利用EPMA、EBSD、XRD、TEM和热压缩测试，研究了Y元素对无取向6.5%Si钢铸态组织、有序相、中温变形和软化机制的影响。结果表明，当Y含量为0.017%和0.15%时，钢液中形成高熔点Y₂O₃ + Y₂O₂S/Y₂O₂S-YP复合稀土化合物，促进异质形核。凝固末期，枝晶间形成Y₂Fe₁₄Si₃化合物，凝固组织得到明显细化。铸锭的基体有序度与Y含量呈反比关系。500℃压缩实验结果表明，不同Y含量铸锭的塑性变形均由位错滑移机制主导。含Y试样峰值应力对应的临界应变降低，加工软化提前，加工硬化率下降，动态软化作用增强。热压缩试样的位错密度正比于Y含量，低基体有序度和高形变诱导无序作用是含Y试样动态软化作用增强的主要原因。

With the rapid development of electric, electronics, and military industries, there is an urgent demand for high-performance electrical steel. Non-oriented 6.5%Si electrical steel is an advanced soft magnetic material that exhibits excellent high-frequency soft magnetic properties, such as low iron loss, high magnetic permeability, and near-zero magnetostriction, which attracts considerable attention and has broad application prospects in the high-frequency field. Microalloying of rare earth elements, including Ce, La, and Y, is known to improve the ductility of 6.5%Si electrical steel. However, there are relatively few studies on the enhancement mechanism of medium-temperature plasticity of 6.5%Si electrical steel by addition of Y. In this study, the effect of Y on the solidification microstructure, ordered phase, warm compression behavior, and softening mechanism of non-oriented 6.5%Si electrical steel was investigated by EPMA, EBSD, XRD, TEM, and hot compressive test. The results indicated that the addition of 0.017% and 0.15% of Y led to the formation of high-melting-point Y₂O₃ + Y₂O₂S/Y₂O₂S-YP compounds in the melt which effectively promoted heterogeneous nucleation. At the end of the solidification process, the interdendritic rare-earth compounds were identified as Y₂Fe₁₄Si₃ and the solidification microstructure was obviously refined. In addition, with the increasing Y content, the ordered degree of the matrix decreased. The compression test at 500^oC indicated that the deformation mechanisms of all the specimens were dominated by a dislocation slip. The critical strain corresponding to the peak stress of the specimens doped with Y decreased. The advancement of the work softening stage and reduction in the following work hardening rate suggested that the dynamic softening effect was enhanced in the specimens doped with Y. After deformation, the matrix was in a disordered state, however, the dislocation density in the matrix was directly proportional to the Y content. Eventually, the primary reason for the enhancement of the dynamic softening effect was attributed to the low ordered degree and high deformation-induced disordering of the matrix by addition of Y.