Flux-Cored Arc Welding (FCAW) Flashcards

What is the primary difference between FCAW-G and FCAW-S?

Answer: FCAW-G uses external shielding gas; FCAW-S is self-shielded via flux in the core

FCAW-G (gas-shielded) requires an external shielding gas like CO2 or Ar/CO2 mix, while FCAW-S (self-shielded) generates its own shielding from the flux core — no external gas needed.

Which AWS electrode classification is used for a flux-cored wire suitable for all-position welding with CO2 shielding gas?

Answer: E71T-1C

E71T-1C: E=electrode, 7=70 ksi tensile, 1=all-position, T=tubular (flux-cored), 1=usability designation, C=CO2 shielding gas.

Excessive wire extension (stick-out) in FCAW will typically cause:

Answer: Reduced current, lower heat input, and incomplete fusion

Excessive CTWD (Contact Tip to Work Distance / stick-out) increases resistance in the wire, which reduces current, lowers heat input, and can lead to incomplete fusion or cold lap.

Porosity in FCAW welds is most commonly caused by:

Answer: Contamination (moisture, rust, oil) or shielding gas disruption

Porosity results from gas trapped in the weld pool. Sources include moisture on the base metal or wire, oil/rust contamination, insufficient gas coverage, or wind disturbing the gas shield.

In FCAW, the work angle for a horizontal fillet weld is typically:

Answer: 45 degrees (bisecting the joint angle)

For a horizontal fillet weld, the electrode is typically held at 45 degrees (bisecting the angle between horizontal and vertical members), directing the arc into the root of the joint.

Which polarity is standard for most FCAW-G electrodes?

Answer: DCEP (reverse polarity)

Most FCAW-G electrodes require DCEP (electrode positive, reverse polarity) to achieve the proper arc characteristics, penetration, and slag coverage.