Growth and strain behavior of columnar grains in Fe-0.5%Mn alloy by hot-rolling

Abstract

The growth and strain evolution of columnar grains in a Fe-0.5%Mn alloy subjected to hot rolling, cold rolling, and austenite-to-ferrite transformation were studied through electron backscattering diffraction analysis. Because of the formation of the three-layer hot-rolled microstructures with more equal and higher grain orientation spread values (GOSVs), double-layer toothed slender columnar grains with an approximate {100} texture and high GOSVs were obtained. The generation of double-layer toothed coarse columnar grains with a rotated cube texture and higher GOSVs was attributed to the formation of a more inhomogeneous hot-rolled microstructure. Driven by the anisotropic strain energy and surface effect and because of the advantageous austenitic grain size, unique three-layer sandwiched microstructures comprising a surface and under layer of coarse columnar grains with high GOSVs and an inner layer of equiaxed grains with low GOSVs were obtained.