【摘要】 针对连铸过程中水口吹Ar工艺导致的铸坯缺陷,利用Cu质水冷插针进行物理模拟实验,研究了气泡在连铸坯固/液界面处的运动行为.通过观察气泡在固/液界面的运动行为,研究气泡被铸坯捕获机理.同时,对现场铸坯进行了取样分析,发现弯月面处生长的枝晶是气泡被凝固坯壳捕获的一个重要因素,进而提出生产中采用水口电磁制动和结晶器窄面处电磁搅拌的方法来改善铸坯质量,减少气泡凝入铸坯.更多还原

【Abstract】 Ar gas was injected to the nozzle during continuous casting to prevent from nozzle clogging caused by solid inclusions,however,some gas bubbles were captured by the initial solidified billet shell,and subsequently billet defects were formed in final product.In present work,a physical model applying mold simulator was designed and used to investigate the bubble behavior in the solid/liquid interface.Different mold simulator angels and bubble diameters were considered,three typical behaviors were observed,some bubbles were captured by the solidified shell,several bubbles coalescence in the solid/liquid interface,and other bubbles stayed in the interface for a moment,and then left.The possible mechanism of gas bubble entrapped in solidified shell was analyzed.Besides, industrial billets were studied,many dendrites were found around the hole,it was considered to be a key factor for gas bubble engulfed in the solidification billets in the meniscus area.Further more,the effective technologies,such as electrical brake near the submerged entry nozzle and electrical stirring in the mold narrow face,can improve billet quality and reduce gas bubbles in solidified shell were imposed.更多还原