LAUSR

Pre-aging (PA) treatment, employed shortly or for a long time after solution treatment, has different effects on the age-hardening of Al-Mg-Si automotive sheets. Here, the influence of natural aging and PA on the age-hardening behavior was systematically investigated. The aging response decreased with increasing room temperature (RT) storage time and RT storage time before PA treatment. The clustering activity before paint bake-hardening (BH) had little effect on the average r values of the alloy sheets. The hardness of the NA0 sample (No RT + No PA) was higher than that of NA0PA sample (No RT + PA) during paint BH at 185°C. The difference in hardness decreased significantly with increasing RT storage time. The cluster type formed before paint BH significantly affected the size and distribution of the strengthening precipitates, resulting in a variation in peak aged hardness.