The Effect of Chemical Composition and Processing Technology on the Microstructure, Texture and Earing Behavior of DR Tinplate

The influence of alloying elements and processing technology on the microstructure, crystallographic texture and earing propensity has been investigated in two kinds of DR tinplate differing in Ti content: steel A, no Ti addition, and steel B 0.015% added. The cementite distribution, second-phase particles and the content of dissolved carbon and nitrogen atoms were obtained by SEM, TEM and XPS, respectively. Since the two steels develop both a partial 〈110〉//RD fiber and a {111}//ND fiber, the relative intensities of the several vital texture components seem to differ visibly. There are three types of strengthening mechanisms involved here: strengthening by grain size reduction, solution strengthening and strain hardening. That the tensile strength of steel B is greater than A implies the third mode plays a dominant role in the strength increasing for the DR tinplate. The crystallographic texture of materials not only results in a “preferential orientation” of the mechanical property, but also takes the primary responsibility for ears forming during drawing. Increasing the second cold-rolled reduction is not favorable to reduce the ear height, but this situation seems to be ameliorable. The average ears height of steel B is smaller than that of A, which demonstrated a low level of solute atoms and an ideal texture characteristic before deformation could alleviate the adverse effect caused by an elevated second cold reduction.