Dependence of KISCC on Loading Rate and Crack Orientation in Ti-6AI-6V-2Sn

Abstract

Abstract The dependence of KISCC on loading rate was investigated for Ti-6AI-6V-2Sn in 3.5% NaCI for both the WR and RW orientations. Crack initiation was determined to occur when a spike in electrochemical potential was observed. The measured KISCC values were a minimum at an intermediate loading rate, which is indicative of hydrogen embrittlement through hydride formation. The strain rate at which minimum KISCC values were observed corresponded closely with the theoretical minimum strain rate for hydrogen transport by dislocations as Cottrell atmospheres. KISCC values were lower for RW specimens than for WR specimens due to a more favorable orientation of hydride habit planes with respect to the tensile axis.