Effect of stabilization annealing on SCC susceptibility of beta-annealed Ti-6Al-4V alloy in 0.6 M NaCl solution

Abstract

The effect of stabilization annealing on the stress corrosion cracking (SCC) susceptibility of beta-annealed Ti-6Al-4V (Ti64) alloy was examined in an aqueous 0.6 M NaCl solution under various applied potentials of +0.1, -0.05 and -0.1 V vs E-corr, respectively, at a strain rate of 10 (-6) s (-1). The stabilization annealing substantially improved the resistance to SCC of beta-annealed Ti64 alloy in 0.6 M NaCl solution under cathodic applied potentials, while the effect was marginal under an anodic applied potential. It was also noted that the areal fraction between ductile and brittle fracture of beta-annealed Ti64 specimens, which were slow strain rate tested in 0.6 M NaCl solution, varied with stabilization annealing and applied potentials. The effect of stabilization annealing on the SCC behavior of beta-annealed Ti64 alloy in SCC-causing environment was discussed based on the micrographic and fractographic observation.