Numerical Simulation And Process Research On Axial Thermal Expansion Of 25Mn Cast Ring

With ring parts are widely used in industrial manufacturing such as superior quality machine tool industry, defense manufacturing, aerospace industry, etc, the demand of medium and large rings of different requirements and different varieties are growing daily. The primary purposes of manufacturing industry research are how to reduce production costs, improve the production quality and production efficiency, reduce resource consumption and pollution emissions.This topic is funded by Key National Natural Science Foundation of(51135007), the National Natural Science Foundation(51205270), priority to the development of institutions of higher learning doctoral fund plan(20111415130001). This topic focus on the research of increasing the quality of "shape" and "integrity" of casting process of the ring rolling.How to make the production of the ring parts high efficiency, high quality, low energy consumption and low pollution is studied in detail.Taking the as-cast 25 Mn as ring material, radial-axial thermal rolling forming process of rectangular flange ring is simulated by use of simufact.forming software platform. The diameter of formed flange ring is 1556 mm, and the inner diameter of formed flange ring is 1325.5mm. The high of formed flange ring is 106 mm. First of all, theory of hot rolling for radial axial ring production is researched. Numerical simulation of finite element model for cast ring radial-axial hot rolling is established. Secondly, effects of different process parameters on the shape quality and forming process of the cast ring radial-axial rolling are researched. At the same time, two different velocity control methods is taken to analyze it's influence on microstruture of the forming ring. Compared with the results under different control methods, ring diameter growth control of feed speed is better than that of radial-axial feeding control rolling process. Finally, focused on the determination method of the ring blank size, blanks with different high thick ratio and different rolling ratio is analyzed. The optimum blank design method is suitable for billet casting ring. Experimental test is carried out according to the simulation results. Test results are in accord with the simulation results. Mechanical properties of the forming ring can meet the design and operational requirementsAll the results show that the equivalent plastic strain field, the distribution of equivalent stress field and temperature field are uneven for as-cast 25 Mn ring billet in the process of hot rolling. Distribution of these field can improve by optimizing the radial-axial feed rate control scheme and change design method of the ring, which will improve the forming quality of flange microstructure. All the research results can provide a theoretical basis for rolling parameters optimization and industrial production of large flange cast-rolling compound forming process.