Investigation of formability of three-layered brass-IF steel-brass composite

In this research, three-layered composite of brass-IF steel-brass was fabricated by cold roll bonding process (CRB) and formability of composite were investigated. Due to high work hardening of composite during rolling process, specimens were heat treated at annealing temperatures at 500°Ϲ through 700 °Ϲ for 10 min. Formability properties of composite were investigated by using tensile, anisotropy and Erichsen tests. The results showed that, heat treatment after rolling resulted in occurrence of recrystallization phenomenon in composite, consequently a reduction tensile strength and rising strain hardening rate. Dome height created by Erichsen test prior to heat treatment was 10/53 mm, by annealing composite at 500℃, Dome height reached at 14.62 mm. By increasing annealing temperature to 600℃ and owing to relatively high stacking fault energies of IF steel, recrystallization solitary occurred in brass layer. Nevertheless, as a result of upward trend of annealing temperature up to 650℃ as well as resultant driving force, recrystallization occurred in all layers and gradient of formability properties increased. As at 700℃, recrystallization phenomenon was completed in the composite and dome height was peaked at 17/29 mm. Moreover, by increasing annealing temperature, normal anisotropy and planer anisotropy respectively increased and decreased. Anisotropy properties of composite in comparison with brass and IF steel during complete recrystallization, it was clear that production of brass-IF steel-brass composite caused to improve normal anisotropy in brass and reduce negative effects of planer anisotropy in IF steel.