Chapter 10 Knowledge Check

Chapter 10

Quiz yourself using the following chapter review questions to check how well you can recall the material.

Review Questions

1. True or False: The addition of Carbon Dioxide (CO2) as a shielding gas allowed GMAW to be used on ferrous metals.
2. What does GMAW stand for?
   1. Gas Metal Arc Welding
   2. Gas Manufacturing and Arc Welding
   3. General Metal Arc Welding
   4. Gas Mixed Arc Welding
3.  Question
   1. Constant current (CC)
   2. Constant voltage (CV)
   3. Pulsed current (PC)
   4. Variable current (VC)
4. True or False: A spool gun helps reduce wire jamming in GMAW when working with aluminum.
5. A plastic gun liner is used for welding                        or other soft metals  in GMAW.
6. Before accessing the internal components of a welding machine, what is the most important safety measure?
   1. Keep the gas flow constant.
   2. Turn on the machine for cooling.
   3. Wear a welding helmet.
   4. Turn the machine off and/or disconnect from the power supply.
7. What size drive rollers should be used in a wire feeder?
   1. Drive roller size should be slightly larger than wire diameter.
   2. Drive roller size should be slightly smaller than wire diameter.
   3. Drive roller size should be must match wire diameter exactly.
   4. Drive roller size does not matter.
8. The letter “r” in a GMAW mild steel electrode classification represents .                   .
9. Which gas is commonly used in GMAW for welding aluminum?
   1. Oxygen
   2. Helium
   3. Argon
   4. Nitrogen
10. True or False: GMAW-P is a form of pulsed spray transfer with lower heat input, making it ideal for thinner base metals.

Answer Key

1. True. GMAW was developed for welding non-ferrous metals, but adding CO2 as a shielding gas increased its potential.
2. Gas Metal Arc Welding. Gas Metal Arc Welding is the currently accepted term for this process.
3. Constant voltage (CV). A constant voltage machine is used as a power source for GMAW, maintaining a consistent  arc length.
4. True. Spool guns and push pull guns are used to reduce the chance of feeding problems when welding with soft wires.
5. Aluminum. The plastic liner reduces friction and wear on soft welding electrode wires.
6. Turn the machine off and/or disconnect from the power supply. When working on any piece of equipment, it is essential to de-energize it to prevent accidents.
7. Drive roller size should be must match wire diameter exactly. The drive rollers need to match the wire size to properly feed the wire through the whip/gun.
8. Rod. GMAW wire electrodes are identical to GTAW filler rods, the only difference being the lengths they are packaged as.
9. Argon. Argon is commonly used for non-ferrous metals like Aluminum and copper.
10. True. As the welding machine pulses between high and low current, the heat input is reduced.