Why are arc welding electrodes coated?

The coating on arc welding electrodes serves a crucial function in protecting the molten metal from oxidation. When welding, the intense heat generated can cause the metal to become molten and highly reactive, particularly with oxygen and moisture present in the air. The coating facilitates a protective barrier around the molten weld pool by releasing gases that displace oxygen, creating an inert atmosphere. This not only helps to prevent oxidation but also stabilizes the arc and enhances the overall quality of the weld.

In contrast, while managing overheating, increasing welding speed, and reducing noise can be relevant to the welding process, they are not the primary functions of the electrode coating. The prevention of oxidation is critical to achieving a strong, durable bond in welded joints.