Principles of GMAW Assessment

The polarity utilized when welding with the GMAW process is:

• DCEP
• DCEN
• AC

To set the polarity when welding with the GMAW process:

• Both Install the welding cables on the correct terminals and Use the polarity selector switch on the power source
• Install the welding cables on the correct terminals
• Use the polarity selector switch on the power source
• Install the correct drive roll

The loss of shielding gas when welding outdoors can cause weld failures as a result of:

• All of the above
• Porosity
• Other undesirable discontinuities in the weld
• Lack of fusion

GMAW may be used to weld which of the following metals?

• All of the above
• Steel
• Stainless Steel
• Aluminum

A constant voltage system strives to keep which variable(s) constant?

• Arc length
• Stick out
• Shielding gas
• None of the above

How is current carried to the arc in the GMAW process?

• The electrode is energized by the contact tip that then carries the current to the arc.
• The shielding gas carries the electric current to the nozzle.
• The current is picked up at the drive rollers by the electrode and carried through the liner, the diffuser and the contact tube to the arc.
• None of the above

Which statement explains the role of shielding gas in GMAW?

• To force the atmospheric air away from and thus protect the molten metal from the devastating effects of the unwanted reactions with the atmospheric oxygen, nitrogen and water vapor.
• The shielding gas acts as a factor in the method of metal transfer from the electrode to the weld joint.
• Helps shape the cross section of the weld deposit to increase molten metal temperature, stabilize the arc and regulate penetration.
• None of the above

The GMAW process was first developed to weld ____________________________.

• Inconel
• Steel
• Aluminum
• None of the above
• Stainless steel

The earliest mode of metal transfer was known as:

• Spray transfer
• Short circuit transfer
• Globular transfer
• None of the above
• STT

The addition of a reactive gas to the shielding gas improved arc stability and permitted new metals to be welded. The first reactive gas utilized was:

• Oxygen
• Carbon dioxide
• Argon
• Nitrogen
• Helium