Distribution Research On Twin-roll Strip Casting Interface Heat Transfer Coefficient

Because of its short process, low cost, low energy consumption and other advantages twin-roll strip continuous casting get the steel practitioners’ much attention. During the casting process, the hot molten steel directly contacts with crystal rolls and cooled rapidly within a very short time. In the whole process of the contact, the interfacial heat transfer between molten poll and crystal roll is accompanied by complex flow and phase transitions, and the interface heat transfer coefficient between the thin strip-casting roller decides the quality and performance of the casting strips. Therefore, the study of interface heat transfer coefficient has deep theoretical values and practical significance.In this paper, the contact interface heat transfer coefficient along contact arc of molten pool and crystal roll in twin roll strip casting was taken as the object of study. Using the finite element software ANSYS, the molten pool model, the crystal roll model and the contact pressure model were established. ANSYS Parametric Design Language(APDL) was applied to set implement various model’s boundary conditions, solution and post-processing. Then, through the results gotten by experimental study group fitted a contact interface heat transfer coefficient function formula which was used to realize the coupling of molten poll model and crystal roll model.According to the ANSYS models and ANSYS Parameter Design Language, temperature field and flow field of molten poll, temperature changes of crystal roll surface and stress after Kiss point were simulated. Using APDL solved the molten poll model and crystal roll model calculations, through multiple iterations,and ultimately got variation of heat flux along the contact arc and the poll temperature field, flow field and temperature field of crystal roll. Using the final models the influence of different pouring temperatures and casting speed on the interface contact heat transfer coefficient were researched. The results show that before Kiss point the heat flux reduces as the decreasing of contact temperature and after Kiss point due to the rolling load generated the heat flux increases rapidly.