Shielded arc welding, also known as manual metal arc welding or stick welding, is a welding process that uses a welding rod coated with fluxing material. This flux coating plays a crucial role in the welding process and helps to create a shielded atmosphere around the weld pool.

Explanation:

1. Shielded Arc Welding:
Shielded arc welding is a type of arc welding process where an electric arc is created between the welding rod and the workpiece. The heat generated by the arc melts the base metal and the electrode, creating a weld pool. The molten metal solidifies to form the weld joint.

2. Welding Rod:
In shielded arc welding, a welding rod or electrode is used as a filler material. The welding rod is made of a metal alloy that matches or complements the base metal being welded. The electrode is held in an electrode holder and is consumed during the welding process.

3. Flux Coating:
The welding rod used in shielded arc welding is coated with a fluxing material. Flux is a chemical compound that is used to protect the weld pool from atmospheric contamination. The flux coating on the welding rod plays several important roles:

- Shielding: The flux coating creates a shielded atmosphere around the weld pool, preventing the molten metal from coming into contact with atmospheric gases such as oxygen and nitrogen. This shielded environment helps to minimize the formation of defects in the weld, such as porosity and oxidation.

- Deoxidizing: The flux coating contains deoxidizing agents that react with oxygen in the weld pool, reducing the formation of oxides. This helps to improve the quality of the weld joint.

- Slag Formation: During the welding process, the flux coating melts and forms a slag layer on top of the weld. The slag acts as a protective barrier, preventing the weld from recontamination and promoting the solidification of the weld. It also helps to shape the weld bead and provides additional mechanical support.

- Arc Stabilization: The flux coating helps to stabilize the electric arc, ensuring a consistent and controlled heat input during the welding process.

In conclusion, in shielded arc welding, a welding rod coated with fluxing material is used. The flux coating provides shielding, deoxidizing, and slag-forming properties, which are essential for achieving high-quality weld joints.