摘要
脉冲磁致振荡(pulse magneto oscillation,PMO)凝固均质化技术已成功应用于中等尺寸矩形坯和圆坯的连铸生产中。为探索PMO技术在小方坯中应用的可能性,研究了实际生产条件下结晶器脉冲磁致振荡(mold pulse magneto oscillation,M-PMO)技术对连铸小方坯夹杂物分布与数量的影响,比较了不同PMO工艺参数和线圈位置对小方坯中夹杂物上浮净化效果的影响。在连铸过程中钢液中夹杂物的变化主要受钢液流动的影响,为了探究PMO作用下结晶器内钢液的流场分布规律,建立数学模型来描述实际PMO处理过程,并采用COMSOL软件进行数值模拟。结果表明,M-PMO上位线圈处理与下位线圈处理形成的流场相同,只是下位线圈处理形成的流场位置相对下移100 mm。上位线圈处理能有效降低下冲钢液对液相穴的冲击深度,下位线圈处理略微增加了钢液对液相穴的冲击深度。研究分析夹杂物数量和尺寸变化后发现,M-PMO上位线圈有利于大尺寸夹杂物的上浮,减少铸坯中夹杂物总数量,且随着峰值电流的增大,大于10μm夹杂物减少效果明显,体积减少率由26.07%增加到41.17%;而下位线圈有利于减少小尺寸夹杂物数量,3~5μm夹杂物最多可以减少10.61%;同时,当增大脉冲频率时,下位线圈能够有效消除钢液冲击深度,加深对大尺寸夹杂物上浮的不利影响。通过对不同尺寸夹杂物运动趋势的分析,最终得出M-PMO上位线圈的应用可以有效改善夹杂物分布以及钢锭质量。
Pulse magneto oscillation(PMO)solidification homogenization technology has been successfully applied to the continuous casting production of medium-sized rectangular billet and round billet.To explore the possibility of PMO technology in billets,the effect of mold pulse magneto oscillation(M-PMO)technology on the distribution and quantity of inclusions in billets under actual production conditions was studied.The effects of different PMO process parameters and coil position on the floating purification effect of inclusions in billets were compared.The changed of inclusions in molten steel during continuous casting is mainly affected by the flow of molten steel.In order to explore the flow field distribution of molten steel in the mold under the action of PMO,a mathematical model was established to describe the actual PMO treatment process and the COMSOL software was used for numerical simulation.The results show that the flow field formed by M-PMO upper coil treatment is the same as that formed by lower coil treatment,except that the flow field position formed by lower coil treatment moves down by 100 mm.The upper coil treatment can effectively reduce the impact depth of molten steel on liquid cavities,while the lower coil treatment slightly increases the impact depth of molten steel on liquid cavities.After studying and analyzing the change of inclusion quantity and size,it is found that the upper coil of the M-PMO is conducive to the floating of large-size inclusions,reducing the total number of inclusions in the slab.With the increase of peak current,inclusions that larger than 10μm have a significant reduction effect and the volume reduction rate increases from 26.07%to 41.17%.The lower coil is conducive to reducing the number of small inclusions,inclusions of 3-5μm can be reduced by 10.61%at most.At the same time,the lower coil can effectively eliminate the adverse effect of deep steel impact on the floating of large inclusions when the pulse frequency is increased.Through the analysis of the movement trend of inclusions with different sizes,it is concluded that the application of the M-PMO upper coil can effectively improve the distribution of inclusions and the quality of ingots.
作者
李开创
李莉娟
蔡常青
许英华
徐衡
翟启杰
LI Kai-chuang;LI Li-juan;CAI Chang-qing;XU Ying-hua;XU Heng;ZHAI Qi-jie(Center for Advanced Solidification Technology,Shanghai University,Shanghai 200444,China;Fujian Sansteel Minguang Co.,Ltd.,Sanming 365000,Fujian,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第4期58-68,共11页
Iron and Steel
基金
国家自然科学基金资助项目(52130109)。
