低温取向硅钢硅酸镁底层形成过程  

Formation process of forsterite film in grain-oriented silicon steel manufactured by acquired inhibitor method

作　　者：王现辉 刘兆月 李瑞凤 高倩 滕仁昊 WANG Xian-hui;LIU Zhao-yue;LI Rui-feng;GAO Qian;TENG Ren-hao(Center of Product Research and Development,Shougang Zhixin Qian′an Electromagnetic Material Co.,Ltd.,Qian′an 064404,Hebei,China;School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Central Iron and Steel Research Institute,China Iron and Steel Research Institute Group,Beijing 100081,China)

机构地区：[1]首钢智新迁安电磁材料有限公司产品研发中心,河北迁安064404 [2]北京科技大学材料科学与工程学院,北京100083 [3]中国钢研科技集团有限公司钢铁研究总院有限公司,北京100081

出　　处：《钢铁》2022年第6期150-158,共9页Iron and Steel

基　　金：河北省重点研发计划资助项目(20311005D)。

摘　　要：取向硅钢硅酸镁底层是产品结构的重要组成部分,低温取向硅钢底层的控制是难点,也是限制产品性能提升的瓶颈。以往对取向硅钢硅酸镁底层的形成研究较少,高磁感取向硅钢薄规格化高性能产品开发及品质提升缺乏理论支撑。为此,采用高温退火中断试验法对低温取向硅钢硅酸镁底层的形成过程进行了模拟,研究了底层的微观结构、成分特征的演变规律,明确了硅酸镁底层在高温退火过程中的反应形成过程。温度约为900℃时,样品表面开始发生Mg2SiO4颗粒的形核,随着温度继续升高,Mg2SiO4晶核不断长大;温度约为1050℃时,样品表面的Mg2SiO4开始致密化,温度约为1100℃时,表层硅酸镁的致密化基本完成,硅酸镁底层形成的关键温度为900~1100℃。另外,研究中发现,在硅酸镁底层的下方生成的Al2O3·MgO尖晶石颗粒连结基体和Mg2SiO4,形成了“钉扎”结合层。硅酸镁底层形成过程MgO中的Mg2+由表面向氧化膜内扩散并与SiO2反应,同时氧化膜内SiO2发生熟化,1000℃以上基板中的AlN分解释放出的铝则向氧化膜交界及通过氧化膜向表面扩散与Mg2SiO4等反应形成尖晶石。优良的底层结构形成是由原脱碳退火氧化膜表层1μm左右形成致密的Mg2SiO4,其余2~3μm厚度转化成一定数量的椭球Al2O3·MgO的尖晶石“钉扎”结合层,其主要控制方向为提高氧化膜活性、选用高活性MgO、添加低熔点反应助剂等。The forsterite film of oriented silicon steel is an important part of product structure.The control of forsterite film is not only aprocess difficulty,but also a bottleneck of improvement of product performance.However,there are few previous studies on the formation of forsterite film,and there is a lack of theoretical support for the development and quality improvement of thin standardized high-performance products of high magnetic induction oriented silicon steel.Therefore,the formation process of forsterite film in grain-oriented silicon steel manufactured by the acquired inhibitor method was simulated by a high temperature annealing interruption experiment,and the microstructure and composition evolution of forsterite film during annealing were analyzed.The reaction formation process of forsterite film during high temperature annealing was clarified.The Mg2SiO4particles nucleate on the surface of the steel at about 900℃and grow up as the increase of annealing temperature.Up to 1050℃,the Mg2SiO4particles begin to become compact,and the densification process finishes at about 1100℃.The key temperature for the formation of forsterite film is 900-1100℃.In addition,the Al_(2)O_(3)·MgO spinel is formed under the forsterite film that can make a"pinning effect"on the forsterites film.During the formation of forsterite film,the Mg2+of MgO diffuses from the surface to the oxide film and reacts with SiO2.At the same time,SiO2in the oxide film matures.The content of Al released by AlN decomposition in the substrate above 1000℃reacts with Mg2SiO4to form spinel.The excellent forsterite film structure is formed by the original decarburization annealing oxide film surface layer 1μm to form dense Mg2SiO4and the rest 2-3μm thickness into a certain amount of ellipsoidal Al_(2)O_(3)·MgO spinel for"pinning"bonding layer.Its main control directions are,improving the activity of oxide film,selecting high activity MgO,adding low melting point reaction additives,etc.

关 键 词：取向硅钢 硅酸镁底层 氧化膜 高温退火 尖晶石 

分 类 号：TG161[金属学及工艺—热处理]