液氮冷却润滑条件下冷轧带钢实验研究
发布时间：2018-10-08 08:01
【摘要】：工艺冷却和润滑是冷轧技术的核心之一,在传统的冷轧工艺中,一般采用乳化液进行润滑和冷却,针对传统乳化液和纯油轧制存在的问题和不足,本文提出一种利用液氮来代替乳化液进行冷却和润滑的新型技术方案,有望解决传统冷轧过程中存在的乳化液污染,循环系统维护困难以及带材表面质量难以控制的问题。本研究就是针对液氮冷却和润滑给冷轧润滑理论和冷却系统设计等带来的一系列新问题而提出的,通过该研究,不但可以弄清液氮在冷轧过程中的冷却和润滑机制,为液氮的控制与合理利用提供科学依据,而且有望建立新的冷轧冷却润滑系统,为新一代轧制冷却和润滑技术的开发提供了新思路。论文主要工作和研究结果如下： (1)通过对液氮喷射过程的理论分析和计算,以液氮稳定膜态沸腾理论为基础,提出了理论换热系数计算模型,分析了单一变量对液氮喷射换热系数的影响,在此基础上进行了液氮喷射冷却轧辊实验研究,通过理论分析,给出了各个实验参数对换热系数的影响,最后通过数学方法回归出了各参数与换热系数的模型公式,为液氮应用冷轧轧辊温度场的计算奠定了基础。 (2)液氮应用冷轧条件下,其强冷性会对轧材和轧辊的性能产生影响,因此对轧辊材质和带材的低温特性进行了实验研究,分别对其进行了低温压痕硬度测试、拉伸和冲击试验,带材在-20℃时冲击功明显下降,随着冷却温度的下降,轧材和轧辊的硬度、强度都有所提高。 (3)液氮冷却润滑可明显降低带钢表面残油和残铁含量,提高冷轧后带钢表面清洁性；液氮冷却润滑下冷轧带钢获得了比传统方式更低的带钢温度和轧辊温度；利用Hill轧制力反算了轧制过程中的摩擦系数,得出液氮冷轧过程的摩擦系数,确定液氮冷却润滑下润滑状态为边界润滑。 (4)对液氮在平整轧制过程中的应用可行性进行了实验研究,结果表明,液氮在大延伸率和小延伸率平整过程中都表现出了很好的延伸率和轧制力控制稳定性,液氮的应用还提高了轧辊对带钢的遗传复制率,获得了更好的轧后带钢表面粗糙度,延长轧辊的使用周期。
[Abstract]:Process cooling and lubrication are the core of cold rolling technology. In the traditional cold rolling process, emulsion is generally used to lubricate and cool, aiming at the problems and shortcomings of traditional emulsion and pure oil rolling. In this paper, a new technical scheme of cooling and lubricating with liquid nitrogen instead of emulsion is proposed, which is expected to solve the problems of emulsion contamination in traditional cold rolling process, difficult maintenance of circulating system and difficult control of strip surface quality. This study is aimed at a series of new problems brought by liquid nitrogen cooling and lubrication to cold rolling lubrication theory and cooling system design. Through this study, not only the cooling and lubrication mechanism of liquid nitrogen in cold rolling process can be clarified. It provides a scientific basis for the control and rational utilization of liquid nitrogen, and it is expected to establish a new cold rolling cooling lubrication system, which provides a new idea for the development of a new generation of rolling cooling and lubrication technology. The main work and results are as follows: (1) based on the theoretical analysis and calculation of liquid nitrogen injection process, a theoretical model of heat transfer coefficient is proposed based on the theory of liquid nitrogen stable film boiling. The influence of a single variable on the heat transfer coefficient of liquid nitrogen injection is analyzed. Based on this, the experimental study of liquid nitrogen spray cooling roller is carried out. The influence of each experimental parameter on the heat transfer coefficient is given through theoretical analysis. Finally, the model formulas of each parameter and heat transfer coefficient are regressed by mathematical method, which lays a foundation for the calculation of temperature field of cold rolling roll with liquid nitrogen. (2) under the condition of cold rolling with liquid nitrogen, its strong chilling property will affect the properties of rolling material and roll. Therefore, the low temperature properties of roll material and strip are studied experimentally, and the hardness of indentation at low temperature, tensile test and impact test are carried out respectively. The impact energy of strip decreased obviously at -20 鈩，
本文编号：2256025
[Abstract]:Process cooling and lubrication are the core of cold rolling technology. In the traditional cold rolling process, emulsion is generally used to lubricate and cool, aiming at the problems and shortcomings of traditional emulsion and pure oil rolling. In this paper, a new technical scheme of cooling and lubricating with liquid nitrogen instead of emulsion is proposed, which is expected to solve the problems of emulsion contamination in traditional cold rolling process, difficult maintenance of circulating system and difficult control of strip surface quality. This study is aimed at a series of new problems brought by liquid nitrogen cooling and lubrication to cold rolling lubrication theory and cooling system design. Through this study, not only the cooling and lubrication mechanism of liquid nitrogen in cold rolling process can be clarified. It provides a scientific basis for the control and rational utilization of liquid nitrogen, and it is expected to establish a new cold rolling cooling lubrication system, which provides a new idea for the development of a new generation of rolling cooling and lubrication technology. The main work and results are as follows: (1) based on the theoretical analysis and calculation of liquid nitrogen injection process, a theoretical model of heat transfer coefficient is proposed based on the theory of liquid nitrogen stable film boiling. The influence of a single variable on the heat transfer coefficient of liquid nitrogen injection is analyzed. Based on this, the experimental study of liquid nitrogen spray cooling roller is carried out. The influence of each experimental parameter on the heat transfer coefficient is given through theoretical analysis. Finally, the model formulas of each parameter and heat transfer coefficient are regressed by mathematical method, which lays a foundation for the calculation of temperature field of cold rolling roll with liquid nitrogen. (2) under the condition of cold rolling with liquid nitrogen, its strong chilling property will affect the properties of rolling material and roll. Therefore, the low temperature properties of roll material and strip are studied experimentally, and the hardness of indentation at low temperature, tensile test and impact test are carried out respectively. The impact energy of strip decreased obviously at -20 鈩，
本文编号：2256025
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