Microstructural investigation on deformation behavior of high purity Fe-Cr-Ni austenitic alloys during tensile testing at different temperatures

In this paper, optical and transmission electron microscopy techniques and tensile tests were used to investigate the deformation behavior of high purity Fe-Cr-Ni austenitic alloys during low temperature deformation. Microstructural investigations revealed that deformation-induced martensitic transformations occurs through the steps γ→ε→α′. Remarkably, it was found that the contributions of both stacking fault energy (SFE) and driving force should be considered in explaining the occurrence of deformation-induced α′-martensite, which significantly affects the mechanical behavior of the alloy. Further, the findings confirmed the previous works suggesting that the low SFE of the alloy does not necessarily lead to dislocations planarity.