Research progress on effects of Sn and Sb on magnetic and mechanical properties of non-oriented silicon steel

Non-oriented silicon steel is a critical material for manufacturing drive motor cores in new energy vehicles, and its magnetic properties, mechanical properties directly determine the energy consumption and performance of the drive motors. Studies have shown that the addition of Sn and Sb can effectively enhance the magnetic flux density and reduce the iron loss of non-oriented silicon steel. Meanwhile, experimental results demonstrate that the incorporation of Sn and Sb strengthens the strength, hardness, and certain toughness of non-oriented silicon steel, thereby improving its mechanical properties. In recent years, synergistically optimizing the comprehensive properties of non-oriented silicon steel through microalloying （e.g., adding elements such as Sn and Sb） has emerged as a research hotspot and cutting-edge direction in this field. Based on this, this paper aims to systematically review the action mechanisms and related research progress of Sn and Sb on the microstructure, magnetic properties, and mechanical properties of non-oriented silicon steel. Special focus is placed on analyzing the segregation behavior of Sn and Sb at grain boundaries and their regulatory mechanism on the formation space of textures. When Sn and Sb enter the crystal interior, they induce lattice distortion and generate high strain energy, promoting their segregation to grain boundaries. Simultaneously, due to their strong electronegativity, they tend to acquire free electrons at grain boundaries, forming a stable structure. This paper provides a detailed review of the research progress made by relevant enterprises and research institutions at home and abroad regarding the improvement of magnetic properties of non-oriented silicon steel by Sn and Sb. The segregation of an appropriate amount of Sn and Sb at grain boundaries not only hinders grain boundary migration and refines grain size but also inhibits the nucleation and growth of the unfavorable 111 texture, reduces the surface energy of （100） grains, and promotes the development of the favorable 100 texture. Furthermore, Sn and Sb can suppress the precipitation of fine inclusions （AlN and MnS） in non-oriented silicon steel, increase the precipitate size, and thus improve the magnetic properties.