连铸保护渣液/固非均匀润滑及瞬态摩擦机制研究

Mold flux is the interaction link between shell and mold, and also the transmission bridge for heat transfer and lubrication functions. Scientifically comprehending about the distribution and evolution of mold flux has a significant effect on quality control for initial solidified shell. Based on the research of inverse lubrication/friction problem and experimental measurements of transient friction, this project is supposed to explore the non-uniformity of liquid/solid lubrication, and investigate the inherence relationship between non-uniformity friction and thermo physical properties of mold flux. Furthermore, considering the dynamic behavior of mold oscillation and lubrication, the inverse model coupled flow and friction behavior of mold flux is going to be built. Through separating the components of liquid and solid friction from total measured friction, the periodical change of flux flow, channel pressure and liquid / solid friction are to be inversely deduced, and the action mechanism of mold oscillation on the liquid/solid transient friction is also studied. Finally, the research conclusions of inverse calculation and experimental measurements will be integrated to disclose the dominant elements over lubrication and surface cracks. In view of the multiple actions of non-uniformity and periodical friction, this project is to explore the typical characters, critical conditions and general rules during formation of surface cracks. The results will further enhance comprehension of complex friction behavior, and establish experimental and theoretical foundation for lubrication regulation of mold flux.

保护渣是坯壳和结晶器交互作用的纽带，也是传递导热、润滑等功能的桥梁，揭示保护渣液/固摩擦的分布、演化与控制规律，对于初生坯壳的质量调控极为关键。本项目拟在润滑/摩擦反问题和瞬态摩擦力实证研究的基础上，系统探索液/固渣膜润滑与摩擦的非均匀特征，研究其与保护渣理化性能间的内在关联和影响规律。进一步考虑结晶器振动与渣膜润滑的动态行为，构建保护渣流动/摩擦反问题数值模型，借助从实测摩擦力中提取的液/固摩擦分量，逆推并反演渣膜运动、渣道动态压力和液/固摩擦的周期变化，探讨结晶器振动对液/固摩擦瞬态演化的影响与作用机制。通过整合反问题解析与瞬态摩擦实证研究结论，厘清支配润滑与诱发裂纹的主要因素，探索非均匀与周期摩擦双重作用下，表面裂纹形成的典型特征、极限条件和一般规律。研究结论可望深化对保护渣液/固摩擦行为的理解和认识，为其性能调控提供实验基础和理论依据。

本项目基于现场建立的结晶器温度、热流、摩擦力在线检测系统，围绕连铸结晶器保护渣的流动/消耗及渣膜的传热/润滑/摩擦，通过联合现场实证、数值计算、定量研究与机理解析等多个环节，重点研究了液/固渣膜与润滑/摩擦行为的真实分布状态，探讨了保护渣理化性能对液/固摩擦的影响和作用机制。系统考察了液态、固态渣膜与气隙的厚度分布，以及渣膜润滑和摩擦的非均匀特征，研究其与保护渣理化性能间的内在联系和影响规律；在此基础上，通过整合反问题解析与瞬态摩擦实证研究结论，探讨了结晶器振动对保护渣流动及消耗的周期性影响，研究渣膜运动随振动工艺、正/负滑脱参数的变化规律，为进一步揭示液/固瞬态润滑/摩擦行为与结晶器周期振动、保护渣理化性能间的有机联系，奠定了理论基础和实验依据。本项目的各项研究内容均按原计划顺利推进，按期圆满完成。.本项目研究主要包括以下几部分关键内容：.1）.基于反问题的结晶器内钢液流动-传热-凝固耦合计算；.2）.板坯结晶器铜板全尺寸建模及应力/变形数值仿真；.3）.保护渣液/固渣膜、气隙分布反问题及其非均匀性；.4）.液/固渣膜、气隙传导/辐射热阻模型开发与机理探讨；.5）.结晶器振动作用下的液渣周期性流动行为建模与分析；.6）.保护渣消耗及润滑/摩擦行为数值计算及影响因素研究；.执行过程中，严格按照项目计划书按步骤、分年度、有层次地开展研究，目前上述研究工作已全部完成，研究结果的整理和总结已经完成，学术论文的整理和进一步发表尚在进行中。截止到2019年1月，本项目研究已发表学术期刊论文14篇，其中，SCI刊源文章11篇，EI刊源12篇。本项研究获授权发明专利2项，授权软件著作权5项，并有4项发明专利正在申请。.项目研究结果为考察保护渣复杂的传热和摩擦行为，进一步认识结晶器周期振动作用下的瞬态摩擦、液渣流动及保护渣消耗，提供了理论基础和实验依据。圆满完成项目预定的各项内容和研究目标。