Influence of Pretreatment, Environment and Strain Rate on Stress Corrosion Cracking of the Aluminum Alloy 7075-T6

摘要

It is shown that the pretreatment of aluminum alloy 7075-T6 according to the German standard for stress corrosion testing LN 65666 results in a surface attack of the material, which might influence stress corrosion cracking (SCC) results. Addition of chromate ions to the LN 65666 environment eliminates the general corrosion of the material, but the stress corrosion time is drastically increased. Addition of hydrogen peroxide, or the use of synthetic seawater decreases the time-to-failure as compared to a 3 wt percent NaCl-environment. A decrease of the strain rate produces a more distinct SCC behavior in all environments.