Effect of Uniaxial Tension on the Microstructure and Texture of High Mn Steel

Cold-rolled to 42% thickness reduction and annealed at 500, 625, and 700 C, an Fe-17Mn-3Al-2Si-1Ni-0.06C wt% steel is subjected to uniaxial tension and characterized via digital image correlation and electron back-scattering diffraction. The cold-rolled and 500 C samples return similar microstructures comprising predominantly α0-martensite and remnant e-martensite fractions and a trace fraction of untransformed austenite (γ) before and after uniaxial tension. For the 625 and 700 C samples, uniaxial tension results in the transformation of the initially reverted and recrystallized γ into e and α0- martensite via strain localization. The γ shows the formation of h111iγ, h100iγ double-fiber texture, whereas the e and α0-martensite show the development of the {hkil}e and h110iα0 || ND fibers, respectively. 1012gh1011ie extension twinning is also observed in e-martensite upon uniaxial tension. The cold-rolled sample exhibits a mixed brittle and ductile fracture mode. The fracture of the 500 C sample is similar to that of the cold-rolled sample, whereas the 625 and 700 C samples display a ductile fracture mode.