The aluminum-clad hard aluminum alloy is placed on both sides of the milled billet and welded by hot rolling. The thickness of the aluminum cladding layer is generally 4% of the plate thickness. Hot rolling is generally performed above the recrystallization temperature. Hot rolling can be carried out on a single-stand reversing rolling mill, or continuous rolling on multiple stands. In order to improve the yield and production efficiency, large-scale ingot rolling was developed, and the ingots weighed more than 10 to 15 tons. Factories with an annual output of less than 100,000 tons generally use four-roller reversible hot rolling and hot coiling technology. The thickness of the hot-rolled strip is about 6 to 8 mm. Factories with an output of more than 100,000 tons mostly adopt single-stand or two-stand, three-stand, or five-stand continuous rolling after the four-roller reversing hot rolling mill is opened, and hot finish rolling is performed. The strip thickness can reach 2.5 to 3.5 mm. The hot-rolled strip is rolled into a coil and used as a cold-rolled billet. In order to ensure the best plasticity of the metal, hot rolling should be carried out under a single-phase structure.
The hot rolling billet temperature of LY11, LY12 and other alloys is 400~455℃. The deformation rate in the first few passes is generally within 10%, and then gradually increases. The pass deformation rate of pure aluminum and soft aluminum alloy can reach 50%, while that of hard aluminum alloy is about 40%. The total deformation rate of hot rolling can reach more than 90%. Cold rolling is often performed at room temperature. Through cold rolling, thinner plates and strips with precise dimensions, smooth and smooth surfaces can be obtained, and work-hardened plates and strips with specific mechanical properties can be obtained.