快速升温对无取向电工钢氧化层及磁性能的影响规律  

Influence of rapid heatingon the oxide layer and magnetic properties of non-oriented electrical steel

作　　者：易正鑫 张毅[1] 乔军[1] 贺立红[1] 关云鹏 YI Zhengxin;ZHANG Yi;QIAO Jun;HE Lihong;GUAN Yunpeng(WISDRI Engineering and Research Incorporation Limited,Wuhan 430223,Hubei,China;Collaborative Innovation Center of Steel Technology,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中冶南方工程技术有限公司,湖北武汉430223 [2]北京科技大学,钢铁共性技术协同创新中心,北京100083

出　　处：《金属功能材料》2024年第5期19-26,共8页Metallic Functional Materials

基　　金：国家自然科学基金(51931002);中冶集团181重大研发项目(UAK042101)。

摘　　要：以含硅量2.9%(质量分数)的新能源汽车用无取向电工钢冷轧板为研究对象,在工业氮气气氛(含氧质量分数为0.5%)及高的变温速率情况下进行连续退火模拟实验,之后进行分类,选取其中具有代表性的6种不同程度氧化等级的退火板。利用金相显微镜(OM)、扫描电镜(SEM)、能谱分析仪(EDS)及磁性能分析仪(MPA)等,针对各样品分别在酸洗前后测量其中高频情况下的铁损及磁感值,观察了其侧面氧化层结构。分析得出在高的升温速率下其氧化层结构以及磁性能的影响规律等。结果表明了,无取向电工钢作为含硅量比较高的Fe-Si合金,在高的升温速率条件下,其氧化层中仍然是以常见的Fe_(2)SiO_(4)为主,且通常存在于氧化铁皮与基体之间,其内氧化层的厚度在0.2~1.4μm之间,外氧化层厚度在0.5~8.2μm之间,且内氧化层与外氧化层的厚度成正比;在快速升温条件下,大部分样品在酸洗完后铁损反而会上升,磁感变小,磁性能变差;对于磁感来说,所有氧化等级样品的磁感变化相对差值均小于3%,变化不大;氧化层级为5的样品由于Fe_(2)SiO_(4)/FeO相以网格状形态分布在方铁矿晶界附近,磁性能受氧化层的影响最大,其他等级的影响较小。A new energy vehicle-oriented non-oriented electrical steel cold-rolled sheet with a silicon content of about 2.9%was selected as the research object.Continuous annealing simulation experiments were conducted in industrial nitrogen atmosphere(with an oxygen content of 0.5%)and high cooling rates.Afterwards,the samples were classified,and 6representative annealed sheets with 6different oxidation levels were chosen.The optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),and magnetic property analyzer(MPA)was used to measure the iron loss and magnetic flux density of the samples before and after acid pickling under high frequency conditions,and the structure of the side oxide layer was observed.The influence of the oxide layer structure and magnetic properties at high heating rates was analyzed.The results showed that for the Non-oriented electrical steel with a relatively high silicon content of Fe-Si alloy,under high heating rates,the oxide layer was mainly composed of common Fe_(2)SiO_(4),usually found between the oxide scale and the substrate.The thickness of the inner oxide layer ranged from 0.2μm to 1.4μm,while the outer oxide layer thickness ranged from 0.5μm to 8.2μm,with the thickness of the inner and outer oxide layers being proportional.Under fast heating conditions,most samples showed an increase in iron loss after acid pickling,with reduced magnetic flux density and deteriorated magnetic properties.Regarding magnetic flux density,the relative change in magnetic flux density for all samples with different oxidation levels was less than 3%,indicating insignificant changes.Samples with an oxidation level of 5showed the greatest impact on magnetic properties due to the distribution of Fe_(2)SiO_(4)/FeO phases in a grid-like structure near the grain boundaries of magnetite crystals,while samples with other oxidation levels had lesser impact.

关 键 词：快速升温 无取向硅钢 组织 磁性能 表面氧化层 

分 类 号：TG142.1[一般工业技术—材料科学与工程]