How well do you really understand MIG welding? Here are some questions (and answers) to test your knowledge! Write down your answers, then go to the answers page to see how you did!

1.) In the GMAW process, what is the primary source of deoxidizers and alloying elements that contribute to the purity and mechanical properties of the weld metal?

A. The wire
B. The shielding gas
C. The mode of transfer
D. The weld parameters

2.) What is the purpose of copper coating on MIG wires?

A. To prevent rust
B. To increase contact tip life
C. To assure good electrical conductivity
D. All the above

3.) What elements are most commonly added to GMAW wires as deoxidizers?

A. Molybdenum and Copper
B. Nickel and Molybdenum
C. Manganese and Silicon
D. Silicon and Chromium

4.) Rust is a source of:

A. Silicon
B. Oxygen
C. Manganese
D. Nickel

5.) In GMAW, using 100% CO2 shielding gas produces:

A. less spatter and concave welds
B. more spatter and convex welds
C. more spatter and flatter welds

6.) What type of power supply is commonly used for general GMAW welding?

A. Constant Current
B. Constant Voltage
C. Pulse
D. Syncrowave

7.) As the percentage of CO2 in the shielding gas increases, the amount of alloy recovered in the weld metal:

A. increases
B. decreases
C. stays the same

8.) What does the “D” indicate on a wire classified as an ER 80S-D2?

A. Downhand use only
B. 0.5% Molybdenum
C. No preheating required
D. 1% Molybdenum

9.) What limitation exists for use of GMAW-Spray transfer?

A. Position of welding
B. Polarity
C. Mechanical Properties
D. Highher Diffusable Hydrogen

10.) Cold Lap can occur with:

A. Short circuit transfer
B. Globular transfer
C. Spray transfer
D. All of the above

11.) For Globular transfer in GMAW, what shielding gas is used?

A. 75% Argon, 25% CO2
B. 100% CO2
C. 92% Argon, 8% CO2
D. 85% Argon, 15% CO2

12.) What is the major reason for using a Modified Spray?

A. Increased travel speed
B. Higher Deposition efficiency
C. Uses less shielding gas
D. Better mechanical properties

13.) Generally, what is the minimum Argon percentage required to achieve a “true” spray transfer?

A. 75%
B. 70%
C. 80%
D. 90%

14.) What is the major advantage of GMAW over SMAW?

A. Higher Deposition
B. Simplicity of equipment
C. Portability
D. Versatility

15.) What limits the short circuit current?

A. Inductance
B. Slope
C. Wire Feed Speed
D. Voltage

16.) Why would you use the GMAW Pulse-Spray mode of transfer?

A. Increased deposition rate over spray
B. All position capability
C. Uses less shielding gas
D. Higher current levels