Processing twining induced plasticity steel through simple shear extrusion

Microstructure and deformation behavior of twinning induced plasticity steel processed by simple shear extrusion are investigated. Two appropriate dies with the maximum distortion angle of 30° and 45° are designed and constructed. Results show that the twin fraction increases while the twin spacing decreases as the equivalent strain rises in the deformation channel. The hardness reaches to its maximum at the middle of the deformation channel and decreases in the second half of the channel due to reversal straining. A similar trend is observed for dislocation density. The crystallite size is determined as 710 nm and 500 nm after one pass of simple shear extrusion with maximum distortion angle of 30° and 45°, respectively.

► TWIP steel is processed successfully through SSE without any segmentation. ► Twin fraction increases and twin spacing decreases as the plastic strain is raised. ► The strain reversing causes the decrease in the hardness and dislocation density.