شبيه سازي اجزاي محدود فرايند جوشكاري زيرپودري لوله هاي API 5L - X70 با درز جوش مستقيم مورد استفاده در صنايع نفت و گاز

FE Simulation of Submerged Arc Welding of API 5L·X70 Straight Seam Oil and Gas Pipes

[II this paper, all uncoupled thermo-mechunical nonlinear FE analysis of submerged arc welding process f or straight seum large diameter oil and gas pipes to determine residual stresses is presented. Tile analysis starts with thermal PQ/1 where, bi-ettiptical Goldak equation is used f or applying heat input distribution. Af terward, a certain code checks the elements one by one in order to determine the metallurgical phase transformations during cooling p rocess based on cooling time fr om 800·C 10 500°C (lSI5)ʹ Theil the associated mechanical properties ofeach element is cotcutated and assigned to the corresponding element to execute the stress analysis phas e. A good agreement is observed between simulation results und experimental results obtained from metallography and hole drilling test me/hod. [11 addition /0 the results related to the special case studied in this research, undertaking severe nonlinearit ies due to phase transf ormati on of the API X70-5L material and defining the equivalent material properties during phase transfo rmation are of lire new aspects of this research..