无取向硅钢DG47A冶炼全流程夹杂物分析  

Analysis of inclusions in whole smelting process of non-oriented silicon steel DG47A

作　　者：曹建其 陈超[1] 薛利强 栗周 赵健[1] 林万明[1,5] CAO Jian-qi;CHEN Chao;XUE Li-qiang;LI Zhou;ZHAO Jian;LIN Wan-ming(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China;No.2 Steelmaking Plant,Shanxi Taigang Stainless Steel Co.,Ltd.,Taiyuan 030030,Shanxi,China;College of Artificial Intelligence and Big Data for Medical Sciences,Shandong First Medical University and Shandong Academy of Medical Sciences,Jinan 250117,Shandong,China;Department of Materials Science and Engineering,Harbin Institute of Technology,Shenzhen 518055,Guangdong,China;College of New Energy and Materials Engineering,Shanxi Electronic Science and Technology Institute,Linfen 041075,Shanxi,China)

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024 [2]山西太钢不锈钢股份有限公司炼钢二厂,山西太原030030 [3]山东第一医科大学医学人工智能与大数据学院,山东济南250117 [4]哈尔滨工业大学(深圳)材料科学与工程学院,广东深圳518055 [5]山西电子科技学院新能源与材料工程学院,山西临汾041075

出　　处：《钢铁》2023年第2期61-71,共11页Iron and Steel

基　　金：山西省科技重大专项资助项目(20191102004);国家自然科学基金资助项目(51904204);山西省回国留学人员科研资助项目(2022-040)。

摘　　要：在某企业生产的中高牌号DG47A(Fe-2%Si-0.36%Al-0.26%Mn)无取向硅钢热轧板中发现有长度达50μm左右的团簇状镁铝尖晶石夹杂物,这会影响后续加工过程的产品质量。通过对BOF→RH→中间包→铸坯进行取样分析和热力学计算研究其冶炼流程中夹杂物的演变规律。采用扫描电子显微镜和能谱仪(SEM-EDS)对夹杂物的形貌、尺寸和种类进行分析,通过热力学计算了镁铝尖晶石夹杂物的生成条件,使用热力学计算软件PANDAT计算了该钢种凝固过程析出相变化规律。结果表明,RH脱碳后,夹杂物为SiO_(2);RH加铝3 min后,有Al_(2)O_(3)和少量SiO_(2)夹杂物;在RH加硅铁、纯锰合金化后,出现Al_(2)O_(3)-MgO和含MnS的复合夹杂物;在加入脱硫剂后,出现含CaS的复合夹杂物;RH破空后,不再有单相Al_(2)O_(3)夹杂,出现Al_(2)O_(3)-MgO-MnS夹杂物,并发现少量含MgS的夹杂物。中间包及铸坯中多为Al_(2)O_(3)-MgO-CaS和Al_(2)O_(3)-MgO-MnS复合夹杂物,随着浇注的进行,CaS和MnS在复合夹杂物中的含量有增加的趋势,MgO质量分数均保持为25%左右。CaS和AlN等夹杂物通常包裹在Al_(2)O_(3)-MgO夹杂物的外侧边缘。在铸坯中也有大量单独析出的AlN、MnS类夹杂物。RH加铝阶段,夹杂物平均尺寸为20~25μm,RH破空后下降至2~5μm。中间包和铸坯中,随着钢液的冷却,第二相在夹杂物表面析出,夹杂物平均尺寸为3~6μm,略有增大。热力学计算结果表明,1873 K下当钢液中Mg质量分数大于0.00026%时,则生成Al_(2)O_(3)-MgO夹杂物。钢液在冷却过程中,随着温度的降低,先后析出AlN和MnS夹杂物。For a high grade non-oriented silicon steel DG47A(Fe-2%Si-0.36%Al-0.26%Mn),clustered Al_(2)O_(3)-MgO spinel inclusion with a length of 50μm,which may influence the product property in the sequent process,is found in a hot rolled sheet produced by a steelmaking plant.By analyzing the samples taken from the BOF→RH→tundish→continuous casting slab production process and thermodynamic calculation,the evolution of inclusions in the smelting process of this steel grade are studied.The morphology,size and type of inclusions were analyzed by scanning electron microscope and energy dispersive spectrometer analysis(SEM-EDS).The formation condition of Mg-Al spinel inclusion was calculated by thermodynamics.In addition,the mechanism of precipitation phase during solidification process was calculated by PANDAT software.The results show that SiO_(2)is the main inclusion after RH decarburization.There are Al_(2)O_(3)and a small amount of SiO_(2)inclusions after 3 minutes of adding aluminum in RH.Afterwards,Al_(2)O_(3)-MgO and MnS-containing composite inclusions are formed after adding alloys of ferro-silicon and manganese in RH treatment.CaS-containing composite inclusions are formed after adding desulfurizers.There are no single Al_(2)O_(3)inclusions before the content of CaS and MnS in the composite inclusions tended to increase,and MgO remained at about 25%.CaS and AlN inclusions are wrapped around the outer edge of Al_(2)O_(3)-MgO inclusions.The AlN and MnS inclusions were found in slab.After adding aluminum in RH,the average size of the inclusions is about 20-25μm,and decreased to about 2-5μm before tapping of RH.In the tundish and the slab,with the cooling of the molten steel,the second phase precipitated on the surface of the inclusions,and the average size of the inclusions slightly increased to around 3-6μm.The thermodynamic calculation results show that,at 1873 K,when the Mg content in the molten steel is greater than 0.00026%,Al_(2)O_(3)-MgO inclusions are formed.During the cooling process of molten steel,Al

关 键 词：无取向硅钢 冶炼全流程 夹杂物 镁铝尖晶石 热力学计算 

分 类 号：TF76[冶金工程—钢铁冶金]