Abstract: The oriented silicon steel 0.04%-0.05% C, 3.03% -3.10% Si with yttrium contents of 0.026% , 0.058% and 0.14% are prepared in the laboratory by the 50 kg vacuum-induction furnace through conventional process. The composition, morphology, quantity, size and distribution of inclusions in steel are studied by SEM. The microstructure and texture of oriented silicon steel 2.4 mm hot rolled plate, 0.3 mm cold rolled sheet and a nnealed at 830 °C and 1050 °C are analyzed by OM and EBSD. The experimental results show that, with increasing Y content in steel, the size of inclusions becomes larger and the long-bar inclusions change to a spherical shape, their inhabitation becomes weaker. Therefore, the grain size after primary recrystallization gradually increases with increasing Y content. With Y content of 0. 026% silicon steel, the grain size after primary recrystallization is the smallest. The high storage energy of small grains provides a sufficient driving force for the high temperature annealing grain growth. Therefore, the average grain size after high temperature annealing is 115.7 μm, which is the largest. In the silicon steel with Y content of 0.026% , some Goss grains grow abnormally and Goss ( {110} ＜001＞) texture with strength of 5 appears, while a large amount of y texture still existed in silicon steel with Y content of 0.058% and 0.14%. Since the inclusion size in 0.026% Y steel is the smallest, it has a certain pinning effect, which makes the primary recrystallized grain finer. With the increase of Y content, the size of inclusions in 0.058% Y and 0.14% Y steel increase obviously, which weakens its inhibition on grain growth in the primary recrystallization process.

Key words: Oriented Silicon Steel , Texture , Inclusions , Yttrium Microalloying

摘要： 使用50 kg真空感应炉常规流程工艺在实验室制备钇含量分别为0.026%、0.058%和0.14%的0.04%~0.05%C,3.03%~3.10%Si取向硅钢。采用SEM研究了钢中夹杂物成分、形貌、数量、尺寸和分布；利用OM和EBSD分析了取向硅钢2.4 mm热轧板、0.3 mm冷轧板、830 ℃和1050℃退火板组织和织构。实验结果表明：随着钢中Y含量的升高，夹杂物发生粗化，长条形夹杂物转变为球形，抑制晶粒长大效果减弱，所以一次再结晶热处理 后硅钢板晶粒尺寸随着Y含量的增加逐渐变大。Y含量为0.026%的硅钢一次再结晶晶粒尺寸最小，其较高的储 存能为高温退火晶粒长大提供了足够的驱动力，因此，其高温退火晶粒尺寸最大，平均晶粒尺寸为115.7 μm冷轧硅钢板高温热处理后,Y含量为0.026%的硅钢中部分Goss晶粒异常长大，出现了强度为5的GoSs({110} ＜001＞)织构，而Y含量为0.058%和0.14%的硅钢中依旧存在大量的丫织构。由于含0.026% Y钢中夹杂物尺寸 最小,具有一定的钉扎作用，从而使得一次再结晶晶粒更加细小。随着Y含量的增加,0.058% Y和0.14% Y钢中 夹杂物的尺寸明显增加,使其在一次再结晶过程中对晶粒长大的抑制作用减弱。

关键词: 取向硅钢, 织构, 夹杂物, 钇微合金化