Study On Temperature Field Under Heavy Reduction Rolling Of Broade Wide AZ31 Magnesium Alloy Sheet

The light-weight demand of Aviation, aerospace, weapons and equipment, large ships and high-speed trains makes the demand of wide magnesium alloy sheet and its assembly part increase rapidly,therefore it has an important strategic significance to develop broade wide magnesium alloy sheet. Magnesium alloy strip rolling is an important direction in studying wrought magnesiun alloys.We can get products with fine homogeneous and excellent mechanical properties,if we roll the plate with relatively high temperature and heavy reduction to make magnesium alloy produce completely dynamic recrystallization, so that it has a relatively high practical significance for improving the production efficiency and reducing the production costs. And the temperature is the most important process parameter of magnesium alloy strip rolling process, which directly affects the dynamic recrystallization during the rolling process and the plastic deformation mechanisms, thus affecting the final microstructure and properties. Therefore, it is the premise of guaranteeing the rolling products’ quality to study the temperature changes and internal temperature distribution during the rolling process. In the rolling process, it is necessary to adjust and control the rolling temperature in order to obtain products with excellent properties. The purpose of this project is to study the change of temperature field under heavy reduction with experimental method and numerical simulation method.By Gleeble-3800 hot-simulated testing machine, we make the high-temperature-compression thermal-simulation experiment to get flow stress curve which can provide reliable data to support the theory analysis for the subsequent finite element software to simulate the rolling process. Besides, we make plane strain compression experiment to simulate the rolling process. Through metallographic test, we can get organization variation at different reduction rates and rolling temperature to achieve optimal forming properties of magnesium alloys.In this paper, we make dimensional model of magnesium alloy sheet to simulate heavy reduction rate rolling process at different process parameters, such as rolling temperature, reduction ratio and roll preheat temperature, etc., for which we make a preliminary study of the suitable rolling reduction rate. Then we analyze the rule of temperature field along the direction of width, study the heat transfer mechanism of magnesium alloy strip during rolling process, and establish the temperature model for optimal temperature control of magnesium alloy during hot rolling.For the phenomena of strip edge’s temperature dropping, and to improve the edge crack problem caused by temperature drop, we put forward edge-induction-heating to compensate the edge temperature, then we establish electromagnetic-thermal coupling model to analyze the change of edge temperature.