AWS Filler Metals & Consumables 2

Question 1

Which shielding gas mixture is most commonly used for GMAW of carbon steel to balance arc stability, spatter reduction, and penetration?

Accepted Answer

75% Argon / 25% CO₂ (C25)

Answer

A 75% Ar / 25% CO₂ mixture (C25) is the industry standard for carbon steel GMAW because it provides excellent arc stability, reduced spatter, and good weld bead profile.

Question 2

In self-shielded flux-cored arc welding (FCAW-S), where does the shielding of the weld pool come from?

Accepted Answer

Decomposition of flux compounds within the wire core

Answer

In FCAW-S, the flux ingredients packed inside the hollow tubular wire decompose under welding heat to generate shielding gases and slag that protect the molten pool without any external gas supply.

Question 3

In the AWS FCAW electrode classification E71T-1C, what does the 'T' designate?

Accepted Answer

Tubular (flux-cored) electrode construction

Answer

The 'T' in FCAW electrode classifications designates that the electrode is tubular (flux-cored), distinguishing it from solid wire electrodes used in GMAW.

Question 4

For GTAW (TIG) welding of Type 304 austenitic stainless steel, which filler metal is most commonly specified?

Accepted Answer

ER308L

Answer

ER308L is the standard filler for Type 304 stainless; the 'L' (low carbon) designation minimizes sensitization and carbide precipitation in the heat-affected zone.

Question 5

AWS A5.20 covers filler metals used in which welding process?

Accepted Answer

Flux-cored arc welding (FCAW) of carbon steel

Answer

AWS A5.20 is the specification for Carbon Steel Electrodes for Flux-Cored Arc Welding, classifying both gas-shielded (FCAW-G) and self-shielded (FCAW-S) tubular electrodes.

AWS Practice Test

AWS Practice Test

AWS Filler Metals & Consumables 2