Shielded Metal Arc Welding (SMAW)
SMAW flux purpose, electrode classification (E6010, E7018), low hydrogen storage, arc striking, electrode angles, positional welding, and filter lens shade selection per CSA W117.2.
- Explain the primary purpose of flux in SMAW
- Decode AWS electrode classification numbers
- Describe proper storage requirements for low hydrogen electrodes
- Demonstrate correct arc striking and electrode angle techniques
- Identify proper techniques for vertical-up welding
- Select the correct filter lens shade for SMAW by amperage per CSA W117.2:19/R2023
Leçon 1
SMAW Flux Function & Electrode Basics
The Role of Flux
The primary purpose of flux in SMAW is to shield the weld pool from atmospheric contamination. As the flux coating burns, it produces a gas shield that displaces atmospheric oxygen and nitrogen from the weld zone. Simultaneously, the melted flux forms a liquid slag that floats on top of the molten weld pool, providing additional protection as the metal solidifies.
Additional Flux Functions
Beyond shielding, flux serves several other purposes. It adds alloying elements to the weld metal, stabilizes the arc, controls the viscosity and surface tension of the molten pool, and influences the shape of the weld bead. Different flux compositions produce different welding characteristics, which is why electrode selection is critical for each application.
Exam Tip
The exam specifically asks for the primary purpose of flux. The answer is always shielding the weld pool from atmospheric contamination - not increasing speed, increasing penetration, or reducing spatter.
The primary purpose of flux in SMAW is to shield the weld pool from atmospheric contamination. The flux coating produces a protective gas shield and liquid slag layer over the molten weld metal.