SAW Welding Techniques & Process Control 2 — Questions and Answers
Question 1: In SAW, what effect does increasing travel speed have on the weld bead?
- Wider bead with more penetration
- Narrower bead with less penetration (Correct answer)
- Wider bead with less penetration
- No change in bead geometry
Correct answer: Narrower bead with less penetration
Higher travel speed reduces heat input per unit length, resulting in a narrower bead with shallower penetration.
Question 2: Which SAW technique involves two electrodes fed simultaneously into a single weld pool?
- Series SAW
- Tandem SAW
- Twin-wire SAW (Correct answer)
- Parallel electrode SAW
Correct answer: Twin-wire SAW
Twin-wire SAW uses two electrodes connected to the same power source, feeding into a single molten pool to increase deposition rate.
Question 3: What is the primary purpose of flux backing in SAW of single-sided groove welds?
- To increase deposition rate
- To support the molten pool and form a sound root bead (Correct answer)
- To preheat the base metal
- To reduce flux consumption
Correct answer: To support the molten pool and form a sound root bead
Flux backing supports the weld pool on the root side, preventing burn-through and producing a fully fused root bead.
Question 4: In tandem SAW, the leading electrode is typically set to which polarity to maximize penetration?
- AC
- DCEP (DC electrode positive) (Correct answer)
- DCEN (DC electrode negative)
- Pulsed DC
Correct answer: DCEP (DC electrode positive)
DCEP on the leading electrode concentrates heat at the workpiece, maximizing penetration into the joint.
Question 5: What welding parameter most directly controls the width of the flux coverage zone in SAW?
- Wire feed speed
- Flux hopper height above the work (Correct answer)
- Travel speed
- Contact-tip-to-work distance
Correct answer: Flux hopper height above the work
The height of the flux hopper above the workpiece determines how wide the flux pile spreads, affecting coverage width.
Question 6: When welding with AC in SAW, what advantage does it offer over DCEP for multi-wire applications?
- Higher deposition rate on the leading wire
- Reduced arc blow between adjacent arcs (Correct answer)
- Greater penetration depth
- Lower flux consumption
Correct answer: Reduced arc blow between adjacent arcs
AC alternating polarity reduces magnetic arc blow interference between adjacent electrodes in multi-wire setups.
Question 7: A welder notices the slag is difficult to remove after SAW. What is the most likely cause?
- Excessive travel speed
- Incorrect flux type for the base metal (Correct answer)
- Too high arc voltage
- Insufficient preheat
Correct answer: Incorrect flux type for the base metal
Using a flux chemically mismatched to the base metal can produce slag with poor release characteristics.
SAW Welding Techniques & Process Control 2
In SAW, what effect does increasing travel speed have on the weld bead?