Corrosion Fatigue Mechanism on Hot-Forged AA6082 Aluminum Alloy

Abstract

An attempt has been made to understand the corrosion fatigue phenomenon in AA6082 aluminum hot-forged parts. Fatigue and corrosion fatigue experiments of forged parts produced by two different feedstock materials have been performed in the lab air and in a corrosive 3.5% NaCl solution under different stress levels. The scanning electron microscopy was used to study the rupture and to identify failure modes. With corrosion and mechanical stress working together, the failure occurred earlier in the specimens subjected to a 3.5% NaCl solution as compared to those subjected to the lab air irrespective of the material forms (cast-forged or extruded-forged). The corrosion fatigue performance of these specimens with different stress levels as well as the crack initiation and propagation were elaborated. It was found that there is no significant variation in corrosion fatigue resistance for final cast-forged and extruded-forged products.