Study on the Mold Flow State Influenced by Two-hole Nozzle

The particle image velocimetry-PIV technique was used to study the factors affecting the flow state in the continuous casting mold.i With the increase of casting speed,the distance of narrow face impact point to level decreases,and difference in the level flow velocity decreases,resulting in the flow state tending to be symmetric. With increasing immersion depth,the position of stream impact to narrow face tends to be symmetrical,and the level flow velocity reduces,then level fluctuation decreases. It is concluded that suitable immersion depth of nozzle plays an important role in stabling mold flow.Nozzle clogging has a significant influence on the flow field in the mold.With the degree of right nozzle clogging increasing,the flow velocity,flow angle and position of narrow impact on both sides of nozzle present asymmetric.Large difference in the surface velocity causes high frequency of eddy current occurrence,and then producing volume slag,uneven solidification or cold-shut.Therefore,measures such as hydrogen blowing should be adopted to reduce the incidence of nozzle clogging.