What produces the shielding gas and slag layer to protect the weld deposit in the SMAW process?

• A. Core wire
• B. Weld puddle
• C. Flux coating
• D. None of the above

Answer: (C)

In SMAW, shielding comes from the flux coating on the electrode. When the electrode heats and melts, the flux decomposes and releases shielding gases that blanket the molten weld, protecting it from the surrounding air. At the same time, the flux forms a slag layer that floats over and then solidifies on top of the weld, further shielding and shaping the deposited metal as it cools. The core wire is just the filler metal, and the weld puddle is the molten metal itself—not the source of shielding. There’s no external shielding gas involved in SMAW, so the flux coating is the essential source of both the shielding gas and the slag.