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Influence of coiling conditions on IF steel properties

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Mechanical properties and structure of interstitial free (IF) steel in dependence on hot rolling conditions and coiling conditions are given. The influence of finished hot rolling conditions over temperature Ar3 (austenitic rolling), finished hot rolling conditions below temperature Ar1 (ferritic rolling) and coiling temperature are described. The tools of process controlling (deformations, temperatures, strain rate, time) for recrystallization, precipitation and phase transformation are discussed. Graphical dependences of mechanical properties and ferritic grain size on coiling temperatures are shown. The best processes conditions from point of view obtain of mechanical properties in class SEDDQ (super extra deep draw quality) in hot rolled strip are concluded. W artykule przedstawi[...]

Mathematical simulation of deformation behaviour in Equal Channel Angular Rolling process

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During the last decade, fabrication of bulk nanostructured metals and alloys using severe plastic deformation (SPD) has been evolving as a rapidly progressing direction of modern materials science that is aimed at developing materials with new mechanical and functional properties for advanced application [1]. The principle of these developments is based on grain refinement down to the nanoscale level in bulk billets using SPD. Ultra-fine grained material produced by IPD are characterized by increased value of strength, fatigue properties and mechanical properties of superplasticity. These properties depend from nanosize grain structure, its distribution in the material, stress, texture and other structural properties. The authors [2] highlighted the important fact, that the evolution of structure during the IPD is not related to the transformation of the microstructure of UFG structure with high angled grain boundaries. After IPD using, nanosize structure polyhedral materials is achieved, by dislocations slides, or dislocations rotations inside grains and slides on grain boundaries [3, 4]. Various processes of intensive plastic deformations have been proposed for the process of drafting the UFG materials using a simple slip. The application of severe plastic deformation (SPD) to conventional polycrystalline metals provides a powerful tool for refine the grain size to the submicrometer or nanometer range [1]. Ultra-fine grained materials (UFG, grain size less than ~1 μm) with unique mechanical and physical properties can be produced by severe plastic deformation [5÷11], such as a noble technique called equal channel angular rolling (ECAR). Lee et al. [12] proposed that Φ can be adjusted from 100° to 140° for producing ultra-fine grains with high angles of mi[...]

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