Simulation And Experimental Study On Wear Characteristics And Mechanism Of The Powder Forging Die

Powder metallurgy is a non-cutting manufacturing process, it has the advantages of saving raw materials, saving time and saving energy sources, correspondingly highlighting the economic benefits. Hot powder forging (P/F) refers to place the preform sintering after heating in a closed die forging into parts of the process, it is a kind of less or no cutting near net shape processing technology. Hot forging technology of powder process is complex, the wear forms of mould is between the powder sintered material and dense die steel, it is a hot (temperature)-force (friction) and chemical medium (lubricant) multivariate nonlinear dynamics under the mutual coupling, the die life is short and production costs are too high. So that research the wear characteristics and die wear mechanism of mold in the process of P/F is very important to find the methods to slow down the die wear.This paper chooses H13steel used in the experiment, by optimizing heat treatment process, design and manufacture of moulds, set up the experimental apparatus. Forging the same initial density pre-forging stock to different product densities of three groups in powder hot forging experiments, Study the wear characteristics of the mold with forging change of density. Experimental results show that the amount of die wear increases as the size of the forging are increased density, the wear of mandrel slightly serious than female die, the wear of die unevenly along the axial direction, the maximum amount of wear is upper die. Microstructure analyses of experimental die anatomical and conclude that sintered powder billet forging process in the presence of typical abrasive wear between the die and.The existence of a more serious mold surface oxidation wear phenomena simultaneously. The product of oxidation wear is Fe2O3and Fe3O4, the wear process of powder hot forging die is oxidation and spalling alternating dynamic balance process.Finite element simulation is more commonly used in analyzing the numerical field of engineering technology, this paper establishes the three-dimensional model of powder hot forging, according to the results of powder hot forging die wear and experiment and with the help of the finite element software DEFORM-3D to the hot powder forging process are studied by numerical simulation, the generalized Backstepping calculated Archard wear theory for wear powder heat coefficient K forging, the value of wear coefficient is1.272e-6. The above research improve the Archard wear theory. Based on the simulation analysis of die wear, the simulation results show that:the amount of die wear increased with increasing forging density, the mold closer to the upper end of the more serious wear above relative density at92%or more.Finally, this paper chooses to wear effect of forging way, forging temperature and forging speed as the parameters of the simulation optimization, trying to find not only can ensure the forgings (size, density uniformity) but also can make the die wear minimal optimal forging method and forging process of combination, aimed at solve the problem die life of high density of powder hot forging is short. The optimization results show that the best way for both sides:forging blank and die and the mandrel are left to take sides of flow gap, recommended forging temperature1050to1100℃and forging speed is200-300mm/s.