SCC Behavior of Steel in Fuel Ethanol and Butanol

This paper summarizes the results of a laboratory testing program to evaluate stress corrosion cracking (SCC) susceptibility of carbon steel in fuel grade ethanol (FGE) per ASTM D4806, synthetic ethanol blends simulating FGE, and butanol. Biologically obtained butanol has been proposed as an alternative to ethanol. This study compares the two for their potential to induce environmental cracking. The tests results include both fracture mechanics and slow strain rate tests for the determination of crack growth rates, threshold stress intensity for SCC and conventional SSR ratios as an indication of SCC. In these test conditions, butanol was less prone to promote SCC of steel than fuel-grade ethanol.