Study On The Influence Mechanism Of Emulsion On The Temperature Of Cold Rolling Work Roll And The Rolling Interface

With the rapid development of basic manufacturing and high-tech,the requirements for cold rolled products are also increasing.Emulsion mainly plays a cooling and lubricating role in the cold rolling process.This paper establishes a mathematical model for cold rolling,deduces the heat flowing into the work roll,and establishes a simulation model for the cold rolling process.The influence of emulsion on the temperature and thermal crown of the work roll is studied,providing a basis for predicting and controlling the changes in thermal crown of the work roll during the cold rolling process.At the same time,a restricted shear lubrication model was established to study the lubrication behavior of cold rolling interface emulsion from the molecular level,providing a basis for studying the lubrication mechanism of emulsion in the cold rolling deformation zone.Firstly,a mathematical model of cold rolling heat flux was established,and the friction heat and deformation heat of the rolled piece during the cold rolling process were derived.Furthermore,the heat flux flowing into the work roll was further derived.The results indicate that the heat flux density is relatively high in the middle and gradually weakens towards both sides.Due to the severe lateral flow of metal at the edges,there will be a slight increase.Secondly,an Abaqus work roll model and a Fluent emulsion spray model were established for the cold rolling process.A joint simulation of Abaqus and Fluent was conducted using Mp CCI to analyze the effect of emulsion on the temperature and thermal crown of the work roll.The results show that the cooling effect of the emulsion is best when the spraying distance is controlled within 140 mm,the spraying speed is 25 m/s,and the spraying angle is 170 °.Moreover,a decrease in emulsion viscosity will reduce the cooling effect and ability of the emulsion.Finally,based on molecular dynamics research methods,a restricted shear model for the cold rolling deformation zone was established,and the lubrication behavior of the emulsion in the cold rolling deformation zone was analyzed and calculated.The dynamic concentration classical lubrication model was explained at the molecular level.The results indicate that increasing the limiting shear rate is beneficial for improving the compressive strength of the emulsion film,reducing the friction coefficient,and reducing the viscosity of the emulsion film.The increase in temperature will reduce the degree of solidification of the film,reduce the friction coefficient and viscosity.An increase in water content will facilitate the uniform distribution of the emulsion,while also reducing the friction coefficient of the film to a certain extent;Increasing the thickness of the emulsion film will reduce friction.