Numerical Simulation On Open-Die Forging Of Gear Blanks

Open-die forging is a forging process that the billets was pressed to produce plastic deformation in the mold cavity with a flash gutter, and the billets form scheduled non-defective products at certain temperature. Open-die forging is a important method in part blank production, and has been widely used in the machinery, ships, automobiles and other industries.In order to make metal fill in blank cavity completely, in particularly in sharp corner and high-gluten. Its role is to prevent the flow of streams and to promote filling of metal into mold cavity, which relies mainly on frictional resistance of flash gutter when forging.Open-die forging must be designed with flash gutter and determining flash gutter height h, flash gutter width b, fillet radius R, friction factor m and the wedge a. Select appropriate parameters and forms of flash gutter have an important influence not only on forging filling, but on die life, material flow as well as the utilization of metal.In this paper, first, gear blanks of a gear plant in Shaanxi Province were used as the research object, forging process of gear blanks and die design was based on these model. Second, According to the rigid-plastic finite element method, filled situation, deformation force, temperature and the amount of stress-strain distribution of the field during the forging deformation is obtained by rigid-plastic finite element method, and the production of defects during forging process was also analyzed by the finite element numerical simulation. Through finite element simulation analysis, the paper studies a number of key factors such as:the amount of reductionΔH when upsetting, initial forging temperature and the friction conditions impact on the forging process,and then optimizes and obtains the process of qualified forging and die parameters. by numerical simulation, the paper respectively, studies the amount of reduction when upsetting and depressed intial forging temperature impact on gear blanks forming process, the amount of reduction obtainedΔH= 117.5mm, whenΔH=117.5mm, a smaller deformation force is needed to help improve the die life during the gear blanks forming process, while forging in order to avoid over-burning, the aintial forging temperature of 1000℃ is recommended in order to obtain good quality forgings.In addition, forms and parameters of flash gutter play a very important role on cavity-filled situations and requirements for deformation force. In order to study forms and parameters of flash gutter impact on forging process, the common flash gutter and flash gutter with wedge-shaped are studied by using orthogonal test method, The key factors of flash gutters are concluded by research on two kinds of flash gutters effect on the deformation force and filling of gear blanks deformation process. Optimization program on forms and size parameters of flash gutters is proposed by analysis of stimulation results of forming.By numerical simulation, the paper respectively, studies the amount of reduction when upsetting and depressed intial forging temperature impact on gear blanks forming process, the amount of reduction obtainedΔH=117.5mm, whenΔH=117.5mm, a smaller deformation force is needed to help improve the die life during the gear blanks forming process, while forging in order to avoid over-burning, the aintial forging temperature of 1000℃is recommended in order to obtain good quality forgings.the paper studies parameters of the common flash gutter and the flash gutter with wedge-shaped effect on the deformation of gear blanks by analysis of the orthogonal test. its laws is:height h of common flash gutter of the most significant impact on deformation force F, followed by width b of the common flash gutter. recommend height h values of the common flash gutter between the 2.5-3.5mm, radius r between the values between the 1.5mm-2.5mm.Tail height H of the flash gutter with wedge-shaped of the most significant impact on deformation force F, followed by the wedge angle a, recommend values of tail height H values between 1.5-2.0mm, radius R between1.5mm-2.0mm.Select deformation force of the best combination of size from 16 tests, the common flash gutter:b= 12mm, h= 3.5mm, r=2.0mm, and flash gutter with wedge-shaped:a= 9°, b= 8mm, H= 2mm, R= 2.0mm, the common deformation force by using flash gutter is larger than that by using flash gutter with wedge-shaped, while the filling by using the latter is better than the former.Conclusion obtained from analysis of stimulation results has a guiding role in the production of forging gear blanks.