Test Your Knowledge
- Name the welding processes covered in this chapter that can use a shielding gas to shield the weld area.
- What type of welding current can be used with GTAW?
- A GTAW electrode is held in the torch by a(n) _____.
- GTAW welding power sources are constant _____ machines.
- What is the advantage of using a constant voltage power source?
- Why is a high-frequency voltage used continually in an ac circuit that is being used for GTAW?
- List five reasons why argon is more frequently used for GTAW than helium.
- When GTAW, which shielding gas is best for use in cross drafts? Gives the best cleaning action? Provides the greatest heat conductivity?
- A regulator controls and measures _____. A flowmeter measures and controls the _____ of gas flow.
- The maximum amperage used on a gas-cooled GTAW torch is generally _____ amperes.
- What determines the nozzle diameter that should be used for GTAW or GMAW?
- What is the advantage of using thoriated tungsten electrodes?
- The color coding of a 2% thoriated tungsten electrode is _____.
- The arc welding power source used for GMAW and FCAW produces a constant _____.
- GMAW power sources have a sloping voltage curve. How much slope should the curve have for use with carbon dioxide (CO2) gas?
- Increasing the wire feed rate in GMAW or FCAW increases the _____ in the circuit.
- The shielding gas mixture suggested in Figure 7-41 for welding low-alloy steel with the short circuit GMAW process is _____% –_____% He, _____% –_____% Ar, and_____% –_____% CO2.
- Which gas produces the deepest penetration when used in GMAW?
- To produce better metal transfer through the arc, reduce spatter, and stabilize the arc, _____ and _____ are added to argon or helium.
- Describe the following GMAW electrode completely: ER90S-B3L.
- What two methods can be used in FCAW to shield the weld from atmospheric contamination?
- When feeding a FCAW electrode through the wire feed mechanism, care must be taken not to _____ the flux cored wire.
- Describe five functions that flux can perform during flux cored arc welding.
- Describe the following FCAW electrode completely: E80T-2.
- What number filter lens is recommended for welding steel with the GTAW process and current of 80A? For welding steel using the GMAW process and a current of 220A?