Covered Electrodes:

In addition to establishing the arc and supplying filler metal for the weld deposit, the electrode introduces to the other materials into or around the arc, or both. Based upon the type of electrode being utilized, the covering performs one or more of the following functions :

1. Provides a gas to shield the arc and avoid excessive atmospheric contamination of the molten filler metal.

2. Provides deoxidizers, scavengers and fluxing agents to cleanse the weld and prevent excessive grain increase in the weld metal.

3. Establishes the electrical characteristics of the electrode.

4. Provides a slag blanket to defend the hot weld metal from the air and increase the bead shape,  mechanical properties and surface cleanliness of the weld metal.

5. Provides a means of adding alloying elements to alter the mechanical properties of the weld metal.