酸溶铝和铌含量对取向硅钢夹杂物特征的影响

摘 要：为了掌握Als（酸溶铝）和Nb含量对取向硅钢中夹杂物特征的影响，借助场发射扫描电镜(FE-SEM)结合能谱仪(EDS)和图像分析软件研究了钢中夹杂物类型、数量、尺寸及尺寸分布，结合钢液凝固过程中溶质元素的微观偏析模型，重点分析了Als和Nb含量影响钢中AlN和NbN析出的机制。结果表明，钢中的夹杂物以NbN、AlN和AlN-NbN为主，夹杂物尺寸分布由Als和Nb含量综合影响。Als含量的增加使含氧复合夹杂物中Al2O3含量增加，SiO2含量降低，促进了钢中硅酸盐类氧化物夹杂的去除，但大大增加了AlN和AlN-NbN夹杂的偏析析出。Nb含量的增加使夹杂物的平均尺寸变小，促进了钢中NbN在凝固前沿的提前析出和以氧化物为核心析出。Als主要影响钢中的氧化物和氮化物夹杂，Nb通过影响与Als结合的O和N的活度影响钢中氧化物和氮化物夹杂的析出特性。

Effect of acid soluble aluminum and niobium content on inclusion characteristics of grain oriented silicon steel

Abstract： In order to elucidate the effect of Als (acid soluble aluminum) and Nb content on the characteristics of inclusions in grain oriented silicon steel, the type, quantity, size and size distribution of inclusions were studied by the field emission scanning electron microscope (FE SEM) equipped with an energy dispersive X ray spectroscopy (EDS) and image analysis software. Combined with the micro segregation model of solute elements during solidification, the precipitation mechanism of AlN and NbN inclusions was analyzed specially. The results indicate that the inclusions are mainly NbN, AlN and AlN-NbN, and the size distribution of the inclusions is affected by Als and Nb simultaneously. With the increase of Als content added in the steel, the content of Al2O3 in the oxide composite inclusions increases, while that of SiO2 decreases. The increase of Als content promotes the removal of silicate inclusions in the steels, but the segregation precipitation of AlN and AlN NbN inclusions increases. With the increase of Nb content added in the steel, the average size of inclusions reduces. The increase of Nb content promotes the earlier precipitation of NbN at the solidification front and its precipitation with oxides as the core. Als mainly affects the precipitation characteristics of oxide and nitride inclusions in the steel, and Nb also affects the oxides and nitrides precipitation characteristics via affecting the activity of oxygen and nitrogen combined with Als.