Welding steel components more efficiently with thick wire

Welding thick steel components has always posed significant challenges, especially when bridging large seam gaps efficiently. Researchers at the Laser Zentrum Hannover e.V. (LZH) are developing an innovative process for hybrid laser arc welding using thick wire to address this challenge. This breakthrough technology promises to significantly enhance welding speed, reduce material use, and increase overall resource efficiency.

The Innovation: Hybrid Laser Arc Welding with Thick Wire

As part of the "ÖkoHybrid" project, the LZH team aims to make welding faster and more efficient by introducing a process that uses thick wires—3 mm in diameter—to close large seam gaps with fewer welding layers. Traditional welding methods often require multiple layers to bridge such gaps, which can be time-consuming and resource-intensive. By feeding thick wire into the welding zone, the process significantly reduces the number of layers needed.

An additional laser beam is integrated to stabilise and accelerate the process, ensuring precision and reliability. This hybrid approach combines the strengths of gas metal arc welding (GMAW) with those of laser beam welding, achieving high deposition rates and exceptional welding speeds.

Developing a Stable and High-Performance Welding Process

The researchers are focusing their efforts on welding fine-grained structural steels with sheet thicknesses of up to 20 mm. These steels are commonly used in shipbuilding, vehicle manufacturing, and pipeline construction due to their high strength and lighter weight compared to conventional structural steels.

To accomplish this, the LZH team is developing a novel hybrid processing head that integrates a commercially available laser beam source with an output of 3 kW and a welding power source with an output of up to 40 kW. The welding power source is being developed by project partner ELMA-Tech GmbH, while FÖRSTER welding systems GmbH is creating a complete system for the hybrid welding process. Additionally, the Westsächsische Hochschule Zwickau is conducting fundamental investigations into the gas metal arc welding (GMAW) process and testing the characteristics of the welded joints.

The combined processes—laser beam welding and GMAW—achieve high deposition rates and faster welding speeds. By using 3 mm thick wire, the system allows for a significant amount of material to be deposited in a single pass. This reduces the number of layers required for welding, streamlining the process while maintaining stability and quality.

Meeting Demands in the Heavy Steel Sector

The heavy sheet metal sector has a growing demand for faster and more efficient welding solutions, particularly for industries like shipbuilding, pipeline construction, and vehicle manufacturing. Fine-grained structural steels, commonly used in these applications, present unique challenges for welding.

These steels offer higher strength and allow for thinner material usage, reducing overall component weight and material costs. However, welding fine-grained structural steels requires careful control of cooling times. If the material cools too slowly, the weld may lack sufficient strength and toughness. Conversely, cooling too quickly can lead to cracks and high-hardness seams.

To address these challenges, the researchers are optimising the welding process to achieve higher deposition rates and increased welding speeds while maintaining the ideal cooling times. This ensures the welded components retain the necessary mechanical properties, such as strength and toughness, without compromising quality.

Laser Zentrum Hannover e.V. (LZH)

The Laser Zentrum Hannover e.V. (LZH) is an independent, non-profit research institute committed to advancing research, development, and consulting in photonics and laser technology. Established in 1986 and supported by the Lower Saxony Ministry of Economics, Transport, Building, and Digitalisation, the LZH promotes applied research with nearly 200 employees.

The institute is at the forefront of innovation, offering smart photonics solutions for a range of challenges. Its interdisciplinary teams of natural scientists and engineers work across the process chain—from component development for laser systems and quantum technologies to laser applications in medical technology, agriculture, and lightweight construction for the automotive sector.

To date, the LZH has successfully launched 18 spin-offs, creating a strong bridge between fundamental science, applied research, and industry. By leveraging the power of light, the LZH continues to foster innovation across various sectors.

ÖkoHybrid: Advancing Resource-Efficient Welding

The "ÖkoHybrid" project, officially titled "Economical high-performance welding of fine-grain structural steels using laser MSG hybrid welding of larger wire diameters," is part of the "Central Innovation Programme for SMEs (ZIM)." Funded by the Federal Ministry for Economic Affairs and Climate Action (grant no. KK5111716KT3), the project emphasises innovation in welding technology to enhance efficiency and sustainability.

Specifically, the sub-project, "Process development for laser beam MIG hybrid welding with larger wire diameters," focuses on creating a resource-efficient welding process that meets the demanding requirements of fine-grain structural steels while significantly reducing material waste and energy consumption.

The Future of Welding Technology

The innovative work being done by LZH and its partners has the potential to revolutionise the welding industry. By integrating thick wire and hybrid laser arc welding technology, the process not only improves welding speed and efficiency but also supports sustainable manufacturing practices. With industries demanding faster, more cost-effective solutions, the "ÖkoHybrid" project stands out as a groundbreaking step toward the future of welding steel components.

This advancement aligns with the broader goals of reducing resource consumption and enhancing productivity in manufacturing, setting a new standard for efficiency and sustainability in the heavy sheet metal sector.

Source: Laser Zentrum Hannover e.V.