Abnormal mold level fluctuation during slab casting of peritectic steels  

作　　者：Zhong-kuai Jiang Zhi-jian Su Cheng-qian Xu Jin Chen Ji-cheng He 

机构地区：[1]Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education),Northeastern University,Shenyang 110004,Liaoning,China [2]Shanghai Meishan Iron and Steel Co.,Ltd.,Nanjing 210039,Jiangsu,China [3]School of Metallurgy,Northeastern University,Shenyang 110004,Liaoning,China

出　　处：《Journal of Iron and Steel Research International》2020年第2期160-168,共9页

基　　金：National Natural Science Foundation of China(No.U1560207);Special thanks are given to Shanghai Meishan Iron and Steel Co.,Ltd.for industrial trials and application.

摘　　要：Abnormal mold level fluctuation is frequently observed in high-speed casting,especially for peritectic steels,which has been shown to severely deteriorate product quality.Both an online electromagnetic sensor and an ibaAnalyzer are used to analyze the frequency and amplitude of massive mold level fluctuation data from the slab casting process of different steel grades using different casting speeds,slab widths and physical parameters of mold flux.The results show that in the slab continuous casting process of peritectic steels,the main frequency and equivalent amplitude of abnormal mold level fluctuations first increase and then decrease with increasing the carbon content.In the production of various grades of steel,the main frequency of abnormal mold level fluctuation and the equivalent amplitude increase with increasing the casting speed,while the main frequency of abnormal mold level fluctuation changes little with increasing the casting width.The main frequency of abnormal mold level fluctuation is positively related to the surface tension of the mold flux.Based on these results,a new mechanism has been presented.It is shown that the abnormal mold level fluctuation is mainly induced by shell bulging while moving through the rollers,and resonance occurs when the frequency approaches the natural frequency of the molten steel in mold,which results in a large amplitude of the abnormal mold level fluctuation.Based on this mechanism,a new equation for the resonance frequency of molten steel is proposed.The improved method based on this mechanism has proved to be effective in controlling abnormal mold fluctuations.

关 键 词：SLAB continuous CASTING ABNORMAL MOLD level FLUCTUATION Resonance frequency PERITECTIC steel Surface tension 

分 类 号：TF341.6[冶金工程—冶金机械及自动化]