Head Face Throat Defect Of Round Billet Large Forgings During Stretching Process

Large forgings is mainly applies to the national economic construction, nationaldefense industry construction and the large equipment and devices of the key parts of themodern science. With the rapid development of economy in China, various industriesequipment is more and more larger. Which requires the weight and size of the largeforgings is more and more bigger and the quality is more and more higher. In theproduction of large forgings, free forging is the only forging method, and stretching step isthe most important and commonly basic process of the free forging. There are manydefects in the stretching process, such as non-metallic inclusion, internal cavities defect,surface crack, folding and head face throat. Domestic and foreign scholars always standfirm on how to improve the quality of large forgings by carrying on a long-term andin-depth research, and achieved gratifying results. But, few people has done deep researchin view of head face throat defect. In this paper, researching the head face throat defect isbased on present production has theoretical significance and practical application value.In this paper, according to the head face throat in the actual production of company.Firstly, study and discuss the reason of metal occurred plastic deformation from the theory.Secondly, according to the actual production process and the DEFORM-3D finite element,then display the process of the head face throat defect. Compared with the simulationresult and real defect, we can find there shape and size are complete similarity. Thirdly,further analysis the reason of the head face throat defect. Then we can find the basic causeis that the parameters of the stretching process are not appropriate. And put forward to theselection principles and the value range of decreasing the head face throat defect, andforming a new scheme. On this basis, using DEFORM-3D software simulation theforming process of the head face throat defect in the siping anvil stretching step.According to the simulation results, analysis the forgings quality form internal stress andstrain state. Finally, measured the value of the head face throat and matched curves withthe numbers. Then we can select the best parameter combination direct, convenient andaccurate according to the curves. In this paper, simulation process to close to the actualproduction, in the spirit of seeking truth from facts, and strive to combine theory and practice.