AWS Welding Techniques 3 — Questions and Answers
Question 1: What is the function of a weaving motion during welding?
- To increase travel speed and reduce heat input
- To widen the bead and improve fusion at the toes of the weld (Correct answer)
- To decrease the amount of filler metal deposited
- To reduce the need for joint preparation
Correct answer: To widen the bead and improve fusion at the toes of the weld
A weaving motion oscillates the electrode side-to-side to widen the weld bead and promote fusion at both toes, which is useful for filling wide grooves or bridging gaps.
Question 2: In SMAW, what happens if the arc length is too long?
- Increased penetration and narrow bead
- Decreased spatter and cleaner weld
- Excessive spatter, porosity, and undercut (Correct answer)
- Improved shielding gas coverage
Correct answer: Excessive spatter, porosity, and undercut
An excessively long arc in SMAW reduces penetration, increases spatter, causes porosity from atmospheric contamination, and can lead to undercutting.
Question 3: Which AWS electrode classification indicates a low-hydrogen electrode suitable for high-strength steels?
- E6010
- E6013
- E7018 (Correct answer)
- E6011
Correct answer: E7018
E7018 is a low-hydrogen iron-powder electrode with a tensile strength of 70,000 psi, designed for welding high-strength and low-alloy steels requiring low hydrogen deposits.
Question 4: What welding technique is recommended when making a root pass in a groove weld with a backing bar?
- High heat with maximum weave width
- Keyhole technique to ensure full fusion through the root (Correct answer)
- Rapid travel speed to minimize heat input
- Multiple stringer passes without pausing
Correct answer: Keyhole technique to ensure full fusion through the root
The keyhole technique creates a small opening (keyhole) at the leading edge of the weld pool to ensure complete fusion through the root opening and against the backing bar.
Question 5: What is porosity in a weld, and what is a common cause?
- Cracks from high residual stress
- Cavities formed by gas trapped in the solidifying weld metal, often from moisture or contamination (Correct answer)
- Incomplete fusion between weld passes
- Excessive weld reinforcement above the base metal surface
Correct answer: Cavities formed by gas trapped in the solidifying weld metal, often from moisture or contamination
Porosity consists of gas pockets trapped in the solidified weld metal, commonly caused by moisture on the electrode, contaminated base metal, or insufficient shielding gas coverage.
Question 6: What is the primary advantage of the spray transfer mode in GMAW?
- It works best at very low amperage settings
- It produces a spatter-free weld with high deposition rates, ideal for thick materials (Correct answer)
- It is the only transfer mode suitable for overhead welding
- It requires no shielding gas
Correct answer: It produces a spatter-free weld with high deposition rates, ideal for thick materials
Spray transfer propels fine droplets axially across the arc at high velocity, resulting in minimal spatter, high deposition rates, and deep penetration on thick base metals.
Question 7: When welding vertical-up, how should the electrode angle typically be oriented?
- 5 to 10 degrees downward (push angle)
- 90 degrees perpendicular to the work with no travel angle
- 5 to 15 degrees upward (forehand angle toward direction of travel) (Correct answer)
- 45 degrees pointing downward toward the base plate
Correct answer: 5 to 15 degrees upward (forehand angle toward direction of travel)
For vertical-up welding, the electrode is tilted 5 to 15 degrees upward in the direction of travel so the arc force helps support the molten pool against gravity.
AWS Welding Techniques 3
What is the function of a weaving motion during welding?