Experimental study on material properties of hot rolled and continuously cast aluminum strips in cold rolling

Initial aluminum strips for cold rolling are usually produced by hot finishing rolling and twin-roll casting. Identification of the difference in material properties of the initial strips and of the strips in subsequent processing is very desirable. The delivered samples AA1050 consist of three kinds of cast strips and hot rolled strips (HRSs). Extensive laboratory experiments were carried out to determine microstructure, mechanical properties (tensile strength, yield stress, elongation, area reduction, elastic modulus, hardness and impact energy) and formability. The initial strips were rolled to 0.5–0.8 mm at a 2-high mill and further to 0.07 mm thickness at a 20-roll mill. In cold rolling process the heat treatment was done. The continuously cast strip (CCS) presents mainly as cast microstructure, while the HRS presents mainly deformed microstructure. The main differences in tensile strength and yield stress occur, when the initial strips are directly rolled. With a homogenization prior to cold rolling the differences disappear practically. However, the HRS has higher strain hardening effect. The strip from CCS has worse deep drawability than that from HRS and has higher recrystallization temperature.