Research On Surface Defcets Of Shaft Parts Formed By Cross Wedge Rolling

The technology of cross wedge rolling began in the 20th century 60's, as a shaft forming processing technology compared with the traditional process of forging or cutting material It has utilization to high, forming good quality, higher tool life advantages. The cross wedge rolling process overcome some difficulties in the development of the forging method of processing methods to encountered, and widen the field of forging production. Currently at home and abroad, the cross wedge rolling process has become the main axis machining methods. But as an advanced manufacturing process. Cross wedge rolling technology also has its ainevitble flaws and shortcomings. For example, need special equipment, rolling and restrictions on large-diameter pieces.With the low carbon economy and the technology of near net shape proposaled, energy section of material in the manufacturing sector increasingly high demand Ruhetigao forming quality, to avoid the defect effects on improving material utilization rate will be wedge rolling process of the main topics and trends.Cross wedge rolling process of technological development around the rolling forming precision and quality have done more research and achieved many results, the practical application of cross wedge rolling basis. But with the wide range of cross wedge rolling technology application and promotion, more and more product by cross wedge rolling plays an important part in the machinery industry, so the application wedge rolling technology to produce higher and higher precision parts, and defects problem has seriously hindered the development of this technology, especially the rolling surface defects restricts the quality and performance, the defects production of cross wedge rolling in the deformation include surface defects and internal defects. On the cross wedge rolling defects in materials and fracture of the internal and foreign scholars have made a lot of work, and draw many important conclusions, the analysis of their formation mechanism is also more thorough and well-established views, but with the recent net shape technology to the progressive development,and improvement of research and the elimination of cross wedge rolling. the surface defects become increasingly more necessary.The topic for the main basis for forging technology and wedge rolling technology, a number of surface defects on summarize, prediction analysis of its causes. As the wedge rolling process is a complex three-dimensional plastic deformation process, the deformation mechanism is very complicated, so the study also limited the defect mechanism of internal defects on the surface defects of the research system is not perfect, with the rapid development of computer technology and the emergence of large-scale simulation software, the technology of numerical simulation in the plastic forming rapidly and used widely, many countries will present numerical simulation method is applied to the field of cross wedge rolling process, despite our nation in the field of cross wedge rolling with a high level,But many respects are relying on actual production experience in the processing. Finite element simulation technology in the field of cross wedge rolling, still in its infancy, relatively narrow scope of the study, using the finite element method to simulate the deformation process can be rolled throughout the deformation process in all aspects of information, It can reveal defects mechanism to reduce production costs and improve material utilization, precision products contribute to the production process and quality assurance.This paper will also using the numerical simulation method, adopting the more sophisticated simulation software DEFORM-3D three-dimensional software for detailed analysis, as DEFORM-3D modeling software itself does not have the function of establish model, at first by three-dimensional modeling software CATIA-V5 establish two die geometry which plate mold and roll mold , as the friction factor has a crucial role in the rolling , it affects the success or failure of the simulation directly, so must use of simulation software to simulate the ring upsetting test method to determine the friction coefficient and friction state. After the adjustment of different process parameters on the whole rolled wedge rolling process simulation. Simulation process is completed, using DEFORM-3D software, after the data processor of information, get rolling in the axial and longitudinal stress, velocity distribution changes, etc., compared to rolling roll in the plate and two rolling under way stress distribution. Analysis of process parameters under different conditions on the rolling capacity of the shoulder injury, used to study the formation mechanism of surface defects and propose solutions. In the simulation, to simulate the actual production of surface defects may occur in species, such as slipping, falling, ends concave heart defects, convex edge, this paper main researched the defect type rolling shoulder defects produce a convex edge. The analysis of the detailed simulation of the causes and the defect mechanism, and via roll and plate comparison of two different rolling conditions , At the same time analysing the rform surface of mold to optimize the design, use of approach of pit deformation friction. forming a more perfect effect, so as to avoid the convex edge defects. This paper also discussed the development of cross wedge rolling process in the wide-angleβ, forming angleαandΦsection reduction rate of the rolling surface, studied the amount of damage to arrive at process parameters on the rolling surface defects. Finally, by the actual cross wedge rolling machine rolling in the laboratory, using different methods and process parameters of friction, the numerical simulation results were verify the feasibility, through analysis of defects in the actual production of other factors, compared experiments and numerical simulation results, getting some relevant conclusions.