framework for pitting corrosion based on pit growth stability that was recently published in a series of papers. A key new concept in the framework is the maximum pit dissolution current density, idiss,max, which describes the capacity of pit dissolution for given conditions. Comparison of idiss,max with the critical diffusion current densities associated with pit repassivation and salt film formation generates new insights to interpret previous observations in a self-consistent way. A mathematical framework describing the behavior of a salt film in a pit and the role of salt films in pit growth will be presented. A novel cryo-based approach for FIB/SEM analysis of the salt film in a pit provides high resolution images that support the model. The framework allows for clear descriptions of the conditions determining the critical pitting temperature, pitting potential and repassivation potential, as well as the influence of alloying effects in stainless steels.
Gerald S. Frankel is Distinguished Professor of Engineering in the Department of Materials Science and Engineering, and Director of the Fontana Corrosion Center at the Ohio State University. His primary research interests are in the passivation and localized corrosion of metals and alloys, corrosion inhibition, protective coatings and atmospheric corrosion. He is a member of the editorial board of The Journal of the Electrochemical Society and Corrosion and is a fellow of NACE International, The Electrochemical Society, and ASM International. He received the W.R. Whitney Award from NACE International in 2015, the U.R. Evans Award from the UK Institute of Corrosion in 2011, the OSU Distinguished Scholar Award in 2010, the 2010 ECS Corrosion Division H.H. Uhlig Award, and the Alexander von Humboldt Foundation Research Award for Senior US Scientists in 2004. From 2012-2016, he served as a member of the Nuclear Waste Technical Review Board after being appointed by President Obama. In 2016, he became the director of a DOE-funded Engineering Frontier Research Center focused on the performance of nuclear waste forms.