A Study on the Efficient Method of Underwater Welding Education for Commercial Diver

Abstract

Although the requirements of underwater welding has been increasing in the marine field, limited studies have been conducted on the systematic approaches for underwater welding education. The present study was conducted to provide baseline data to understand the educational underwater welding process for commercial diving candidates. For this, optimal welding parameters for underwater were configured, experimental welding dives were conducted, and weld coupons were inspected and analyzed.The results of this study can be summarized as follows respective weld passes. In the root pass, the insufficient weld deposit sizes owing to the fast weld speed were the main defects. In the second pass, non-paralleled beads and insufficient weld convexity were the main defects. In the third pass, incomplete deposit between the beads and the unplaned weld surface were the main defects. Finally, macro-etching test revealed incomplete penetration, slag inclusion, undersize of weld and unplaned weld profile.The aforementioned weld defects must be reduced for beginner welder divers, selecting welding parameters such as suitable amperage, accurate work angle, and weld speed as the main variables.