Coetsee, TheresaDe Bruin, Frederik Johannes2023-08-012023-08-012022-08-25Coetsee, T.; De Bruin, F. Application of Unconstrained Cobalt and Aluminium Metal Powders in the Alloying of Carbon Steel in Submerged ArcWelding: Thermodynamic Analysis of Gas Reactions. Applied Sciences 2022, 12, 8472. https://DOI.org/10.3390/app12178472.2076-3417 (print)10.3390/app12178472http://hdl.handle.net/2263/91755DATA AVAILABILITY STATEMENT : The data sets presented in this study are available upon request to the corresponding author.The application of cobalt and aluminium powders in unconstrained format, not as metal powder in tubular wire nor as pre-alloyed powder, is used in this work to simplify weld metal alloying. The objective of this study is to demonstrate the application of unconstrained cobalt and aluminium powders in Submerged Arc Welding SAW to alloy the weld metal and to control the weld metal oxygen content. Aluminium powder is used to control the oxygen potential at the weld poolslag interface in order to prevent oxidation of cobalt. The results presented here show that with the addition of Aluminium powder, 70% yield of Cobalt was achieved from the cobalt powder to the weld metal. The carbon steel base-plate material and weld wire materials combination were alloyed to 5.3% Co and 4.2% Al, whilst controlling the weld metal total oxygen content to 230 ppm. Thermodynamic analysis is applied to investigate the possible chemical interaction reactions between Co and Al compounds, as well as the role of the reactions on Co yield to the weld pool. The application of unconstrained metal powders ensures productivity gains in the overall SAW process because the time consuming and expensive manufacturing of alloyed wire and alloyed powder are eliminated.en© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.PyrometallurgyPowderCobaltOxygen controlAluminiumWeldingEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-12SDG-12: Responsible consumption and productionEngineering, built environment and information technology articles SDG-13SDG-13: Climate actionArticle