冷轧润滑过程中的轧制界面热效应研究

Study of Surface Thermal Effects in the Process of Cold Rolling with Lubrication

通常对冷轧过程的润滑进行分析时,不考虑热效应。但实际生产和实践中发现,当速度较大或者轧制变形量比较大时界面热效应不可忽略。采用综合考虑冷轧润滑过程中轧件表面热量的产生和传导关系,推导出轧件以及润滑膜的温升计算模型,并通过二辊轧制纯铝板的实验来进行验证和说明。结果表明:冷轧润滑过程中,轧件的温升随着轧制速度和压下率的增大而增大,压下率对轧件温升的影响大于轧制速度的影响;对轧件温升起主要作用的是塑性变形热,在轧制变形区内轧件的温度随着变形的增大而增大,并且在最大变形处附近轧件的温度达到最大;润滑膜的温升主要受到轧件表面温升的影响,润滑膜温度随着轧制压下率的增大而升高,当轧制压下率和轧制速度较小时,润滑膜的温度变化不是很明显。

The thermal effects are often neglected in the process of cold rolling with lubrication.However,in the actual practice of rolling process,when the rolling speed or the rolling deformation is huge enough,thermal effects can not be ignored.The relations between heat generation and conduction were considered comprehensively during cold rolling with lubrication.The thermal models for work piece and lubricant film were set up.The calculation data of the thermal models were verified with experimental data in the rolling process of pure aluminum sheets.The results show that temperature of rolling sheets rises when the reduction rate and rolling speed increase,while the effect of reduction ratio is greater than that of rolling speed.The main reason for temperature rising is the hot plastic deformation.Temperature increases with the increasing of rolling deformation and gets to its peak near the maximum deformation point.Temperature of lubricating film is mainly influenced by rolling surface temperature and it increases with the increasing of rolling deformation.When the rolling deformation and the rolling speed are relatively small,the temperature change of lubricating film is not very obvious.