Underwater wet welding made simple: benefits of Hammerhead~® wet-spot welding process

摘要

A new method of wet welding was investigated to evaluate potential improvements in weld quality, ease of use, increased welding speed and the elimination of welding skill. The new welding process, which has been called Hammerhead 'wet-spot' welding, eliminates the need for skilled welder-divers as well as traditional cleaning and preparation techniques normally associated with conventional manual metal arc (MMA) wet welding. In addition, the process also allows welding to be conducted in nil visibility, yet remains a MMA process, using a specially designed Fe-Cr-Ni-Mo electrode.rnThe process utilises a control device, which must be pre-set before the diver enters the water. Through this device, weld parameters are controlled and quality is maintained, thus the role of the diver is simplified to three steps: make contact with the material, strike the arc and maintain pressure to the electrode while welding.rnA series of spot welds were produced both wet and dry on 8.0mm carbon steel plates. The welds were evaluated with regard to ease of use and setting up of the device, speed and final weld quality. Initially, the performance of the process was assessed and usage diagrams produced. Work regarding an automated version of the system has also been proposed.