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Finite Element Simulation of Multi-Pass Reversing Hot Rolling for High Temperature Alloy

Author: ZhouJia
Tutor: CuiZhenShan
School: Shanghai Jiaotong University
Course: Materials Processing Engineering
Keywords: multi-pass reversing hot rolling elasto-plastic finite element simulation thermo-mechanical coupled rolling
CLC: TG331
Type: Master's thesis
Year: 2009
Downloads: 251
Quote: 3
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Abstract

GH4169 is a Ni-Fe-Cr based high temperature alloy. It has been used in industries like aviation, energy and chemical engineering. Plate hot rolling is a highly nonlinear elasto-plastic large deformation process, which is quite difficult to be modeled by analytical models. With the development of computational science, finite element method has been widely used to simulate the rolling process. But most of these studies are based on 2D models where the variables in width direction can not be considered. Some 3D simulations were also carried out in past years; however, the studies mainly focus on single pass simulation while simulations on multi-pass hot rolling are rarely to be reported. Besides that, in most reported works the rolls were treated as rigid bodies, by which the elastic roll deformation resulted by the roll-bending force, rolling force and temperature variation can not be considered, but it is critical important to the plate quality. The high temperature alloy usually shows great resistance to deformation so that the elastic deformation of the roll has to be considered when investigating the plate profile. The main contents and results of this paper are as follows:In this paper, MSC.Marc is employed to establish a large deformation elasto-plastic thermo-mechanical coupled FE model for simulating the multi-pass reversing hot rolling. In the model, an equivalent elastic roll is developed. The model can be adopted to continuously simulate the whole process without manual operation. The difference in temperature between the head and tail part of the rolled piece is investigated in the model. The research shows that by using quasi-static solution method the results are much better than using dynamic transient method. The multi-pass hot rolling of GH4169 alloy plate was simulated and the results showed that the model obtained satisfactory precision. Through simulation, the variations of deformation, temperature, plate profile as well as rolling force are studied. This demonstrated that the model can be used to study plate profile undertaken multi-pass hot rolling.In hot rolling, strip temperature, rolling force and deformation are three key parameters which affect the quality of the finished products. To explore the impact of those parameters on rolling process, this paper uses the 3D FE model which individually changes the reduction, initial temperature, rolling speed, contact heat transfer coefficient and heat convection coefficient to analysis the influence on the rolling process. It can help to improve and optimize the rolling process.

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