FEM Simulation And Research Of The Radial Forging Process Of P91 Thick-walled Seamless Steel Pipe

Thick-walled seamless steel pipes whose service conditions are heavy and complex are used mainly in the trades like electric industry,chemical industry and heavy machinery.Thus,improving the quality of thick-walled seamless steel pipes to ensure the safety and reliability during the operation of which is of crucial importance to the improvement of the technology of thick-walled seamless steel pipe and national economy.In order to produce thick-walled seamless steel pipe via radial forging to meet the need of market we combine the advantages of P91(10Cr9MolVNb)and the advantages of radial forging.Meanwhile,we use the numerical modeling software called Qform to make the simulation experiment of radial forging of thick-walled seamless steel pipe made from P91(10Cr9MolVNb)and choose a preferred plan from two stimulations of radial forging.During the simulation of radial forging,according to the process requirements,we only change the feed of the workpiece and the rotation angle to set all the other parameters as constant value to confirm the best process program.The feeds of the first radial forging are 22.2mm,50mm,100mm,150mm,200mm separately and the rotation angles of the workpieces should be 15°,20°,25°,30°,35°,40°.Set the number of strike of every simulation process as 44 times.Looking through the temperature field,effective strain,flow stress,load-time curve graph and the surface quality of the forge piece exported from Qform,combined with the efficiency of radial forging,we set the optimum technology parameter as follows.The feed should be 100mm and the rotation angles should be four quantitative value ranging from 25° to 40°.According to the conclusions drew from conditions above,when the feed is 100mm and the rotation angle is 35°,the metal flow of the forge piece metal can be much more of uniformity and better mechanical property and few defects of surface quality can be found,being favourable to the property of forge piece in all directions.By means of numerical simulation of whole course,theoretical analysis,combined with experimental verification,the experiment remarkably improve the quality,utilization of material and production efficiency of radial forging workpiece,shortening the development period of new product,to reduce the cost of production strengthening the market competitiveness of the products.In the meantime,the experiment provides the theoretical basis and the practical significance for the large-scale seamless steel pipe of our country in the future.