The effect of partial recrystallization on the corrosion resistance of EN AW6082 forged components evaluated with different tests

Abstract

Structural automotive components are extensively made of aluminum alloy forgings, due to the elevate strength and low weight required. These products are frequently subjected to recrystallization. Recrystallization, often limited to surface or forging portions, is expected to reduce its tensile strength and corrosion resistance, but the literature is scarce on this subject. For a more comprehensive understanding, the present research studied the corrosion behavior of samples collected from EN AW 6082-T6 forged components, designed to expose both recrystallized and not recrystallized surfaces to the corrosive environment. Several standardized corrosion tests (i.e., PV 1113, ISO 11846, and VW 96380) were applied to assess the most representative with respect to real field exposure. Tensile tests were performed in four different conditions, recrystallized and not recrystallized specimens in an as-forged state or after corrosion. The recrystallization led to a reduction in tensile properties, but this gap was compensated by a higher corrosion resistance than the not recrystallized samples. Consequently, the mechanical properties became comparable after the corrosion test.