Effect of chloride on stress corrosion cracking susceptibility of carbon steel in simulated fuel grade ethanol

The corrosion behavior and cracking susceptibility of carbon steel in simulated fuel grade ethanol (SFGE) were investigated over a wide range of chloride concentration. Steel corrosion in SFGE was investigated by electrochemical measurements on micro-electrodes. The cracking susceptibility was evaluated in slow strain rate tests in aerated SFGE at the free corrosion condition, and in deaerated SFGE with supporting electrolyte at applied anodic potentials equal to the aerated open circuit potentials in the same solution. Steel is susceptible to cracking in the aerated and deaerated SFGE environments within a particular chloride concentration window. Chloride is required for the occurrence of ethanol cracking, but it is not the controlling factor of crack growth.