低碳铝镇静钢铸坯长度方向上T.O和夹杂物的分布规律研究

Study on the Distribution of T.O and Inclusions in the Length of Low Carbon Aluminum-killed Steel Slab

研究了“转炉-RH-双流板坯连铸”工艺生产的SPHD低碳铝镇静钢铸坯火焰清理前后沿长度方向上的全氧含量及夹杂物数量、尺寸的变化规律。结果表明:随着拉坯长度的增加,铸坯T.O含量逐渐降低,坯头T.O含量比坯尾的高15 ppm-20 ppm。同时,夹杂物数量密度和面积率减小。未经火焰清理的铸坯存在尺寸100μm以上的大型夹杂物。火焰清理后,铸坯中>40μm以上的夹杂物显著减少,未见100μm以上的夹杂物。

The variation of total oxygen content and the number and size of inclusions along the length direction of SPHD low carbon aluminum-killed steel slab before and after slab scalping was studied.The SPHD steel was produced by converter-RH-slab continuous casting process.The results show that the content of T.O decreases gradually with the increase of casting length,and the content of T.O in the head of the slab is 15 ppm-20 ppm higher than that in the tail.At the same time,the inclusion quantity density and area ratio also decrease.There are still large inclusions of size 100μm or more in the unskinned slab.After slab scalping,linclusions of size above 40μm in the slab are significantly reduced,but no inclusion above 100μm was found.