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研究了双辊薄带连铸Fe-2.7%Si合金铸带组织和析出物的形貌特征及分布规律。结果表明,实验钢铸带中间区域具有以表层柱状晶为主、中心细小等轴晶共存的组织,且细小等轴晶区厚度约为600μm,尺寸为10μm~40μm,晶内有大量亚晶。铸带初始织构较为漫散。铸带中的析出物主要为AlN和MnS的复合析出,通常以MnS周边包围AlN的形态存在,析出的位置主要在晶界、亚晶界附近及晶内。表层析出物尺寸为50nm~500nm,中心层尺寸更为粗大,甚至包括1μm以上的特大型析出物。同时,铸带中存在一定的位错,可在一定程度上促进第二相粒子的快速细小析出。
The morphology and distribution of microstructure and precipitates in the cast strip of Fe-2.7% Si alloy cast by twin-roll strip casting were studied. The results show that the microstructure of the experimental strip is dominated by surface columnar crystals and fine central equiaxed grains coexist. The fine equiaxed zone has a thickness of about 600μm, a size of 10μm ~ 40μm and a large amount of subgrains. The initial texture of the casting belt is diffuse. The precipitates in the cast strip are mainly the composite precipitates of AlN and MnS, and usually exist in the form of AlN surrounded by the periphery of the MnS. The precipitates are mainly located near the grain boundaries, the subgrain boundaries and within the crystal. The size of the surface precipitates is from 50 nm to 500 nm, the size of the center layer is more coarse, and even the extra large precipitates of 1 μm or more are included. At the same time, there is a certain dislocation in the casting belt, which can promote the rapid and fine precipitation of the second-phase particles to a certain extent.