Which term describes the time during which shielding gas continues to flow after the welding current stops?

• A. Preflow
• B. Backflow
• C. Flow rate
• D. Postflow

Answer: (D)

Postflow is the period after the welding current stops when shielding gas continues to flow to cover the weld as it cools. This keeps the weld protected from air, preventing oxidation, moisture uptake, and porosity while the metal solidifies. Before welding, a brief preflow helps purge air and establish the gas blanket; during welding, the flow maintains shielding; after welding, postflow ensures the weld remains protected until the heat has diminished enough to resist contamination. Flow rate describes how much gas is delivered, not how long it lasts, and preflow or other terms don’t refer to the time after the arc ends.