3D Numerical Analysis And Experimental Research On The Temperature Field Of High-frequency Resistance Welding Process Of Longitudinal Seam Welded Pipe

At present,with the development of oil and gas resources to the deep sea and alpine regions,the working environment of welded pipe is becoming worse.In order to avoid significant losses,the quality of the weld must be continuously increased to produce high performance,high value-added products to meet the increasingly stringent quality requirements of the welded pipe industry.The welding quality of the weld determines the quality of the pipe,and the heating temperature is an important factor affecting the quality of the weld.Based on the study of high frequency welding process and electromagnetic heating principle of Longitudinal Welded Pipe,ANSYS software was used to simulate the electromagnetic heating process of high frequency contact pipe.The research work mainly includes:(1)Based on ANSYS software,Aiming at the problem of three-dimensional coupling simulation of the motion field,electromagnetic field and temperature field during the welding process,the geometric model is established for the electromagnetic heating process of high frequency contact pipe,and the element selection,meshing and physical environment are created according to the "Node load movement" method.The three-dimensional numerical calculation of the temperature field of the high-frequency contact welding process of the straight Longitudinal Welded Pipe was carried out by using the physical environment method and the APDL language.The distribution of the temperature field at the weld of the whole pipe was obtained.The distribution characteristics of the temperature field of the tube and the cross section of the tube are analyzed.(2)In this paper,the temperature difference between the surface of the tube and the "hourglass" is calculated and compared with the temperature difference between the wall thickness and the wall thickness of the pipe wall.Measure the quality of welding standards,pointing out that thick-walled welded pipe welding process with better quality welding.(3)The effects of different electrical parameters and geometric parameters on heating quality and heating rate were studied by ANSYS software.The variation of temperature field under different parameters was obtained.(4)In order to verify the results of the computer simulation of the temperature field,the metallographic test was made at the production site and the metallographic experiment and the microhardness experiment were carried out.The thermal simulation experiment of N80 steel was carried out by Gleeble-3 800 thermal simulator according to the thermal cycling curve in the simulation process.The metallographic experiment and microhardness experiment were carried out.By comparing the metallographic of metallographic samples and thermal simulations,the accuracy of the "hourglass" temperature field of high frequency welding is verified by computer simulation.