Patent ID: 8342232

Claim:
A method of producing an aluminum alloy slab by a continuous casting and rolling line having a twin-belt casting machine and a skin pass rolling machine, not having a rolling machine behind said skin pass rolling machine, and taking up the skin pass rolled slab directly by a coiler, said method comprising: producing an aluminum alloy slab by casting with said twin-belt casting machine and skin pass rolling machine, wherein said skin pass rolling machine provides a reduction rate of the slab, providing a casting slab speed detecting means between said twin-belt casting machine and said skin pass rolling machine, comparing the slab speed calculated from said slab speed detecting means with a line speed setting to obtain a difference and a residual error between the current slab speed and the line speed setting, controlling the roll speed of said skin pass rolling machine by proportional and integrated control in response to said difference and residual error so as to correct the speed of the skin pass rolling machine without changing said reduction rate, simultaneously calculating a suitable belt speed of said twin-belt casting machine from said line speed setting and a solidification shrinkage rate of said aluminum alloy so as to drive the belt drive system and synchronize the roll speed of said skin pass rolling machine and the belt speed of said twin-belt casting machine.