Influence of nozzle side-hole divergence angle (0-12°) on argon bubble behavior and flow field of liquid in mould for 230 mm x 1 300 mm slab has been studied by using discrete phase model

and verified by water model test. Results show that increasing nozzle divergence angle can significantly reduce the impact depth and floating area of argon bubbles at free surface of liquid ； especially with divergence angle 9°

the flow field in mould is better and the free surface of liquid is smaller

it is available to remove the inclusions in liquid and reduce the probability of slag entrapment. The double strands 230 mm slab commercial casting results show that as compared with second strand slab without divergence angle nozzle the occurrence of slag entrapment ratio of first strand slab with installed divergence angle 9° nozzle decreases by 5.9%-14.8%.