Flux-cored welding wire VS Solid welding wire

Welding wire can be divided into solid cored wire and flux-cored wire according to its structure. Most solid core wire is made of cold drawn steel wire, mainly include submerged arc welding wire (carbon steel, low alloy steel welding wire, stainless steel wire), gas shielded arc welding wire( TIG welding wire, MIG and MAG welding wire, CO2 welding wire), electro slag welding wire, surfacing welding wire, copper wire, nickel welding wire, aluminum welding wire, iron wire, etc. The flux-cored wire is a coating solid metal wire made of flux powder wrapped in the outer layer, that’s mainly iron powder, TiO2, SiO2, BaF2, Fe-Mn, Fe-Si, Al, Mg, etc, playing a series of beneficial parts in the welding process, such as protecting droplet and pool from oxidation, nitriding, assisting weld forming, stabilizing arc, deoxidation, desulfurization and alloying. Today here we will analyze their main differences in this article: 

Deposition rate

Deposition speed refers to the amount of metal deposited on the weldment per unit time in the process of fusion welding. Flux-cored wires fuse faster than solid electrodes because they allow a larger welding current to be used (shown below). Compared with solid cored wire, because its current is concentrated on the outer steel surface, offering a large current density and larger resistance heat generated; In addition, the flux-cored wire has a small splash, and its molten metal can be more efficient into the pool.

Welding wire typesWelding wire diameter /mmBest welding current range/AAllowable welding current range/A
Solid welding wire0.640~9030~180
 Flux-cored welding wires1.280~30070~350

Welding efficiency

Flux-cored wire can be continuously automated and semi-automated production, which greatly saves the time of changing electrode, arc starting and arc closing and other auxiliary processes. Compared with solid wire, flux-cored wire welding spatter less, weld forming, reduce the time of cleaning spatter and repairing weld surface, not easy to plug the nozzle, which is more suitable for robot welding compared with CO2 solid cored wire.

The cost

Compared with the manual electrodes and solid wire, flux-cored wire is expensive. However, the flux-cored wire can greatly shorten the production cycle and guarantee the weld quality, with a comprehensive cost economy, which is much lower than electrode arc welding, and about the same as CO2 solid cored wire.


The flux-cored wire is mainly used for flat welding and fillet welding in construction machinery, heavy machinery, steel frame, bridge, etc. Solid welding wire is widely used as filler metal or conductive metal wire welding material. It is used as filler metal in gas welding and tungsten gas shielded arc welding. It is both a filler metal and a conductive electrode in submerged arc welding, electroslag welding and other fusion gas shielded arc welding.

Moisture resistance

ISO 3834-2:2005 Quality requirements for fusion welding of metallic materials state: “The manufacturer shall establish and implement procedures for the storage, storage, identification and use of welded materials to avoid moisture, oxidation and damage, in accordance with the recommendations of the supplier.”

Flux-cored wire has a continuous gap on the side of its steel layer due to the constraints of its manufacturing form, it cannot be exposed to the air for too long after opening the package, in order to prevent excessive moisture absorption and affect the welding quality. For flux-cored wire and other welding materials with powder layer, manufacturers can usually specify the basic requirements for drying, storage and drying. There are no requirements for the storage of solid cored wire, generally does not need to be dried before use, but this does not mean that solid cored wire has no requirements, consult the welding wire manufacturer for details.

What’s K-TIG welding?

Keyhole TIG welding, K-TIG for Short, is a new high current TIG welding technology developed by Australia CSIRO company in 2000. K-TIG welding technology is a high-speed one-side full penetration weld process, which requires no wire, no groove or no professional operators, but can weld metal up to 16mm thick and 100 times faster than conventional TIG welding.

K-TIG welding is based on the traditional TIG welding through the large current (> 300A) to form a large arc pressure and weld pool liquid metal surface tension to achieve a relative balance, forming a hole to achieve deep welding. Stable welding process, beautiful welding forming, weld microstructure and mechanical properties are better than TIG welding, is a high efficiency, high speed, low-cost welding method. The tungsten electrode diameter is greater than 6mm (commonly used diameter is 6.3-6.5mm, the Angle of the end is 60o), the welding current is up to 600~650A, the arc voltage is 16~20V, under the action of such a high specification parameters, the electromagnetic shrinkage of the arc is greatly improved, showing the arc straightness, arc force and penetration ability are significantly enhanced.

In welding, the arc “sinks” deeply into the base metal, forcing the molten metal around the molten pool to form keyholes. If the arc pressure, the reaction force of metal vapor on the sidewall of the keyhole, the surface tension of the liquid metal and the pressure inside the liquid metal reach a dynamic balance, the keyhole will exist stably. As the arc progresses, the pool metal is fused behind the arc and cooled to form a weld, similar to the plasma “keyhole” welding method.

304 Stainless steel K-TIG
1One Side Welding Both Sides FormationNoYesYesYes
2Maximum depth of fusion20mm3mm10mm16mm
3Medium and thick plate grooveNoYesNoNo
4Medium and thick plate once formingNoNoYesYes
5Apperance qualityGoodGoodNot goodGood
6Welding alignment clearance≤2≤2≤0.5≤2
7Welding ConsumablesNeed welding wire and fluxNeed more wiresNeed plasma gasNeed less wires
8Maximum welding speed400mm/min200mm/min500mm/min1000mm/min
9Arc initiation/closure defectsYesNoYesNo
10Rated load ratio60%60%60%100%
Comparation of SAW, TIG, K-TIG

The features of K-TIG welding

  • Automatic welding, simple operation, no welding wire filling, the whole process is one-way full penetration welding.
  • High efficiency, low energy consumption, fast welding speed, the speed is more than 5-10 times of ordinary TIG/GTAW. It allows weld defects to form highly stable, self-correcting full penetration weld holes in a variety of special metals. The clearance of welding parts can be up to 2 mm.
  • The medium thickness metal plate can realize single-sided welding and double-sided forming without groove opening, with beautiful welding seam, small deformation and no root cleaning on the back. 
  • It can weld carbon alloy steel, stainless steel, titanium alloy, nickel base alloy, cobalt alloy and zirconium materials, especially for large diameter Austenitic stainless steel. K-TIG deep penetration argon arc welding in 16mm titanium, 14mm zirconium, 13mm Austenitic stainless steel, Hastelloy, nickel-chromium and various nickel-cobalt alloys and 9mm conductive materials (such as Ferritic steel and carbon steel) to achieve a single side welding double side forming. When the welding speed is 250-300mm/min, it can weld through the stainless steel below 14mm at a time.

What’s A-TIG Welding?