Flux-cored arc welding


Flux-cored arc welding

Flux-cored arc welding (FCAW) is a semi-automatic or automatic arc welding process. FCAW requires a continuously-fed consumable tubular electrode containing a flux and a constant voltage or, less commonly, a constant electric current welding power supply. An externally supplied shielding gas is sometimes used, but often the flux itself is relied upon to generate the necessary protection from the atmosphere. The process is widely used in construction because of its high welding speed and portability.

FCAW was first developed in the early 1950’s as an alternative to shielded metal arc welding (SMAW). The advantage of FCAW vs. SMAW is that the use of stick electrodes (like those used in SMAW) was unnecessary. This helped FCAW to overcome many of the restrictions associated with SMAW.

Two Types of FCAW

The first type of FCAW is the type that requires no shielding gas. This is made possible by the flux core in the tubular consumable electrode. However, this core contains more than just flux; it also contains various ingredients that when exposed to the high temperatures of welding generate a shielding gas for protecting the arc. This type of FCAW is preferable because it is portable and has excellent penetration into the base metal. Also, the conditions of air flow do not need to be considered.

The second type of FCAW uses a shielding gas that must be supplied by an external supply. This type of FCAW was developed primarily for welding steels. In fact, since it uses both a flux cored electrode and an external shielding gas, one might say that it is a combination of gas metal (GMAW) and flux-cored arc welding (FCAW). This particular style of FCAW is preferable for welding thicker and out-of-position metals. The slag created by the flux is also easier to remove. However, it cannot be used in a windy environment as the loss of the shielding gas from air flow will produce visible porosity (small craters) on the surface of the weld.

FCAW key process variables

* Wire feed speed (and current)
* Arc voltage
* Electrode extension
* Travel speed
* Electrode angles
* Electrode wire type
* Shielding gas composition (if required) Note: FCAW wires that don't require a shielding gas commonly emit fumes that are extremely toxic; these require adequate ventilation or the use of a sealed mask that will provide thea welder with fresh air.
* Travel Angle.

FCAW advantages and applications

* FCAW may be an "all-position" process with the right filler metals (the consumable electrode)
* No shielding gas needed making it suitable for outdoor welding and/or windy conditions
* A high-deposition rate process (speed at which the filler metal is applied) in the 1G/1F/2F
* Some "high-speed" (e.g., automotive applications)
* Less precleaning of metal required
* Metallurgical benefits from the flux such as the weld metal being protected initially from external factors until the flux is chipped away
* Low operator skill is required

"Used on the following alloys:"
* Mild and low alloy steels
* Stainless steels
* Some high nickel alloys
* Some wearfacing/surfacing allo

FCAW disadvantages

Of course, all of the usual issues that occur in welding can occur in FCAW such as incomplete fusion between base metals, slag inclusion (non-metallic inclusions), and cracks in the welds, etc . . . But there are a few concerns that come up with FCAW that are worth taking special note of:
* Melted Contact Tip – happens when the electrode actually contacts the base metal, thereby fusing the two
* Irregular wire feed – typically a mechanical problem
* Porosity – the gases (specifically those from the flux-core) don’t escape the welded area before the metal hardens, leaving holes in the welded metal
* More costly filler material/wire as compared to GMAW
* Less suitable for applications that require painting, such as automotive body works

References and further reading

American Welding Society, Welding Handbook, Vol 2 (9th ed.)

"Flux Cored Welding." Welding Procedures & Techniques. 23 June 2006. American Metallurgical Consultants. 13 Sep 2006 .

Groover, Mikell P. Fundamentals of Modern Manufacturing. Second. New York City: John Wiley & Sons, INC, 2002.

"Solid Wire Versus Flux-Cored Wire - When to Use Them and Why." Miller Electric Mfg. Co. 13 Sep 2006 .


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Flux cored arc welding (FCAW) — Flux cored arc welding (FCAW). См. Дуговая сварка с флюсом. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • Arc welding — uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non consumable electrodes.… …   Wikipedia

  • Shielded metal arc welding — (SMAW), also known as manual metal arc (MMA) welding, flux shielded arc welding …   Wikipedia

  • Gas metal arc welding — RMD redirects here. RMD may also refer to IRA Required Minimum Distributions. Gas metal arc welding …   Wikipedia

  • Gas tungsten arc welding — TIG welding of a bronze sculpture Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG …   Wikipedia

  • Submerged arc welding — (SAW) is a common arc welding process. Originally devolved by the Linde Union Carbide Company. It requires a continuously fed consumable solid or tubular (flux cored) electrode. The molten weld and the arc zone are protected from atmospheric… …   Wikipedia

  • Welding — is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld puddle ) that cools to… …   Wikipedia

  • Flux (metallurgy) — Rosin used as flux for soldering A flux pen used f …   Wikipedia

  • Welding power supply — A welding power supply is a device that provides an electric current to perform welding. Welding usually requires high current (over 80 amperes) and it can need above 12,000 amps in spot welding. Low current can also be used; welding two razor… …   Wikipedia

  • Welding defect — A welding defect is any flaw that compromises the usefulness of the finished weldment. According to the American Society of Mechanical Engineers (ASME) welding defect causes are broken down into the following percentages: 41% poor process… …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.