| The T-tee is one of the most important element of the pipe connections in power plant.The forming technology of T-tee from abroad last century has been relatively backward.Especially in recent years,the ultra-supercritical technology has become the major technical developmental direction of thermal power generation.With the continuous boiler upgraded,there are many changes with the size,structure,thickness of the T-tee designed.Utilizing conventional forming technology of T-tee will cause the more quality problems,lower efficiency as well as higher cost.Multi-ram extrusion forging is an advanced precision forging technology not only with the deeply application of aviation,aerospace,military and the other industries,but also suitable for forming technology of T-tee in the ultra-supercritical boiler.Due to the large size,rigorous requirements of equipment,etc.,Multi-ram extrusion forging technology has not been widely used in the boiler manufacturing industry.In this paper,by means of finite element numerical simulation and experimental verification,multi-ram extrusion forging technology has been applied to forming technology of T-tee in the ultra-supercritical boiler.By means of numerical simulation,we obtain a multi-step way of multi-ram extrusion forging process.According to the simulation results,we analyze the changes with time of velocity field,equivalent stress field and loading force under the metal plastic forming process.According to results of the study,loading ways and loading mold structure are optimized.The forging process is verified by experiment in coordination with the forging operation and the general hydraulic machine.The experimental results verify the feasibility and validity of the method,which can be applied in forming technology of T-tee in the ultra-supercritical boiler.It breaks through the limitation that the traditional method can't produce highly branched tee.It will be the future direction of the forming technology of the T-tee. |
PDF Full Text Request