Certified Welder Welding Process Application 3 — Questions and Answers
Question 1: Submerged Arc Welding (SAW) is most commonly used for:
- Welding thin materials under 1/8 inch
- High-deposition-rate welding of thick, flat, or horizontal joints in production settings (Correct answer)
- Overhead and vertical welding positions
- Welding of aluminum and non-ferrous metals
Correct answer: High-deposition-rate welding of thick, flat, or horizontal joints in production settings
SAW excels at high-deposition flat and horizontal welding of thick materials, making it ideal for shipbuilding, pressure vessels, and structural fabrication.
Question 2: When welding aluminum with GMAW, which shielding gas is most commonly used?
- 100% CO2
- 75% Argon / 25% CO2
- 100% Argon (Correct answer)
- 100% Helium
Correct answer: 100% Argon
100% Argon is the standard shielding gas for GMAW on aluminum because it provides good arc stability and the cleaning action needed for aluminum oxide removal.
Question 3: In Resistance Spot Welding (RSW), the weld is formed by:
- Melting filler metal between two copper electrodes
- Applying pressure and electrical resistance heat between two overlapping workpieces (Correct answer)
- Burning through the top layer to fuse the bottom layer
- Using flux to bond two metals under pressure
Correct answer: Applying pressure and electrical resistance heat between two overlapping workpieces
RSW creates a weld nugget through the combination of electrode pressure and the heat generated by electrical resistance at the interface of the workpieces.
Question 4: What is the purpose of back-purging with argon when welding stainless steel pipe using GTAW?
- To cool the weld faster and prevent cracking
- To protect the back side of the root pass from oxidation (sugaring) (Correct answer)
- To increase penetration on thick-wall pipe
- To preheat the inside of the pipe before welding
Correct answer: To protect the back side of the root pass from oxidation (sugaring)
Back-purging fills the pipe interior with argon to shield the root weld from oxygen and nitrogen, preventing oxidation (sugaring) that degrades corrosion resistance.
Question 5: Which welding process uses a non-consumable electrode and separate filler rod added by hand?
- GMAW
- SMAW
- GTAW/TIG (Correct answer)
- FCAW
Correct answer: GTAW/TIG
GTAW uses a non-consumable tungsten electrode to maintain the arc while the welder manually feeds filler rod into the weld pool as needed.
Question 6: Electroslag Welding (ESW) is best described as a process that:
- Uses a slag blanket to conduct current and provide heat for welding thick vertical joints in one pass (Correct answer)
- Requires external shielding gas and horizontal joint positioning
- Uses electrode rotation to distribute heat evenly on thin materials
- Creates welds by explosive pressure between two metal surfaces
Correct answer: Uses a slag blanket to conduct current and provide heat for welding thick vertical joints in one pass
ESW uses a conductive molten slag pool that generates resistance heat to weld extremely thick vertical joints in a single pass.
Question 7: When using FCAW-G (gas-shielded flux-cored), the most common shielding gas mixture is:
- 100% Argon
- 100% CO2 or 75% Ar / 25% CO2 (Correct answer)
- 50% Argon / 50% Helium
- 100% Helium
Correct answer: 100% CO2 or 75% Ar / 25% CO2
FCAW-G typically uses 100% CO2 or a 75/25 Argon/CO2 blend, which provides good penetration and arc stability for carbon steel.
Certified Welder Welding Process Application 3
Submerged Arc Welding (SAW) is most commonly used for: