Investigation On Homogenization Of Fluid-thermal Field Of1235and3004Al Melt In Cast-rolling

:The fluid-thermal field of melt in nozzle cavity was analyzed by finite element simulation analysis software (COMSOL Multiphysics) based on the3004aluminium alloy cast-rolling production line whose dimension was1080mm×6.8mm and the1235aluminium alloy cast-rolling production line whose dimension was2090mm×6.8mm. Nozzle structure was also optimized according to the simulation results and it was verified by experiment. In this paper, the main research contents and conclusions are as follows:(1) The viscosity of1235and3004aluminum alloy melt were measured by viscometer for high temperature melt, and established the relationship between viscosity and temperature ranging from660-750℃. Temperature of casting nozzle wall was measured, and established the function relation between nozzle wall heat transfer rate and the position of the nozzle.(2) The melt fluie-thermal field finite element simulation model of cast-rolling was established based on production condition, the detection analysis was proved the model was in highly reliability.(3) Analyzed the influence of the narrow inlet nozzle structure on3004aluminium alloy melt fluid-thermal field by FEM, the results showed that the gap between spacers was a local impact factor to melt fluid-thermal field, space of flow channel was a macroscopic impact factor, the angle of the front block and spacer’s shape were factors to affect the direction of melt flow.(4) The reason of surface defects in the3004aluminum alloy cast-rolling plate mentioned in this paper was that vortex in nozzle cavity caused disorder fluid-thermal field, then, caused unreasonable surface defects. Nozzle structure was optimized according to the simulation results and it was verified by experiments..(5) The comparative analysis showed open-type nozzle was more suitable for1235aluminum alloy wide cast-rolling plate production, the fuction of spacers in the open-tye nozzle was supprt but not shunt, the adverse impact to melt could be minimum when the shape of spacers was wedge-type.(6) The microstructure between middle and side of1235cast-rolling plate produced using the open-type nozzle was tested, the results showed that the plate was homogeneous. It indicated that it was feasible to produce wide cast-rolling plate using open-type nozzle.