FC Mold Ⅱ电磁制动中磁场匹配对金属液流影响  

INFLUENCE OF MAGNETIC FIELD INTENSITY MATCH OF FC MOLDⅡON METAL FLOW

作　　者：贾皓[1] 张振强[1] 于湛[1] 邓康[1] 雷作胜[1] 任忠鸣[1] 

机构地区：[1]上海大学材料学院,上海200072

出　　处：《金属学报》2012年第9期1049-1056,共8页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目50674066~~

摘　　要：通过物理模拟实验研究板坯连铸流动控制结晶器(flow control moldⅡ,即FC MoldⅡ)电磁制动过程中,磁场强度和分布对结晶器内金属液流动的影响规律.实验中,以水银为模拟工质,在模型拉速为0.41,0.52和0.82 m/min(分别相当于生产拉速1.00,1.30和2.00 m/min),电磁制动的上区磁场强度B_1=0.18,0.36和0.50 T,下区磁场保持B_2=0.50 T不变的匹配(组合)条件下,考察结晶器(模型)内的水银流态和流速分布,并以此分析上、下区磁场强度匹配(组合)对水口出流、液面流动以及结晶器窄面模壁所受冲刷等的影响规律.结果表明,在上述拉速条件下,FC MoldⅡ电磁制动的上、下区磁场强度匹配关系,分别取B_1/B_2=0.36,0.72和1.00时,结晶器中金属液的制动效果最好.Electromagnetic brake （EMBr） affects the flow field in mold during the slab contin- uous casting process. Flow control mold Ⅱ （FC Mold Ⅱ） has been developed to resolve the defects of the third generation （flow control mold） of EMBr which the braking effect on meniscus is too strong to make the surface flow excessively stabilize and it would be prone to freezing and related defects. To gain a fundamental understanding of FC Mold Ⅱ, a mercury physical model was developed to inves- tigate the influence of the magnetic field intensity match on metal flow in FC Mold Ⅱ based on the 1350 mm×230 mm slab continuous casting process in a factory. The flow regime and velocity distribu- tion in mold were measured by ultrasound Doppler velocimeter （UDV） with the maximum magnetic field intensity of the upper pair of magnetic poles Bi=0.18, 0.36 and 0.50 T respectively and the max- imum magnetic field intensity of the down pair of magnetic poles B2--0.50 T, while the mold casting speed is 0.41, 0.52 and 0.82 m/min respectively corresponding to the practical casting speed 1.00, 1.30 and 2.00 m/min respectively. The influences of the magnetic field intensity match on the flow discharged from the nozzle, the flow near the meniscus and the washing intensity to the mold narrow wall were analyzed and studied. The results showed that, when the magnetic field intensity match of the upper and the lower pair of magnetic poles B1/B2 ≤ 1, with the continuous casting speed increas- ing, the value of Bi/B2 should increase in order to get an ideal braking effect. The value of B1/B2 should be 0.36, 0.72 and 1.00 respectively when the model casting speed is 0.41, 0.52 and 0.82 m/min respectively. The increasing of the intensity of the magnetic field reduces the ＂flow passage＂ effect caused by EMBr, and is conducive to the formation of the plug flow under the electromagnetic braking region.

关 键 词：板坯连铸 流动控制结晶器 金属流动 电磁制动 物理模拟 

分 类 号：TF777[冶金工程—钢铁冶金]