Effect of Controlled Rolling on Texture Development in a Plain Carbon and a Nb Microalloyed Steel

Abstract

The effect of finish rolling temperature was investigated on texture formation in a plain C and a 0.034% Nb microalloyed steel. When finish rolled at 1020°C (i.e. within the γ recrystallization range), the textures in both steels contain the {001}<110> and {110}<110> components. The sharpness of the {001}<110> component generally increases with decreasing finish rolling temperature down to 630°C, while the {110}<110> component gradually weakens and finally disappears after ferrite rolling. The microalloyed steel displays much sharper texture than the plain C steel when finish rolled at 870°C (i.e. within the γ pancaking range for the Nb steel) and at 730°C (in the γ+α intercritical range). After finish rolling at 870°C, the major texture components in the microalloyed steel are {113}<110> and {332}<113>, in addition to the above two, while the plain C steel texture only contains some low intensity maxima. When finish rolled at 730°C, weak peaks appear at {223}<110> and {554}<225> in the plain C steel and stronger ones at {4411}<110> and {554}<225> in the microalloyed steel. After warm rolling at 630°C, the major texture components in both steels are {223}<110>, {554}<225> and {001}<110>.
The {001}<110> and {110}<110> components are obtained, by transformation, from the {100}<001> (cube) and {122}<212> (twinned cube) components of the recrystallized γ. By contrast, the {113}<110> and {332}<113> components originate, respectively, from the {112}<111> (copper) and {110}<112> (brass) components of the unrecrystallized γ. During continued rolling in the γ+α or α range, these transformation texture components are further modified by deformation and ultimately give rise to the stable end orientations which constitute the well-known warm rolling texture in steels.