Effect of Cooling Rate on SCC Susceptibility of beta-Processed Ti-6Al-4V Alloy in 0.6M NaCl Solution

Abstract

The effects of cooling rate on the stress corrosion cracking (SCC) susceptibility of beta-processed Ti-6Al-4V (Ti64) alloy, including BA/S specimen with furnace cooling and BQ/S specimen with water quenching, were investigated in 0.6M NaCl solution under various applied potentials using a slow strain rate test technique. It was found that the SCC susceptibility of beta-processed Ti64 alloy in aqueous NaCl solution decreased with fast cooling rate, which was particularly substantial under an anodic applied potential. The micrographic and fractographic analyses suggested that the enhancement with fast cooling rate was related to the random orientation of acicular alpha platelets in BQ/S specimen. Based on the experimental results, the effect of cooling rate on the SCC behavior of beta-processed Ti64 alloy in aqueous NaCl solution was discussed.