工程科学学报.第42卷,增刊1:109-118.2020年12月 Chinese Journal of Engineering,Vol.42,Suppl.1:109-118,December 2020 https://doi.org/10.13374/j.issn2095-9389.2020.03.12.s08;http://cje.ustb.edu.cn 气氛保护电渣重熔过程中氧化物-CaS复合夹杂物的演变 刘伟建),史成斌四,徐吴驰,郑顶立),吕士刚2,李晶),郭宝善 1)北京科技大学钢铁治金新技术国家重点实验室,北京1000832)邢台钢铁有限责任公司,邢台054027 ☒通信作者,E-mail:chengbin.shi@ustb.edu.cn 摘要利用扫描电镜分析了自耗电极和电渣重熔钢中夹杂物的特征,结合热力学计算,分析了氧硫复合夹杂物在电渣重熔 过程中的转变机理.结果表明,电渣重熔采用气氛保护结合脱氧操作可以将自耗电极全氧质量分数由0.0017%降低至 0.0008%.电渣重熔之后钢中小于3um夹杂物的比例显著增加.自耗电极中的夹杂物为CaS与含质量分数3%和11%左右 Mg0的CO-Al2O,-SiOz-Mg0结合的两类复合夹杂物.电渣过程未被去除的氧化物夹杂中的SiO2被钢液中酸溶铝还原,保 留至电渣锭中.电渣锭中含约1%Mg0和2%SiO2且成分均匀的CaO-Al20,-SiO2-Mg0是在电渣过程中新生的夹杂物.自耗 电极中的CaS通过分解为钢液中溶解Ca和S.以及通过与液态氧化物夹杂中A12O3反应的途径在电渣过程被去除.电渣锭 中低熔点氧化物夹杂周围环状CaS是钢液凝固过程中溶解S、酸溶铝A!与氧化物夹杂中CO的反应产物,高熔点氧化物夹 杂周围环状CS是钢液凝固过程中Ca和S偏析后反应新生的夹杂物.复合夹杂物中补丁状CaS是在电渣重熔钢液冷却过 程中由复合夹杂物熔体中析出的 关键词非金属夹杂物:硫化物:电渣重熔:超低氧:硫化物容量 分类号TF769.2 Evolution of oxide-CaS complex inclusions during protective atmosphere electroslag remelting LIU Wei-jian,SHI Cheng-bin,XU Hao-chi),ZHENG Ding-li),LU Shi-gang?,LI Jing,GUO Bao-shan 1)State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China 2)Xingtai Iron and Steel Co.,Ltd.,Xingtai 054027,China Corresponding author,E-mail:chengbin.shi@ustb.edu.cn ABSTRACT The inclusions in the consumable steel electrode and electroslag remelted steel were characterized using a scanning electron microscope(SEM)equipped with an energy dispersive X-ray spectrometer(EDS).The evolution mechanism of oxide-sulfide complex inclusions during electroslag remelting (ESR)was elucidated based on inclusion experimental identification and thermodynamic calculation.The results show that the combination of protective atmosphere and deoxidation operation during ESR lowers the total oxygen content from 0.0017%in the electrode to 0.0008%in the ingot.The number proportion of the inclusions smaller than 3 um in the steel greatly increases after ESR.The inclusions in the steel electrode are two oxide-sulfide complex types of CaS+CaO-Al2O3-SiOz-Mgo containing about 3%Mgo and CaS+CaO-Al2O3-SiOz-MgO containing about 11%MgO.SiO2 in the original oxide inclusions that had not been removed in ESRR process was reduced by soluble aluminum in liquid steel,and the products remain in the ESR process until in remelted ingot.The CaO-Al2O3-SiO2-Mgo inclusions with uniform elements distribution,which contain about 1%MgO and about 2%iOz,in the ingot are newly formed oxide inclusions in the ESR.Cas inclusions in the steel electrode were removed during the ESR through dissociating into soluble calcium and sulfur in liquid steel,and in the way of reacting 收稿日期:202003-12 基金项目:国家自然科学基金资助项目(51874026.52074027)气氛保护电渣重熔过程中氧化物–CaS 复合夹杂物的演变 刘伟建1),史成斌1) 苣,徐昊驰1),郑顶立1),吕士刚2),李 晶1),郭宝善2) 1) 北京科技大学钢铁冶金新技术国家重点实验室,北京 100083 2) 邢台钢铁有限责任公司,邢台 054027 苣通信作者,E-mail: chengbin.shi@ustb.edu.cn 摘 要 利用扫描电镜分析了自耗电极和电渣重熔钢中夹杂物的特征,结合热力学计算,分析了氧硫复合夹杂物在电渣重熔 过程中的转变机理. 结果表明,电渣重熔采用气氛保护结合脱氧操作可以将自耗电极全氧质量分数由 0.0017% 降低至 0.0008%. 电渣重熔之后钢中小于 3 μm 夹杂物的比例显著增加. 自耗电极中的夹杂物为 CaS 与含质量分数 3% 和 11% 左右 MgO 的 CaO–Al2O3–SiO2–MgO 结合的两类复合夹杂物. 电渣过程未被去除的氧化物夹杂中的 SiO2 被钢液中酸溶铝还原,保 留至电渣锭中. 电渣锭中含约 1%MgO 和 2%SiO2 且成分均匀的 CaO–Al2O3–SiO2–MgO 是在电渣过程中新生的夹杂物. 自耗 电极中的 CaS 通过分解为钢液中溶解 Ca 和 S,以及通过与液态氧化物夹杂中 Al2O3 反应的途径在电渣过程被去除. 电渣锭 中低熔点氧化物夹杂周围环状 CaS 是钢液凝固过程中溶解 S、酸溶铝 Al 与氧化物夹杂中 CaO 的反应产物,高熔点氧化物夹 杂周围环状 CaS 是钢液凝固过程中 Ca 和 S 偏析后反应新生的夹杂物. 复合夹杂物中补丁状 CaS 是在电渣重熔钢液冷却过 程中由复合夹杂物熔体中析出的. 关键词 非金属夹杂物;硫化物;电渣重熔;超低氧;硫化物容量 分类号 TF769.2 Evolution of oxide –CaS complex inclusions during protective atmosphere electroslag remelting LIU Wei-jian1) ,SHI Cheng-bin1) 苣 ,XU Hao-chi1) ,ZHENG Ding-li1) ,LÜ Shi-gang2) ,LI Jing1) ,GUO Bao-shan2) 1) State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China 2) Xingtai Iron and Steel Co., Ltd., Xingtai 054027, China 苣 Corresponding author, E-mail: chengbin.shi@ustb.edu.cn ABSTRACT The inclusions in the consumable steel electrode and electroslag remelted steel were characterized using a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). The evolution mechanism of oxide–sulfide complex inclusions during electroslag remelting (ESR) was elucidated based on inclusion experimental identification and thermodynamic calculation. The results show that the combination of protective atmosphere and deoxidation operation during ESR lowers the total oxygen content from 0.0017% in the electrode to 0.0008% in the ingot. The number proportion of the inclusions smaller than 3 μm in the steel greatly increases after ESR. The inclusions in the steel electrode are two oxide –sulfide complex types of CaS+CaO –Al2O3–SiO2–MgO containing about 3% MgO and CaS+CaO –Al2O3–SiO2–MgO containing about 11% MgO. SiO2 in the original oxide inclusions that had not been removed in ESRR process was reduced by soluble aluminum in liquid steel, and the products remain in the ESR process until in remelted ingot. The CaO–Al2O3–SiO2–MgO inclusions with uniform elements distribution, which contain about 1%MgO and about 2%SiO2 , in the ingot are newly formed oxide inclusions in the ESR. CaS inclusions in the steel electrode were removed during the ESR through dissociating into soluble calcium and sulfur in liquid steel, and in the way of reacting 收稿日期: 2020−03−12 基金项目: 国家自然科学基金资助项目(51874026,52074027) 工程科学学报,第 42 卷,增刊 1:109−118,2020 年 12 月 Chinese Journal of Engineering, Vol. 42, Suppl. 1: 109−118, December 2020 https://doi.org/10.13374/j.issn2095-9389.2020.03.12.s08; http://cje.ustb.edu.cn