Stress corrosion cracking of 316L austenitic stainless steel in high temperature ethanol/water environments

• Main Author: Gulbrandsen, Stephani
• Language: en_US
• Published: Georgia Institute of Technology 2013
• Subjects: Ethanol and water solutions; Stainless steel; Stress corrosion cracking; Austenitic stainless steel Stress corrosion; Austenitic stainless steel Cracking; Biomass energy; Lignin Oxidation
• Online Access: http://hdl.handle.net/1853/47815

There has been an increase in the production of bio-fuels. Organosolv delignification, high temperature ethanol/water environments, can be used to separate lignin, cellulose, and hemicelluloses in the bio-mass for bio-fuel production. These environments have been shown to induce stress corrosion cracking (SCC) in 316L stainless steel. Previous research has been done in mixed solvent environments at room temperature to understand SCC for stainless steels, but little is known about the behavior in high temperature environments. Simulated organosolv delignification environments were studied, varying water content, temperature, pHe, and Cl- content to understand how these constituents impact SCC. In order for SCC to occur in 316L, there needs to be between 10 and 90 volume % water and the environment needs to be at a temperature around 200°C. Once these two conditions are met, the environment needs to either have pHe < 4 or have more than 10 ppm Cl-. These threshold conditions are based on the organosolv delignification simulated environments tested. SCC severity was seen to increase as water content, temperature, and Cl- content increased and as pHe decreased. To prevent failure of industrial vessels encountering organosolv delignification environments, care needs to be taken to monitor and adjust the constituents to prevent SCC.