Grydin O. Development of scientific and technological basis of twin-roll casting processes with an intensive metal forming at production of the thin strips with advanced mechanical properties

The thesis is devoted to solving a problem of the scientific and technological basis development of twin-roll casting process with an intensive metal forming at the production of thin strips with advanced mechanical properties by theoretical and experimental analysis of the plastic deformation zone formation princeples under taking into account the contact interactions between processed metal and the tool. In terms of the twin-roll casting of an alloyed medium-carbon high-strength steel the principles of the plastic deformation zone parameters formation depending on a combined influence of the technological process parameters such as initial metal temperature, casting speed, strip thickness, total length of the solidification-deformation zone and rolls diameter are theoretically obtained. The scientific conceptions of the contact interaction princeplces between the tool and metal at twin-roll strip casting with an intensive metal forming, reflected in the change of the tool surface microrelief and the thermal evolution in the "metal-roll" system at the processing of various materials are developed. An experimental method for determination of the deformation zone length at twin-roll casting is evolved. The formation principles of the thin strips with advanced mechanical properties of a clad aluminum-steel compound as well as heat-treatable EN AW-6082 and EN AW-7020 aluminum alloys depending on the thermal and deformational parameters of twin-roll casting with an intensive metal forming and subsequent longitudinal rolling are established. Practical recommendations for a strips of advanced mechanical properties production optimization in the process chains with twin-roll casters are suggested. The laboratory twin-roll casting unit allowing the material processing with the material feed plane variation from vertical to horizontal and intensified cooling of the tool is designed, manufactured and commissioned. The methods for mechanical properties and microstructure evolution in situ analysis of metallic materials are developed. The results obtained in the thesis are applicated in industry as well as in the bachelors and masters learning courses