Numerical Simulation And Experimental Study On The Forming Process Of Large Diameter High Grade Steel Pipe Fittings

It is an important development trends to pressurization of large diameter high grade steel piping in the construction of long distance oil and natural gas transportation piping. This project is mainly applied for numerical simulation of finite element and experimental study on the forming process of large diameter high grade steel fittings of the second line of E-W Piping Line which is a key project in China. The study object of this paper isΦ508mm andΦ1219mm equal diameter tee with X80 piping steel. The forming process of equal diameter tee is systematically studied by means of DEF0RM-3D software. The main research work is as follows:1. Flow stress-strain is determined on X80 piping steel under different temperature and strain rate and necessary date is provided for the foundation of material model of numerical simulation.2. FEM Simulation is applied to the forming process ofΦ508mm equal diameter tee. Fitting forming is studied for different process parameters and mold parameters condition. Based on the results of numerical simulation, reasonable forming process and parameters are obtained.3. Forming process ofΦ508mm equal diameter tee is verified by experiment. It is indicated that the result of numerical simulation is similar to experiment.4. FEM Simulation is applied to the analysis of the forming process ofΦ1219mm equal diameter tee. The forming technology for the production of large diameter high grade steel fittings is put forward.The project development period is reduced due to the research work described in this paper, mold cost is saved and research cost is reduced. The research result is of theoretical significance and guiding roles in some extent for other series of fitting products.