An Experimental and Theoretical Evaluation of Microstructure Coarsening in Duplex Stainless Steels
2013 (English)In: Steel Research International, ISSN 1611-3683, Vol. 84, no 11, 1126-1137 p.Article in journal (Refereed) Published
The coarsening of duplex stainless steel microstructures at temperatures above 1000C was investigated experimentally and theoretically. Hot-rolled duplex 2205 and superduplex2507 samples were heat treated isothermally at 1100C up to 700 h, and also between 1000 and 1250C for 24 h. The ferrite content and the microstructure coarseness, quantified by the measured austenite spacing, AS, were evaluated. It was found that theobserved coarsening could be described using Ostwald ripening theory expressed as AS**n-AS0**n=kt, where AS0 is austenite spacing of the as-delivered material, k the rateconstant, n the exponent, and t the heat treatment time. Using regression analysis, n and k were evaluated and the resulting predictions compared with literature theories andresults. The results were also calculated according to the original Lifshitz, Slyozov,Wagner (LSW) theory with parameters taken from literature, as well as with the Dictra software for diffusion and growth in multicomponent systems. The calculations indicated that while the classical LSW theory failed to give a good description of the experimentalresults, the Dictra simulations proved very accurate, even though systems of equal ferrite and austenite content are considerably outside the intended range of applicability of the software.
Place, publisher, year, edition, pages
2013. Vol. 84, no 11, 1126-1137 p.
Austenite spacing, Duplex stainless steel, Heat treatment, Microstructure, Ostwald ripening
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-121336DOI: 10.1002/srin.201200323ISI: 000328148100007ScopusID: 2-s2.0-84887318813OAI: oai:DiVA.org:kth-121336DiVA: diva2:618459
QC 20140617. Updated from In press to Published.2013-04-282013-04-282014-06-23Bibliographically approved