Dissertation Proposal Defense - B. Aydin Baykal
Prof. Preet M. Singh, Advisor, MSE
Prof. Faisal M. Alamgir, MSE
Prof. Victor A. Breedveld, ChBE
Prof. Hamid Garmestani, MSE
Prof. Arun M. Gokhale, MSE
“Flow-Assisted Erosion-Corrosion of Steels in Pulping Liquors Containing Particulates”
Erosion-Corrosion is a type of corrosion where mechanical (erosive) and chemical (corrosive) effects combine to accelerate material loss due to corrosion. Erosion-corrosion can cause a higher rate of wastage compared to the sum of its components through its negative impact on the reformation of a thin, protective oxide layer on the surface of metals. Some of the important industrial failures by erosion-corrosion have been reported in the pulp and paper, mining, nuclear, petrochemical and pharmaceutical industries. Some of these industries employ alkaline environments such as pulping liquors or digestion of aluminum containing bauxite-ore in hot caustic solution, where erosion-corrosion has been observed.
While erosion-corrosion maps have been produced and modeling has been done in certain low pH, and/or chloride containing environments, the effect of alkaline environments on passive film properties and thus erosion-corrosion has not been explored. This study aims to systematically understand the effect of flow on the stability of protective passive films. Electrochemical methods (e.g. linear polarization resistance-LPR and anodic polarization) will be used to quantify the effect of flow related variables and other environmental factors on corrosion of C1018 carbon steel, 304L and 316L austenitic stainless steel and 2205 duplex stainless steel in simulated pulping liquors, highly alkaline environments of kraft pulp mills. Surface characterization using SEM and XPS will provide information about the passive film composition and properties. Factors that will be systematically explored in this study include the particle size, particle volume, temperature, viscosity, and the surface roughness of alloy samples. After each individual factor has been examined, this work will provide a predictive model of erosion-corrosion under alkaline environments.