Evaluation of Commercial and Next Generation Alumina-Forming Austenitic Foil for Advanced Recuperators

Author(s):  
Bruce A. Pint ◽  
Sebastien Dryepondt ◽  
Michael P. Brady ◽  
Yukinori Yamamoto

Alumina-forming austenitic (AFA) steels represent a new class of corrosion- and creep-resistance austenitic steels to enable higher temperature recuperators. Several commercial batches of the first AFA composition have been produced with different thicknesses and widths over 39cm. This commercial AFA foil was successfully folded by two manufacturers. Creep and laboratory oxidation results at 650°-800°C are presented to compare to conventional recuperator alloy performance. While this initial effort was successful, concerns with cost and ease of production suggested that a leaner AFA composition with a lower final annealing temperature would be more attractive for commercial applications. Therefore, several new AFA compositions are being evaluated in laboratory trials and compared to the initial material for down selection of a better AFA composition for commercialization.

Author(s):  
Bruce A. Pint ◽  
Sebastien Dryepondt ◽  
Michael P. Brady ◽  
Yukinori Yamamoto ◽  
Bo Ruan ◽  
...  

Alumina-forming austenitic (AFA) steels represent a new class of corrosion- and creep-resistant austenitic steels designed to enable higher temperature recuperators. Field trials are in progress for commercially rolled foil with widths over 39 cm. The first trial completed 3000 hrs in a microturbine recuperator with an elevated turbine inlet temperature and showed limited degradation. A longer microturbine trial is in progress. A third exposure in a larger turbine has passed 16,000 hrs. To reduce alloy cost and address foil fabrication issues with the initial AFA composition, several new AFA compositions are being evaluated in creep and laboratory oxidation testing at 650–800 °C and the results compared to commercially fabricated AFA foil and conventional recuperator foil performance.


Author(s):  
Bruce A. Pint ◽  
Sebastien Dryepondt ◽  
Michael P. Brady ◽  
Yukinori Yamamoto ◽  
Bo Ruan ◽  
...  

Alumina-forming austenitic (AFA) steels represent a new class of corrosion- and creep-resistant austenitic steels designed to enable higher temperature recuperators. Field trials are in progress for commercially rolled foil with widths over 39cm. The first trial completed 3,000h in a microturbine recuperator with an elevated turbine inlet temperature and showed limited degradation. A longer microturbine trial is in progress. A third exposure in a larger turbine has passed 16,000h. To reduce alloy cost and address foil fabrication issues with the initial AFA composition, several new AFA compositions are being evaluated in creep and laboratory oxidation testing at 650°–800°C and the results compared to commercially fabricated AFA foil and conventional recuperator foil performance.


Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.


2016 ◽  
Vol 06 (02) ◽  
pp. 1630003 ◽  
Author(s):  
Zhen Fan ◽  
Jingsheng Chen ◽  
John Wang

Ferroelectric random access memory (FeRAM) based on conventional ferroelectric perovskites, such as Pb(Zr,Ti)O3 and SrBi2Ta2O9, has encountered bottlenecks on memory density and cost, because those conventional perovskites suffer from various issues mainly including poor complementary metal-oxide-semiconductor (CMOS)-compatibility and limited scalability. Next-generation cost-efficient, high-density FeRAM shall therefore rely on a material revolution. Since the discovery of ferroelectricity in Si:HfO2 thin films in 2011, HfO2-based materials have aroused widespread interest in the field of FeRAM, because they are CMOS-compatible and can exhibit robust ferroelectricity even when the film thickness is scaled down to below 10 nm. A review on this new class of ferroelectric materials is therefore of great interest. In this paper, the most appealing topics about ferroelectric HfO2-based materials including origins of ferroelectricity, advantageous material properties, and current and potential applications in FeRAM, are briefly reviewed.


1997 ◽  
Vol 5 (1-6) ◽  
pp. 171-177 ◽  
Author(s):  
H.K. Liu ◽  
R. Bhasale ◽  
Y.C. Guo ◽  
J. Horvat ◽  
B. Zeimetz ◽  
...  

1998 ◽  
Vol 5 (10) ◽  
pp. 597-608 ◽  
Author(s):  
James D. Rodgers ◽  
Patrick Y.S. Lam ◽  
Barry L. Johnson ◽  
Haisheng Wang ◽  
Soo S. Ko ◽  
...  

2020 ◽  
pp. 70-73
Author(s):  
V. F. Kadorkina ◽  
M. S. Shevtsova

Relevance and methods. In the conditions of southern mid-Siberia, biological features and seed productivity of 26 biotypes of the nursery of the initial material of the Psathyrostachys juncea (Russian wildrye) of 2015 sowing are presented. The work was carried out in accordance with the methodological guidelines on the selection of fodder crops and the methodology of the State Commission for Crop Testing and Statistical Data Processing — using the package of application programs "Snedecor," and B.A. Dospehova (1985), in the Excel program.Results. Phenological observations made it possible to determine the period of passage of the phases of development of samples of the slice collector from sprouts to caking, exit into the tube and shingling. The greatest stability of uniform growth from the period of spring growth to colossal is observed in biotype — K 12. Quick-ripe biotypes K 1, K 4, K 5, K 9, K 12, K 16, K 24 period from the beginning of vegetation to seed ripening is 65–75 days. Biotypes K 1, K 3, K 5, K 12, K 18 are noted by number of productive stems, length of colos, weight of seeds from 1 plant.


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