Flux Core Arc Welding is a popular welding process, it is a tubular wire that is filled with flux. The arc is initiated between the continuous wire and the base metal. The flux is filled in the core of the consumable, it melts during the welding process and shields the weld pool from atmospheric contamination. This welding process is very interesting because it generally provides good penetration into the base metal and is normally used in mild alloy steels, low alloy steels, stainless steels & high nickel alloys.
The Flux-cored arc welding process is further bifurcated into two self-shielded FCAW (without shielding gas) and gas shielded FCAW (with shielding gas). The difference between the two is due to different fluxing agents which are present in the consumables, which provide different benefits to the user. Usually, self-shielded FCAW is used for the outdoor welding process where the wind would blow away the shielding gas. The fluxing agents in self-shielded FCAW are designed to not only deoxidize the weld pool but also to allow for shielding of the weld pool and metal droplets from the atmosphere.
Flux-cored wire, welding can be performed in two ways first the carbon dioxide gas can be used with the flux to provide additional shielding and the flux core alone can provide all the shielding gas and slagging materials. In the process where the shield gas is used Co2 is most widely used because of its low costing and deep penetration. The direct current electrode positive (DCEP) is commonly employed as in the FCAW process. The process of welding through flux-cored arc welding is semi-automatic, here the feeders feed the wire consumable to maintain the continuity, and the arc length is adjusted by the power source. FCAW process is a combination of all excellent characteristics of shielded metal arc welding (SMAW/Stick welding) & gas metal arc welding (GMAW/MIG) because continuous wire provides high depositions and the flux helps in shielding the weldment as well as external gas is also used to do the same.