Thermomechanical Treatment for Enhancing Deep Drawability of Copper-Bearing Bake Hardening Steel

A two-step rolling-annealing process has been developed to increase the < 111 >//ND (gamma fiber) component in the recrystallization texture of a copper-bearing bake hardening steel. The two step process comprises the first rolling by a low reduction in thickness and subsequent annealing at 780 degrees C, followed by the second rolling by a high reduction and subsequent annealing at 780 degrees C. The first rolling process aims at seeding the gamma fiber oriented grains, so that they can grow at the expense of differently oriented grains developed in the second rolling process. In this way the density of gamma fiber component in the recrystallization texture of the bake hardening steel much increases compared with that in the conventional one-step rolling-annealing process.