| Process
|
Notes
|
| Resistance
|
- Pressure + current causes melting together
- Butt, seam, spot
|
| Oxy-Acetylene
|
- Melted by oxy flame, filler metal added
- Earliest welding
- Can weld steel, cast iron, and some non-ferrous alloys
|
| Electric Arc
|
- Melted by electrode which acts as filler (consumed)
- Flux used to prevent oxidation
- Faster than oxy
|
| MIG
|
- Continuous (consumable) feed wire/electrode – faster
- Inert gas (e.g. argon) to prevent oxidation
- Easily automated - used extensively in manufacturing
|
| TIG
|
- Tungsten (non-consumable) electrode
- Filler rod
- Inert gas shield
- Stainless steel, aluminium & titanium alloys – welds reactive metals
|