Available at: https://digitalcommons.calpoly.edu/theses/3129
Date of Award
6-2025
Degree Name
MS in Civil and Environmental Engineering
Department/Program
Civil and Environmental Engineering
College
College of Engineering
Advisor
Wang, Long
Advisor Department
Civil and Environmental Engineering
Advisor College
School of Education
Abstract
Many structures do not fail from poor design, but instead from environmental degradation. Corrosion is one mode whose effects can be diminished, but not eliminated, by employing corrosion resistant materials, such as 304 stainless steel, which are still subject to pitting corrosion. Pitting corrosion is a chemical process of the localized removal of material leaving cavities. Despite the prevalence of pitting corrosion, there has been limited testing conducted of the effect of stress during corrosion. This study conducted accelerated controlled corrosion experiments with and without mechanical loading and various corrosion times. Pit morphology of different conditions was analyzed with statistical methods including characterizing the probability distribution of pit depths and pit effective radii. Several distributions were fit to the resulting data, and it was determined that both the log-normal and Pearson Type III distributions had better goodness-of-fit than the generally used Gumbel or Generalized Extreme Value distributions. Additionally, there was found to be little correlation between the depth of the deepest pits and their apparent size.
To quantify the effect on performance of plate members subjected to pitting corrosion, pitted samples were mechanically tested. Mechanical properties including yield strength, ultimate strength, and modulus of elasticity were identified and the corresponding reduction identified. Additionally, a preliminary finite element model was created using test results, producing a model which exhibited a strength reduction due to pitting.