Method of making 6xxx aluminium sheets with high surface quality

Abstract

The invention is directed to a method for producing a 6xxx series aluminium sheet comprising the steps of homogenizing an ingot made from a 6XXX series aluminium alloy comprising in wt. % Si: 0.4-0.7, Mg: 0.2-0.4, Mn: 0.05-0.30, Fe: 0.03 to 0.4, Cu up to 0.3, Cr up to 0.05, Zn up to 0.15, Ti up to 0.1 wt %, rest aluminium and unavoidable impurities up to 0.05 each and 0.15 total, rough hot rolling on a reversible mill to a rough hot rolling exit thickness with a rough hot rolling exit temperature less than 420° C., finish hot rolling the ingot to a hot rolling final thickness with a tandem mill and coiling at the hot rolling final thickness with a hot rolling exit temperature less than 300° C., cold rolling to obtain a cold rolled sheet. The products obtained according to the method of the invention are particularly useful for automobile hood inners as they have the requested mechanical properties for pedestrian safety and surface quality.

Dependencies are inferred from the claim text.