Practice Test GeeksAWS Practice Test
← All AWS Flashcard Decks

Gas Metal Arc Welding (GMAW/MIG) Flashcards

7 cards from real AWS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Gas Metal Arc Welding (GMAW/MIG) flashcards as text

  1. In pulsed GMAW (GMAW-P), what is the primary advantage over conventional spray transfer?

    Answer: Allows spray-like transfer at lower average heat input, enabling out-of-position welding

    GMAW-P alternates between peak and background current to achieve spray transfer droplet detachment at a lower average heat input, making out-of-position welding on thinner materials feasible.

  2. When qualifying a GMAW procedure per AWS D1.1, changing from ER70S-3 to ER70S-6 wire with the same diameter typically:

    Answer: Is a non-essential variable and does not require re-qualification

    Under AWS D1.1, changing between filler metals of the same F-number and A-number classification is a non-essential variable that does not require re-qualification of the WPS.

  3. A GMAW gun's liner becomes kinked or contaminated. What is the most likely symptom during welding?

    Answer: Erratic wire feeding causing arc instability and burn-back

    A damaged or contaminated liner creates friction that causes intermittent wire feeding, leading to arc instability, burn-back, and inconsistent bead quality.

  4. What is 'burn-back' in GMAW and what typically causes it?

    Answer: The wire fusing to the contact tip when wire feed speed is too low relative to voltage

    Burn-back occurs when wire feed speed is insufficient relative to the arc voltage, causing the arc to climb up the wire and fuse it to the contact tip.

  5. Which shielding gas mixture is generally preferred for GMAW on austenitic stainless steel to minimize carbon pickup and maintain corrosion resistance?

    Answer: 98% Ar / 2% O2 or 98% Ar / 2% CO2

    A tri-mix or binary argon gas with only 1–2% CO2 or O2 provides arc stability while minimizing carbon introduction that could sensitize the stainless steel HAZ.

  6. In a T-joint fillet weld made with GMAW, what is the correct electrode angle to ensure proper fusion to both the web and flange members?

    Answer: 45° bisecting the joint angle, with 5–15° travel angle

    For a T-joint fillet, the electrode should bisect the 90° joint angle at approximately 45° with a 5–15° drag or push travel angle to distribute heat evenly to both members.

  7. According to AWS standards, what is the minimum preheat temperature typically required for GMAW on A36 steel greater than 1-1/2 inches (38 mm) thick?

    Answer: 225°F (107°C)

    AWS D1.1 Table 4.2 requires a minimum preheat of 225°F (107°C) for A36 steel with thickness over 1-1/2 inches to prevent hydrogen-induced cracking.