Research On Temperature Field And Stress Field Of Induction Welding Heat Treatment Of Metal Pipe

Natural gas pipelines have been in service for a long time in complex terrains such as frozen soil areas and Gobi.The huge temperature changes have caused non-negligible deformations of the pipes,and even fractured welded joints.Therefore,the field of gas transportation puts forward higher requirements on the quality of pipe joints.At present,most factories heat the welded parts of pipes through centralized induction heating.This method often causes excessive temperature differences in the wall thickness of the pipe welds,and large temperature differences will affect the quality of the welds.In this paper,the double-heat source induction heating heat treatment method is used to inductively heat the welded part of the welded pipe.It aims to reveal the influence of the complex influencing factors in the induction heating on the weld performance,reduce the temperature difference of the pipe wall thickness and improve the welding quality.The main content of this article includes:Based on ANSYS finite element software,the numerical model of pipe girth welding is established,involving electric-magnetic-thermal-force multi-field coupling,and the temperature distribution of pipe girth welding induction heating is analyzed.On this basis,the extrusion welding of metal pipes was realized using DEFORM software,and finally the pipe heat treatment was carried out in ANSYS finite element software,a coupling model was established and the influence of centralized induction heating on the temperature of the metal pipe wall thickness was analyzed.In order to effectively reduce the temperature difference in the wall thickness direction of the welded seam of the metal pipe,the double heat source method is used for induction heating of the metal pipe,and the process of heating,cooling and reheating is adopted to obtain the temperature field distribution of the heat-affected zone of the welded pipe and the weld.,And deeply explored the distribution of temperature field and stress field inside the pipe weld.The effect of geometric parameters(the distance between two coils,the distance between the coil and the metal pipe,and the heating angle)and electrical parameters(current density and frequency)on the temperature of the weld and the heat-affected zone during the induction heating process of the pipe dual-heat source method is explored.And the stress field after induction heat treatment of the metal pipe with dual heat sources is also simulated and analyzed.Perform experimental analysis on the heat treatment numerical model of pipe welding and dual heat sources,and use the results of temperature measurement experiments to verify the accuracy of the temperature field simulation results of the pipe dual heat source heating;use the blind hole method to check the stress field simulation of the pipe dual heat source induction heating The accuracy of the results.