Inclusion characterization in whole smelting process of 20CrMnTi gear steel
XU Guo-fang1, ZHANG Xue-liang2, YANG Shu-feng2, LI Jing-she2, BAI Xu-xu2
1. Xinxing Ductile Iron Pipes Co., Ltd., Wuhu 241002, Anhui, China; 2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Abstract: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.
许国方, 张雪良, 杨树峰, 李京社, 白旭旭. 20CrMnTi齿轮钢冶炼全流程的夹杂物分析[J]. 中国冶金, 2020, 30(11): 23-28.
XU Guo-fang, ZHANG Xue-liang, YANG Shu-feng, LI Jing-she, BAI Xu-xu. Inclusion characterization in whole smelting process of 20CrMnTi gear steel[J]. China Metallurgy, 2020, 30(11): 23-28.
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