Underwater Electric Welding Fixation Inspection Technology Research and Application

Abstract: Submerged electric welding fixing inspection engineering is a key technology in the field of marine engineering, involving complex underwater operational environments and high safety risks. This article discusses underwater welding methods, technical challenges, fixture design, inspection methods, and safety regulations, exploring the current technological progress and its application in engineering practices, providing reference for related projects.

I. Overview of Underwater Electric Welding Technology

Underwater electric welding is mainly divided into three types: wet welding, dry welding, and local dry welding. Each type has its own characteristics:

Wet Welding: Welding directly in water, cost-effective and widely applicable, but the quality of the welds is susceptible to the cooling rate and relatively unsafe.

2. Dry Welding: Isolated from the water environment by a gas chamber, offering high weld quality and safety; however, the equipment is complex and has limited depth applicability.

3. Local Dry Welding: A combination of wet and dry welding benefits, utilizing a local drainage system to create a dry environment, currently in the research phase.

Section 2: Technical Challenges and Solutions for Underwater Welding Fixation Inspection

Welding Quality Assurance

● Question: Utilizing welding rods, in conjunction with pre-weld heating and post-weld保温 measures, to reduce weld seam content.

Poor visibility: Introduce underwater camera systems and robotic assisted positioning, combined with real-time ultrasonic imaging technology to monitor weld bead formation.

Stress Concentration Control: Designed with flexible connection bases, optimized through finite element analysis to disperse welding stress.

2. Fixed Installation Design and Inspection

● Fixed Installation Requirements:

○ Water Jet Resistance: Made with high-strength materials, combined with hydraulic or mechanical clamping structures.

Corrosion Resistance: Selected titanium alloys or coated protection to extend underwater service life.

Rapid installation: Modular design for easy disassembly, reducing underwater operation time.

● Testing Methods:

Non-Destructive Testing (NDT): Ultrasonic Testing (UT), Magnetic Particle Testing (MT), Radiographic Testing (RT), etc., for evaluating weld defects.

Underwater Robot Inspection: Equipped with a multi-sensor system for weld seam appearance inspection and stress testing.

Section 3: Safety Standards and Technological Innovation

1. Core security measures

● Electric shock prevention: Use DC power, insulate welding machine and diving suit, and set up an automatic power-off device.

● Fire and explosion proof: Remove flammable materials prior to operation, use inert gas protection, and monitor underwater gas concentrations in real time.

● Emergency Response: Equipped with backup gas supply systems and communication devices, and formulated an underwater escape plan.

2. Technological Breakthroughs Since 2024

● Laser Welding Technology: Submerged high-energy laser welding achieves high efficiency and low heat input, significantly improving welding quality.

● Intelligent Monitoring System: Drones + AI algorithms analyze welding parameters in real-time, predicting weld seam defects and safety hazards.

● Robotic Welding: Underwater welding robots equipped with force feedback control systems, suitable for complex seabed terrains.

Four: Engineering Practice Cases

In the repair project of a marine platform, wet welding is used to fix underwater pipelines, with the following measures ensuring the quality of the project:

Employ flexible connection bases to dissipate stress and prevent crack propagation.

2. Perform ultrasonic and magnetic particle inspections within 24 hours after welding to ensure a 100% pass rate for welds.

3. Introduce underwater robots for periodic inspections of fixed installations, monitoring bolt loosening and corrosion conditions.

V. Conclusion and Outlook

Underwater electric welding fixing inspection projects are evolving towards intelligence and automation. In the future, it is necessary to further break through the technical bottlenecks of welding under deep-sea high-pressure conditions, develop new anti-corrosive materials, and improve the online monitoring system for underwater welding quality to promote a comprehensive enhancement of safety and efficiency in marine engineering.