汽车面板钢铸坯表层洁净度控制

Surface cleanliness control of automobile panel steel slab

采用扫描电镜检测、物理模拟研究以及数值模拟分析等手段,研究了汽车面板钢(IF钢)连铸坯凝固钩(hook)对表层洁净度的影响机理。结果表明,在IF钢连铸坯皮下1~3mm内夹杂物数量明显高于其它区域。凝固钩捕集夹杂物的主要形式有3种,包括弯月面附近捕集、液面以下捕集以及部分捕集的夹杂物逃逸。随着拉速和过热度的提高,凝固钩长度变短,夹杂物被凝固钩捕捉的几率下降。

In this study,the distribution of inclusions at different depths beneath the shell surface was analyzed by auto-SEM. Water simulations and numerical simulation measurements were conducted to reveal the mechanism of inclusions captured by hooks.The results show that the inclusions are maximizing at 1-3 mm depths from the slab surface.Three kinds of inclusion movements in hook region were found：captured by the meniscus,captured below the meniscus and some of captured inclusions return to liquid steel.Most of the inclusions were captured near the meniscus which may lead to the highest inclusions amount near the surface of slab.Additionally,the number of inclusions captured by hooks will reduce with increasing the casting speed and casting temperature.