Welder Red Seal · Question
A shipyard welder is using FCAW-G with E71T-1M H4 wire and 75% Argon/25% CO2 shielding gas to weld 10 mm (0.4 in) thick mild steel in the flat position. Post-weld inspection reveals elongated, worm-like voids just below the weld surface. What is the most probable cause of these defects?
Elongated, worm-like voids, often called wormholes or vermicular porosity, are characteristic of hydrogen entrapment, frequently caused by moisture in the flux
Start free practice for Welder Red Seal
154 questions · no signup required · 40 free questions per day
Question: A shipyard welder is using FCAW-G with E71T-1M H4 wire and 75% Argon/25% CO2 shielding gas to weld 10 mm (0.4 in) thick mild steel in the flat position. Post-weld inspection reveals elongated, worm-like voids just below the weld surface. What is the most probable cause of these defects?
Answer options:
- Insufficient preheat temperature. ✅ Hydrogen entrapment from damp flux.
- Excessive voltage settings.
- Inadequate shielding gas coverage.
Correct answer: Hydrogen entrapment from damp flux.
Explanation: Elongated, worm-like voids, often called wormholes or vermicular porosity, are characteristic of hydrogen entrapment, frequently caused by moisture in the flux (damp wire). While voltage can affect porosity, and inadequate gas shielding causes random porosity, wormholes specifically point to hydrogen sources.
Start free practice for Welder Red Seal
154 questions · no signup required · 40 free questions per day
More about Welder Red Seal
Related Questions
- A welder is fabricating a pressure vessel component using FCAW-G with an E70T-1 wire. The procedure specifies
- A welder is preparing to weld 20 mm (0.8 in) thick high-strength low-alloy (HSLA) steel using FCAW-G. The weld
- A structural steel fabricator is using FCAW-S (E71T-8 wire) to weld heavy sections of structural steel in an o
- When performing FCAW-G (gas-shielded flux-cored arc welding), a welder notices the arc is unstable and the wir
- A structural welder is performing overhead FCAW-G on 12 mm (0.5 in) thick steel with an E71T-1 wire. The weld
- A welder is setting up an FCAW-S machine for welding in a remote location without access to external shielding
More for Welder Red Seal candidates
Practice tests
Question explanations
- A welder is fabricating a pressure vessel component using FCAW-G with an E70T-1 wire. The procedure specifies
- A welder is preparing to weld 20 mm (0.8 in) thick high-strength low-alloy (HSLA) steel using FCAW-G. The weld
- A structural steel fabricator is using FCAW-S (E71T-8 wire) to weld heavy sections of structural steel in an o
- When performing FCAW-G (gas-shielded flux-cored arc welding), a welder notices the arc is unstable and the wir
Ready to practice?
Free, no signup required. Build a wrong-question list as you go.
Start Free Welder Red Seal Practice →Related courses
Other Canadian certifications candidates often prepare for alongside this one.