Structural Changes of Polycrystalline Fe-Mn-Si Based Austenitic Alloys by Deformation

Structural changes of polycrystalline Fe-Mn-Si-Cr austenitic alloys by deformation at room temperature were studied by X-ray diffraction measurements using synchrotron radiation. The results showed that stress-induced martensitic transformation occurred by deformation, whereby a part of the face centered cubic structure in the alloy matrix (austenic phase) was transformed to the close packed hexagonal structure (ε-martensite phase). When the shape of the alloy deformed at room temperature was partially recovered by annealing at about 673K, indicating that the reverse transformation of martensite formed stress-induced transformation took place by heating. The crystallographic orientation relationships in the transformation and the reverse transformation were investigated in polycrystalline Fe-Mn-Si-Cr alloys. In addition, the crystallographic orientation changes in Fe-Mn-Si-Al alloys showing twining induced plasticity and transformation induced plasticity were also studied.報文Original Pape