1000~2200 mm宽板坯连铸机结晶器流场优化与应用

Application and Optimization of Mould Flow Field in 1000 mm-2200 mm Wide Slab Caster

为改善某厂超低碳钢连铸过程中出现偏流、跳棒及水口堵现象,通过对中间包透气上水口、塞棒和浸入式水口等连铸功能耐材进行改进,将透气上水口改用特殊的弥散式透气材质,吹入的氩气气泡沿水口内壁形成均匀的气幕,表面气孔率较改进前提高5.2%,防止了夹杂物在水口内壁蓄积,缓解水口堵;将塞棒棒头由中心部位的吹氩孔由1个改为6个,实现360°均匀吹入氩气,减少棒头夹杂物蓄积;将浸入式水口改用无碳,低铝,高硅内衬,改变水口内壁材质,防止浸入式水口堵塞。改进后耐材在超低碳钢上推广应用,使得每浇次跳棒次数减少0.83次、降幅31.8%,水口堵造成的在线更换浸入水口频次减少了0.38支、降幅41.3%,稳定结晶器液面控制精度,提升冷轧卷夹杂合格率0.238%,并提高了单中间包连浇炉数0.53炉、增幅8%,使1000~2200 mm宽板坯连铸机结晶器流场得以优化。

In order to improve bias flow,jump bar and water plugging phenomenon during ultra-low carbon steel continuous casting process in a factory,through the tunish breathable on the nozzle,plug rod and immersion nozzle such as continuous casting function resistant material improvement,switch the air top nozzle to switch to special diffusion breathable material,blowing into the argon bubbles along the nozzle form uniform air curtain.The surface stomatal rate is 5.2%higher than that before the improvement,which prevents the accumulation of inclusions in the inner wall of the nozzle and alleviates the clogging of the nozzle.One argon hole located in center is changed to six holes of stopper rod,which can realize 360°even argon blowing around its head and decrease inclusion collection on the head.The SEN adopts merterials of carbon free,low aluminum,high silicon content.These refractory can react with the inclusion on the wall of SEN,which prevents its clogging.After the application of improved resistant materials in ultralow carbon steel,the number of jumping rods per casting is reduced by 0.83 times and 31.8%,the frequency of online replacement of SEN caused by nozzle plugging is reduced by 0.38 pieces and 41.3%,and the control accuracy of crystallization level is stabilized,the qualified rate of cold rolled coil inclusion is improved by 0.238%,and the number of single tunish casting heats is increased by 0.53 heats and increasing by 8%,thus optimize the flow field of mould.It is proved to put forward to optimize 1000 mm-2200 mm caster's mould flow field.