YANG Wen
,
CAO Jing
,
WANG Xin-hua
,
XU Zhi-rong
,
YANG Jie
钢铁研究学报(英文版)
The behavior of non-metallic inclusions in LCAK (low carbon aluminum killed) steel produced by BOF (basic oxygen furnace)-LF (ladle furnace) refining-FTSC (flexible thin slab continuous caster) production route was investigated. The results showed that, LF refining for LCAK steel could decrease the wT[O] significantly, and the inclusions were modified by Ca treatment, which prevented nozzle clogging efficiently. However, owing to the unstable casting condition in the earlier stage of casting, a severe reoxidation occurred, accompanied with mold slag entrapment. The transformation of non-metallic inclusions during the steelmaking process was Al2O3→MgO-Al2O3 type inclusion→MgO-Al2O3-CaO type inclusion with a CaS ring, and the mechanism of the transformation was proposed and discussed via thermodynamic and kinetic analysis. Besides, to avoid CaS precipitation, the product of w2[Al]×w3[S] in steel should be less than 2.0×10-10 at 1873 K, which remands higher desulfurization ratio during LF refining.
关键词:
LCAK steel
,
ladle refining
,
FTSC
,
non-metallic inclusion
