Types Of Welding Processes

Picture stating "types of welding processes."

 

There are over 40 types of welding but only four welding processes are commonly used world wide including:

  • SMAW –  Shielded Metal Arc Welding also called Arc and Stick welding
  • GMAWGas Metal Arc Welding also called MIG welding
  • FCAWFlux Cored Arc Welding also called Flux Cored
  • GTAWGas Tungsten Arc Welding also called TIG and Heliarc

 

The Four Common Types of Welding Processes

“List of Common Types of Welding Processes”

In this article we will explore all the common types of welding processes and also provide an overview of the less common types of welding.

 

1) SMAW (Shielded Metal Arc Welding)

SMAW is also known as stick welding and sometimes referred to as arc welding. The SMAW welding process was first patent in 1890 by C.L. Coffin of Detroit, Michigan but was not widely available and perfected until the late 1920’s.

Stick welding utilizes a metal rod called an electrode or “stick” coated with a layer of welding flux. When the flux burns it creates a gas that protects the arc, removes oxygen and among other things cleans the base metal being welded.  The actual metal rod melts due to the electrical arc and becomes what we call “filler metal.”

There are literally 100’s of different types and brands of welding electrodes that can weld a variety of base metals including carbon steel, stainless steel and aluminum.

Advantages of (SMAW) stick welding

  • Low equipment cost
  • Great for confined space welding, ability to bend the welding rod/electrode
  • Great for outdoor and fairly windy conditions
  • Capable of welding on somewhat dirty or rusted metal surfaces
  • Does not require an external gas bottle (shielding gas)

Disadvantages of (SMAW) stick welding

  • Slag must be removed from welds
  • Has a large heat affected zone
  • Not suitable for production welding due to a lower metal deposition rates
  • Can be utilized to weld aluminum but is not recommended as a first choice

 

2) GMAW (Gas Metal Arc Welding)

GMAW  is also known as and commonly called MIG (Metal Inert Gas) welding. MIG welding become a mainstream and economical type of welding in the early 1950’s. GMAW utilizes a wire spool as an electrode that is continually and automatically fed into the weld pool.

Picture of an aluminum spool gun for mig welding aluminum.
Aluminum Spool Gun

This makes it an excellent type of welding in production and manufacturing settings. Since the bare wire electrode does not contain any welding flux you must use a shielding gas while MIG welding. The shielding gas is often 100% Argon but other inert gasses can be used.

There are many different types of MIG welding wire including stainless, aluminum and other alloys. An aluminum spool gun must be utilized though when using aluminum MIG welding wire.

 

Advantages of (GMAW) MIG welding

  • Extremely high metal deposition rates
  • User friendly and the easiest type of welding to learn
  • MIG welding is “clean”, meaning that there is no slag to remove and weld splatter is minimal
  • A versatile welding process that can be used on many different types of base metals
  • Suitable for welding thin metals (less than 20 gauge)

Disadvantages of (GMAW) MIG welding

  • Not suitable for welding “dirty” or even slightly rusted metal
  • Equipment costs are higher than other types of welding
  • Can not be reliably used in windy conditions as the shielding gas can be blown away easily
  • Work must be close to the wire spool feeder/welder

 

3) FCAW (Flux Cored Arc Welding)

FCAW is very similar to MIG welding in the fact that it utilizes a wire electrode that is continuously fed into the weld pool. There are two main differences though.

  • FCAW does not use an externally bottled shielding gas like MIG welding. FCAW wire has a welding flux in the core or center of the wire that when burned creates the shielding gas.
  • FCAW is excellent for welding thicker metals and but will not produce quality welds (generally speaking) on base metals that are thinner than about 20 gauge.

Similar to SMAW/Stick welding Flux Cored welding produces a slag that must be removed from the weld.

Advantages of FCAW over GMAW/MIG welding

  • Can be used to weld “dirtier” or slightly rusted metals
  • Excels at welding thicker metals
  • Better in windy conditions

 

4) GTAW (GAS Tungsten Arc Welding)

GTAW is also commonly referred to as TIG welding and sometimes Heliarc. It is commonly used to weld alloys, aluminum and plate as well as pipe. TIG/GTAW utilizes a non-consumable tungsten electrode, inert gas and a separate bare wire filler rod. The tungsten produces a very fine, thin and stable arc suitable for almost all types of base metals. As the weld pool is formed by the electrical arc the filler metal is added manually with the other hand.

TIG welding first came into use in the early 1940’s during WWII. It was then referred to as Heliarc welding because the inert shielding gas used then was Helium.

 

Advantages of (GTAW) TIG welding

  • Excels at welding thinner metals
  • Has a very small heat affected zone
  • Offers precise control and produces very high quality welds in the hands of an experienced welder
  • Produces very clean welds with no slag and no spatter
  • Excellent for welding exotic and alloy metals

Disadvantages of (GTAW) TIG welding

  • Low metal deposition rates
  • Requires a highly skilled welder to produce satisfactory weld
  • Costly to weld thicker metals
  • Requires a shielding gas from an external gas bottle

 

The 14 Uncommon Types of Welding Processes

“List of Uncommon and Specialized Types of Welding Processes”

1) Explosion Welding (EXW)

Explosion Welding uses a chemical explosive to accelerate one piece of metal into another thus bonding them together. Basicly one piece of metal is thrown so hard against another that it bonds immediately. Explosion welding is often used for cladding metal.

 

2) Oxy-fuel Welding (OAW)

Oxy-fuel welding, also commonly referred to as torch welding utilizes oxygen gas and a fuel gas like acetylene to produce a flame capable of melting the base metal. When the weld pool is formed a bare wire welding rod/filler metal is manually added with the other hand. The torch that is used is the same type of torch used for cutting but has a specially designed welding tip to produce a fine, high temperature flame.

Other types of oxy-fuel welding include the following:

 

3) Submerged Arc Welding (SAW)

Submerged Arc Welding is a wire fed welding process (similar to GMAW/MIG) that is capable of extremely high metal deposition rates. That actual arc is concealed from veiw under a bath of granulated, dry flux.

 

4) Atomic hydrogen welding

Atomic hydrogen welding utilizes an electrical arc and two tungsten electrodes and a shielding gas of hydrogen. This type of welding produces one of the hottest flames known to man at 6,191.6 degrees fahrenheit and is capable of melting tungsten.

 

5) Carbon Arc Welding (CAW)

Carbon arc welding is a type of welding that utilizes an electrical arc between the base metal and carbon electrode. The arc reaches temperatures of over 3,000 degrees celsius instantly bonding the metal.

 

6) Plasma Arc Welding (PAW)

Plasma arc welding is similar to GTAW/TIG but differs in the fact that it produces a much hotter 50,000 degree fahrenheit “plasma arc” in order to melt the base metal. Plasma can be defined simply as a super heated gas.

 

7) Resistance Spot Welding

Resistance spot welding is often used in factory setting to produce very small welds. Two very small and pinpointed welding electrodes pass an electrical current between them. When the base metal is  between the two electrodes it becomes molten and bonds together.

 

8) Upset Welding (UW)

Upset welding is when you get angry and weld… Ok not really. Upset welding applies a a through two base metals, heats them and then applies pressure to the two base metals. This type of welding is often used to join butt joints.

 

9) Coextrusion Welding (CEW)

Coextrusion Welding forces two or more metals through a die and the shear force bonds them together.

 

10) Cold Pressure Welding (CW)

Cold pressure welding is sometimes called Contact Welding, it requires no heat or liquid metal. This welding process uses a large amount of pressure applied to both metals in a vacuum in order to adhere them together. This process is most often used in electronics manufacturing.

 

11) Forge welding (FOW)

Forge welding is the oldest type of welding known to man. Both sections of metal to be welded are heated to a high temperature and then pounded or forged together with a manual hammer or automated hammer.

 

12) Friction welding (FRW)

Friction welding is a type of welding that uses heat generated from mechanical friction and pressure. This welding process is common in the aviation and auto manufacturing industry.

 

13) Hot pressure welding

Hot pressure welding is a welding processes that uses heat and mechanical force is applied to the workpiece in order to bond them.

 

 14) Ultrasonic Welding

Ultrasonic welding is a process where vibrations are used to bond two metals together.