FCAW and GMAW Differences, Features, Principles and Applications

The major FCAW and GMAW differences are in their consumables. GMAW uses a consumable wire electrode and that of FCAW uses flux-cored wire for laying welds. FCAW (Flux Cored Arc Welding) also known as flux-cored. This is the other most popular name of it in the welding industry. It is one of the welding processes known for joining metals. FCAW carries some of the features of GMAW, SMAW and SAW types. GMAW (Metal Inert Gas Welding) also known as MIG welding.

Post Highlights:

FCAW and GMAW Meaning
GMAW and FCAW Brief History
FCAW and GMAW Differences
Principles of FCAW and GMAW
FCAW and GMAW Equipment/Machine
Electrodes for FCAW and GMAW
Features of FCAW and GMAW
Applications of FCAW and GMAW
FCAW and GMAW Disadvantages
Job Types for FCAW and GMAW
FCAW and GMAW Employment Areas

FCAW and GMAW Differences, Meaning, Features, Principles, Equipment, Electrodes, Applicants, Disadvantages, Career Options

What is Flux Cored Arc Welding (FCAW)?

FCAW or flux-cored is a welding process that employs a wire containing certain materials in its core. After burning, it produces shielding gases and lays welds. Flux-cored arc welding is a bit difficult welding process due to its internal shielding. The shielding is very positive and produces some spatter. After laying welds, there is a slag covering it and normally it is removed. FCAW welding is mainly suitable for mild steel applications outdoors.

What is Gas Metal Arc Welding (GMAW)?

GMAW or Metal Inert Gas welding is a welding technique that uses a consumable wire electrode. Further, it makes an electric arc between metal and electrode for laying the welds. In the process, heat is produced between the metals, which melts them and makes weld joints. Welders mainly use MIG welding for attaching metals like steels, aluminum, and non-ferrous materials as well.

Brief History of FCAW and GMAW

History of FCAW – FCAW-G process (gas-shielded flux-cored arc welding) was first developed in the late 1950s. Over the years, manufacturers made so many improvements to their equipment and products. In old times, it was limited to the line of low alloy steel electrodes and carbon steel. It was offering this either for all welding positions or flat and horizontal only.

During that time, there were relatively few variations in the formulations of electrodes. Mostly, one available electrode was intended to be employed for different applications and welding processes. Often, either 100% carbon dioxide (CO2) shielding gas or mixed argon (Ar)/ CO2 shielding gas was to be applied.

In the 1950s, it was a general manufacturing philosophy of developing an electrode intended to be used for all products. However, it was successful to some extent in meeting the demands of welding markets.

But in modern times, the trends have been changed. Industrial designers and structural engineers are emphasizing of specifying higher-strength, lower-weight steels for cost savings and productivity. And this consideration, many industries have made these base materials their first choice.

History of GMAW – Bronze Age has the roots of the GMAW process. After so many years, Edmund Davy of England discovered acetylene in 1836 A.D. The electric generator was invented in the mid of the 19th century. Besides this, in those days, Arc welding with the carbon arc and metal arc was developed. In addition, resistance welding became a practical joining process.

As the years passed, many changes took place and new methods replaced by old ones. New techniques made modern welding industry handy and welder-oriented. At present, almost every metal is joined either by this process or that process. The use of inert gas with small amounts of oxygen became popular in the early 1960s and it provided the spray-type arc transfer.

Russian, formerly known as the Soviet Union, has developed an inertia welding process in recent years. It is a specialized process employed only where a volume of similar parts is be welded. The Laser welding process is somewhat the latest invention in the welding industry. Basically, laser technology can concentrate a huge amount of energy in a small space. Further, the concentration provides a powerful heat source. Laser welding can cut both metals and non-metals.

Differences between FCAW and MIG (GMAW)

Both the welding types have many differences despite some similarities. The differences between FCAW and GMAW are as follows.

FCAW (Flux Cored Arc Welding)	GMAW (Gas Metal Arc Welding)
FCAW produces both slag and spatters after welding and it needs to be clean.	GMAW has lower spatter and slag. So, the operator can obtain good travel speed. It is the easiest type of welding to learn.
It is good for outdoor works as the flux is in the wire and can produce positive shielding even in bad weather or windy conditions.	MIG welding can weld many types of materials such as nickel alloys, stainless, aluminum, and thinner material as well.
The flux-cored process is more suitable for thicker materials due to no risk of cold lapping.	GMAW welding is the best in terms of cosmetic appearance as it creates lower spatter than FCAW.
FCAW process is internal shielding.	The GMAW process is external shielding.

Generally, no single welding process is complete and cannot fix everything. Welders need to apply other welding types by keeping in mind various variables such as material thickness, wire feed speed, voltage settings, shielding gas, weld appearance, and location of the worksite.

Principle of FCAW and GMAW

FCAW Principle – FCAW is a welding process that employs a wire containing certain materials in its core. It produces shielding gases after burning and lays welds. The flux-cored process is generally a bit difficult way because of its internal shielding. The shielding is very positive and produces some spatter. It also lays a slag that covers the weld. Normally it is removed after cooling. The main function of slag is to protect the weld in molten form and imparts it time to cool. Most of the mild steel applications outdoor use the FCAW process.

Versions of FCAW Process-

The two basic versions of the FCAW process are self-shielded flux-cored arc welding (FCAW-S) and gas-shielded flux-cored arc welding (FCAW-G).

GMAW Principle – It is a welding type that uses a consumable wire electrode. Further, it makes an electric arc between metal and electrode for laying welds. Gas metal arc welding produces heat between metals, that further melts them and results in weld-joints. Metal industries related to non-ferrous materials, aluminum, and steels employ MIG welding for their operations.

FCAW and GMAW Equipment and Machines

FCAW Equipment
The FCAW equipment is almost similar to the GMAW process. The basic welding kit consists of the following items.

First (welding gun)

Second (power source)

Third (wire feeder and controls)

Fourth (welding cables)

GMAW Equipment
The four basic industrial components for GMAW are as follows.

First (Power Source)

Second (wire drive and accessories such as drive rolls, guide tubes, reel stand, etc.)

Third (gun and cable assembly design for shielding gas and the electrode to the arc.)

Fourth (shielding gas apparatus and accessories)

Electrodes for FCAW and MIG Welding Processes

FCAW Electrodes – The electrodes divided into two categories i.e. self-shielded, flux-cored electrodes (FCAW-S), and gas-shielded, flux-cored electrodes (FCAW-G). Originally, they were developed as a higher productivity extension of SMAW electrodes. These electrodes are tubes of steel with flux at the core. These electrodes are wrap-able into a coil or spool.

Some Specific FCAW Electrodes –

“HD” type FCAW-G electrodes – designed for high-deposition, out-of-position capability. (i.e., UltraCore® HD-C, UltraCore® HD-M).
“SR” type FCAW-G electrodes – used for stress-relieved applications. (i.e., UltraCore® SR-12).
FCAW-G electrodes – applied on chromium-molybdenum (Cr-Mo) steels. (i.e., Cormet 1, Cormet 2).
FCAW-G electrodes – designed for pipe welding applications. (i.e., Pipeliner® 81M, Pipeliner® 101M, Pipeliner® 111M).
FCAW-G electrodes – designed to be used with a specific type of shielding gas. (i.e., UltraCore® 71C, UltraCore® 71A85).
FCAW-G electrodes – employed in exceptionally high deposition rates in the flat and horizontal positions. (i.e., UltraCore® 70C, UltraCore® 75C).
FCAW-G electrodes – improved low-temperature toughness properties. (i.e., UltraCore® 712A80, UltraCore® 81Ni2A75-H).
FCAW-G electrodes – used on higher-strength steels (i.e. 80 ksi, 90 ksi, and 100 ksi minimum tensile strength). (i.e., UltraCore® 81Ni1A75-H, Outershield® 91K2-H, Outershield® 690-H).

GMAW Electrodes – Generally, welders need to match the electrode with base metal properties. Along with this, other parameters are welding position, type of transfer and resistance, abrasion, and heat.

GMAW Carbon Steel Electrodes-

ER70S-2 electrode – used for both single and multiple pass welding.
ER70S-3 (SuperArc® L-50) – used in both single and multiple pass welding applications.
ER70S-4 (SuperArc® L-54) – designed for both single and multiple pass welding.
ER70S-6 (SuperArc® L-56) – best suited for welding on base materials with moderate to high levels of mill scale.
ER70S-7 – can be used with argon/CO2 binary gas mixtures.
ER70S-G

GMAW-C Carbon Steel Composite Electrodes-

E110C-G (Metalshield® MC-1100) – used to weld over high levels of mill scale on base materials.
E70C-6M (Metalshield® MC-6 and Metalshield MC-706) – an excellent choice for welding on base materials with high levels of mill scale.
E90C-G (Metalshield® MC-900) – well suited to weld over high levels of mill scale on base materials.

Features of FCAW and GMAW

Some of the features of FCAW are as follows:

Normally, FCAW imparts high welding productivity.
It lays high quality and consistent welds with fewer defects.
FCAW process can weld both outdoor or in shop welding.
The welding arc has good visibility.
FCAW is suitable for all positions with the right filler metal.
The welding type has a high deposition rate.
FCAW is easier to learn vis-a-vis other welding processes.
It is more forgiving of rust, scale, and other base metal contaminants.
FCAW provides excellent weld penetration.

Some of the features of GMAW are as follows:

GMAW can weld a wide range of material types and thicknesses.
It emits less welding fumes in comparison to SMAW and FCAW processes.
GMAW has higher electrode efficiencies i.e. between 93% and 98%, compared to other welding processes.
Suitable for high-ended techniques like high-speed robotic, hard automation, and semiautomatic welding applications.
GMAW leaves less weld spatter and slag which cleans up weld fast and easy.
It has a lower hydrogen weld deposit i.e. generally less than 5mL/100g of weld metal.
GMAW is can lay welds in all welding positions.
It provides an excellent weld bead appearance.
GMAW requires lower heat input in comparison to other welding processes.
The equipment components of GMAW are readily available and affordable.
GMAW process has a higher welder efficiency and operator factor, vis-a-vis other open arc welding processes.

Benefits/Applications of FCAW and GMAW

Some of the benefits of FCAW are as follows:

FCAW process is a good choice for thicker materials due to no risk of cold lapping.
It has the capability to overcome atmospheric contamination.
FCAW can weld even in bad weather conditions or suitable for outside welding activities.

Some of the benefits of GMAW are as follows:

GMAW has generally lower cost per length of weld metal deposited to that of other open arc welding processes.
There is a minimal post-weld cleanup in the GMAW process.
Welders can handle poor fit-up with GMAW-S and STT modes.
GMAW has less distortion with GMAW-S (Short-Circuit Transfer Mode), STT™ (Surface Tension Transfer™), and GMAW-P (Pulsed Spray Transfer Mode).
The cost of GMAW electrodes is lower.
GMAW process produces less welding fume as well.

Disadvantages of FCAW and GMAW

The following are some disadvantages of FCAW.

FCAW emits a high level of harmful noxious fumes, and necessarily require ventilated.
The equipment of FCAW is more costly than other welding processes.
FCAW process is not well-suited to all types of metals.
Welders should remove every time the slag covering the weld.
FCAW type has a possibility of mechanical problems such as irregular wire feed, melted contact tips, and porosity of the weld.
The equipment is less portable than SMAW or GTAW processes.
FCAW process has a higher electrode wire cost vis-a-vis a solid electrode wire.

The following are some of the disadvantages of GMAW.

The use of argon based shielding gas for axial spray and pulsed spray transfer modes is costlier than 100% carbon dioxide (CO₂).
GMAW only can weld flat or horizontal welding positions in higher heat input mode of axial spray.
The welding type is limited to thin materials due to the lower heat input of the short-circuiting mode of metal transfer.
And GMAW is limited to thicker base materials if there is a higher heat input axial spray transfer.

Job Types for FCAW and GMAW

Some of the job types for FCAW and GMAW welding are as follows:

FCAW Job Types	GMAW Job Types
Combination Welder	Structural MIG Fitter/Welder
Combo Welder	Combination Welder
Entry Welder (Welder Trainee)	Apprentice Welder-Fitter
Fitter	Short-Arc (GMAW) Welder
Pipe Welder/Fitter	Welder (Fabrication)
Shop Pipe Welder	MIG Welder
Structural Welder (Entry Level)	Sub Arc Welder
Truck Assembler	Fabricator/Installer
Welder Fitter	Fab Shop Welder (Pipe)
Welder II	Pipe Welder
Welders (FCAW)	Welding Technician (Production)

Companies Offering Jobs for FCAW and GMAW Welders

Aspiring applicants can find jobs in the following best companies.

ALL Crane, Brook Park, OH
APTIM, Westwego, LA
BA Fabrication, Tucson, AZ
Brown & Root Industrial Services, Freeport, TX
Comfort Systems Mid-South, Montgomery, AL
Edwards Moving & Rigging, USA
FTS International, Aledo, TX
Phillips 66, Sweeny, TX
Pohlad Companies, Brunswick, GA
McDermott, Willis, TX.

Conclusion

After reading various aspects of the FCAW and GMAW welding process, both carry some similarities despite differences. Thus, both play a crucial role in welding activities in the industry.

Related: Other Welding Types