摘要:
采用粒子图像测速-PIV技术, 研究影响连铸结晶器内部流动状态的因素。研究表明:随着拉速的增大, 窄面的冲击点位置距离液面的高度差减小, 液面的流速差减小, 流动状态趋于对称;随着浸入深度的增加, 流股冲击到窄面的冲击位置趋于对称, 液面流速下降, 液面波动减小, 因此, 适当的水口浸入深度对结晶器内流动状态的稳定具有重要作用;水口堵塞对结晶器流场影响严重, 随着右侧孔堵塞度增加, 水口两侧流速、出流角度、冲击窄面位置都发生不对称现象, 同时表面流速差变大致使涡流出现次数变多, 易产生卷渣, 发生凝固不均匀或结冷钢等现象, 对钢坯质量产生影响。因此, 在实际操作时应采取吹氢等措施, 减少水口堵塞的发生率。
Abstract:
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.
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