The Impact Of Hyperbaric Gas Ambient To GMAW Welding ARC Shape

Underwater hyperbaric dry GMAW welding technology is the keytechnology of the underwater equipment’s maintenance, such asshipping, ocean platform, seabed pipeline. In recent years, along withthe country’s requirement to marine resources application more andmore, its importance is also gradually emerges. Due to the hyperbaricambient effect on welding characteristics, the welding parameters aredifferent between underwater welding and atmospheric welding. To gethigh quality, high efficiency underwater welding technology parameters,the effect of hyperbaric ambient on GMAW welding arc shape needs tobe systemic researched.Base on the aid of existing underwater hyperbaric weldingexperiment cabin, this paper used high-speed camera system andAnanlysator Hannover of welding parameters, set up the experimentsystem to research hyperbaric GMAW welding arc shape.Welding experiments were carried out under atmospheric pressure,0.3MPa,0.5MPa and0.7MPa pressure. Through observation andanalysis of high-speed camera pictures and Ananlysator Hannover data, the effect of hyperbaric ambient on arc shape were discussed.The experiment results show that: with the rise of ambient pressure,The critical current of the arc from the bell shaped cone graduallybecome larger, arc length gradually became short, and arc stability alsomore and more became worse. In the same welding current condition,with the rise of ambient pressure, the width arc cathode area graduallynarrowed, arc compressed more and more serious, and arc shape turnedfrom bell jar form gradually into ellipsoid.Using finite element analysis software CFX, the finite elementmodel was established to study hyperbaric GMAW welding and researcharc behavior at different ambient pressure by numerical simulationanalysis. With increasing of the ambient pressure, GMAW welding arctemperature decreased, arc shape from bell jar form gradually becomeellipsoid, the same as the deformation law of experiment.