管道全位置焊接方法和缺陷控制研究综述OA

With growing requirements in energy transmission safety,all-position pipeline welding—capable of accommodating various welding postures and stably controlling the molten pool—has become crucial for ensuring weld quality.During all-position welding,the changing welding postures and the significant influence of gravity on the molten pool often cause typical defects,such as lack of root penetration,root concavity,and incomplete sidewall fusion.This paper summarizes the main pipeline welding methods,including Tungsten Inert Gas(TIG)welding,gas metal arc welding(GMAW),and high-energy beam welding.Major control methods from domestic and international research are reviewed:firstly,process methods based on optimization of current/voltage waveforms and heat source parameters,which significantly improve root penetration;secondly,passive and active control methods employing physical and electromagnetic support,which effectively suppress root concavity and burn-through;thirdly,rotating-arc and weaving-arc techniques based on arc motion control,which effectively eliminate incomplete-sidewall-fusion defects.Future prospects for improving the quality and efficiency of intelligent and automated pipeline welding are also discussed.