基于双辊薄带连铸制备低铁损、高磁感、薄规格硅钢板的组织性能控制机理

In the present project, twin-roll strip casting technique will be introduced to the manufacturing process of thin-gauge grain-oriented and non-oriented silicon steel. It was found in the early studies that the new process has some characteristics that are absent in the conventional manufacturing process based on thick slab casting technique. For example, the initial solidification microstructure can be changed, the inhibitors are easy to be controlled, and the processes are flexible, and so on. The present study will focus on the controlling mechanism of microstructure, texture, precipitation and magnetic properties, which are very important for thin-gauge silicon steel. The origin, evolution, and strengthening mechanism of Goss texture will be fully clarified through the whole manufacturing process of thin-gauge grain-oriented silicon steel. The design of inhibitors and strengthening mechanism will also be investigated. Furthermore, the evolution of microstructure, texture, and precipitation and the optimization mechanism will be revealed through the whole manufacturing process of thin-gauge non-oriented silicon steel. The technical route and the twin-roll strip casting, secondary cooling, rolling, and heat-treatment process will be designed and optimized in order to make clear the relationship between microstructure, process and magnetic properties. The key theoretical points of controlling microstructure and properties together with the key processing window will be thus established through the whole manufacturing process of thin-gauge silicon steel based on twin-roll strip casting technique. The aim of the present work is to respectively prepare 0.18~0.20mm thick grain-oriented silicon steel and 0.10~0.15mm thick non-oriented silicon steel with low iron loss and high magnetic inductivity.

本项目将双辊薄带连铸引入薄规格取向硅钢和无取向硅钢的制造流程，针对前期研究工作中发现的新流程铸带坯凝固组织可控、抑制剂易控、工艺流程柔性化等显著区别于传统厚板坯流程的本质特点，围绕薄规格硅钢制备中关键的组织、织构、析出相及磁性能控制问题开展研究。阐明基于双辊薄带连铸制备薄规格取向硅钢全流程条件下Goss织构的起源、演变及强化控制机理，以及抑制剂设计和强化控制机理；揭示基于双辊薄带连铸制备薄规格无取向硅钢全流程条件下组织、织构、析出相的演变及优化控制机理；开展技术路线设计和双辊薄带连铸、二次冷却、轧制及热处理工艺的设计与优化，弄清组织—工艺—磁性能三者的对应关系。据此建立基于双辊薄带连铸制备薄规格硅钢板组织性能控制的关键理论要点，找到关键的工艺控制窗口，制备出磁性能优异的0.18~0.20mm厚的低铁损、高磁感取向硅钢原型钢以及0.10~0.15mm厚的低铁损、高磁感无取向硅钢原型钢。

基于厚/薄板坯连铸的电工钢生产流程不但工序冗长、工艺窗口狭窄，而且，非常高的轧制压缩比导致组织、织构恶化，磁性能优化控制难度很大，制造（超）薄规格产品时尤甚。本项目提出将具有亚快速凝固和近终成形特性、显著区别于传统连铸的双辊薄带连铸技术引入（超）薄规格取向硅钢和无取向硅钢的制造流程，围绕低铁损、高磁感、薄规格硅钢制备中关键的组织、织构、磁性能控制问题开展研究，继续挖掘双辊薄带连铸在制备新型高性能硅钢品种上的优势和潜力。.阐明了基于双辊薄带连铸制备低铁损、高磁感、（超）薄规格取向硅钢板全流程的Goss织构起源与演变规律、抑制剂演变规律，揭示了二次再结晶行为与初次再结晶行为之间的依赖关系及控制机理，研究并打通了制备工艺技术路线，弄清了组织—工艺—磁性能三者的对应关系，找到了关键的工艺控制要素，并在实验室条件下成功制备出0.23mm厚的高磁感、薄规格取向硅钢原型钢，铁损P17/50为0.97~1.04 W/kg，磁感B8达到1.92~1.94 T，优于现有工业化HiB产品的磁感指标。还基于二次再结晶法成功制备出0.05~0.15mm厚的高性能超薄规格取向硅钢原型钢，磁感B8为1.72~1.84T，相当或部分优于日本NIKKIN DENJI KOGYO公司的传统三次再结晶产品。阐明了基于双辊薄带连铸制备低铁损、高磁感、（超）薄规格无取向硅钢板全流程的组织、织构演变规律及一体化控制机理，研究并打通了制备工艺技术路线，弄清了组织—工艺—磁性能三者的对应关系，找到了关键的工艺控制要素，并在实验室条件下成功制备出0.10、0.15mm厚的高性能超薄规格无取向硅钢原型钢，磁感指标可达B50=1.66~1.68T，明显优于日本NIKKIN DENJI KOGYO公司产品，高频铁损指标为P10/400=12.6~16.0 W/kg，略高于后者，低频铁损指标为P15/50=2.5-2.6 W/kg，略低于后者。.通过上述研究工作初步建立起基于双辊薄带连铸制备低铁损、高磁感、薄规格硅钢板组织性能控制的关键理论要点，为薄规格硅钢薄带连铸产业化提供了重要的基础数据和原型技术。对于丰富薄带钢连铸理论及电工钢织构控制理论具有重要的科学意义。.相关研究成果出版研究报告1部，发表（含录用）SCI收录论文16篇，获授权中国发明专利11项。