Texture, Mechanical Properties, and Formability of a Lightweight Steel during Cold Rolling and Annealing

In this work, the texture evolution, mechanical properties, and formability of cold-rolled lightweight steel annealed at 500, 600, 700, and 800 degrees C for 30 min were investigated. The phases in the annealed specimens mainly included ferrite, austenite, and martensite. The retained austenite showed a trend of increasing and then decreasing with the increase in annealing temperature. At the annealing temperature of 700 degrees C, the retained austenite content reached the maximum value of 53.0%, resulting in a large amount of martensitic TRIP effect during the subsequent deformation. So the steel obtained the optimal mechanical properties with the ultimate tensile strength of 1613 MPa, ultimate elongation of 30.2%, and largest product of strength and ductility of 48.7GPa%. In addition, the annealing temperature of 700 degrees C was conducive to the stamping texture of {111} <110> orientation, as well as higher strength, and the plastic strain ratio (r), the strain hardening index (n), and the flexural strength ratio (R-eL/R-m) were 1.25, 0.55, and 0.41, respectively, the material obtained excellent formability.