What is submerged arc welding primarily protected by?

Submerged arc welding (SAW) primarily utilizes a granular fusible flux to protect the weld. This flux is essential because it creates a protective layer over the molten weld pool. It effectively blocks atmospheric contaminants such as oxygen and nitrogen from interfering with the welding process, which can lead to defects in the weld. The flux not only shields the molten metal but also contributes to the stability of the arc and can help refine the weld metal's chemical composition by adding alloying elements.

The uniqueness of submerged arc welding lies in its method of operation, where the arc is submerged beneath this layer of flux. The process ensures that the weld is made in a controlled environment, which is less susceptible to the issues that can arise in other welding processes that rely on external shielding gases or coatings.

In contrast, options involving inert gas atmosphere, tungsten electrodes, and electrode coatings pertain to other welding methods like gas tungsten arc welding (GTAW) or shielded metal arc welding (SMAW), which follow different principles and shielding requirements. Thus, the granular fusible flux is fundamentally vital for the SAW process, marking it as the primary form of protection during welding.