Papers by Author: Janusz Ryś

Abstract: The present research is a part of project dealing with structural aspects of ferrite and austenite co-deformation in duplex stainless steels. The examination concerned a development of ferrite and austenite microstructures, major deformation mechanisms operating in both phases and texture formation upon cold-rolling of a model duplex type steel. The investigations showed that the band-like morphology of two-phase structure formed upon processing together with specific starting textures obtained after a preliminary thermo-mechanical treatment exerted significant influence on texture and microstructure development in both constituent phases. Microstructure and texture evolution in examined duplex steel significantly differed from those in one-phase steels. These differences resulted first of all from the role of the phase boundaries acting as the barriers for dislocation movement and affecting the processes of strain localization at higher deformations.

Abstract: The present examination is a part of project concerning a deformation behavior of duplex type ferritic-austenitic stainless steels. The investigations included the analysis of ferrite and austenite microstructures formed in cold-rolled sheet of super-duplex stainless steel, major deformation mechanisms operating in both constituent phases and changes in morphology of two-phase structure after the thermo-mechanical treatment and subsequent cold-rolling. Duplex type stainless steels develop the band-like ferrite-austenite morphology in the course of hot- and cold-rolling. This specific two-phase structure creates different conditions for plastic deformation in comparison to single phase steels. The interaction of both phases upon deformation exerts fairly significant influence on structure and texture formation in both constituent phases and in consequence affects the material properties and its behavior upon further processing.

Abstract: The present research is a part of project which concerns a deformation behavior of duplex type ferritic-austenitic stainless steels. This paper focuses on the examination of ferrite and austenite textures formed upon thermo-mechanical treatment and deformation textures developed during cold-rolling of super-duplex stainless steel sheet. The character and stability of the textures observed in both phases over a wide deformation range are the result of two-phase morphology formed upon hot- and subsequent cold-rolling. The specific band-like morphology of the ferrite-austenite structure creates different conditions for plastic deformation due to the interaction of both phases and considerably constrained lattice rotations. That is why the processes governing the texture formation in duplex steels are supposed to change in comparison to single phase steels affecting final rolling textures of ferrite and austenite.

Abstract: The present examination concerns a comparison of rolling texture development in two stainless steels of duplex type with different intensities of ferrite and austenite initial textures after a preliminary treatment, namely; clearly defined strong textures of both phases in one steel and nearly random textures in the case of the second one. Essentially the constituent phases in both duplex steels tend to develop the rolling textures comparable with those in single phase steels. However, the final textures display certain differences in comparison to the typical ferrite and austenite rolling textures. In both duplex steels the formation and character of the final deformation textures is strongly influenced by the band-like morphology of the ferrite-austenite structure and the process of texture formation proceeds in different way depending on the initial orientation distribution.

Abstract: A development of deformation textures was examined in ferritic-austenitic duplex type steel subjected to cold-rolling within the range up to 90% of reduction by applying different rolling schedules. The investigations included X-ray phase analysis, texture measurements and microstructure observations by means of light microscopy. The experimental results indicate at the occurrence of strong initial textures in both component phases after preliminary thermo-mechanical treatment. Formation of the ferrite-austenite banded structure in the course of rolling along with the stability of major texture components, related by Bain orientation relationship, exert considerable effect on the development of the ferrite and austenite rolling textures.