镀锡基板钢非稳态浇注铸坯洁净度分析

Cleanliness Study of Tinning Plate Steel Slab Under Unsteady Process

为研究非稳态浇注对镀锡基板铸坯洁净度的影响,对BOF-LF-CC工艺生产的头坯、混交坯、换水口铸坯、尾坯进行取样分析,对铸坯中T.O、[N]、显微夹杂物、大型夹杂物及钢液成分与正常浇注状态下铸坯进行了对比。结果表明:非稳态浇注条件下,T.O、[N]含量由高到低顺序依此为:尾坯>头坯>混交坯>换水口,其中尾坯中T.O含量为44×10^(-6),较正常坯升高了92.5%,N含量为85×10^(-6),是正常坯的4.08倍;显微夹杂物平均含量由高到低的顺序依次为:混浇坯>尾坯>换水口>头坯,混浇坯显微夹杂平均水平为18.44个/mm2,是正常坯的2倍;非稳态浇注铸坯中大型夹杂物含量由高至低分别为:混浇坯>尾坯>头坯>换水口,混浇坯中的大型夹杂物总量达到1 496 mg/(10kg);非稳态浇注铸坯的C含量普遍高于正常坯水平,Als含量低于正常坯水平。

In order to research the impact of unsteady casting process on tin-plate slab, the first slab, mixed slab, SEN-changing slab and last slab produced under unsteady process were sampled and analyzed. The T.O, [N] content, micro inclusions and large inclusions were compared with that of normal slab. The results show that the T.O and [N] content under unsteady casting process from high to low can be expressed as follows, last slab 〉 first slab 〉 mixed slab 〉 SEN-changing slab. The content of the T.O is 44 xl0~, increased by 92.5% compared with normal slab, and the content of [N] is 85 x 10~, which is 4.08 times than normal slab in last slab. The average content of micro inclusions from high to low can be expressed as follows, mixed slab 〉 last slab 〉 first slab 〉 SEN-changing slab. The average number of micro inclusions is 18.44/mm2, which is twice the normal slab. The average content of large inclusions from high to low can be expressed as follows, mixed slab 〉 last slab 〉 first slab 〉 SEN-changing slab, the number of large inclusions reach 1 496 mg/（10kg）. The C content in unsteady slabs is higher than normal slab and Als content is lower than normal slab.