Serrated flow accompanied with dynamic type transition of the Portevin-Le Chatelier effect in austenitic stainless steel

摘要

In order to further understand high-temperature deformation behavior and its-related mechanical prop-erties,the Portevin-Le Chatelier(PLC)effect in an Fe-19Cr-13Ni-0.2C austenitic stainless steel was in-vestigated using high-temperature digital image correlation(DIC)analysis.Under the tensile testing at temperatures from 473 to 623 K,different types of serrated flow appeared even at a constant applied strain rate,and the type transition took place dynamically in a certain order with deformation time.DIC analysis revealed that the dynamic type transition of the serrated flow obeys the PLC band propagation behavior,and that the transition of the PLC band propagation behavior could be attributed to the PLC band nucleation manner.Numerical modeling also proved that the nucleation manner of PLC band nu-cleation is determined by the spatial-temporal coupling effect.