Materials Science Forum, Vol.495-497, 393-398, 2005
An EBSD investigation on deformation-induced shear bands in Ti-bearing IF-steel under controlled shock-loading conditions
We report the results of the microstructural characterization of a Ti-bearing IF-steel deformed at high strain rates (approximate to 6.10(4) s(-1)) in a split Hopkinson bar. The shock-loading tests were performed in hat-shaped specimens to induce the formation of adiabatic shear bands (ASB). The samples were deformed at 223 K and 298 K. High-resolution electron backscatter diffraction (EBSD) reveals the development of an ultrafine-grained structure within the ASB. A closer inspection reveals the presence of deformation twins in grains adjacent to the shear band. These twins bend towards the ASB suggesting that mechanical twinning occurs before the flow associated to shear banding. The results of microtexture have indicated the presence of a sharp < 111 > gamma-fiber texture in the ASB for both temperatures.