Stress corrosion effects on ADC12 Al alloy tungsten inert gas welding joint in 3.5 wt% NaCl solution.

The stress corrosion behavior of ADC12 Al alloy tungsten inert gas (TIG) welding joint (WJ) outside its elastic deformation range was studied using electrochemical testing methods combined with surface analysis techniques in 3.5 wt% NaCl solution at 30 °C. The results showed that, with the enlargement of imparted stress, the corrosion potential of the TIG WJ shifted positively, the corrosion current density increased, and the polarization resistance decreased, indicating that the corrosion rate of the TIG WJ increased with the enlargement of imparted stress. With the prolongation of immersion time, the corrosion rate of the TIG WJ increased and then subsequently decreased. In addition, the plasticity and ductility of the TIG WJ decreased with the enlargement of imparted stress. When the imparted stress was 2100 N and 4200 N, the corrosion products on its surface were mainly composed of Al 2 O 3 and Al(OH) 3. This study provided a theoretical basis for the selection of structural materials and welding methods in the automotive, marine and aerospace fields. • The stress corrosion behavior of the Al alloy TIG WJ was studied. • The corrosion rate of the Al alloy TIG WJ increased with the increase of imparted stress. • The plasticity and ductility of the Al alloy TIG WJ decreased with the increase of imparted stress. • The Al alloy TIG WJ is in an active dissolution state under 4200 N stress. [ABSTRACT FROM AUTHOR]