Physical simulation of additively manufactured super duplex stainless steels: microstructure and properties
2020 (English)In: Additive Manufacturing, ISSN 2214-8604, E-ISSN 2214-7810, Vol. 34, article id 101269Article in journal (Refereed) Published
Abstract [en]
The behavior of high performance super duplex stainless steel (SDSS) during additive manufacturing (AM) has been investigated using a novel arc heat treatment technique. Tungsten inert gas (TIG) arc pulses were applied on a disc shaped sample mounted on a water-cooled chamber to physically simulate AM thermal cycles. SDSS base metal and a duplicated additively manufactured structure (DAMS) were used as initial microstructures. Samples were melted one, five, or 15 times by arc heat treatment. Samples were also produced with a controlled slope down of the current to create slower cooling compared to pulsing. Microstructure characterization and modelling were performed to study the evolution of microstructure and properties with successive AM cycles. Microstructural changes were dependent on the number of reheating cycles, cooling rate, and peak temperature. In particular, the DAMS austenite morphology and fraction changed after reheating to peak temperatures above 700 °C. Nitrides and sigma were observed in the high and low temperature heat affected zones, respectively. Sensitization to corrosion was more pronounced in reheated DAMS than in the base metal. Hardness was increased more by multiple remelting/reheating than by slow cooling. It was found that AM thermal cycles significantly affect SDSS properties especially for an initial microstructure similar to that produced by AM. © 2020 Elsevier B.V.
Place, publisher, year, edition, pages
Elsevier, 2020. Vol. 34, article id 101269
Keywords [en]
Additives, Cooling, Corrosion, Heat affected zone, Heat treatment, Industrial heating, Inert gases, Microstructural evolution, Morphology, Thermal cycling, Initial microstructures, Manufactured structures, Microstructural changes, Microstructure and properties, Microstructure characterization, Super duplex stainless steel, Treatment techniques, Water-cooled chambers, Duplex stainless steel
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
URN: urn:nbn:se:hv:diva-15730DOI: 10.1016/j.addma.2020.101269ISI: 000555845400002Scopus ID: 2-s2.0-85084542579OAI: oai:DiVA.org:hv-15730DiVA, id: diva2:1460358
Funder
Knowledge Foundation, 201401302020-08-242020-08-242025-09-30Bibliographically approved