Study On Improving The Quality.of Secondary Wedge Rolled Pieces By Non-Uniform Temperature Field

Cross wedge rolling is a new technology for shaft parts forming and considered an integral part of advanced manufacturing technology today, which has very high production efficiency , higher utilization ratio of the material and low production cost. By the characteristics of cross wedge rolling process, the maximum reduction of cross wedge rolling can not be greater than 75%. It would be broke with the forming part in axial direction Therefore, the larger area reduction for axial parts is usually used secondary wedge rolling forming.It is to say that the same section is rolled twice in a whirl, because the complex of cross wedge rolling,it is difficult to master .So the center of workpiece would prone to loose parts (Mannesmann effect). It is concluded that the second cross wedge rolling is more prone to be loose than normal cross wedge rolling .The purpose of this paper is to weaken Mannesmann effect which in the secondary wedge rolling forming based on in-depth analysis of the research situation at home and abroad .By th method of JTS, searching the reasonable temperature to weaken Mannesmann effect in the secondary wedge rolling forming.to meet strength and life-time of rolling pieces in use.First of all, model is built by sortware and then numerical simulation analysis would be done ,at last explain that why the secondary wedge rolling more likely to be loose.Secondly, using of 2D plane strain simulation for the rolling pieces of ideal crust layer thickness and temperature.Thirdly, according to the above conclusion, make an analysis of the stress and strain in the rolling pieces internal part under the ideal non-uniform temperature field using 3D finite element numerical simulation.Finally, based on the conclusions of the ideal non-uniform temperature field, optional methods of the principal coefficients on influencing non-uniform temperature are explored by numerical simulation and water-cooled experiments.Find out the reasonable non-uniform temperature to weaken Mannesmann effect which in the secondary wedge rolling forming, improve quality of the core part of. rolling pieces.