The Effect of Applied Stress on Environment-Induced Cracking of Aluminum Alloy 5052-H3 in 0.5 M NaCl Solution

Abstract

The environment-induced cracking (EIC) of aluminum alloy 5052-H3 was investigated as a function of applied stress and orientation (Longitudinal rolling direction—Transverse: LT and Transverse—Longitudinal rolling direction: TL) in 0.5 M sodium chloride solution (NaCl) using a constant load method. The applied stress dependence of the three parameters ( time to failure; $t_f$, steady-state elongation rate, $I_{\text{ss}}$, and transition time at which a linear increase in elongation starts to deviate, $t_{\text{ss}}$ ) obtained from the corrosion elongation curve showed that these relationships were divided into three regions, the stress-dominated region, the EIC- dominated region, and the corrosion-dominated region. Aluminum alloy 5052-H3 with both orientations showed the same EIC behavior. The value of $t_{\text{ss}}$/ $t_f$in the EIC-dominated region was almost constant with $0.57\pm 0.02$independent of applied stress and orientation. The fracture mode was transgranular for 5052-H3 with both orientations in the EIC-dominated region. The relationships between log $I_{\text{ss}}$and log $t_f$for 5052-H3 in the EIC-dominated region became a good straight line with a slope of −2 independent of orientation.