帘线钢中非金属夹杂物的控制技术研究

Non-Metal Inclusion Control Technique for Tire Cord Steel

采用转炉、LF精炼、真空处理、软吹、连铸工艺生产帘线钢,将钢水中S、P、Ti、As等残余元素的含量尽可能降低,出钢采用含超低铝和钛的合金,使用低碱度的酸性渣进行炉外精炼,严格控制钢中酸溶铝含量,同时控制渣中MgO、Al2O3含量,将帘线钢中的非金属夹杂物控制在锰铝榴石(3MnO-Al2O3-3SiO2)和位于钙斜长石(CaO-Al2O3-2SiO2)和假硅灰石(CaO-SiO2)共晶线周边的玻璃态塑性夹杂区域内,尽可能降低钢中不可变形夹杂物,如Al2O3和(Mg、Mn)O.Al2O3的数量和大小,通过控制钢中钛、氮含量来消除TiN(TiCN)夹杂。

Tire cord steel is produced by oxygen converter, ladle furnace, vacuum degassing and billet casting processes at No. 1 steelmaking plant, WISCO. The residual elements in steel such as S,P.Ti. As are controlled as low as possible. The extra low Aland Ti ferrous alloys are used during converter tapping, and acid ladle slag for re- fining processes. The dissolved A1 in liquid steel, Alz 03 and MgO in ladle slag are limited strictly. The deformable, glassy and low melting point inclusions, which locate in the regions of plastic inclusions between anorthite and pseu- do-wollastonite, and spessartite in CaO-SiO2-Al2O3 and SiO2-MnO-Al2O3 respectively, can be obtained. Mean- while,the size and amount of undeformable inclusions such as Al2O3, （Mg,Mn）O ·Al2O3 can be controlled as low as possible. TiN （TiCN） inclusions can be eliminated by controlling titanium and nitrogen content in steel.