The textures of cold-rolled AISI 304 austenitic steel were the object of the investigations. The austenite steel was deformed by cold-rolling to 20, 40 and 70% reduction. A significant amount of martensite, formed due to the strain induced (γ®a’) transformation, was detected in the deformed structure by applying magnetic and X-ray diffraction methods. Texture analysis was performed on the basis of the orientation distribution functions (ODFs) calculated from the experimental pole figures. The texture measurements of both phases were conducted from the center layers of the cold-rolled strip. In the case of metastable austenite AISI 304 steel the texture development was very complex because three processes were proceded simultaneously during the cold-rolling, namely: plastic deformation of the austenitic g-phase, strain induced phase transformation γ®a’ and deformation of the formed a’-martensite. These processes resulted in the presence of two phases in the structure of the steel with a definite crystallographic relationship and orientation changes of both phases with increasing of the deformation. Thus, the resultant deformation texture of the investigated steels is described by the austenite and martensite texture components. The rolling texture of γ-phase describes mainly orientations from the fiber α =<110>║ND and the major components of the martensite deformation texture are orientations from the fibers α1=<110>║RD and γ ={111}║ND.

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Microstructural changes in the age-hardenable Fe-28wt.%Mn-9wt.%Al-1wt.%C steel during ageing at 550• C for various times have been investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The steel was produced in an induction furnace and the ingot, after homogenization at 1150• C for 3 hours under a protective argon atmosphere, was hot-rolled and subsequently cold-rolled up to 23% reduction. The sheet was then aged at 550• C for various times in an argon atmosphere and cooled in air. XRD analysis and TEM observations revealed a modulated structure and superlattice reflections produced by spinodal decomposition, which occurred during ageing at 550• C. The existence of satellites suggests that either (Fe,Mn) 3 AlC x carbides were formed within the austenite matrix by spinodal decomposition during cooling or chemical fluctuactions occurred between the (Fe,Mn) 3 AlC x carbides and the austenitic matrix.Keywords: high-manganese austenitic steel, spinodal decomposition, carbides, microstructure W pracy analizowano zmiany mikrostruktury w stali Fe-28%wt.Mn-9%wt.Al-1%wt.C zachodzące podczas starzenia w temperaturze 550• C w różnych czasach. Stal Fe-28Mn-9Al-1C wytopiono w próżniowym piecu indukcyjnym. Po odlaniu wlewek homogenizowano w temperaturze 1150• C przez 3 godziny w atmosferze argonu. Wlewek walcowano na gorąco a następnie na zimno do 23 % odkształcenia. Próbki po odkształceniu starzono w temperaturze 550• C dla różnych czasów w atmosferze argonu i chłodzono na powietrzu. Obserwacje elektronomikroskopowe starzonej stali Fe-28Mn-9Al-1C ujawniły modulowaną strukturę i refleksy od nadstruktury, co było efektem rozpadu spinodalnego, który miał miejsce podczas procesu starzenia. Występowanie satelitów na zapisach dyfrakcyjnych sugeruje, że węgliki (Fe,Mn) 3 AlC x powstały w osnowie austenitycznej na skutek rozpadu spinodalnego zachodzącego podczas chłodzenia czy fluktuacji chemicznych występujących pomiędzy węglikami (Fe, Mn) 3 AlC x i osnową austenityczną.

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