The microstructure evolution of a TWIP steel (30Mn-3Si-3Al) during equal channel angular pressing (ECAP) was investigated experimentally. After one pass, a large number of deformation twins with band widths of 10~40 nm were produced. At the same time, these deformation twins were cut down by microshear bands. With increase of pressing passes, more twinning systems were activated and twin bands intersected each other, curved and fragmented finally. Also, both the number and the width of shear bands were increased, which cut twinning bands and refine more area of microstructure. After 4 pressing passes, ultrafine grains with sizes of 40~120 nm were obtained. While several areas within which deformation twins were not cut down were distributed in the matrix of ultrafine grains. The width of these twin bands was decreased to 5~20 nm.
Microstructure Evolution of TWIP Steel (30Mn-3Si-3Al) during Equal Channel Angular Pressing[J]. Journal of Iron and Steel Research, 2009, 21(12): 32-32