Submerged Arc Welding (SAW) is a process in which an arc is developed between a consumable bare wire electrode and the workpiece. A pile of granular flux is deposited on the work surface ahead of the electrode. The arc forms within the flux, thereby melting a portion of the flux blanket that shields the molten weldpool and adjacent base metal. The granular flux gives protection from atmospheric contamination. The method is generally mechanized and is employed to achieve very high deposition rates, e.g., for heavy section material. SAW is generally characterized by high heat input, high penetration, and, thus, dilution of the molten pool by base metal. As with the Shielded metal arc welding (SMAW) process, submerged arc welding is commonly applied to stainless steels and nickel alloys. Nevertheless, SAW can be used to join low alloy steels (LAS), including high-strength LAS.[ref] ASM Handbook, Volume 6: Welding, Brazing, and Soldering. “Welding of Low-Alloy Steels.” D.L. Olson, T.A. Siewert, S. Liu, and G.R. Edwards, editors, p 662-676, (ASM International, Metals Park, OH, 1993).[/ref] Flux metal reactions are usually complex, and welding conditions have been closely controlled to obtain consistent weld metal composition. The effects of the high heat input of SAW are normally considered before selecting this process.[ref]NACE International Work Group T-1F-21G. “Use of Corrosion-Resistant Alloys in Oilfield Environments.” Report No. 1F192, (NACE International, Houston, TX, 2000).
This is a very instructive video by Arc Energy Resources on the submerged arc welding (SAW) process.
Many thanks to Milos Djukic and Hugo Julien for providing the link to the video.