• Schell, N.
• Martin, S.
• Schimpf, C.
• Brokmeier, H.-G.
• Ullrich, C.
• Stark, Andreas
• Rafaja, David

Abstract

The interplay of microstructural mechanisms controlling the deformation-induced martensitic phase transformationsand the texture formation in all phases of a metastable austenitic Cr-Mn-Ni steel was investigatedusing in situ synchrotron radiation diffraction under uniaxial compression and ex situ electron backscatterdiffraction. With increasing deformation, the originally fully austenitic steel transformed to a mixture ofγ-austenite, ε-martensite and α´-martensite. The face centred cubic γ-austenite formed a fibre texture {110} withrespect to the deformation direction. The texture degree increased progressively with increasing deformation.The hexagonal close packed ε-martensite was preferentially oriented with the reciprocal direction {1013} alongthe load axis. The texture degree was nearly independent of the deformation extent. The body centredα´-martensite formed a mixed texture {100} & {111} along the deformation direction. The texture component{100} was very strong in the early stages of the α´-martensite formation, but it deteriorated with increasingdeformation. The texture evolution is explained by the competition between the transformation texture, severaldeformation-induced mechanisms, which are highly sensitive to the local orientation of the grains with respect tothe acting force, like the stacking fault formation and martensitic transformation in austenite, and the variantselection in both martensites and the twinning of α´-martensite.

Topics

• impedance spectroscopy
• grain
• phase
• steel
• texture
• electron backscatter diffraction
• stacking fault