The effects of chromium addition and heat treatment on the microstructure and tensile properties of Fe-24Al(at.%)

✍ Scribed by P.I. Ferreira; A.A. Couto; J.C.C. de Paola

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 531 KB
• Volume: 192-193
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(94)03231-9

✦ Synopsis

Fe-24Al (at.%) base alloys containing O-6 at.% Cr were elaborated by melting and casting under argon atmosphere. The ingots obtained were initially homogenized at 1000 "C for 5 h in air, then hot rolled at temperatures in the range 1000-800 "C. The hot rolled strips obtained were submitted to two heat treatments: 800 "C for 1 h, and 800 "C for 1 h plus 500 "C for 9 days. Tensile test specimens were machined from the hot rolled and heat treated strips. Samples for transmission electron microscopy and X-ray diffraction were taken from the as-rolled and annealed material for microstructural characterization.

The best combination of ductility and yield strength is obtained for the ahoy Fe-24A1-2Cr (at.%) heat treated at 800 "C for 1 h. The material heat treated at 800 "C for 1 h presents a partially recrystallized microstructure containing the a (disordered) and B2 (ordered FeAl) phases. The additional heat treatment at 500 "C for 9 days leads to a microstructure containing both a and DO, (ordered Fe,Al) phases with degradation of the mechanical properties.