论文部分内容阅读
通过对国内某厂BOF-LF-VD工艺生产的GCr15轴承钢全流程取样,系统研究了GCr15生产过程中大颗粒氧化物夹杂的变化行为。分析各工序氧氮含量的变化,扫描电镜观察夹杂物的形貌、大小,能谱分析仪分析夹杂物成分,钢质纯净度分析仪统计分析夹杂物的数量和当量直径ECD(Equivalent Circular Diameter)。研究表明,该流程可以获得T[O]的平均含量为9×10-4%;LF到站夹杂物基本为Al2O3系并含有少量CaO,LF喂铝后夹杂物中出现MgO,LF精炼过程中CaO含量逐渐升高,VD结束后CaO含量有所降低,MgO含量上升;LF和VD精炼后钢中夹杂物粒径大小和数量都显著下降,同时在大包到中间包之间注流被卷入空气。热力学分析表明夹杂物中的MgO来自钢包中的耐火材料,夹杂物中CaO来自于炉渣中CaO。
Through the sampling of the whole process of GCr15 bearing steel produced by a BOF-LF-VD process in a certain plant, the change behavior of large-grain oxide inclusions during GCr15 production was systematically studied. The changes of oxygen and nitrogen content in each process were analyzed. The shape and size of inclusions were observed by scanning electron microscopy. The composition of inclusions was analyzed by energy spectrum analyzer. The number of inclusions and the equivalent diameter of ECD (Equivalent Circular Diameter) . The results show that the average content of T [O] in this process can reach 9 × 10-4%. The inclusions from LF to the station are basically Al2O3 and contain a small amount of CaO. When LF is fed with aluminum, MgO and LF appear in the inclusions CaO content gradually increased, CaO content decreased after VD, MgO content increased; LF and VD refined steel inclusions in the size and the number of significant decline in the same time, between the big package to the tundish was injected volume Into the air. Thermodynamic analysis shows that the MgO in the inclusions comes from the refractory in the ladle and the CaO in the inclusions comes from the CaO in the slag.