Gas mixture generally associated with globular transfer on steel?

Gas mixture generally associated with globular transfer on steel?

• A. 80% AR/20% CO2
• B. 100% CO2
• C. 90% AR/10% CO2
• D. 70% AR/30% CO2

Answer: (B)

Globular transfer in GMAW of carbon steel is strongly influenced by the shielding gas. Shielding with pure CO2 makes the arc more reactive, causing larger droplets to form and detach irregularly, which leads to globular transfer with noticeable spatter and a rough bead. When argon is mixed with CO2 (as in the other options), the arc becomes more stable and the transfer tends toward spray or pulsated spray with finer droplets and a smoother bead. So, pure CO2 is the gas that generally yields globular transfer on steel.

Globular transfer in GMAW of carbon steel is strongly influenced by the shielding gas. Shielding with pure CO2 makes the arc more reactive, causing larger droplets to form and detach irregularly, which leads to globular transfer with noticeable spatter and a rough bead. When argon is mixed with CO2 (as in the other options), the arc becomes more stable and the transfer tends toward spray or pulsated spray with finer droplets and a smoother bead. So, pure CO2 is the gas that generally yields globular transfer on steel.