Study On Modeling And Rolling Force Prediction Model For Hot Rough Rolling Of 5052 Aluminum Alloy

The process of hot rolling is related to a lot of physical parameters, such as pressure, velocity, flux, temperature etc.It's also related to a lot of complex processes, such as elastic and plastic deformation, heat-force coupling process, microstructure and performance transformation of strip.By point of view in control, rolling process of metal possessed typical characteristic of multivariable, nonlinear and strong coupling.With the development of rolling technology, mathematical models played a important role in reducing energy and enhancing quality of products. So it was necessary to establish mathematical models which matched the actual results.Under the background of the process of hot rough rolling of aluminum strip in one factory and many references including foreign and Chinese, mathematical models of temperature, deformation resistance and rolling force were studied.Firstly, based on heat transfer theories, the main factors which caused the changes of temperature of the rolled piece and rollers during the hot rough rolling process were analysed, and making a brief introduction of the temperature change, and its analytic methods in the rolling process was made. Meanwhile, according to the characteristics of hot rough rolling and heat transfer theories, factors which influenced material temperature such as the influence of heat radiation, thermal conductivity by roll contact and plastic deformation on temperature variation were evaluated. Then the calculating model of temperature was established. It predicted material temperature change of each pass due to deformation, friction, roll contact and heat exchange accurately. It was guided by the calculation of the mathematical model of deformation resistance later.Secondly, the hot compression deformation tests of 5052 aluminum alloy at elevated temperature were performed on Gleeble-1500 system, with the deformation temperature ranged from 300℃to 500℃and strain rates from 0.01 s-1 to 20 s-1. Constitutive analysis suggestes that the peak stress can be represented by a Zener-Hollomon parameter in the hyperbolic-sine-type equation, and then the mathematical model of deformation resistance .Thirdly, preset of rolling force was very important in modern computer controlled hot rough roll production and it was the kernel of computer preset models. On the basis of classic rolling theories, rolling force model of aluminum alloys in hot rough roll was investigated.Factors which influenced rolling force including radius of elastic flattened roll, stress stat coefficient and average yield stress(deformation resistance)were evaluated in order to establish the model. The comparison between calculations and measured values of the rolling force indicated that the rolling force model has good precision of prediction with an error between 5%~7%. The results showed that the optimization models were feasible and available.Meanwhile, all program compiled by means of MATLAB in this paper would help us use these models perfectly.