轴承钢夹杂物行为的原位观察

发布时间：2018-08-27 07:14

【摘要】：利用高温共聚焦激光显微镜(CLSM)将4个炉次的高等级轴承钢样品加热至液态,炼钢温度下动态原位观察夹杂物碰撞长大行为,保温后快速冷却,再利用扫描电镜观察试样中的夹杂物,并用能谱分析EDS确定其成分。结果表明,未经过高温共聚焦显微镜处理的轴承钢原始样中夹杂物主要是尖晶石核心外包覆CaS;经过相应处理的轴承钢试样中夹杂物则主要是球状铝酸钙夹杂物,并观察到部分液态的铝酸钙夹杂物在钢液-气相界面铺展,同时观察到了铝酸钙夹杂物与镁铝尖晶石碰撞长大。根据观察结果可判断,轴承钢钢液中液态化程度高的铝酸钙夹杂物相互碰撞以及其与镁铝尖晶石之间的碰撞融合长大是形成Ds夹杂物的重要原因,降低钢中钙含量可以降低夹杂物中的CaO含量,从而提高夹杂物熔点以降低其在钢液中的液态化程度,从而减少Ds夹杂物形成。
[Abstract]:High-grade bearing steel samples of four heats were heated to liquid state by high-temperature confocal laser microscopy (CLSM). The collision growth behavior of inclusions was observed dynamically in situ at steelmaking temperature. The inclusions in the samples were cooled rapidly after heat preservation. The inclusions in the samples were observed by scanning electron microscopy and their compositions were determined by EDS. The inclusions in the original bearing steel samples treated by focusing microscope are mainly spinel core coated with CaS, and the inclusions in the bearing steel samples treated by focusing microscope are mainly spherical calcium aluminate inclusions. It can be concluded from the observation that the collision between the highly liquid calcium aluminate inclusions in bearing steel and the collision and fusion growth between the inclusions and magnesia-alumina spinel are the important reasons for the formation of Ds inclusions. Reducing the calcium content in steel can reduce the content of CaO in inclusions, thereby increasing the melting point of inclusions to reduce the content of CaO in inclusions. Its low liquid content in molten steel reduces the formation of Ds inclusions.
【作者单位】：上海交通大学金属基复合材料国家重点实验室;宝山钢铁股份有限公司研究院;
【分类号】：TG142.1

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