Which statement best describes the purpose of polarity options in GTAW?

Which statement best describes the purpose of polarity options in GTAW?

• A. Polarity is chosen based on material to be welded
• B. Polarity fixes filler metal type
• C. Polarity controls shielding gas flow
• D. Polarity has no effect on heat distribution

Answer: (A)

In GTAW, polarity options control where most of the arc heat goes and how the arc behaves, so you pick polarity based on the material you’re welding. For steels and many common metals, using direct current with the electrode negative concentrates heat in the workpiece, giving deeper penetration and good fusion while reducing tungsten wear. For aluminum and other reactive metals, alternating current helps break up surface oxides and keeps the tungsten from overheating, promoting a stable, clean weld. Filler metal selection and shielding gas flow are separate decisions and not dictated by polarity, and polarity does affect heat distribution, so stating that it has no effect isn’t accurate.

In GTAW, polarity options control where most of the arc heat goes and how the arc behaves, so you pick polarity based on the material you’re welding. For steels and many common metals, using direct current with the electrode negative concentrates heat in the workpiece, giving deeper penetration and good fusion while reducing tungsten wear. For aluminum and other reactive metals, alternating current helps break up surface oxides and keeps the tungsten from overheating, promoting a stable, clean weld. Filler metal selection and shielding gas flow are separate decisions and not dictated by polarity, and polarity does affect heat distribution, so stating that it has no effect isn’t accurate.