Effect of aging temperature on phase decomposition and mechanical properties in cast duplex stainless steels

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:690

Article

Mburu, Sarah¹  Kolli, R. Prakash¹  Perea, Daniel E.²  Schwarm, Samuel C.¹  Eaton, Arielle²  Liu, Jia²  Patel, Shiv¹  Bartrand, Jonah²  Ankem, Sreeramamurthy¹ 

[1] Univ Maryland, Dept Mat Sci & Engn, 2144 Chem & Nucl Engn Bldg,090, College Pk, MD 20742 USA

[2] Pacific Northwest Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA

关键词: Spinodal decomposition;    Duplex stainless steel;    Atom probe tomography;    m(23)C(6) carbide;    G-phase;   

DOI  :  10.1016/j.msea.2017.03.011

来源: Elsevier

【 摘 要 】

The microstructure and mechanical properties in unaged and thermally aged (at 280 degrees C, 320 degrees C, 360 degrees C, and 400 degrees C to 4300 h) CF-3 and CF-8 cast duplex stainless steels (CDSS) are investigated. The unaged CF-8 steel has Cr-rich M23C6 carbides located at the delta-ferrite/gamma-austenite heterophase interfaces that were not observed in the CF-3 steel and this corresponds to a difference in mechanical properties. Both unaged steels exhibit incipient spinodal decomposition into Fe-rich alpha-domains and Cr-rich alpha'-domains. During aging, spinodal decomposition progresses and the mean wavelength (MW) and mean amplitude (MA) of the compositional fluctuations increase as a function of aging temperature. Additionally, G-phase precipitates form between the spinodal decomposition domains in CF-3 at 360 degrees C and 400 degrees C and in CF-8 at 400 degrees C. The microstructural evolution is correlated to changes in mechanical properties.

【 授权许可】

Free