Per: Jakob Kraner (Institute of Metals and Technology, Lepi pot 11, SI-1000 Ljubljana, Slovenia ), Irena Paulin (Institute of Metals and Technology, Lepi pot 11, SI-1000 Ljubljana, Slovenia ), Matjaž Godec (Institute of Metals and Technology, Lepi pot 11, SI-1000 Ljubljana, Slovenia ), Heinz Palkowski (Department of Metal Forming and Processing, Institute of Metallurgy, Faculty of Natural and Materials Science, Clausthal University of Technology, Robert-Koch-Straße 42, DE-38678 Clausthal-Zellerfeld, Germany), Goran Kugler (DepartmEnt of Materials and Metallurgy, Faculty of Natural Sciences and Engineering, University of Ljubljana, Aškerčeva cesta 12, SI-1000 Ljubljana, Slovenia ), Peter Fajfar (DepartmEnt of Materials and Metallurgy, Faculty of Natural Sciences and Engineering, University of Ljubljana, Aškerčeva cesta 12, SI-1000 Ljubljana, Slovenia )
Abstract:
The study of asymmetric rolling on the AA 5454 aluminium alloy plates was carried out. The plates were taken directly from the industrial hot rolled sheet. They were cold rolled on the laboratory mill with different rotation speed of the upper and the lower work roller with the strains around 33 % and 44 %. To get closer to the industrial conditions the maximal dimensions of the rolled plates for laboratory rolling mill and the special industrial lubricant was used. After deformation the plates were annealed to the soft condition. This research was focused through all possible effects of asymmetric rolling: the reduction of rolling force, the increase of strain at same set roll gap, the bending of workpiece, the finer microstructure, the heterogeneous texture and as consequence of that the better mechanical properties. The asymmetric rolling with favourable mechanisms in the deformation zone created the material with the homogeneous hardness in the cross section and with the LOWER anisotropy, which is crucial for improvement of formability properties of aluminium work hardened alloys and get closer to properties of steels. In the presented paper the general impact and different effects of speed difference of rollers was investigated on cold rolled aluminium alloy. Obtained and analysed results explain the function of asymmetry in rolling process and the options to implement the asymmetric rolling in industrial plant.
