A CO2 arc welding shielding gas can break down in the welding arc and form carbon monoxide. Is this statement True or False?

A CO2 arc welding shielding gas can break down in the welding arc and form carbon monoxide. Is this statement True or False?

• A. True
• B. False
• C. Not applicable
• D. Depends on arc current

Answer: (A)

In an arc welding arc, the shielding gas is exposed to temperatures that are hot enough to break chemical bonds. Carbon dioxide molecules can dissociate in that intense heat, turning into carbon monoxide and oxygen. Because of this, part of the shielding gas in the arc can exist as carbon monoxide rather than as intact CO2. That’s why the statement is true: the CO2 shielding gas can break down in the welding arc and form carbon monoxide. The extent of breakdown tends to increase with higher arc energy (current/voltage), which is why CO2 shielding is more prone to this effect under hotter, more energetic conditions.

In an arc welding arc, the shielding gas is exposed to temperatures that are hot enough to break chemical bonds. Carbon dioxide molecules can dissociate in that intense heat, turning into carbon monoxide and oxygen. Because of this, part of the shielding gas in the arc can exist as carbon monoxide rather than as intact CO2. That’s why the statement is true: the CO2 shielding gas can break down in the welding arc and form carbon monoxide. The extent of breakdown tends to increase with higher arc energy (current/voltage), which is why CO2 shielding is more prone to this effect under hotter, more energetic conditions.