On the relation between the stressing direction and stress corrosion sensitivity of 7075 alloy thick plate

Abstract

This investigation was performed to study the orientation dependence of the stress corrosion sensitivity and the influence of the rolling reduction in 7075-T6 alloy thick plates. The results obtained are as follows:
(1) The orientation dependence of the stress corrosion sensitivity of 7075-T6 thick plates was influenced significantly by the stress component acting in the short transverse direction.
(2) Within the rolling reduction by which the specimen was not recrystallized, the stress corrosion resistance in the short transverse direction was improved with an increase of the rolling reduction.
(3) In regard to the stress corrosion sensitivity of the plate surfaces, the unrecrystallized structure obtained by less than 92%reduction was relatively insensitive, while the recrystallized structure was sensitive.
These results show that grain boundaries, especially those lying perpendicular to the stressing direction play an important role in the stress corrosion sensitivity of 7075 alloy.