电磁搅拌连铸坯凝固组织白亮带成因结构分析.pdfVIP

电磁搅拌连铸坯凝固组织白亮带成因结构分析 李 平 隋晓红 陆晓锋 马立国 唐雪峰 黄玉平 王阿鼎 （鞍钢技术中心，鞍山 114009 ） 摘 要 电磁搅拌使连铸坯产生白亮带, 其机理的多种假说目前尚无全面解释的定论，其组织结构少有研究。作者 检验观察研究了大量生产中白亮带铸坯的凝固组织，经热酸浸、枝晶检验分析，观察到了白亮带内部组织的结构， 得出了一个新的形成机理来解释白亮带产生原因及其结构形成原因, 即白亮带是由铸坯中迎着搅拌钢液流密集生 长的二次枝晶簇组成的，通常呈单层白亮带结构，在板坯中可见双层或三层白亮带结构。在白亮带层产生负偏析， 在两个白亮带层中间层是正偏析层。1 关键词 连铸 钢坯 白亮带 Microstructure and Formation Mechanism of White Band in Electromagnetic Stirring Continuous Casting Billets Li Ping Sui Xiaohong Lu Xiaofeng Ma Liguo Tang Xuefeng Huang Yuping Wang Ading （Angang Technology Center, Anshan, 114009 ） Abstract It is well known that electromagnetic stirring may result in white bands in continuous casting billets. Their formation mechanism has not been satisfactorily explained according to existing numerous hypotheses. And their microstructure is also scarcely researched. In this paper, a number of massively produced continuous casting billets with white bands were corroded by heat acid and dendrite crystals were checked on white bands, microstructure within the white bands was observed. A new explanation for the formation mechanism of the white bands and their microstructure was proposed. The white bands were composed of secondary dendrite clusters which grew against the stirring steel liquid flow. Microstructure with double or triple layers of white bands was found in slabs. Negative segregation was produced in white band layer, and positive segregation layer was located between the two white band layers. Key words continuous casting, billet, white band 在连铸生产中广泛采用电磁搅拌来改善连铸坯的中心疏松和中心偏析等缺陷, 中国连铸坯质量检验标 准对白亮带还没有确切的规定。关于白亮带形成原因的解释，主要有溶质冲刷机理[4] [1]