Corrosion and stress corrosion cracking of ultra-high-purity Mg5Zn

摘要

This paper reports on the measurement of the corrosion rate, and the stress corrosion cracking threshold stress, for ultra-high-purity Mg-5Zn. The corrosion rate was higher than the intrinsic corrosion rate of ultra-high-purity Mg, attributed to the quality of the corrosion product film. The threshold stress for stress corrosion cracking, at an applied stress rate of 0.00016 MPa s(-1), was equal to 0.7 times the yield stress in air. The ductility of the cracking indicated that the stress corrosion cracking mechanism was probably hydrogen enhanced localized plasticity. (C) 2015 Elsevier Ltd. All rights reserved.