MMET 181 - Exam 2 with Complete
Solutions
Affects of positive or negative weldment in arc welding. (189) Correct Ans-- Positive = less
energy, shallow
- Negative = more energy, deep penetration
(SMAW) Shield Metal Arc Welding Correct Ans-- Type of fusion welding (Arc)
- A coated electrode is used to provide energy to the weld and necessary shield gas
- Pro: min oxidation, simple, economical
- Con: Slag removal, change of electrode
TIG Welding Correct Ans-- Fusion Welding (Arc)
- Tungeston = electrode (avoid consumption of electrodes)
- External Shielding Gas
- Pro: No electrode wear, no slag, high quality weld
- Con: Need filler, high heat loss due to gas flow
SAW Welding Correct Ans-- Type of fusion welding (Arc)
- Granular flux deposits = shielding
- Long consumable ectrode used
- Pro: Ease of authomation, shield visible sparks, mimimize spatter
- Con: Limit to horizontal whelding, slag removal
,Resistance Spot Welding Correct Ans-- A current flows across the copper electrode and melts
the two sheets.
- Just used for metal sheets
- Pro: No shielding gas, no filler material, mass production
- Con: Conductive sheets, no corner welding, possible leak
Where does the weld occur in resistance spot welding? Correct Ans-Between the two sheets
Flash Welding Correct Ans--Types of fusion welding
- Similar to resistance welding but can be used for different shapes.
- air is squeezed out = no oxygen
- Pro: No oxidation, fast, no slag
- Con: Conductive material only, butt joint only, flash removal
- Typical application: chains, pipelines
Energy Beam Welding Correct Ans-- Type of fusion welding
- Used for small and precise welds
- High power density
- Low energy
Types of Energy Beam Welding Correct Ans--Laser
, + Pro: high power density, fast, in air operations
+ Con: Reflective, thermal defects
E-Beam
+ pro: high power density, fast, deep penetration
+ Con: Vacuum, conductive material
I-Beam
+ Pro: High power density, fast
+ Con: Vacuum, conductive materials
Types of Solid State Welding Correct Ans-- Friction
- Stir
Solid State Welding Correct Ans-High pressure + low heat = melting
Friction Welding Correct Ans-- Type of Solid State welding
- Utilizes heat generated by mechanical friction for welding
- pro: conductive/non-conductive, no shielding gas, no slag
- Con: Flash removal, symmetric parts only
Stir Welding Correct Ans-- Type of solid state welding
- Uses rotating tool to but weld two components.
- Pro: conductive/non-conductive, no shielding gas, no slag
Solutions
Affects of positive or negative weldment in arc welding. (189) Correct Ans-- Positive = less
energy, shallow
- Negative = more energy, deep penetration
(SMAW) Shield Metal Arc Welding Correct Ans-- Type of fusion welding (Arc)
- A coated electrode is used to provide energy to the weld and necessary shield gas
- Pro: min oxidation, simple, economical
- Con: Slag removal, change of electrode
TIG Welding Correct Ans-- Fusion Welding (Arc)
- Tungeston = electrode (avoid consumption of electrodes)
- External Shielding Gas
- Pro: No electrode wear, no slag, high quality weld
- Con: Need filler, high heat loss due to gas flow
SAW Welding Correct Ans-- Type of fusion welding (Arc)
- Granular flux deposits = shielding
- Long consumable ectrode used
- Pro: Ease of authomation, shield visible sparks, mimimize spatter
- Con: Limit to horizontal whelding, slag removal
,Resistance Spot Welding Correct Ans-- A current flows across the copper electrode and melts
the two sheets.
- Just used for metal sheets
- Pro: No shielding gas, no filler material, mass production
- Con: Conductive sheets, no corner welding, possible leak
Where does the weld occur in resistance spot welding? Correct Ans-Between the two sheets
Flash Welding Correct Ans--Types of fusion welding
- Similar to resistance welding but can be used for different shapes.
- air is squeezed out = no oxygen
- Pro: No oxidation, fast, no slag
- Con: Conductive material only, butt joint only, flash removal
- Typical application: chains, pipelines
Energy Beam Welding Correct Ans-- Type of fusion welding
- Used for small and precise welds
- High power density
- Low energy
Types of Energy Beam Welding Correct Ans--Laser
, + Pro: high power density, fast, in air operations
+ Con: Reflective, thermal defects
E-Beam
+ pro: high power density, fast, deep penetration
+ Con: Vacuum, conductive material
I-Beam
+ Pro: High power density, fast
+ Con: Vacuum, conductive materials
Types of Solid State Welding Correct Ans-- Friction
- Stir
Solid State Welding Correct Ans-High pressure + low heat = melting
Friction Welding Correct Ans-- Type of Solid State welding
- Utilizes heat generated by mechanical friction for welding
- pro: conductive/non-conductive, no shielding gas, no slag
- Con: Flash removal, symmetric parts only
Stir Welding Correct Ans-- Type of solid state welding
- Uses rotating tool to but weld two components.
- Pro: conductive/non-conductive, no shielding gas, no slag
