基于白云鄂博稀土及铌多金属共生矿取向硅钢热轧带的物理冶金行为

The project aims to study the theoretical problems of the long-term impact of the structure and performance of the high value added steel materials based on the residual rare earth and niobium in Bayan 0bo. Around the key scientific problems oriented silicon steel production process is proposed based on Bayan Obo rare earth and Nb multi-metal Ore Fe-Si alloy hot rolled physical metallurgical behavior of research technical route and experimental research method.Utilization Key Laboratory of integrate Exploitation of Bayan Obo Multi-metal Resources,IMUST, thermodynamics and kinetics materials, component design phase diagram were starting to prepare Fe-3.1% Si , Rare Earth and Niobium on equiaxed and columnar grains influence of slab solidification microstructure, Rare Earth and Niobium on oriented silicon steel in the hot rolling process to produce recrystallization, Transformation, texture evolution of rules and mechanisms of behavior. To study the influence of the slab heating process, hot rolling and cooling process on the solid solution and precipitation of the inhibitor.The effect and mechanism of rare earth and niobium on the solid solution and precipitation of the inhibitor slab heating, hot rolling, cooling and coiling process are studied. Proposed research slab heating technology , the technology of hot rolling and hot strip cooling inhibitor solution and precipitation on the law. Grasp the influence of rare earth and solution and precipitation of the inhibitors behavior oriented silicon steel slabs are heated and hot rolling process, It uncover the role of niobium and rare earth-oriented silicon steel slab heating and hot rolling process behavior of physical metallurgy the mechanism for the development of low cost and high performance oriented silicon species provide theoretical support.

基于白云鄂博矿高附加值钢铁材料残留稀土及铌对组织和性能影响长期困扰的理论难题，围绕取向硅钢生产过程中的关键科学问题，提出“基于白云鄂博稀土及铌多金属共生矿取向硅钢热轧带的物理冶金行为”研究的技术路线和实验研究方法。依托内蒙古自治区白云鄂博矿多金属资源综合利用重点实验室，从材料热力学和动力学、相图出发进行成分设计，制备Fe-3.1%Si合金，研究稀土及铌对板坯凝固组织等轴晶及柱状晶的影响规律；研究稀土及铌对取向硅钢热轧过程再结晶、相变、织构演变的影响规律；研究板坯加热工艺、热轧和冷却工艺对抑制剂固溶和析出的影响规律；研究稀土及铌对板坯加热、热轧、冷却和卷取过程抑制剂固溶和析出的影响规律和作用机理。掌握稀土及铌对取向硅钢板坯加热和热轧过程中抑制剂固溶和析出行为的影响规律，揭示稀土及铌对取向硅钢板坯加热和热轧过程中的物理冶金行为的作用机理，为开发低成本及高性能取向硅钢种提供理论支持。

基于白云鄂博矿高附加值钢铁材料残留稀土及铌对组织和性能影响长期困扰的理论难题，围绕基于白云鄂博稀土及铌多金属伴共生矿，取向硅钢生产中的关键科学问题，完成了“稀土及铌对取向硅钢铸态组织及夹杂物影响、稀土及铌对热轧加热过程抑制剂等第二相回溶的影响、热轧过程再结晶、相变、抑制剂的溶析行为”等关键科学问题的研究工作。研究表明:稀土元素Ce的加入没有改变取向硅钢铸锭夹杂物的种类，导致尺寸较大的夹杂物相对增加；铸坯中稀土检测量小于30ppm，稀土均以稀土硫氧化物形式存在，未检测到固溶稀土；残量稀土及铌较高（稀土大于20ppm,铌大于5ppm）,存在形成大尺寸球状含稀土及铌包裹的硫氧化物风险；铸坯在1250℃以上均热时间超过70分钟后，稀土对第二相回溶的影响可以忽略；掌握了稀土对取向硅钢铸坯夹杂物形成和铸坯加热第二相回溶的影响规律和作用机理。稀土对取向硅钢高温铁素体动态再结晶行为没有影响，对静态再结晶影响与对动态再结晶相比较为明显，稀土、变形量及保温时间三者交互作用促进再结晶发生明显；高温变形后，抑制剂析出与再结晶几乎同时发生，变形基体发生部分再结晶后消耗了大量的变形亚结构，导致抑制的析出通道减少，析出相随保温时间增加缓慢；随稀土含量增加硫化亚铜析出降低，对硫化锰和含铝析出相几乎没有影响。在铁素体加奥氏体两相区高温大压下变形，稀土有促进获得细小抑制剂的作用，使得精轧后析出相尺寸略有减少和面密度略有增加；基于白云鄂博矿生产含铜取向硅钢，应考虑稀土对硫化亚铜抑制剂形成量、分布及尺寸的影响，建议硫含量的控制取中上限。本项目的研究成果为基于白云鄂博矿残量稀及铌土含铜取向硅钢成分设计、板坯加热及变形工艺制定，实现取向硅钢热轧带组织及抑制剂类型、尺寸及分布的精准控制，提供了理论和实验依据，研究成果已在实际生产中获得应用。