Role of the crystallographic texture in anisotropic mechanical properties of a newly-developed hot-rolled TRIP steel

In general, hot-rolled steels have higher strength but lower ductility in the transverse direction. In this work, the effects of the crystallographic texture on the anisotropic tensile properties of a new hot-rolled TRIP steel, named DF-TRIP steel, were investigated by electron backscatter diffraction. The tensile tests showed that the hot-rolled steel exhibited nearly the same yield strength but different TRIP effects when loaded along the rolling direction and transverse direction. The low anisotropy in yield strength was explained by the negligible difference in rolling texture in the ferrite due to strain-induced dynamic ferrite transformation. However, a lower Taylor factor of the austenite was found along the rolling direction, leading to early onset of slip and thus providing nucleation sites for strain-induced martensitic transformation. This new hot-rolled steel shows higher ultimate strength and better total uniform elongation in the rolling direction.