METHOD FOR MAKING SHEETS OF ALUMINIUM ALLOYS Russian patent published in 2000 - IPC

FIELD: manufacture of sheets of aluminium alloys. SUBSTANCE: method comprises steps of homogenization, cooling with rate 5-50 C/h until 100-150 C; heating up to hot rolling temperature equal to 360-540 C; hot rolling and annealing hot rolled blank. Before cold rolling sheet blank is annealed at least-stability temperature for 1-6 hours and it is cooled until 100-150 C, cold rolled and subjected to final heat treatment. Hot and cold rolling steps are realized during one or several stages in lengthwise or crosswise direction relative to axis of ingot. Cold rolling is performed with deformation degree equal to 15-40%. Final heat treatment includes solid-solution treatment at 450-540 C, subsequent cooling until 20-40 C, artificial aging or annealing at 280-395 C with subsequent cooling at rate 20-750 C/s until 100-150 C. At several stage of hot rolling sheets are heated before each stage up to 360-450 C. Method allows to increase viscosity of rupture, to lower anisotropy of properties at high strength of wide (up to 3000 mm) sheets used in aerospace and ship building industry branches. EFFECT: enhanced quality of aluminium sheets. 5 cl, 1 exp, 2 tbl