Research on GTAW Arc Behavior under High Pressure

Underwater hyperbaric welding is firstly used by the offshore industry. It is welding under extreme condition. Arc is much influenced by water depth or ambient pressure. But arc behavior greatly influence quality of joints. nfluence of ambient pressure on arc behavior (geometry, stability, voltage, current density, temperature and efficiency) is investigated. Experiment is carried out in chamber. The results show that arc voltage is increased with the ambient pressure, and current density is increased with the ambient pressure, arc brightness is increased, but arc temperature is decreased. Suggestions for the research on arc are put forward.