连铸板坯三角区裂纹的影响因素

Influencing Factors on Triangular Zone Cracks in a Continuously Cast Slab

通过对连铸坯硫印数据库的分析,得到了普碳钢连铸板坯三角区裂纹的影响因素.结果表明,三角区裂纹随着S含量、过热度、拉速和铸坯断面宽度的增加而越来越严重.以此为基础,提出了生产过程中控制三角区裂纹的原则.C含量控制为0.13％;[Mn]/[S]>25,过热度小于25℃,拉速低于1.30m/min,浇铸宽断面铸坯时应加强铸坯窄边的冷却强度,保证良好的铸机设备精度.

The influencing factors on triangular zone cracks were obtained by analyzing the database of sulphur printing results of continuously cast slabs. The result indicates that triangular zone cracks get worse with the increasing of sulpher content, superheat, casting speed and width of the slab. On the basis of that, the responding control principles were proposed as follows. The content of carbon should be near to the lower limit 0.13%. When the content of sulphur is between 0.015% and 0.020%, the content of manganese should be between 0.375% and 0.50% to assure the ratio of manganese to sulphur is above 25. The superheat of steel in tundish should be below 25 ℃ and the casting speed below 1.3 m/min. It is very necessary to improve the intensity of secondary cooling in the narrow side of a wider slab and ansure the precision of continuously cast machine.