Test Your Knowledge
- Name three benefits of using GMAW.
- The polarity used for almost all GMAW and FCAW is DCE _____ or DC _____ _____.
- Name three metal transfer methods.
- _____ is the property in an electric circuit that slows down the rate of current change.
- Spray transfer only occurs when the current is set above the _____ current.
- Spray transfer only occurs when at least _____ % argon is used.
- Which gun angle gives the deepest penetration—forehand, perpendicular, or backhand?
forehand perpendicular backhand - How many pounds and kilograms of filler metal can be deposited per hour with the spray transfer method?
- Other than setting switches, what are the two main variables made on the welding machine or wire feeder prior to welding?
- A GMAW power source used for pulsed spray transfer must have what additional controls?
- Using spray arc transfer, _____ volts and _____ amperes are used with a 0.045″ (1.1mm) electrode to weld stainless steel.
- _____ volts and _____ amps are used to weld mild steel using short-circuiting transfer and 0.035″ (0.9mm) diameter wire.
- On the wire drive unit shown in Figure 9-23, wire guides and drive rolls are aligned by loosening the _____ _____ securing bolts and moving the _____ _____ up or down.
- To feed the welding wire through the electrode cable to the arc welding gun, the _____ switch is operated.
- What factors must be considered when choosing a shielding gas?
- Argon has a(n) _____ thermal conductivity than helium, so _____ is used to weld thick aluminum or copper sections.
- Why is good ventilation important when using CO2 gas?
- What effect does oxygen (O2) have on the arc when mixed with argon?
- Which gases are suggested for use with pulsed spray transfer?
- What argon flow rate in ft3/hr. and L/min should be used to weld 0.125″ (3.2mm) thick magnesium?
- What part of the gas metal arc welding gun contacts the welding wire and passes electricity to the electrode?
- How can metal spatter be kept from sticking to the nozzle?
- Electrode extension is the distance from the end of the _____ _____ to the end of the _____.
- The suggested travel angle to obtain the best weld pool control with backhand welding is _____ ° to _____ °.
- List three possible causes for an undercut weld bead.