Analysis of substructure of high-mn steels in the context of dominant stress mechanism

In last ten years, leading research centers have been directed to the development of high- Mn steels for manufacturing of parts for automotive industry. The discussed steels with different values of Mn, Al, and Si addition have a medium value of EBU. They usually demonstrate a dominant stress mechanism like twinning induced plasticity TWIP. During the plastic deformation, they may demonstrate a two stress mechanisms like sliding and twinning. The paper presents the results of an analysis of the substructure of high manganese steel after deformation by cold rolling in the context of dominant stress mechanism. The substructure was analyzed by scanning transmission electron microscopy. In the steels, close weaves of dislocations, dislocations tangles, twins and microtwins were observed. It was revealed that the detailed analysis of substructure of the investigated steels after cold deformation could be helpful in determination of the dominant stress mechanism. The obtained results may be used for development of these steels and their plastic deformation models.