Hot rolling generally refers to rolling performed above the recrystallization temperature of the aluminum sheet metal alloys. During hot rolling, the deformed metal has both hardening and softening processes. Due to the influence of the deformation speed, as long as the recovery and recrystallization process is too late, the metal will produce a certain degree of work hardening with the increase of the degree of deformation. However, in the hot rolling temperature range, the softening process plays a leading role. Therefore, at the end of hot rolling, the recrystallization of the metal is often incomplete, and the aluminum alloy sheet and strip after hot rolling show a coexistence of recrystallization and deformation. .
Hot rolling aluminum sheet metal alloys has the following characteristics:
(1) Hot rolling can significantly reduce energy consumption and cost. During hot rolling, the metal has high plasticity and low deformation resistance, which greatly reduces the energy consumption of metal deformation.
(2) Hot rolling can improve the processing performance of aluminum sheet metals and alloys, that is, the coarse grains in the as-cast state are broken, the micro-cracks are healed, the casting defects are reduced or eliminated, the as-cast structure is transformed into a deformed structure, and the processing performance of the metal is improved.
(3) Hot rolling usually adopts large ingot and large reduction rolling, which not only improves the production efficiency, but also creates conditions for improving the rolling speed and realizing the continuous and automation of the rolling process.
(4) Hot rolling cannot control the mechanical properties required by the aluminum sheet metal alloys very accurately, and the organization and properties of hot rolled products are not uniform enough. Its strength index is lower than that of cold work hardened products and higher than fully annealed products; its plasticity index is higher than cold work hardened products and lower than fully annealed products.