Abstract
Underwater wet arc welding as a repair method in offshore and harbor steel structures is a process that will be used more frequently in the future to cope with the increasing number of installations in water. Due to the wet environment, one challenge is the risk of hydrogen-induced cracking, which jeopardizes component safety and occurs as a result of diffusible hydrogen in the weld metal.
In order to identify the sources of hydrogen and model absorption scenarios, it is also necessary to probe the hydrogen content in various areas during the welding process. Thus, the aim of this investigation was the detection of hydrogen in the arc to shed light on the relevant hydrogen sources during underwater wet welding.
Using time-resolved optical emission measurements during the entire welding process, the intensity of individual emission lines during the welding process were analyzed and atomic hydrogen was detected in the arc plasma during underwater wet welding.
A high-speed camera equipped with special double-image optics was used to take simultaneous images of the arc plasma in the process zone. In this way, the uniform distribution of atomic hydrogen in the arc plasma could be described.