含铌钒钛微合金化钢连铸板坯中心偏析的影响因素  

Influencing factors on center segregation in continuously cast Nb-V-Ti-contained micro-alloying slabs

作　　者：刘洋[1] 王新华[1] 张开钧[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083

出　　处：《北京科技大学学报》2007年第9期896-900,共5页Journal of University of Science and Technology Beijing

摘　　要：通过对连铸板坯生产检验的硫印数据库的统计分析,得到了含铌钒钛微合金化钢连铸板坯中心偏析的影响因素.结果表明:中心偏析程度随钢水中C、P、S含量的增加而加重;Mn质量分数高于1.5%以及锰硫比高于300对改善中心偏析有利;高钢水过热度、高拉速和增加铸坯宽度均不利于改善铸坯中心偏析.由于B级以下中心偏析对钢材使用性能影响不大,因此在生产过程中为使铸坯B-1.0级以上中心偏析出现比率降至10%以下,提出如下控制策略:钢液中C、P、S含量尽量按钢种要求的下限控制,Mn含量尽量按上限控制,实际生产中元素控制[C]<0.07%,[P]<0.01%,[S]<0.005%,[Mn]>1.5%,[Mn]/[S]>300;过热度应小于24℃,拉速控制在1.0～1.1m.min-1为宜.应开发合适的二冷配水制度,并提高铸机精度.The factors which influence center segregation of continuously cast slabs were obtained through analyzing the database of sulphur print. It was indicated that center segregation became severer with the increasing contents of carbon, phosphorus and sulfur. Center segregation was reduced obviously if the content of manganese was higher than 1.5 % and the ratio of manganese to sulfur was higher than 300. High degree of superheat, high pulling rate and increasing slab width increased the degree of center segregation. Since center segregation below Class B had little effect on the properties of steel, in order to low the ratio of center segregation of Class B-1.0 down to 10%, several control strategies were presented as follows. The contents of carbon, phosphorus and sulfur should be focalized in the lower range of steel grade demanded, but manganese upper operating range control. The referenced contents of the elements in molten steel are required as the following： [C] 〈 0.07%, [P]〈0.01%, [S]〈0.005%, [Mn] 〉1.5%, and [Mn]/[S] 〉300. The degree of superheat is lower than 24 ℃ and the pulling rate is defined to 1.0-1.1 m·min 1. At the same time, a proper secondary cooling system of water distribution should be developed and the precision of continuous casters should be also improved.

关 键 词：连铸 板坯 中心偏析 微合金化钢 

分 类 号：TF777.1[冶金工程—钢铁冶金]