Underwater Laser Welding/Cladding for High-performance Repair of Marine Metal Materials: A Review

Abstract

With the rapid developments of marine resource exploitation, mounts of marine engineering equipment are settled on the ocean. When it is not possible to move the damaged equipment into a dry dock, welding operations must be performed in underwater environments. The underwater laser welding/cladding technique is a promising and advanced technique which could be widely applied to the maintenance of the damaged equipment. The present review paper aims to present a critical analysis and engineering overview of the underwater laser welding/cladding technique. First, we elaborated recent advances and key issues of drainage nozzles all over the world. Next, we presented the underwater laser processing and microstructural-mechanical behavior of repaired marine materials. Then, the newly developed powder-feeding based and wire-feeding based underwater laser direct metal deposition techniques were reviewed. The differences between the convection, conduction, and the metallurgical kinetics in the melt pools during underwater laser direct metal deposition and in-air laser direct metal deposition were illustrated. After that, several challenges that need to be overcame to achieve the full potential of the underwater laser welding/cladding technique are proposed. Finally, suggestions for future directions to aid the development of underwater laser welding/cladding technology and underwater metallurgical theory are provided. The present review will not only enrich the knowledge in the underwater repair technology, but also provide important guidance for the potential applications of the technology on the marine engineering.

Laser cladding and applications

“…The underwater laser welding/coating method is a progressive method for the maintenance of damaged equipment. In a recent article [55], an examination and engineering outline of the underwater laser welding/coating method is aimed. Foremost, the latest developments and important problems in drainage nozzles all over the world are examined in detail.…”

Influence of Butter Layer Thickness on Microstructure and Mechanical Properties of Underwater Wet 16Mn/304L Dissimilar Welded Joint

“…The underwater local dry welding procedure was highly appealing, due to its ability to achieve high-quality weld and keep costs controlled. Underwater laser welding [2], metal inert gas welding (MIG) [3], and tungsten inert gas welding (TIG) [4] were widely studied alongside local dry welding technologies. In terms of weld quality and cost, the underwater local TIG welding process is the most advantageous option.…”

Laser metal deposition repair of stainless steel 316L parts

“…In the offshore environment, laser welding techniques with water drainage heads allow for underwater repairs without the need to remove the component from the water. The deposition quality is excellent and the technique is less dangerous to the welder than an electric arc process [22].…”

“…As illustrated in Figure 1. 22, they show that by obtaining a finer grain substructure, the number of nucleation sites of the passive oxide layer can be increased, resulting in a thicker passive layer that is more resistant to corrosion. The comparison between standard stainless steel and LMD stainless steel is subjective because it depends on the quality of each steel.…”

“…Then, a reference distance is chosen to select the points of the corresponding ellipsoid, which allows to have the intersection points, as observed in Figure 4. 22. The lower surface is the surface of the ellipsoid below the upper surface given by Equation 4.…”