High Nb, Ta, and Al creep- and oxidation-resistant austenitic stainless steel

Patent · Tue Jul 13 00:00:00 EDT 2010

OSTI ID:1013033

Brady, Michael P ^[1]; Santella, Michael L ^[2]; Yamamoto, Yukinori ^[1]; Liu, Chain-tsuan ^[1]

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1. Oak Ridge, TN
2. Knoxville, TN

An austenitic stainless steel HTUPS alloy includes, in weight percent: 15 to 30 Ni; 10 to 15 Cr; 2 to 5 Al; 0.6 to 5 total of at least one of Nb and Ta; no more than 0.3 of combined Ti+V; up to 3 Mo; up to 3 Co; up to 1 W; up to 0.5 Cu; up to 4 Mn; up to 1 Si; 0.05 to 0.15 C; up to 0.15 B; up to 0.05 P; up to 1 total of at least one of Y, La, Ce, Hf, and Zr; less than 0.05 N; and base Fe, wherein the weight percent Fe is greater than the weight percent Ni wherein said alloy forms an external continuous scale comprising alumina, nanometer scale sized particles distributed throughout the microstructure, said particles comprising at least one composition selected from the group consisting of NbC and TaC, and a stable essentially single phase fcc austenitic matrix microstructure, said austenitic matrix being essentially delta-ferrite-free and essentially BCC-phase-free.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• Assignee: UT-Battelle, LLC (Oak Ridge, TN); University of Tennessee Research Foundation (Knoxville, TN)
• Patent Number(s): 7,754,144
• Application Number: 12/103,837
• OSTI ID: 1013033
• Country of Publication: United States
• Language: English