What are the Different Types of Welding?

There are more than thirty different types of welding, from simple oxy-fuel (using a flame) welding to high-tech processes such as laser beam welding. This article will explain the differences between the four most commonly used welding processes of MIG, TIG, Stick and Flux- Cored arc welding. Though these processes can be done by automated equipment, they are mostly practiced by trained welders.

Stick - Shielded Metal Arc Welding (SMAW)

Shielded Metal Arc Welding, commonly called Stick, is a welding process that uses an electrode (welding rod) to carry the electric current and provide the majority of the weld metal. The electrode consists of a core wire coated in flux. An electric arc is created across the gap when the energized circuit and the electrode tip touches the work piece and is withdrawn, yet still within close contact, generating temperatures of approximately 6500°F. This heat melts both the base metal and the electrode creating the weld. During this process, the molten metal is protected from oxides and nitrides in the atmosphere by a gaseous shield created by the vaporizing of the flux coating. The electrode produces a slag covering on the finished weld.

Typical Uses: Steel Erection, Heavy equipment repair, Construction, Pipeline Welding

 
Advantages Disadvantages
  • Low cost equipment
  • Lower consumable efficiency (waste is produced)
  • Portability
  • Difficult to use on thin materials
  • No need for shielding gas (can be used outside during rain or wind)
  • High operator skill required
  • Works on dirty or rusty metal


TIG - Gas Tungsten Arc Welding (GTAW)

Gas Tungsten Arc Welding, commonly called TIG or Heliarc, is a welding process that uses a non-consumable tungsten electrode to heat the base metal and to create a molten weld puddle. An autogenous (no filler metal) weld can be created by melting two pieces of metal together. An external filler rod can be added into the molten puddle to create the weld bead and increase mechanical properties. Like the GMAW process, the molten weld puddle needs to be shielded by an external gas supply. The most commonly used shielding gas is argon, but argon/helium mixtures can be used on heavy aluminum. GTAW can be used to weld most alloys.

Typical Uses: Aerospace welding, piping systems, motorcycles or bikes

Advantages Disadvantages
  • Clean, high quality welds
  • High operator skill required
  • Ability to weld very thin materials
  • High cost equipment
  • Wide range of alloys can be welded
  • Lower deposition rates
  • Spatter free welds
  • Need external shielding gas
  • Highly aesthetic weld beads
  • Material must be free of rust and dirt


MIG - Gas Metal Arc Welding (GMAW)

Gas Metal Arc Welding, commonly called MIG welding, is a process that uses a continuously fed, solid wire electrode through a welding "gun." The operator pulls a trigger on the welding gun, which feeds the consumable electrode through. An electric arc forms between the electrode and the base material, which heats the base material, causing it to melt, and join.  The molten weld metal is protected from oxides and nitrides in the atmosphere by an externally supplied shielding gas. The most commonly used gas is carbon dioxide or a mixture of argon and carbon dioxide. The GMAW process can be used to weld a wide range of alloys including carbon steel, stainless steel, magnesium, nickel, copper, silicon bronze and aluminum.

Typical Uses: Small to large manufacturing, Auto Body, Fabrication

Advantages Disadvantages
  • Higher Electrode Efficiency (Less Waste)
  • Need external shielding gas
  • Lower Heat Inputs
  • Limited positions (no vertical or overhead)
  • Minimal weld clean up
  • High cost equipment
  • Reduced Welding Fumes
  • Cannot weld thick materials
  • Easiest to learn
  • Material must be free of rust and dirt

Flux-Cored Arc Welding - (FCAW)

Flux-cored Arc Welding is a welding process similar to GMAW, in that it uses a continuously fed electrode, but uses a tubular wire filled with flux instead of a solid wire. There are two types of flux-cored wire, self-shielded and dual shield. Self-shielded is used without the aid of an external gas shield and uses the flux to shield the molten weld puddle. Dual shield uses the flux and an external shielding gas to protect the molten weld puddle. Typical shielding gases are carbon dioxide and argon/carbon dioxide mixes. Self-shielded wires are optimal for outdoor use, even in windy situations. Both wires produce a slag covering on the finished weld.

Typical Uses: Thick materials, Steel Erection, Heavy Equipment construction or repair

Advantages Disadvantages
  • Higher Electrode Efficiency (Less Waste)
  • Creates slag
  • Lower Heat Inputs
  • Not recommended for thin materials
  • Minimal weld clean up
  • A lot of smoke is generated
  • Reduced Welding Fumes
  • High cost equipment
  • No need for external shielding gas