Emulation Analysis On Temperature Field & Stress Field Of The Close Hot Forging Die For Front Wheel Hub Of Car

The working condition of hot forging die is very bad, its service life is very low generally. The cost of the pieces and the economic efficiency of the manufactory were affected directly. The impact forging holds the dominant position in the forging profession. There is a bigger disparity between average service life of hot forging die of our country and the international advanced level. Therefore, how to enhance the service life of hot forging die and how to reduce cost of the pieces are the problems in this industry to be solved urgently.In this paper, regard DEF0RM-2D program as tool, and the closed hot forging die for front wheel hub of car as prototype, we simulate the temperature field and stress field of hot forging die which made of H13, we get the stress field and temperature field when forging die work in succession. We define temperature field when die works in thermal balance as temperature field of working in succession. The heat absorbed in one working cycle equals to heat that die distribute to the environment in the same cycle when forging die works under thermal balance. We get the fluctuating boundary of temperature through tracing the temperature change of points on the line which normal to constant temperature lines, then divide the forging die into fluctuating and gradient area of temperature. In the fluctuating area, the closer to impression surface, the greater temperature gradient is, the max reaches 86.4℃/mm. The maximal efficient stress of the danger point on impression surface reaches to 1870MPa, and reduce to 1750MPa when die under thermal balance state. The real working course proves that the fluctuating area which takes only a little part of die is the main district of damage of hot forging die.Through observing the temperature change of points on impression surface, we find that the stayed time has the most significant influence on temperature field, so we simulate the work course of hot forging die in different stayed time and find that: The longer the stayed time is, the faster the rising of temperature is, it will need less working circles to reach thermal balance. At the same time, the temperature field in working succession is higher. As the forging working going on, we should minimize the stayed time in order to avoid the temperature of die reaching too high.Finally, based on the design thought of multilayer metal hot forging die, we create its simulating model by setting the material of temperature fluctuating area to multilayer metal coating, then simulate its temperature field and stress field. Through contrasting, we find that, multilayer metal forging die can reduce the temperature of impression surface and the efficient stress of forging die, which can achieve the aim of improving the service life of hot forging die.In this paper, we simulate the whole working process about close hot forging die of front wheel hub of car, then divide the temperature area, based on which we simulate the temperature field and stress field of multilayer metal hot forging die. All this work can provide a basis to design the functionally gradient materials (FGM). We believe it will help improving service life of hot forging die a lot.