AGM 2050 TEST 2 QUESTIONS & VERIFIED ANSWERS
MIG - Answers - Metal inert gas
GMAW - Answers - Gas Metal Arc Welding
What is the most common shielding gas - Answers - CO2 (its cheap and readily
available)
What are some advantages of MIG welding? - Answers - - faster than arc welding
- Gaseous shield (no slag)
- minimal skill required
- smaller heat-affect zone
- thick and thin metals
- deep penetration (less prep)
- ferrous and non-ferrous metals
What is the power unit used for MIG welding? - Answers - DC electrode positive
(mostly)
How does the current change if the arc length is shortened? - Answers - increase
current
How does the current change if the arc length is lengthened? - Answers - decrease
current
What can you adjust in MIG welding? - Answers - - Voltage control
- Wire speed feed
- Shielding gas flow rate
- amperage adjustment is automation
What are common wire sizes in MIG welding? - Answers - - 0.030"
- 0.035"<- what we run
-0.040"
What is burnback? - Answers - Wire is fused to contact tip
Why do you not want to use aluminum with a push drive wheel? - Answers - The
aluminum is so soft it will birds nest inside the gun line
What does the contact tip do? - Answers - Transmits current to electrode wire (copper
alloy)
What is the one thing you need to consider for push drive wheels? - Answers - Stiff wire
only
, What do shielding gasses do? - Answers - Displace atmospheric air with a cover
protective gas
What are the properties of nitrogen in welds? - Answers - - decrease ductility = cracks
- porosity in bead
What are the properties in oxygen in welds? - Answers - - CO = porosity
- iron oxides = weakens weld
- can be desirable
What are the properties of hydrogen in welds? - Answers - - cracking due to escape and
voids
- preheat to remove moisture
What does it mean if a gas is inert? - Answers - atoms are very stable
What are the different shielding gasses? - Answers - - argon
- helium
- carbon dioxide
- argon and oxygen
- argon and helium
- argon and carbon dioxide
- helium, argon, and carbon dioxide
What are the properties of argon? - Answers - - low ionization potential, creates stable
arc
- quiet, smooth arc; little splatter
- not for carbon steels
What are the properties of helium? - Answers - - Good conductor; for welding heavy
stock
- Wider welds, less penetration
What are the properties of carbon dioxide? - Answers - - most often used gas in MIG
welding
- good bead penetration, wide beads
- low costs
- unstable arc; splatter
-deoxidizers required (Si, Mn, Al)
What are the properties of argon and oxygen (1-5%)? - Answers - - eliminates
undercutting
- improves weld contour
- SS, carbon steels, low alloy steels
MIG - Answers - Metal inert gas
GMAW - Answers - Gas Metal Arc Welding
What is the most common shielding gas - Answers - CO2 (its cheap and readily
available)
What are some advantages of MIG welding? - Answers - - faster than arc welding
- Gaseous shield (no slag)
- minimal skill required
- smaller heat-affect zone
- thick and thin metals
- deep penetration (less prep)
- ferrous and non-ferrous metals
What is the power unit used for MIG welding? - Answers - DC electrode positive
(mostly)
How does the current change if the arc length is shortened? - Answers - increase
current
How does the current change if the arc length is lengthened? - Answers - decrease
current
What can you adjust in MIG welding? - Answers - - Voltage control
- Wire speed feed
- Shielding gas flow rate
- amperage adjustment is automation
What are common wire sizes in MIG welding? - Answers - - 0.030"
- 0.035"<- what we run
-0.040"
What is burnback? - Answers - Wire is fused to contact tip
Why do you not want to use aluminum with a push drive wheel? - Answers - The
aluminum is so soft it will birds nest inside the gun line
What does the contact tip do? - Answers - Transmits current to electrode wire (copper
alloy)
What is the one thing you need to consider for push drive wheels? - Answers - Stiff wire
only
, What do shielding gasses do? - Answers - Displace atmospheric air with a cover
protective gas
What are the properties of nitrogen in welds? - Answers - - decrease ductility = cracks
- porosity in bead
What are the properties in oxygen in welds? - Answers - - CO = porosity
- iron oxides = weakens weld
- can be desirable
What are the properties of hydrogen in welds? - Answers - - cracking due to escape and
voids
- preheat to remove moisture
What does it mean if a gas is inert? - Answers - atoms are very stable
What are the different shielding gasses? - Answers - - argon
- helium
- carbon dioxide
- argon and oxygen
- argon and helium
- argon and carbon dioxide
- helium, argon, and carbon dioxide
What are the properties of argon? - Answers - - low ionization potential, creates stable
arc
- quiet, smooth arc; little splatter
- not for carbon steels
What are the properties of helium? - Answers - - Good conductor; for welding heavy
stock
- Wider welds, less penetration
What are the properties of carbon dioxide? - Answers - - most often used gas in MIG
welding
- good bead penetration, wide beads
- low costs
- unstable arc; splatter
-deoxidizers required (Si, Mn, Al)
What are the properties of argon and oxygen (1-5%)? - Answers - - eliminates
undercutting
- improves weld contour
- SS, carbon steels, low alloy steels
