Certified Welder Welding Process Application 2 — Questions and Answers
Question 1: Which welding process is best suited for welding thin-gauge sheet metal to minimize distortion?
- Submerged Arc Welding (SAW)
- Gas Tungsten Arc Welding (GTAW/TIG) (Correct answer)
- Flux-Cored Arc Welding (FCAW)
- Shielded Metal Arc Welding (SMAW)
Correct answer: Gas Tungsten Arc Welding (GTAW/TIG)
GTAW/TIG provides precise heat control and low heat input, making it ideal for thin sheet metal with minimal distortion.
Question 2: In GMAW short-circuit transfer mode, metal transfer occurs when:
- The arc voltage is at its highest point
- The wire electrode touches and short-circuits to the base metal (Correct answer)
- Shielding gas pressure exceeds 30 CFH
- Wire feed speed drops below the minimum setting
Correct answer: The wire electrode touches and short-circuits to the base metal
In short-circuit transfer, the wire electrode physically contacts the weld pool, creating a short circuit that melts and transfers the metal.
Question 3: What is the primary advantage of using the Flux-Cored Arc Welding (FCAW) process outdoors?
- It requires no electrical power source
- The flux core provides shielding that is less affected by wind than external gas (Correct answer)
- It produces no spatter compared to other processes
- It operates at lower amperages than SMAW
Correct answer: The flux core provides shielding that is less affected by wind than external gas
FCAW-S (self-shielded) uses flux inside the wire to generate its own shielding, making it resistant to wind that would disrupt external gas shielding.
Question 4: Which parameter most directly controls penetration depth in SMAW welding?
- Electrode diameter only
- Travel speed only
- Amperage (current) (Correct answer)
- Arc voltage
Correct answer: Amperage (current)
Amperage (current) is the primary factor controlling penetration depth in SMAW; higher amperage produces deeper penetration.
Question 5: When welding with the GTAW process, a high-frequency (HF) start is used to:
- Increase wire feed speed automatically
- Initiate the arc without touching the electrode to the workpiece (Correct answer)
- Preheat the base metal before welding
- Clean the weld pool of oxides during welding
Correct answer: Initiate the arc without touching the electrode to the workpiece
High-frequency start allows the TIG arc to be initiated without electrode-to-workpiece contact, preventing tungsten contamination.
Question 6: Plasma Arc Welding (PAW) differs from GTAW primarily because it:
- Uses a consumable electrode instead of tungsten
- Constricts the arc through a nozzle orifice to produce higher energy density (Correct answer)
- Requires no shielding gas
- Can only weld ferrous metals
Correct answer: Constricts the arc through a nozzle orifice to produce higher energy density
PAW constricts the arc plasma through a small orifice in the torch nozzle, creating a stiffer, higher-energy-density arc than GTAW.
Question 7: Which transfer mode in GMAW produces the least spatter and is used for spray-type metal transfer?
- Short-circuit transfer
- Globular transfer
- Spray transfer (Correct answer)
- Pulsed transfer
Correct answer: Spray transfer
Spray transfer uses high voltage and amperage above the transition current to transfer tiny droplets smoothly across the arc with minimal spatter.
