Baranov I. The processes of hydrodynamics and solidification upon receipt of a thin sheet by the method of two-roll casting of alloys based on iron and aluminum

Dissertation is dedicated for the development of the method of calculation and predicting of phisico-technological parameters of the thin sheet preparation by twin roll casting of iron-carbon and aluminum-base alloys in function of hydrodynamics and solidification special features for technological process stability. It was established that the key problem of the low stability of technological process of the thin sheet preparation and thin bar manufacturing driven by high dynamic and interrelated physicohydrodynamic and mechanical parameters which defined by known behavior of thermophysical and hydrodynamic processes in roll bite of twin roll caster. The proposed by the author method of calculation and predicting of twin roll caster phisico-technical parameters based on determination of the crystallization-deformation zone location in roll bite of twin roll caster in function of hydrodynamic and termophisical specialties of metal skin forming on roll mould surface. Using physical simulation and mathematical model results comparison, was developed reliable research and roll bite hydrodynamic processes analysis method. Established two specific zones of the circulation, alloy flow irregularity distribution in roll bite as well as back flow on meniscus surface (ɑ ≥ 20° ), the velocity of the flow is raised accordingly to roll mould diameter and meniscus angle increasing. For determination of crystallization fronts closing point about an rolls axis, based on known experimental data first by the author were calculated crystallization velocity indexes under conditions of twin rolls cast rolling for aluminum К=7,4mm/s0.5 and steel К=4,2 mm/s0.5 that significantly increasing ingots crystallization indexes. This paper presents first measurable limits of the iron-carbon and high-hardness steel plasticity dependence of temperature within the interval “solidus – liquidus”. Acquired mathematical relations provides ability to simulate metal behavior within twin roll casting and other continuous casting processes. Survey results available from dissertation work were used for experimental casting on twin rolls casting machine (PTIMA NAS of Ukraine, Kyiv), and first were established special features of aluminum-base alloys Д16, В95, АМг6 flat products forming within wide crystallization interval (≥100 ° C).