Improvement of bottom-blown regime in the planar flow casting process for preparing Fe-based amorphous ribbons: Numerical simulation and industrial application

Planar flow casting is the main process for large-scale preparation of Fe-based amorphous ribbons. Low-superheat casting can effectively reduce the energy consumption and improve the ribbon performance, but it puts forward higher requirements on the quality of molten steel. In this study, a multiphase (melt-slag-air-argon) coupling model is established for the bottom-blown smelting furnace to simulate the flow field and mixing process. The results show that when the total flow rate of argon is 9 NL·min -1 , although the eccentric arrangements of the single plug can effectively reduce the dead zone ratio, a large slag eye is formed. For the eccentric arrangements of dual plugs, the plug distance and relative angle have significant effects on the smelting effect. The dead zone ratio can be effectively reduced by locating the dual plugs at 0.66R. Under the relative angle of 60°, the two argon plumes converge into a strong plume, resulting in a large slag eye and prolonged mixing time. Under the relative angle of 120°, the flow field uniformity is significantly improved, and the slag eye area is controlled. Thus, 0.66R-120° is the best tested bottom-blown scheme, with a slag eye ratio of 0.28, a dead zone ratio of 0.117, and a mixing time of 142.3 s. Statistical results from 30-day industrial application show that after improving the argon blowing process, the number density of inclusions is decreased by 6.8%, the average coercivity of ribbons decreased from 1.95 to 1.92 A/m, and the specific total loss decreased from 0.0620 to 0.0604 W/kg.