二次氧化对低碳铝镇静钢中间包钢水洁净度的影响

 对薄板坯连铸连轧生产低碳铝镇静钢浇次第一炉开浇初期的中间包钢水取样，运用ASPEX扫描电镜分析了钢中夹杂物数量、尺寸及成分的变化规律。结果表明，二次氧化主要有2种：大气氧化和中间包耐火材料及卷渣造成的氧化。夹杂物的变化受二次氧化方式主次不同影响较大，在本研究的2个浇次中，中间包耐火材料及卷渣造成的二次氧化持续时间较大气氧化长，造成夹杂物数量较多和大量高熔点Al2O3夹杂的持续存在，其平均尺寸也较大，对钢水洁净度影响更大，可见在工业实践中，耐材和卷渣引起的二次氧化也值得高度重视。

Effect of Reoxidation on Cleanliness of Molten Steel in Tundish for Low Carbon Aluminum Killed Steel

Steel samples of low carbon Al-killed steel (LCAK steel) produced by TSCR process were taken from tundish at initial teeming stage in industrial heats. The compositions, sizes distribution and variation of the number of the inclusions were analyzed using ASPEX. The results show that two main factors are considered to be responsible for the reoxidation of molten steel in the tundish, air and tundish refractories or slag entrapments. The style of reoxidation has great impact on the inclusions evolution. Reoxidation caused by tundish refractories or slag entrapments has longer duration than air reoxidation, which results in the increases of number and average size of inclusions, the persistence of high melting point Al2O3 inclusions are also unfavorable to the cleanliness of molten steel. Great attention should be paid to reoxidation caused by tundish refractories and slag entrapments in industrial practice.