Flux Core Wire Welding Information

Flux Core Wire Welding

What is Flux Core Wire Welding (FCAW) - Gasless

Process that uses a wire-fed welding machine. Metals are melted and joined by heating them with an arc between a continuous, consumable electrode wire and the workpiece. The weld is tubular with flux material contained inside the shielding. Added shielding may or may not be supplied from external gas or gas mixture, depending on the type of flux cored wire being used.

Works well on dirty or rusty material Deep penetration for welding thick sections Can be used with or without shielding gas Self-shielded wire are best for windy conditions Recommended to weld: Steel, stainless steel Skill Level: Low

FCAW, Flux Core Wire Welding is similar to gas metal arc welding in many ways.

The flux-cored wire used for this process gives it different characteristics.

Flux Core Wire Welding is widely used for welding ferrous metals and is particularly good for applications in which high deposition rates are needed.

At high welding currents, the arc is smooth and more manageable when compared in using large diameter gas metal arc welding electrodes with carbon dioxide.

The arc and weld pool are clearly visible to the welder. A slag coating is left on the surface of the weld bead, which must be removed.

Since the filler metal transfers across the arc, some spatter is created and some smoke produced.

Uses arc between filler metal electrode and weld pool in which shielding gas is sometimes supplied (flux core wire with gas, usually 75/25) through the gas nozzle without application of pressure, in addition to that obtained from the flux within the electrode.

The FCAW, Flux Core equipment used for flux-cored arc welding is similar to that used for gas metal arc welding. The basic arc welding equipment consists of a power source, controls, wire feeder, welding gun, and welding cables.

A major difference between the gas shielded electrodes and the self-shielded electrodes is that the gas shielded wires also require a gas shielding system.

This may also have an effect on the type of welding gun used.

Fume extractors are often used with this process.

- Electric Arc Between Electrode & Work, Melts the Electrode & Fuses the Joint

- Weld Metal & Slag Form

- The Slag is Lighter than the Molten Metal & Rises to the Top

- Requires Long Electrical StickOut

- Typically 3/4" with + 1/8" Tolerance

- Too Long stickout Causes an Unstable Arc, Increased Spatter, and Decreased Penetration

- Too Short stickout Causes Excessive Arc Length and Premature Melting & Activation of the Core Materials causing Porosity

Good points

- High Efficiencies (90+%)

- Easy Re-strike

- All Position Welding

- Low Hydrogen Weld Deposits

- Bead Appearance

- Little to No Spatter

- High Deposition Rates

- Mechanical Properties

Drawbacks

- Smoke and Fumes

- Portability

- Outdoor Weldability

- Potential for Gas Marks

- High Radiated Heat

- Slag


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