Question

which gas is released in the smaw process causing a shielding affect on the molten weld pool?

carbon dioxide
nitrogen
hydrogen
argon

Explanation:

Identify the SMAW shielding mechanism

Using the SMAW and Flux Covering Function knowledge points

In Shielded Metal Arc Welding (SMAW), the electrode is covered with a flux coating. When the arc is struck, the intense heat decomposes this flux coating, releasing gases that form a protective shield around the molten weld pool to prevent atmospheric contamination.

Determine the specific gas released

Using the Flux Covering Function knowledge point

The decomposition of organic materials (such as cellulose) in the flux coating primarily generates carbon dioxide (\(\text{CO}_2\)) and carbon monoxide (\(\text{CO}\)), which act as the shielding gas. Therefore, carbon dioxide is the correct gas released during this process.

Answer:

• Carbon dioxide (Correct answer)
• Nitrogen
• Hydrogen
• Argon