W800无取向电工钢中氧化物演变规律  

Evolution of oxide inclusions in W800 non-oriented electrical steel

作　　者：胡志远[1] 任强[2] 张立峰[2] HU Zhi-yuan;REN Qiang;ZHANG Li-feng(Qian＇an Steel, Shougang Steel Group, Qian＇an 064400, Heibei, China;School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China)

机构地区：[1]首钢迁钢公司,河北迁安064400 [2]北京科技大学冶金与生态工程学院,北京100083

出　　处：《钢铁研究学报》2018年第4期282-287,共6页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(51725402)

摘　　要：夹杂物是影响无取向电工钢磁性能的重要因素之一,为了研究无取向电工钢生产过程中氧化物特征的变化,对W800无取向电工钢全流程取样分析。采用荧光光谱分析和氧氮联合分析仪分析了炉渣和钢中全氧含量的变化。采用直接磨抛后1∶1盐酸水溶液酸蚀和非水溶液小样电解的方法揭示了钢中氧化物的形貌特征。采用ASPEX对钢中氧化物的成分、尺寸、数量进行分析。试验结果表明,加Al合金化前,钢中的氧化物类型主要为球体或近球体的SiO2和含有少量的SiO2包裹SiO2-MnO;加Al合金化后,氧化物转变为Al2O3和MgO·Al2O3。通过直接磨抛和1∶1盐酸水溶液酸蚀的方法只能揭示出球形和多面体的Al2O3。采用非水溶液电解提取可以看到Al2O3的3种形貌为球体、树枝状和多面体。RH精炼过程中,夹杂物平均成分接近纯Al2O3,MgO的质量分数仅为0.2%。而在中间包冶炼过程中,夹杂物中MgO比例提高。软吹过程对于促进夹杂物长大和去除具有显著效果,也促进了耐火材料的侵蚀,使夹杂物中MgO的质量分数升高至8.1%。由于精炼过程采用较低的碱度和钙铝比,夹杂物中几乎不含CaO。通过Factsage热力学计算得出,随着Al的加入量增多,钢中的夹杂物类型依次为纯SiO2,液态的SiO2-Al2O3和Al2O3,与观察到的结果相符。Inclusion is one of the major factors affecting magnetic properties of non-oriented electrical steel.Steel and slag samples were sampled in the production route of W800 non-oriented electrical steel.The composition of slags and the content of TO were measured by XRF and oxygen and nitrogen analyzer.The morphology,amount and composition of oxide inclusions were analyzed by an automated scanning electron microscope ASPEX.Before adding aluminum,the oxide inclusions are mainly spherical silicon oxide and a few SiO2-MnO wrapped by SiO2.Due to the high affinity with oxygen of aluminum,the oxide inclusions changed to alumina and MgO·Al2O3 spinel after adding aluminum.Only two types of morphologies of Al2O3 can be observed by polishing and acid etching.Sphere shape,cluster and polyhedron shape of Al2O3 can be observed after electrolysis of nonaqueous solution.Therefore,electrolysis of nonaqueous solution is more effective and accurate in revealing the morphologies of oxides.The average content of MgO in inclusions increases to 8.1 mass% during soft blowing,due to the erosion of refractories.The inclusions grows larger and are removed effectively by argon blowing.Nearly no CaO exists in oxides because of low basicity and mass ratio of CaO to Al2O3.With the addition of Al,the inclusions are SiO2,liquid SiO2-Al2O3 and Al2O3,which are in agreement with the observed results.

关 键 词：无取向电工钢 氧化物形貌 热力学 夹杂物 

分 类 号：TG142.1[一般工业技术—材料科学与工程]