Submerse arc welding (SAW) is a welding process that involves the formation of an electric arc between a continuously fed electrode and the workpiece to be welded. A blanket of powdered flux, also known as granules, surrounds and covers the arc, and when melted, provides electrical conduction between the metal to be joined and the electrode.
The granulate, consisting of lime, silica, manganese oxide, calcium fluoride and other compounds that generate a gas protection shield and a slag, which protect the welding zone against atmospheric contamination when deposited submerged, preventing splashes and sparks , in addition to suppressing the intense ultraviolet radiation and fumes that are part of the shielded metal arc welding process. The granulate also helps protect the filler material that cools quickly on the surface of the part, which needs to be properly monitored between thermal cycles to avoid residual stresses after cooling.
Detailed knowledge about the base metal, filler metal and the possible reactions between the two is essential for the success of the coating. This implies rigorous and precise metallurgical analyses.
