Effect of shear strain on the microstructural evolution of a low carbon steel during warm deformation

Abstract

The microstructural evolution of a low carbon steel was investigated under two different conditions with and without shear strain, using electron backscattered diffraction (EBSD) when a uniaxial compression of 67% was applied at a warm working temperature of 773 K. The equivalent strain and shear strain imposed by the compression test were calculated quantitatively by finite element analysis (FEA). As the equivalent strain was increased without any shear strain, the texture of the α and γ fibers was strongly developed, and the grain refinement was accelerated. However, as the shear strain was increased at the same equivalent strain, the thickness of the pancaked ferrite decreased and the texture was weakened. With increasing shear strain, a shear texture, such as (110)//TD and {110}//ND, was observed and a high angle boundary over 15° developed at the expense of low and medium angle boundaries below 15°. The shear strain accelerated the subdivision of the ferrite grain and randomized the texture. © 2010 The Japan Institute of Metals.