锡、铌协同增强低温Hi-B钢抑制剂效果并促进高斯织构形成和稳定的机理解析

AlN is the main inhibitor used in low slab reheating temperature Hi-B grain-oriented silicon steels and the energy consumption is relatively high in the production process. The controllable content range of acid soluble aluminum in the steels is limited and easy to oxidize, which isn't easy to control accurately. The instability of the secondary recrystallisation of the steels restricts the improvement and stability of magnetic properties of the products which is caused by maldistribution of inhibitors originated from nitriding no uniformly and the decomposition of AlN. A new technology will be proposed for producing high quality low slab reheating temperature Hi-B grain-oriented silicon steels with Nb and Sn synergistically added to strengthen the effect of the inhibitor, which will solve the above problems. Sn and Nb content in the steels will be optimally designed. The effect of Sn and Nb on dissolution, precipitation behavior of inhibitors and texture evolution of the steel during hot working processes is studied by static experiments and in-situ observation with high temperature laser scanning confocal microscope, combined with advanced characterization methods for precipitates and steel texture. And synchrotron radiation technique is used to acquire dynamic data of the secondary recrystallisation of the steels and then the data will be analyzed, where mechanism of strengthening inhibitors effect and facilitating Goss texture to form and stabilize synergistically by tin and niobium is clarified. The research results will provide a novel technical access to develop energy conservation, environmental protection and high quality low slab reheating temperature Hi-B grain-oriented silicon steels by utilizing the synergistic effect of inhibitors by controlling the secondary recrystallisation of the steels rationally, and a reference for deciding the matched heat treatment technologic system is also proposed.

低温Hi-B取向硅钢以AlN为主抑制剂，生产能耗偏高，酸溶铝调控范围窄且易氧化，不易精确控制。渗氮不均和AlN分解引起的抑制剂分布不均导致的二次再结晶不稳定制约着产品磁性能的提高和稳定。本项目提出一种采用Sn、Nb协同添加增强抑制剂效果制备低温、高品质Hi-B钢的新工艺，可望解决上述问题。项目将优化设计Sn和Nb的协同加入量，采用静态实验、高温激光共焦显微镜在线观察，结合先进的析出物及织构表征手段，系统研究Sn、Nb含量对热加工全流程中抑制剂析出行为和硅钢织构变化的影响。并采用同步辐射技术获取钢样二次再结晶过程的动态数据加以解析，阐明Sn、Nb增强钢中抑制剂的效果并促进高斯织构形成和稳定的协同作用机理。项目成果可为利用抑制剂的协同作用通过调控织构开发工业化节能、环保、高品质低温Hi-B钢提供新的技术途径，并为制定与抑制剂成分配套的热加工工艺制度提供参考。

低温Hi-B取向硅钢以AlN为主抑制剂，生产能耗偏高，酸溶铝调控范围窄且易氧化，不易精确控制。且渗氮不均和AlN分解引起的抑制剂分布不均导致产品磁性能差且不稳定。本项目将Nb和Sn协同加入钢中，制备了0.0050~0.0300%Als、0~0.100%Nb、0~0.100%Sn不同含量匹配的低温Hi-B钢。系统研究了不同含量Als、Nb、Sn组合加入后，对再加热铸坯、热轧、常化、脱碳、渗氮、高温退火后试样中抑制剂的固溶、析出行为和钢的组织结构演变的影响规律。掌握了Nb、Sn影响AlN析出行为、促进高斯织构形成和稳定的协同作用机理。提出了保证抑制剂有效析出，促进高斯织构发展和稳定的Sn、Nb含量控制水平及其配套的热加工工艺参数控制标准。控制钢中含0.028~0.051% Nb、0.015%~0.028%Als，辅以合适的退火工艺制度，试样的磁性能可以达到1.8T以上，从而具备简化常化或渗氮工艺的潜力。推荐热轧开轧温度为1000℃，终轧温度为940 ℃，模拟卷取温度为570℃。推荐采用1140 ºC×50s +900~930 ºC×100s二段式常化退火工艺。推荐脱碳工艺制度为840℃×180s。发明了一种添加微量Nb制备低温、低成本取向硅钢的方法。Nb的优选控制范围为0.005~0.026%，Sn的控制范围为0~0.100%。解决了现有低温钢初次再结晶长大难以控制、或添加辅助抑制剂元素时工艺复杂及成本增加的问题，可降低铸坯再加热温度6~77℃。对低Nb试样，根据钢中Nb和Als含量控制铸坯再加热温度和脱碳退火时间。根据脱碳退火后初次再结晶尺寸，控制在高温退火阶段进行相应温度区间的缓升温区。采用优选成分和工艺制备的产品可达到1.88T的高磁感的水平。项目研究结果为利用抑制剂的协同作用和合理控制钢的二次再结晶过程开发工业化节能、环保、高品质低温Hi-B钢提供了新的技术途径和参考方法。