Process Optimization About Thin-wall Ring Forging Of Manganese Brass Based On Microstructure Behaviors

As a core part in practical industrial manufacture, thin-wall forgings play an essential role in the field of mechanical transmission. It often been processed by precision forging technique owing to the complexity of shape. While defects like underfilling, fold and cracks frequently occur in the product that perplex scientists and engineers. In the past decades, a great many work were been done by researchers focusing on eliminating these defects. However, the microstructure behaviors of forging material under high temperatures, which also have an effect on the hot precision forging process. Based on previous reports, this paper takes the case of one typical thin-wall forging to investigate several practical issues such as the effects of thermal deformation and dynamic recrystallization on hot forming process. In order to attain optimum process parameters, analysis from the perspective of grain distribution and the level of recrystallization is also performed. The main jobs are listed as follow:①Study on forming technology of the thin-wall forging. The special structure of the forging were analyzed. Various kinds of problems were detected in the simulating process of close-tolerance forging of the thin-wall forging by DEFORM-3D and practical industry, which prepared for the next steps.②Study on hot deformation behavior and processing map of the thin-wall forging. Isothermal compression experiments of manganese brass which the amount of compression is 60%.were performed by thermal physical simulation testing machine under the condition that the strain rate are 0.01s-1、0.1s-1、1s-1、10s-1 and the deformation temperature are 650oC、700oC、750oC、800oC. Kinetic analysis of such hot deformation process were conducted. Then, the reasonable range of the process of manganese brass was attained by the processing map.③Study on recrystallization behavior of the thin-wall forging. Based on the data of physical compression experiments, critical condition of recrystallization was obtained during hot deformation process. The kinetics of recrystallization, dynamic model and average grain sizes model were also constructed. These works are prepared for the nextstep: microstructure simulation in DEFORM-3D.④Study on process parameters optimization of the thin-wall forging. Aiming at optimizing the average grain size and the fraction of dynamic recrystallization, response surface method was adopted to investigate the rule of forgings’ optimization, which is subjected to several different groups of parameters like the initial deformation temperature, the rate of top die and friction factor. Then, the optimized process parameters of the thin-wall forging relate to manganese brass were obtained.All these works mentioned above afford a reliable reference for thin-wall forgings made from manganese brass. Hence, it provides a credible theory for practical manufacture.