Insights from electrochemical crack tip modeling of atmospheric stress corrosion cracking
Ryan Katona, James T. Burns, Rebecca Schaller, Robert G. Kelly
Abstract
Crack tip electrochemical conditions are explored utilizing a reactive transport Finite Element Method model for stainless steel 304 exposed to 3 M NaCl. Under simulated full immersion conditions, a steady state pH of 3 and metal chloride concentration of 1.4 M were calculated. It was determined that an increase in cathode length and a decrease in water layer thickness increases total cathodic current per unit thickness, metal chloride concentrations, and decreases crack tip pH. The presented results and discussion call into question whether electrochemical similitude is achieved between different specimens, crack lengths, and between laboratory specimen and field relevant samples.