High-Powered Laser Welding in Shipbuilding

Laser welding is well established in industries such as automotive, aerospace, and electronics, where it is valued for its precision, low heat input, and high productivity. In recent years, it has also begun to enter the shipbuilding sector, driven largely by the need to improve efficiency and address ongoing skilled labor gaps.

Shipbuilding, however, presents a different environment. It involves thick materials, large structures, and often stricter regulatory requirements. These factors slow down the adoption of new technologies and require a modified approach to implementation.

At the same time, several developments are making high-powered pure laser welding more relevant than ever before. New laser technologies are delivering higher power levels and advanced beam shaping capabilities. Together, these advancements allow better control over weld pool dynamics while achieving the desired joint penetration. This is essential to achieve high-quality welds in thick sections.

This article reviews recent experience applying pure laser welding to ship panels, stiffeners, and T-beam structures. It compares the process to traditional arc welding, highlights advantages, and discusses practical limitations. It also reviews current code limitations and outlines a possible path toward qualified use in production.

Laser Welding in Shipbuilding

Laser welding has already made progress in shipbuilding. Hybrid laser arc welding has been adopted by some shipyards and handheld laser systems are being used for repair and light fabrication. These technologies help lower the barrier to entry and allow shipyards to gain familiarity with laser-based processes.

High-powered pure laser welding (meaning no electric arc assistance and often in the 10+ kW region) is less common but is gaining attention. Historically, a main limitation has been the need for tight joint fitup when welding thick sections. This is being addressed from two directions. On the production side, better cutting and fixturing methods are improving joint consistency. On the laser side, higher power and dynamic beam shaping allow the process to tolerate larger openings and stabilize the weld pool.

Recent projects show that pure laser welding can be applied to core shipbuilding structures such as panels, stiffeners, and T-beams. Improvements to welding processes for these critical shipbuilding weldments have a direct impact on quality, productivity, and cost.

Comparison to Conventional Arc Welding

One of the most significant advantages of laser welding is its low heat input. Conventional arc welding of thick sections often requires multiple passes, which increases total heat input. This leads to distortion and unwanted residual stress. In contrast, laser welding can often achieve complete joint penetration in a single pass. This lower heat input results in minimal distortion. As a result, overall fitup and downstream alignment improve and upstream processes such as cutting, fixturing, and assembly benefit from increased consistency, reducing overall production time and process inefficiencies.

In addition to heat input reduction, laser welding also drives significant savings in consumables. Pure laser welding most commonly utilizes a square butt joint design. This approach uses less than 10% of the filler wire compared to arc welding while eliminating the need for flux and, in many cases, reducing or simplifying shielding gas requirements. Beyond the direct cost of consumables, there are also notable savings in maintenance compared to commonly used arc welding processes.

Pure laser welding differs from hybrid laser welding. Hybrid welding introduces additional complexity by requiring simultaneous control of both laser parameters and arc welding parameters. It also maintains a relatively higher heat input compared to pure laser welding, reducing some of the benefits of distortion control and process simplicity.

In contrast, pure laser welding systems, combined with the use of advanced beam shaping techniques, lead to improved stability and greater control of resulting weld microstructures and mechanical properties.

Practical Limitations

Despite these advantages, challenges remain. Pure laser welding requires tighter joint fitup and better material preparation compared to arc welding. The process can be more sensitive to openings, misalignment, and surface contamination (although it has been shown to tolerate primer coatings to a certain extent). In shipbuilding environments, where large parts are handled and variability is common, achieving consistent preparation can be challenging.

Another constraint is that high-powered pure laser welding requires automation. As a result, it is best suited for well-defined and repeatable production stages.

Equipment cost is also a consideration compared to manual or semiautomatic welding systems. Laser sources, beam delivery optics, automation requirements, and safety systems may require a larger upfront investment. Of course, this should be compared to the savings found when switching to laser welding.

Overall, successful implementation depends on proper process integration, established parameters, and alignment with production areas where the technology provides clear advantages.

Code and Qualification Challenges

Qualification remains a key barrier. In many cases, pure laser welding meets existing weld requirements in terms of quality, mechanical strength, and material properties. Test results from recent applications show that pure laser welds can achieve the required performance for use in shipbuilding.

However, common codes and standards used in shipbuilding were developed around arc welding processes. As a result, some requirements do not directly align with the characteristics of pure laser welding. For example, essential variables defined in welding codes do not adequately address pure laser welding parameters. This becomes even more pronounced when beam shaping is involved. An additional example is tests such as longitudinal weld-only tensile testing. These can be difficult due to the much narrower weld profile compared to processes like submerged arc welding. This creates a gap between demonstrated performance and code acceptance.

Path toward Adoption

There are different paths companies are taking to demonstrate the effectiveness of high-powered pure laser welding. Companies with adequate R&D resources often conduct internal weld qualification programs. Others partner with application labs and other specialized organizations to assist with the qualification process. These approaches are complementary. As data accumulates and adoption becomes broader, more companies will have the confidence to move forward with implementing this advanced welding technology.

Regardless of the approach, adoption of pure laser welding in shipbuilding must start with a clear business case that justifies the investment.

Call to Action

To help revitalize shipbuilding in America, the welding community needs to modernize and adopt advanced welding technologies. High-powered pure laser welding has demonstrated the ability to deliver consistent, high-quality welds in thick sections.

While there are still obstacles to overcome, a critical challenge is to find ways to safely and conservatively, but quickly, adopt laser welding into industry codes. Every industrial welding code; standard; and specification committee, subcommittee, and task group should have a clear plan to address all types of laser welding within their influence. The benefits of doing so will enable the shipbuilding industry to meet the demands placed on it better than they ever have before.

This article was written by Zack Sanders (welding engineer at Civan Lasers Inc.) for the American Welding Society.