The SMAW Process (part 1):
We'll start with our look at welding definitions by discussing one of the most common welding processes: SMAW. SMAW stands for Shielded Metal Arc Welding.It’s also commonly referred to as Stick welding, or generally as Arc welding. (This latter term can loosely apply to other forms of welding).Stick welders use a metal welding electrode as a filler material, to join the two pieces of metal together using an electric arc to heat and melt the metal into a puddle that gradually solidifies. Also called a welding rod, this metal cored electrode is usually some form of steel or stainless steel with a flux surrounding the electrode. The flux is a hard, coating that surrounds the rod down most of the length. While welding this flux serves several purposes.
1) To “shield” and protect the metal while welding, preventing oxygen from the atmosphere getting to the white hot metal and rapidly oxidizing the weld.An oxidized weld is weak and porous.
2) To help clean the metal and remove contaminants from the weld. As the flux interacts with the molten metal it helps to “float” out impurities.
Flux components vary, while some welding rods have an iron powder base, others may have a cellulose base, all with trace amounts of other minerals or metals to form protective cocktail. 3) To provide a certain welding characteristic. Some electrodes due to their flux type weld more smoothly than others.Some because of their flux,cool more rapidly and penetrate more deeply. Welding electrodes are available in a variety of sizes, and purposes.After completing the weld and the weld has sufficiently cooled, the slag (consumed flux that lies on top of the weld) must be removed via chipping or a wire brush.