Effect of inert gas pressure on the properties and carbon footprint of UNS S32760 powders made from waste materials by gas atomization

Super duplex steels are used in various industrial applications where high mechanical strength and corrosion resistance are required. The manufacture of products from powdered base materials has become increasingly interesting in recent years, both for traditional powder metallurgy processes and for additive manufacturing. Due to the high environmental impact of the raw material, which is higher than that of austenitic or martensitic stainless steels, sustainable powder production routes are therefore needed. This research focuses on the production, characterization and sustainability assessment of UNS S32760 super duplex steel powders produced by gas atomization from industrial waste materials. The critical role of gas atomization pressure in determining the process efficiency, properties and carbon footprint of the powders is analyzed. The results show that higher gas pressure leads to narrower atomization plumes and higher gas velocities, with a significant increase in gas consumption and longer atomization cycles. Morphological analysis showed that increasing gas pressure improved atomization efficiency. However, it also resulted in increased powder surface roughness and pore formation. Chemical composition was minimally affected by gas pressure. Energy demand and carbon footprint analyses showed that higher gas pressure reduced the carbon footprint as powder size decreased. Overall, the study shows that adjusting the atomization pressure can reduce the carbon footprint based on the desired final powder size distribution, and provides useful information for improving powder production processes to promote sustainable manufacturing practices.