1. Flux Cored Arc Welding (FCAW)
WIT Pg & Fig. 3.16
Instructor Should Explain:
Similar to GMAW, Except:
Tubular Electrode
Flux Process
Shielding Gas Optional

2. Objective:
SWBAT to identify and describe the FCAW process.

3. Trade Terms
Arc- In Welding the electric arc is produced when the welding current is forced to jump a gap and pass through the air. The air has a high resistance to electrical flow causing the high temperatures, in excess of 10,000 degrees F, need to melt the base materials.
Flux-The role of a flux in joining processes is typically dual: dissolving of the oxides on the metal surface, which facilitates wetting by molten metal, and acting as an oxygen barrier by coating the hot surface, preventing its oxidation.

4. Trade Terms
Shielding- In welding shielding is the act of protecting the molten weld metal from atmospheric contamination. Shielding can be achieved by a shielding gas or by a flux.
Electrode- In arc welding an electrode is used to conduct current through a work piece to fuse two pieces together. In FCAW the electrode is consumed as part of the completed weld.

5. The Flux Cored Arc Welding Process
As defined by the American Welding Society (AWS), flux cored arc welding (FCAW) is an electric arc welding process that fuses metallic parts by heating them with an arc between a continuously fed, consumable, flux cored electrode and the work. Primary shielding for the molten weld metal is obtained from the fluxing ingredients within the tubular electrode that are deposited as slag on top of the weld. The flux cored electrode may be supplemented by an external shielding gas.

6. Self-Shielded FCAW WIT Pg. 3-14 & Fig. 3.16 Instructor Should Explain:
Talk About Each of the Items Listed on Figure

7. FCAW Process Types
There are two process types used for the deposition of metal.
Self Shielded – All of the fluxing ingredients required for the proper transfer of the filler material and shielding of the molten pool are included in the core material.
Gas Shielded – A shielding gas is used in addition to the shielding from the flux core. Carbon dioxide (CO2) can be used alone or with Argon (Ar) in a specified mixture to shield the molten weld metal from outside atmosphere.

8. Modes of operation FCAW can be done in one of two ways.
Semi-automatic- where the weld is made using FCAW equipment and a manual welding gun.
Automatic- The weld is made using specialized equipment and controls that are monitored by the machine operator.

9. FCAW Equipment Power Supply
The power supply provides the welding current needed to melt the base metal and the electrode.
FCAW uses two types of welding current.
Direct Current Electrode Negative (DCEN) for self shielded FCAW
Direct Current Electrode Positive (DCEP) for gas shielded FCAW

10. FCAW Equipment Wire Feeder
The wire feeder is the device that feeds the required amount of filler material at a fixed rate of speed throughout the welding operation.

11. FCAW Equipment Guns
The gun is held by the welder during the welding operation. It is at the tip of the gun where the electrical current is transferred to the filler material. The gun trigger controls the start and stop operation of the machine.
WIT Pg & Fig. 3.18
Instructor Should Explain:
Note the Hand Shield on the Self-Shielded Gun
Self-Shielded Uses Higher Currents, More Heat
Gas Shielding Helps Cool Operation

12. Gas-Shielded FCAW Equipment
WIT Pg & Fig. 3.19
Instructor Should Explain:
Talk About Each Item Shown in Figure:
Shielding Gas Supply Shielding Gas Regulator
Electrode Supply Power Source
Electrode Feed Unit Welding Gun
Cable Assembly Power Supply and Controls
Workpiece Cable Workpiece Clamp
Wire Feed Units Have Two Types:
- Voltage Sensing - Constant Feed

13. Self-Shielded FCAW Equipment
WIT Pg & 3.19 (Cont)
Instructor Should Explain:
Only Difference Is the Gun and the Pinch Rollers

14. FCAW Advantages High productivity Deep penetration High quality welds
All position welding
Tolerates contamination better than GMAW
More suitable for field work than GMAW
Combines the advantages of SMAW (good shielding) and GMAW (high productivity)
WIT Pg. 3-16
Instructor Should Explain:
Discuss Advantage Listed

15. FCAW Disadvantages Slag to contend with during welding Slag removal
Smoky process (esp. self shielded)
Electrode cost
Equipment complexity
WIT Pg. 3-16
Instructor Should:
Discuss Limitation Listed

16. FCAW Discontinuities Slag inclusions Porosity Incomplete fusion
Incomplete joint penetration
WIT Pg. 3-16, 3-17
Instructor Should:
Discuss Each Item Listed

17. FCAW Applications General fabrication of steel and stainless steel
Structural steel fabrication
Pressure vessels for gasses and liquids
Heavy equipment fabrication and repair
Surfacing components to protect against wear.
Hardfacing
Maintenance and repair
WIT Pg. 3-16
Instructor Should:
Discuss Limitation Listed

18. Review Questions

19. FCAW Electrode Classification System Electrode
E X X T - X
FCAW Electrode Classification System
Electrode
WIT Pg. 3-15
Instructor Should Explain:
“E” = Electrode - Current Carrying

20. E X X T - X FCAW Electrode Classification System
Minimum Specified Tensile Strength
WIT Pg. 3-15
Instructor Should Explain:
Strengths Are in 10’s of Thousands

21. FCAW Electrode Classification System Welding Position(s)
E X X T - X
FCAW Electrode Classification System
Welding Position(s)
WIT Pg. 3-15
Instructor Should Explain:
1 = All Positions
0 = Flat Grooves, Fillets & Horizontal Fillets

22. FCAW Electrode Classification System Tubular
E X X T - X
FCAW Electrode Classification System
Tubular
WIT Pg. 3-15
Instructor Should Explain:
Rolled Strip
Mechanical Seam
Flux Filled
Protect From Moisture

23. E X X T - X FCAW Electrode Classification System Chemical Composition
Operating Characteristics
WIT Pg. 3-15
Instructor Should Explain:
Self-Shielded - 3, 4, 6, 7, 8, 10, 11
Requires Gas - 1, 2, 5
G - Multipass
GS - Single Pass

24. Typical FCAW Classification
E71T-1

25. Stainless Steel Electrodes Typical Applications
E308T-X - Welding 304 Base Metal
E308LT-X - Welding 304 or 304L Base Metal
E316T-X - Welding 316 Base Metal
E316LT-X - Welding 316 or 316L Base metal
E309T-X - Welding Stainless to Carbon
For Stainless FCAW Electrodes,
the “X” Indicates the Type of Gas Shielding

26. How Do They Make FCAW Wires