Effect of martensite transformed from reversed austenite on Lüders strain of Fe-0.05C-6Mn-1Al-1.5Si steel

Abstract In this study, the behavior of localized deformation with Luders strain was investigated in Fe-0.05C-6Mn-1Al-1.5Si steel subjected to cold-rolling and intercritical annealing. It was found that Luders strain was reduced from 2.4% to 0.9% with decreasing mechanical stability of austenite. Moreover, the samples that adopted deep-cryogenic treatment after intercritical annealing presented continuous yielding behavior. The further martensite transformation from lower stability of austenite was occurred during deep-cryogenic treatment. This apparent evidence confirms that sufficient content of martensite is an important factor to eliminate Luders strain rather than the behavior of austenite to martensite transformation. This observation expands the current view of reduced Luders strain in medium-Mn steels.