基于形变储能的薄带连铸4.5wt.%Si高硅钢再结晶形核机制及调控理论

薄规格、高硅元素含量和强易磁化织构是中、高频用无取向硅钢的发展方向。前期研究通过“薄带连铸+适度硅元素含量设计(4.5wt.%Si)”的思路，实现了高硅钢超薄带材的短流程高效制备。研究发现诱导形成强易磁化织构是进一步提升其软磁性能的有效途径。本项目拟从形变储能角度出发，以再结晶热力学和动力学理论为基础，系统研究大变形条件下实验钢在回复和形核阶段的亚结构演化及形变储能特征，明确特定取向晶粒的优先形核机制，揭示避免取向钉扎的形变储能临界条件，建立回复过程中亚结构与形变储能的一体化调控准则。项目研究旨在发现基于形变储能的择优取向“适度形核”控制理论与技术，解决再结晶形核机制及调控理论中的关键科学问题，为高品质高硅钢超薄带材开发提供基础理论支撑。

Thin gauge, high silicon content and strong easily-magnetized texture give the developing direction for medium and high frequency non-oriented silicon steel. In the preliminary study, short process and highly efficient preparation of high silicon steel were realized by the idea of “twin roll strip casting + moderate silicon content design (4.5wt.%Si)”. It is found that the induced formation of strong easily-magnetized texture is an effective way to further enhance the soft magnetic properties. The project intends to proceed from the perspective of deformation stored energy. Based on the thermodynamics and kinetic theories of recrystallization, the sub-structure evolution and stored deformation energy characteristics of the experimental steel will be systematically studied during recovery and nucleation stage after large deformation, clarifying the mechanism of priority nucleation for specific orientation, revealing the conditions of stored deformation energy to avoid orientation pinning, and establishing integrated regulation and control guidelines of the sub-structure and stored energy during recovery. The aim of this project is to find the control theory and technology of preferred orientation “appropriate nucleation” based on the stored deformation energy, to solve the key scientific issues about the mechanism and control theory of recrystallization nucleation, and to provide theoretical support to develop high quality high silicon steel ultra-thin strip.