Concomitant Precipitation of Intermetallic β-NiAl and Carbides in a Precipitation Hardened Steel

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 55; no. 3; pp. 870 - 879
• Main Authors: Jakob, S., Hörnqvist Colliander, M., Kawser, J., Rashidi, S., Ooi, S. W., Thuvander, M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2024; Springer Nature B.V
• Subjects: Aging; Aging (metallurgy); Carbides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Intermetallic compounds; Investigations; Materials Science; Metallic Materials; Nanotechnology; Nickel aluminides; Nickel base alloys; Nickel compounds; Original Research Article; Precipitates; Precipitation hardening; Precipitation hardening steels; Spectrum analysis; Steel; Structural Materials; Surfaces and Interfaces; Thin Films
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-023-07291-7

The investigated steel is hardened by precipitation of both intermetallic β-NiAl particles and carbides. Around peak hardness, here reached after aging at 520 °C for 6 h, the number density of β-NiAl particles is 2.4 × 10 24 and 4.4 × 10 23 for carbides, respectively. The carbides and β-NiAl often form co-precipitates with presumably the carbides nucleating on the β-NiAl precipitates. The secondary carbides are mainly of the Cr-rich M 23 C 6 type in the investigated states. The steel has a good resistance against over-aging, whereby the β-NiAl coarsen considerably slower than the carbides.