Investigation of work hardening behavior in multilayered steels architected by twinning induced plasticity steel and martensitic steel during uniaxial tension

Abstract

Abstract To realize deformation mechanisms of twinning induced plasticity (TWIP) steels is always challenging. It is because that two controversial theory (deformation twins induced dynamic Hall and Petch effect vs Portevin-Le Ch a ˆ telier effect) have been long existed and both are thought of contributing to the resulting work-hardening behavior during straining of TWIP steels. In this study, a new class of multilayered steel (MLS) architected by Fe-22Mn-0.6C (wt%) TWIP steel and martensitic steel alternatively was designed to eliminate the Portevin-Le Ch a ˆ telier (PLC) effect, in order to systematically study the relationship of deformation twins and the work hardening behaviors of TWIP steels. After tensile deformation, it was found that the fraction of twins contribute to the higher toughness near the area of the interface in TWIP steel layers annealed at two different temperatures, suggesting that the deformation twins occur more significantly near the interface. It was also found that deformation twins are the main reason resulting in the improvement of the strength-ductility synergy of TWIP steels as well as MLS.