In order to improve a cold rolling lubrication model, the effects of this process on the formation and
evolution of superficial layers in two alloys were studied by coupled surface and microscopy analysis. On
the Al-Mg alloy, the friction on the metal asperities and their crushing provoke, by localized hardening and
heating, the burying of debris in the substrate, the recrystallization of the metal within a layer of 250 nm
and its recovery down to 20 μm. On the steel, the oxide layer mainly becomes amorphous and plastic,
because of a high incorporation of the lubricant, and heterogeneous at the nanoscopic scale.