Some Key Technologies And Multilayer Metal Die In Hot Forging Process

Hot Forging Die is an important processing equipment in Forging industry. It will bear cyclical thermal load and mechanical load during the hot forging process. The service life of hot forging die is short because of its adverse working environment. So, it is important to increase the die service life. In this paper, the final forging process of wheel is simulated, using the software DEF0RM-2D . In order to reveal the working state of hot forging die and find an effective method to prolong the die service life, some key problem affecting the die service life were studied . The contents are as follows :1,The study of Temperature distribution and Tempering Behavior of hot forging die . Temperature is the main factor affecting the die's tempering behavior .The phenomenon of thermal soften will appear when the temperature of die increased ,and it will cause the hardness decrease. The tempering coefficient P determine the hardness . The violent wear lead to die scrap if the tempering coefficient P decrease to some value . The influence of the effective tempering temperature and the effective tempering time on die service life was obtained . Reducing the contact time between workpiece and dies is an efficient approach to improvement of hot forging die service life.2,The analysis of hot forging die wear. The wear of hot forging die was obtained , and the violent wear appear at the mould cavity comer . The wear was determined by interface pressure, sliding velocity, hardness etc . The effective method about improving service life is enhancing the hardness of die . The service life can be predicted by the wear depth. The adequate cooling of hot forging die after each process can improve the service life .3,The preform optimization . The preform shape of workpiece confine the metal flow and control the deformation and affect the microstructure performance . In this paper , the preform optimization is simulated , using the software DEF0RM-2D . The optimization of preform shape can get through reverse operation based on FEM . The optimization preform shape checked by forward operation and the results show that the variation of effective strain trend to uniform , the forming force and the effective stress are decreased.4,The study of multilayer metal die . hi this paper multilayer metal coating was made based on the thought of multilayer metal die design .The Xrd analysis about cladding was detected. The result shows that the cladding can improve the hardness of die .The model of multilayer metal die was built successfully and the analysis was obtained .The comparison of physical field between homogeneous hot forging die and multilayer metal hot forging die was obtained. The temperature peak and the effective stress was decreased. Multilayer metal hot forging die was proved feasible through theoretically and practically .All research provide a reference to the multilayer metal and a basis for the applications of FGM.