Which welding method is often used in the fabrication of large structural steel beams or plate girders?

The chosen answer, submerged arc welding (SAW), is indeed a widely used welding method for the fabrication of large structural steel beams and plate girders. This technique is particularly effective because it employs a continuous feed of wire that is submerged beneath a layer of granular flux, which not only protects the molten weld pool from contamination but also significantly aids in the process by generating heat and stabilizing the arc.

SAW is known for producing high-quality welds with deep penetration and is capable of handling thick materials. This makes it ideal for large-scale applications where strength and integrity are essential, such as in the construction of bridges, buildings, and other significant structural components. The efficiency of this method also allows for faster welding speeds compared to other techniques, which is advantageous in large fabrication tasks.

While other methods like gas tungsten arc welding (GTAW), resistance spot welding (RSW), and shielded metal arc welding (SMAW) have their own applications and benefits, they are less commonly used for large items due to limitations such as speed, penetration depth, and the complexity of handling thick materials. Therefore, submerged arc welding stands out as the preferred choice in this context.