IF钢非稳态浇注铸坯洁净度分析

RESEARCH ON CLEANNESS OF IF STEEL SLAB PRODUCED IN UNSTEADY CASTING PROCESS

为系统分析某钢厂IF钢在非稳态浇注时铸坯洁净度的变化情况,采用气体分析、成分分析、大型夹杂物分析等方法对在非稳态条件下生产的IF钢的头坯、尾坯、换水口坯进行分析。结果表明:头坯内N、T.O、大型夹杂物含量沿拉坯方向逐渐降低,Als含量逐渐升高,头坯前8.5m不适宜IF钢生产,尾坯距尾部2.5m内N、T.O、Als含量波动较大,距尾部4.5m内大型夹杂物数量较高,均在1.41倍以上,尾部4.5m必须切除;换水口坯在换水口位置的前后1.5m内T.O、N、大型夹杂物含量明显升高,在IF钢生产中应进行切除。

In order to analyze the change of unsteady casting process on IF steel slab, the first slab, last slab and SEN-changing slab of IF steel in the unsteady casting conditions are investigated by means of gas analysis, chemical composition analysis and large inclusions analysis. The results show that the content of N, T.O and large inclusions in the first slab gradually decreases along with the casting direction, and the content of Als gradually increases. The 8.5 m before the first slab is not suitable for the production of IF steel. The content of N, T.O and Als fluctuated greatly within 2.5 m from the tail. The number of large inclusions within 4.5 m from the tail is higher, both above 1.41 times, and 4.5 m of the tail must be removed. The content of T.O, N and large inclusions in the SEN-changing slab increases obviously within 1.5 m from the position of the SEN-changing, and should be removed in the production of IF steel.