Strength enhancement and uniform strain distribution through cross route-constrained groove pressing

Abstract

Constrained groove pressing (CGP) is one of the severe plastic deformation techniques for sheet metals to impose large plastic strain and produce ultrafine-grained (UFG) structures without any change in dimensions. Cross route-constrained groove pressing (Cross-CGP), an advanced version of the conventional CGP process, involves two CGP cycles with an equivalent strain of 2.32 per cycle where the square sample is rotated by 90° after performing every cycle of CGP. The strain path in the sheet during conventional CGP and cross-CGP significantly affects the homogenization of mechanical properties. Sheets of low carbon steel are processed through conventional-CGP and cross-CGP routes. The ability to sustain the maximum strain has been increased in the cross-CGP process due to uniform strain distribution. The tensile strength and hardness in the sheet processed through cross-CGP are higher than that of conventional CGP, especially at higher pass numbers. Tensile behavior and hardness in two different orientations (parallel and perpendicular to the groove direction) have been found to be almost the same in the cross-CGP processed sheet.