水基纳米轧制液制备及润滑模型研究

发布时间：2018-02-16 08:01

本文关键词： 轧制液制备纳米添加剂润滑模型　出处：《北京科技大学》2015年博士论文　论文类型：学位论文

【摘要】：板带钢轧制生产向着连续化、自动化、高效率、节能环保的方向发展,使轧制工艺润滑技术得到了前所未有的重视和应用。随着全球范围内能源危机和环境污染日趋严峻,对钢铁行业也提出了实行节能减排、清洁生产的要求。油基轧制润滑剂在使用过程中存在着操作环境恶劣、易腐败变质、油泥难处理等诸多问题,而且难以满足日渐苛刻的生产条件,因此水基轧制液受到越来越多的关注。水基轧制液的快速发展表现出优良的冷却性、清洗性、经济性和安全性等诸多优点,然而也存在着润滑性能不足、防锈性能差等问题。为了解决油基轧制润滑剂及水基轧制液存在的上述问题,需要对新型轧制润滑剂及轧制润滑理论进行深入的研究。随着纳米润滑技术的提出及发展为解决油基润滑剂存在的问题和水基轧制液的缺点提供了新的思路。本文采用物理分散和化学分散相结合的方法实现了纳米TiO2在水基体系中的稳定分散,同时添加了其他水溶性的功能添加剂,按照一定工艺流程制备了适用于热轧及冷轧的全新水基纳米轧制液。通过摩擦学性能、润湿性能及黏度、轧制润滑性能、轧后表面质量等方面对所制备的水基纳米轧制液进行了系统的综合研究,为解决油基润滑剂存在的问题提供了技术途径和条件,对促进轧制润滑技术和纳米轧制液的发展具有十分重要的意义。通过对全新水基纳米轧制液摩擦学性能、摩擦磨损性能研究表明,添加纳米TiO2明显提高水基轧制液承载能力、降低摩擦系数和磨斑直径,摩擦副磨损表面得到显著改善。热轧及冷轧润滑试验表明,使用水基纳米轧制液能够有效降低轧制力,改善轧后表面质量；同时,纳米TiO2的添加提高了水基轧制液的缓蚀性能,冷轧板带钢退火清净性优于乳化液。通过Gleeble热压缩实验表明纳米TiO2具有优异的热分解稳定性和高温润滑性能。根据理论计算分析及热重实验结果进一步表明纳米TiO2在轧制过程中以固体颗粒状态发挥润滑作用。通过热轧润滑实验及对板带钢热轧轧后表面EDS分析,提出了水基纳米轧制液热轧流/固二相协同润滑物理模型。纳米TiO2不仅能够提高水基轧制液承载能力,还能够填充到热轧板表面裂纹中,修复表面缺陷,同时减少氧化铁皮与轧辊的直接接触,改善热轧板带钢轧后表面质量。明确了冷轧水基纳米轧制液润滑处于混合润滑状态,考虑固体纳米TiO2及轧件表面等效粗糙度夹带建立了水基纳米轧制液入口区润滑膜厚度模型,计算分析了纳米Ti02浓度、表面粗糙度对入口润滑膜厚度影响。综合考虑纳米粒子的添加及轧件表面微凸体变形建立了冷轧变形区混合润滑模型,研究了水基纳米轧制液黏度、表面粗糙度特征、压下率等参数对变形区润滑膜压力、接触面积比和膜厚比的影响。
[Abstract]:With the development of continuous, automatic, high efficiency, energy saving and environmental protection in strip rolling production, the lubrication technology of rolling process has been paid more and more attention to and applied. With the global energy crisis and environmental pollution becoming more and more serious, The requirements of energy saving and clean production for iron and steel industry are also put forward. There are many problems in the process of using oil based rolling lubricant, such as poor operating environment, easy corruption and deterioration, difficult to deal with oil sludge, etc. And it is difficult to meet the increasingly harsh production conditions, so more and more attention has been paid to water-based rolling fluid. The rapid development of water-based rolling fluid shows many advantages, such as excellent cooling, cleaning, economy and safety, etc. However, there are some problems such as poor lubricity and poor antirust performance. In order to solve the above problems of oil-base rolling lubricant and water-based rolling fluid, it is necessary to deeply study the new rolling lubricant and rolling lubrication theory. With the development of nano-lubricating technology, a new way of thinking is provided to solve the problems existing in oil-based lubricant and the shortcomings of water-based rolling fluid. In this paper, the method of combining physical dispersion with chemical dispersion is used to realize nanometer TiO2. Stable dispersion in water-based systems, At the same time, other water-soluble functional additives were added to prepare new water-based nano-rolling fluid suitable for hot rolling and cold rolling according to certain technological process. Through tribological properties, wetting properties and viscosity, rolling lubricity, The surface quality after rolling was studied systematically and synthetically, which provided the technical way and condition for solving the problem of oil based lubricant. It is of great significance to promote the development of rolling lubrication technology and nanometer rolling fluid. The tribological properties and friction and wear properties of the new water-based nano-rolling fluids were studied. The results showed that the loading capacity of water-based rolling fluids was obviously improved, and the friction coefficient and wear spot diameter were decreased by adding nanometer TiO2. The results of hot rolling and cold rolling lubrication tests show that the application of water-based nano-rolling fluid can effectively reduce the rolling force and improve the surface quality after rolling, and at the same time, the addition of nanometer TiO2 can improve the corrosion inhibition performance of water-based rolling fluid. The annealing cleanliness of cold rolled strip is superior to that of emulsion. The results of Gleeble thermal compression test show that nano TiO2 has excellent thermal decomposition stability and high temperature lubricity. The theoretical calculation and thermogravimetric analysis further show that nano TiO2 is produced in the state of solid particles during rolling process. Lubricating effect. Through hot rolling lubrication experiment and EDS analysis of the surface of strip after hot rolling, A physical model of hot rolling fluid / solid two-phase synergistic lubrication for water-based nanocrystalline rolling fluid is presented. Nano TiO2 can not only improve the bearing capacity of water-based rolling fluid, but also be filled into the surface crack of hot rolled plate to repair the surface defects. At the same time, the direct contact between the oxide sheet and the roll is reduced, and the surface quality of hot rolled strip is improved. In this paper, the lubrication of cold rolling water based nanometer rolling fluid is in mixed lubrication state. Considering solid nanometer TiO2 and equivalent roughness entrainment of workpiece surface, the thickness model of lubricating film in inlet region of water based nano rolling fluid is established, and the concentration of nano Ti02 is calculated and analyzed. The influence of surface roughness on the thickness of inlet lubricating film was studied. Considering the addition of nano-particles and deformation of micro-protrusions on the surface of workpiece, a mixed lubrication model of cold rolling deformation zone was established, and the viscosity and surface roughness characteristics of water-based nano-rolling fluid were studied. The influence of reduction rate and other parameters on the lubrication film pressure, contact area ratio and film thickness ratio in deformation zone.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG331;TB383.1

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