A Novel Insight into the Mechanism of Plastic Instability Behavior from the Mesoscopic-Scale Strain Analysis in Medium Mn Steel
摘要
The spatiotemporal coupling relationship of strain in different local deformation regions was characterized by digital image correlation (DIC). The Lüders band nucleates at the deviation point of the elastic stress-strain line and begins to propagate at the lower yield point. Propagation of the Portevin-Le-Chatelier (PLC) band leads to the formation of the Band Propagation Region and No-band Region in the entire deformation region. The occurrence of stress serrations is attributed to the periodic strain transferring between the Band Propagation Region and the No-band Region at the mesoscopic scale.