| dc.description.abstract | Corrosion is a prominent field of interest across many industries, and corrosion under insulation (CUI) can be particularly challenging to detect and assess. Not only is visible detection hindered by the insulation material itself, but an enormous variety of other factors such as salt in the environment or leeched ions from the insulation material can accelerate corrosion and cause it to progress in unpredictable ways. While there exist standard methods for replicating industrial CUI in a laboratory setting as closely as possible, new approaches to the study of CUI can help lead to a better fundamental understanding of its processes.
In this study, a novel experimental setup for monitoring and measuring CUI was developed and tested, with an emphasis on simplicity and accessibility of design. Experiments using the new setup were performed successfully and mass loss measurements indicated that the corrosion rate of S235 steel increased by 87% in the presence of insulation material, an increase which aligned well with previous studies of CUI. Thermodynamics and oxygen diffusion processes were considered for possible explanations of the observed increase.
Electrochemical noise (EN) monitoring was performed over the duration of experiments to monitor the development of the corrosion process and to measure noise resistance (Rn) values from which corrosion rates could be calculated. Corrosion rates calculated from Rn were found to be on the same order of magnitude as those from the mass loss measurements, and Rn values for insulated and non-insulated conditions were shown to have similar trends. EN data was analyzed qualitatively for evidence of localized corrosion, and no evidence of localized corrosion could be visibly detected. | |