Research On Effect Of Processing Parameters To Centerline Segregation Of TRC Strip

Twin-roll strip casting(TRSC) is considered as one kind of near net shape materials processing technology, and it can effectively shorten working process, lower energy consumption, and reduce investment, so it is potential to improve the quality of casting strip. At the same time, the processing parameters like casting speed, the width of roll gap, the casting temperature, and the height of molten pool are related to each other closely. The structure of roll-casting strip is non-uniform, the grain is coarse, the columnar crystal is well developed, and the centerline segregation along the direction of width is serious, eventually the defect will decrease the mechanical property, and affect the later manufacture process. The previous researches showed that the processing parameters in twin-roll strip casting have a significant impact on the centerline segregation.According to the technology characteristic of twin-roll strip caster in lab, the solutes mass transfer during solidification in molten pool was analyzed, then a numerical model coupled with solutes field, flow field, heat transfer and solidification has been developed to simulate the physical phenomenon in molten pool of twin-roll strip caster. The model shows the distribution characteristic of solutes and flow field, and the formation of centerline segregation is analyzed in the combined view of flow field and solutes field. Meanwhile, a new principle of liquidus and solidus temperature has been imported to the numerical model to show the influence of alloy elements content. Based on the numerical model, the influence of processing parameters(casting speed, the width of roll gap, the casting temperature, and the height of molten pool) to the centerline segregation has been studied by comparing the flow field especially the velocity along the symmetry line of molten pool and the Kiss point position. The experiment scheme of casting 6061 Aluminum alloy strip by using the twin roll strip caster in lab was designed independently, the experiment has proved the feasibility of twin-roll casting 6061 Al alloy strip and the best processing parameters has also been confirmed. The structure of twin-roll casting 6061 Al alloy strip has been detected, and the mechanical property was compared with the traditional 6061 Al alloy strip. Finally, simulation value and the measuring data of solutes along the width of strip have been compared to analyze and verify the numerical model.A set of research method about twin-roll casting 6061 Al alloy strip is provided in the present work for further understanding and actual production in the future.