Submerged Arc Welding (SAW) Process Overview

Submerged Arc Welding (SAW) is a highly efficient, automatic welding process widely used in heavy fabrication industries. It is characterized by the use of a continuously fed consumable electrode (or electrodes) and a blanket of granular, fusible flux that completely covers the arc and molten weld pool. This flux protects the weld from atmospheric contamination and allows for very high deposition rates.

Submerged Arc Welding Current Capacity

One of the defining features of the Submerged Arc Welding (SAW) process is its ability to operate at very high current levels, significantly higher than many other arc welding processes. This high current is crucial for achieving deep penetration and high welding speeds, making it ideal for joining thick materials.

• AC Current Usage: Submerged Arc Welding commonly uses both Direct Current (DC) and Alternating Current (AC). While DC offers stable arc characteristics, AC is particularly favored in certain applications for its ability to reduce arc blow, which can be an issue with high DC currents. AC current also helps in achieving a smoother bead appearance and can be beneficial when using multiple electrodes.
• High Amperage Capability: The Submerged Arc Welding process is known for its capacity to handle very high currents. For AC current, it is not uncommon for SAW systems to operate with amperages reaching up to 2000 A or even more in specialized applications. These extremely high currents contribute to very high deposition rates and deep penetration, which are essential for welding thick plates efficiently and producing strong, high-quality welds in a single pass or with fewer passes.
• Benefits of High Current: The high current in Submerged Arc Welding allows for:
  • Increased welding speed.
  • Deeper penetration into the base metal.
  • Higher deposition rates of weld metal.
  • Reduced number of passes for thick materials.

Characteristics of Submerged Arc Welding

Beyond its current capabilities, Submerged Arc Welding offers several other key characteristics that make it a preferred choice for heavy industrial applications:

• Automatic Operation: SAW is an automatic process, meaning the welding parameters (current, voltage, travel speed, wire feed speed) are precisely controlled, leading to consistent weld quality and reduced reliance on manual skill during the welding operation.
• High Quality Welds: The flux cover protects the arc and molten pool from atmospheric gases, resulting in very low porosity and excellent mechanical properties of the weld metal.
• High Deposition Rates: Due to high currents and continuous wire feed, SAW offers some of the highest deposition rates among arc welding processes, making it very productive.
• Minimal Fumes and Spatter: The submerged nature of the arc greatly reduces arc glare, fumes, and spatter, creating a safer and cleaner working environment compared to open arc processes.

In summary, the ability of Submerged Arc Welding to utilize high AC currents, typically up to 2000 A, is a fundamental aspect that enables its efficiency and effectiveness in demanding welding applications.