Which transfer mode is associated with 100% CO2 gas on steel?

Which transfer mode is associated with 100% CO2 gas on steel?

• A. Short circuit
• B. Globular
• C. Spray
• D. Pulse

Answer: (B)

When shielding gas affects how metal moves from the wire to the weld pool, 100% CO2 tends to produce larger, lumpier droplets rather than a fine spray. This makes the transfer look “globular”—you get big, irregular droplets that detach and spatter rather than a smooth, atomized spray. The spray transfer mode needs an argon-containing gas mix and higher current to finely atomize droplets, while short-circuit transfer relies on frequent touching of the molten wire to the weld pool at low voltage. Pulse transfer also relies on controlled atomization with a specific gas mix and pulsing current. So, with pure CO2, globular transfer best describes the typical behavior on steel.

When shielding gas affects how metal moves from the wire to the weld pool, 100% CO2 tends to produce larger, lumpier droplets rather than a fine spray. This makes the transfer look “globular”—you get big, irregular droplets that detach and spatter rather than a smooth, atomized spray. The spray transfer mode needs an argon-containing gas mix and higher current to finely atomize droplets, while short-circuit transfer relies on frequent touching of the molten wire to the weld pool at low voltage. Pulse transfer also relies on controlled atomization with a specific gas mix and pulsing current. So, with pure CO2, globular transfer best describes the typical behavior on steel.