关键词: 薄带铸轧, 3% Si取向硅钢, 织构, 夹杂物, 钇微合金化

Abstract: The 3% Si oriented silicon steel containing yttrium is prepared by 50 kg vacuum induction furnace with conventional production process and thin strip casting rolling process, respectively. The casting temperature of thin strip is 1 530 °C with rolling rate 0.3 m/s to 2.5 mm cast strip thickness. The conventional process silicon steel 80 mm cast billet heating temperature is 1 150 °C,hot rolled thickness to 2.4 mm with end rolling temperature 935 ℃.The composition, morphology, quantity, size and distribution of inclusions in steel are studied by scanning-type electron microscope (SEM) and electro-probe microanalyser (EPMA). The microstructure and texture of silicon steel strip, hot rolled plate, 0. 3 mm cold rolled sheet and 870 °C 7 min and 1 100 °C 10 min recrystallzing annealed sheet are analyzed by optical microscope (OM) and electron back-scattering diffraction (EBSD). The experimental results show that, compared with the conventional process, the grains of the thin strip cast rolled silicon steel after the first recrystallization are finer and the strength of 7 texture is 17 ； but the grain size is nonuniform after secondary recrystallization heal treatment, the average grain size is 61 μm, and the partial grain size of Goss orientation bigger than 1 mm. The reason is that the amount of fine yttrium inclusions is too large and the distribution is uneven, and the grain growth in the area where the inclusions gather is obviously inhibited. After secondary recrystallization heat treatment process, the grain size of the silicon steel of yttrium bearing produced by conventional process is uniformly and the average grain size is 102 μm, but the Goss texture is not formed.

Key words: Strip Casting, 3% Si Oriented Silicon Steel, Texture , Inclusions, Yttrium Microalloying