Shielded Metal Arc Welding

Flux-cored arc welding was developed in 1904 by a Swedish engineer named Oscar Kjellberg, who later founded the ESAB company. This process is designated by number 111 in the standard nomenclature NF EN ISO 4063 for welding processes. The French designation is Soudage à l'Arc à l'Électrode Enrobée (SAEE). In the USA, it is known as SMAW (Shielded Metal Arc Welding), while in other English-speaking countries, it is known as MMA (Manual Metal Arc).

Although this welding process is exclusively manual, and therefore not the most productive, it is still widely used, thanks to its wide range of applications and ease of implementation. This is an arc welding process using a fusible electrode. This coated electrode is used to feed metal into the weld bead (metal core of the electrode), and the protection of the molten metal and weld bead is ensured by the coating, which creates more or less gas as it burns. Excess coating produces a slag that protects the weld bead as it cools. This welding process can be found in most fields of mechanically-welded assembly, ranging from DIY or handicraft to high-tech fields where high quality beads are required. This welding process can also be used for surface hardfacing to improve corrosion resistance (stainless steel hardfacing) or wear resistance (hardfacing).

The aim of this article is to describe the technology associated with this welding process in relation to its possible use in mechanically-welded assemblies.

At the end of the article, readers will find a glossary and a table of symbols used.