Journal of Applied Science and Engineering

Published by Tamkang University Press

1.30

Impact Factor

1.60

CiteScore

Yi Long This email address is being protected from spambots. You need JavaScript enabled to view it.1,2, Bi-Cao Peng1,2, Liang Xiong1,2 and Jiao-Jiao Liu1,2

1State Grid Hunan Electric Power Research Institute, Changsha 410007, P.R. China
2Hunan Xiangdian Boiler & Pressure Vessel Inspection Center co., LTD, Changsha 410001, P.R. China


 

Received: June 1, 2017
Accepted: June 27, 2017
Publication Date: March 1, 2018

Download Citation: ||https://doi.org/10.6180/jase.201803_21(1).0012  

ABSTRACT


It is significant to study the properties of NF709R and HR3C during aging, which are the alternative materials for superheater and reheater in ultra-supercritical unit. After different predetermined aging period at 700 C, impact test of NF709R and HR3C were carried out at room temperature, and it was found that the impact toughness of NF709R was better than that of HR3C. Impact fracture surfaces and microstructure of both steels showed intergranular fracture characteristics and M23C6 precipitatedongrainboundaries.Itcanbeinferredthatthetransformation from ductile rupture to brittle after aging connected with the precipitation of M23C6. Applying of first-principles method to study the bond strength between the matrix and M23C6 in both steels found that the interface strength in NF709R was higher than that in HR3C. Through experiments and theoretical calculations, this paper explains the causes of different impact properties of NF709R and HR3C after aging, and proposes a reasonable way to increase the bond strength in austenitic heat-resistant steel.


Keywords: NF709R, HR3C, Interface Strength, First-principles, M23C6


REFERENCES


  1. [1] Viswanathan, R., Sarver, J. and Tanzosh, J. M., “Boilter Materials for Ultra-supercritical Coal Power Plants steam side Oxidation,” Journal of Materials Engineering and Performance, Vol. 15, pp. 255274 (2006). doi: 10.1361/105994906X108756
  2. [2] Viswanathan,R.,Coleman,K.andRao,U.,“Materials for Ultra-supercritical Coal-fired Power Plant Boilers,” International Journal of Pressure Vessels and Piping, Vol. 83, pp. 778783 (2006). doi: 10.1016/j. ijpvp.2006.08.006
  3. [3] Viswanathan, R., Henry, J. F., Tanzosh, J., Stanko, G., Shingledecker, J., Vitalis, B. and Purgert, R., “U.S. Program on Materials Technology for Ultra-supercritical Coal Power Plants,”Journal of Materials Engineering and Performance, Vol. 14, pp. 281 292 (2005). doi: 10.1361/10599490524039
  4. [4] Viswanathan, R. and Bakker, W., “Materialsfor Ultrasupercritical Coal Power Plants-boiler Materials: Part 1,”Journal of Materials Engineering and Performance, Vol. 10, pp. 8195 (2001). doi: 10.1361/10599490177 0345394
  5. [5] Mimura, H. and Ishitsuka, T., “Boiler Pipes and Tubes for Higher Efficiency of Power Generation,” Nippon Steel Technical Report, Vol. 80, pp. 7478 (2000).
  6. [6] Iseda, A., Okada, H., Semba, H. and Igarashi, M., “Long Term Creep Properties and Microstructure of SUPER304H, TP347HFG and 25Cr-20Ni-nb-N for A-USC Boilers,” Energy Materials, Vol. 2, pp. 199 206 (2007). doi: 10.1179/174892408X382860
  7. [7] Sato, T., Fukuda, Y. and Mitsuhata, K., “The Practical Application and Long-term Experience of New Heat Resistant Steels to Large Scale USC Boilers,” Proceedings from the Fourth International Conference on Advances in Materials Technology for Fossil Power Plants, October 2528, Hilton Head Island, South Carolina, pp. 177190 (2004).
  8. [8] Liu, W., Li, J. C., Zheng, W. T. and Jiang, Q., “NiAl(110)/Cr(110) Interface: a Density Fanctional Theory Study,” Physical Review B, Vol. 73, pp. 205421(1)205421(7) (2006). doi: 10.1103/PhysRev B.73.205421
  9. [9] Zhang,Y.,Lu,G.H.,Hu,X.L.,Wang,T.M.,Kohyama, M. and Yamamoto, R., “First-principles Computational Tensile Test on a Na-segregated al Grain Boundary with an Si additive and an Intergranular Embrittlement Suppression Mechanism,”Journal of Physics: Condensed Matter, Vol. 19, p. 456225 (2007). doi: 10.1088/0953-8984/19/45/456225
  10. [10] Tanaka, H., Muruta, M., Abe, F. and Irie, H., “Microstructural Evolution and Change in Hardness in Type 304H Stainless Steel during Long-term Creep,” Materials Science and Engineering A, Vol. 319, No. 321, pp. 788791 (2001). doi: 10.1016/S0921-5093(01) 01012-7
  11. [11] Hammer, B., Hansen, L. B. and Nørskov, J. K., “Improved Adsorption Energetics within Density-functional Theory Using Revised Perdew-Burke-Ernzerhof Functionals,” Physical Review B, Vol. 59, pp. 74137421 (1999). doi: 10.1103/PhysRevB.59.7413
  12. [12] Perdew, J. P., Chevary, J. A., Vosko, S. H., Jackson, K. A.,Pederson, M.R.,Singh,D.J.andFiolhais,C.,“Atoms, Molecules, Solids and Surfaces: Applications of the Generalized Gradient Approximation for Exchange and Correction,” Physical Review B, Vol. 46, pp. 66716687 (1992). doi: 10.1103/PhysRevB.48.4978.2
  13. [13] White, J. A. and Bird, D. M., “Implementation of Gradient-corrected Exchange-correlation Potentials in CarParrinello Total-energy Calculations,” Physical Review B, Vol. 50, pp. 49544957 (1994). doi: 10.1103/ PhysRevB.50.4954
  14. [14] Sourmail, T., “Simultnaeous Precipitation Reaction in Creep-resistant Austenitic Stainless Steels (a doctoral dissertation),” University of Cambridge (2002).
  15. [15] Cheng, S. C., Liu, Z. D., Bao, H. S. and Wang, J. Z., “Investigation of Bar-like Carbides in HR3C Boiler Steel,” Materials Science Forum, Vol. 638, pp. 3105 3110 (2010). doi: 10.4028/www.scientific.net/MSF. 638-642.3105
  16. [16] Peng, B., Zhang, H., Hong, J., Gao, J., Wang, Q. and Zhang, H., “Effect of Aging on the Impact Toughness of 25Cr–20Ni–nb–N Steel,” Materials Science and Engineering A, Vol. 527, pp. 1957–1961 (2010). doi: 10.1016/j.msea.2009.12.039
  17. [17] Peng,B.,Zhang,H.,Hong,J.,Gao,J.,Zhang,H.,Li,J. and Wang,Q.,“The Evolution of Precipitates of 22Cr– 25Ni–mo–nb–N Heat-resistant Austenitic Steel in Long-term Creep,” Materials Science and Engineering A, Vol. 527, pp. 4424–4430 (2010). doi: 10.1016/ j.msea.2010.03.089