20CrMnTi齿轮钢冶炼全流程的夹杂物分析

为明确冶炼过程齿轮钢中非金属夹杂物的演变行为,实现齿轮钢中夹杂物特性的有效控制和提高产品质量,以20CrMnTi齿轮钢为研究对象,通过对LF-VD-CC工艺齿轮钢生产过程的取样分析,利用扫描电子显微镜对冶炼过程不同阶段的夹杂物成分、形貌、尺寸和数量等特性进行系统分析研究。结果表明,LF进站时,夹杂物主要为脱氧产物Al₂O₃-(MnS)和少量的镁铝尖晶石夹杂物;LF化渣后至精炼末期,由于渣/钢反应和耐火材料侵蚀带入的MgO和CaO等,导致夹杂物转变为Al₂O₃-MgO-MnS-CaS和Al₂O₃-MgO-CaO;VD精炼过程中夹杂物的类型基本不变,但从VD破空到铸坯过程,Al₂O₃-MgO-CaO夹杂物基本消失,试样中的夹杂物类型主要为Al₂O₃-MgO-MnS-CaS和TiN-MnS夹杂物。

Inclusion characterization in whole smelting process of 20CrMnTi gear steel

In order to clarify the evolution of non-metallic inclusions in gear steel during smelting process and achieve the effective control of inclusions and improve product quality, the evolution behavior of inclusions in 20CrMnTi gear steel at different stages of smelting process was investigated through sampling during the gear steel production of LF-VD-CC process. A scanning electron microscope was used to systematically analyze the characteristics of inclusion such as composition, morphology, size and quantity. The results showed that the main inclusions were deoxidation products Al₂O₃-(MnS) and a small amount of magnesia-alumina spinel inclusions at the beginning of LF refining. From the slagging to the end of LF refining, the main inclusions transformed to Al₂O₃-MgO-MnS-CaS and Al₂O₃-MgO-CaO due to MgO and CaO brought by slag/steel reaction and refractory corrosion. The type of inclusions in VD refining process was unchanged. But the Al₂O₃-MgO-CaO inclusions were disappeared from VD vacuum broken to slab, and the types of inclusions in the final slab were mainly Al₂O₃-MgO-MnS-CaS and TiN-MnS.