Stress corrosion cracking of a wrought Mg–Mn alloy under plane strain and plane stress conditions

Abstract

Stress corrosion crack growth of a rare earth containing Mg–Mn hot rolled alloy was studied using compact tension and circumferential notch tensile specimens employing constant load in 0.1N NaCl solution saturated with Mg(OH)2. Circumferential notch tensile specimens satisfied plane strain conditions; Log crack velocity versus stress intensity plots yielded slope of 0.5 and 1 for stage I region and threshold stress intensity of 10 and 13MPam1/2 for circumferential notch tensile and compact tension specimens respectively. Fractography showed transgranular features involving hydrogen in stress corrosion cracking.