ALLOY DESIGN AND DEVELOPMENT OF HIGH CR CONTAINING FECRAL FERRITIC ALLOYS FOR EXTREME ENVIRONMENTS

Conference · Tue Oct 01 00:00:00 EDT 2019

OSTI ID:1607120

Yamamoto, Yukinori  ^[1]; Pint, Bruce  ^[1]; Brady, Michael  ^[1]; Babu, Suresh S. ^[2]; Kuo, Chih-Hsiang (Sean) ^[2]; Shassere, Benjamin ^[3]

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1. ORNL
2. University of Tennessee, Knoxville (UTK)
3. University of Tennessee (UT)

A new alloy design concept for creep- and corrosion-resistant, fully ferritic alloys was proposed for high-temperature structural applications in current/future fossil-fired power plants. The alloys based on Fe-30Cr-3Al (in weight percent) with minor alloying additions of Nb, W, Si, Zr and/or Y were evaluated with a design strategy for corrosion resistance though high Cr content, steam oxidation resistance through alumina-scale formation, and high-temperature creep performance through fine particle dispersion of Fe2(Nb,W)-type Laves phase in the BCC-Fe matrix, which target to be used in harsh environments such as combustion and/or steam containing atmospheres, at or above 700°C. The alloys consisted of Fe-30Cr-3Al-1Nb-6W with minor alloying additions exhibited a successful combination of oxidation/corrosion/creep-resistant performances comparable or superior to those of commercially available heat resistant austenitic stainless steels. An optimized thermo-mechanical treatment combined with selected minor alloying addition resulted in a refined grain structure with high thermal stability even at 1200°C, which improved room-temperature ductility without sacrificing the creep performance. The mechanism of grain refinement in the alloy system has been discussed.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1607120
• Resource Relation: Conference: Joint EPRI – 123HiMAT International Conference on Advances in High Temperature Materials - Nagasak, , Japan - 10/20/2019 8:00:00 AM-10/24/2019 8:00:00 AM
• Country of Publication: United States
• Language: English