Alloy Design of Creep- and Oxidation-Resistant 9%Cr Steel for High Efficiency USC Power Plant

Abstract:

Ferritic heat resistant steels are strongly desired to expand their maximum use temperature up to 650°C for application to the next highest temperature components of highly efficient, low emission ultra-supercritical (USC) power plant with maximum steam temperature of 700 °C. This minimizes the requirement of expensive nickel base superalloys. Critical issues for the development of ferritic steels for 650 °C USC boilers are the improvement of oxidation resistance as well as long-term creep rupture strength, including welded joints. The optimized combination of boron addition and dispersion of nanometer-sized vanadium nitrides significantly improves long-term creep strength of 9% Cr steel and also exhibits no degradation in welded joints at 650 °C. The protective Cr₂O₃-rich scale forms on the surface of 9% Cr steel by pre-oxidation treatment in Ar gas, which significantly improves the oxidation resistance in steam at 650°C.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 3-8
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.3
• Online since: January 2012
• Authors: Fujio Abe
• Keywords: Boiler, Coal-Fired Power Plant, Creep Strength, Ferritic Steel, Oxidation, Welded Joint

References

[1] R. Blum and R. W. Vanstone, Proc. of 8th Liege Conference on Materials for Advanced Power Engineering 2006, Liege, Belgium, (2006) p.41.

[2] R. Viswanathan, J. F. Henry, J. Tanzosh, G. Stanko, J. Shingledecker and B. Vitalis, as in.

[1] p.893.

[3] M. Fukuda, Proc. of 5th Intern. Conf. on Advances in Materials Technology for Fossil Power Plants, October 3-5, 2007 (2007) CD-ROM.

[4] T. Horiuchi, M. Igarashi, F. Abe, ISIJ International, 42 (2002) S67.

[5] F. Abe, Intern. J. Materials Research, 99 (2008) 387.

[6] K. Sakuraya, H. Okada and F. Abe, Energy Materials, 1 (2006) p.158.

[7] H. Semba and F. Abe, Energy Materials, 1 (2006) p.238.

[8] F. Abe, Sci. Technol. Advanced Materials, 9 (2008) 013002.

[9] J. Francis, W. Mazur and H. K. D. H. Bhadeshia, Mater. Sci. Technol., 22 (2006) p.1387.

[10] F. Abe, M. Tabuchi, S. Tsukamoto and T. Shirane, Intern. J. Pressure Vessels & Piping, 87 (2010) 598.

[11] F. Abe, M. Tabuchi, H. Semba, M. Igarashi, M. Yoshizawa, N. Komai, A. Fujita, as in.

[3] CD-ROM.

[12] H. Kutsumi, T. Itagaki and F. Abe, Proc. of 7th Liege Conference on Materials for Advanced Power Engineering 2002, edited by J. Lecomte-Beckers, M. Carton, F. Schubert and P. J. Ennis, Liege, Belgium (2002) p.1629.

[13] H. Okubo, S. Muneki, T. Hara, H. Kutsumi and F. Abe, Proc. of the 34th MPA Seminar, MPA, Stuttgart, October (2008) CD-ROM.