Evaluation of Materials Degradation Extent after their Long Term Exposition in Power Plants Equipments

Abstract:

Load processes and their interaction over long-term service exposition influence on degradation of construction materials in the equipment of conventional power plants. A wide range of destructive testing methods and number of test for each of them were used to clarify of the extent and mechanism of the damage steel components of the power plants pressure circuit. Changes of material properties were by those methods evaluated in state after operational exposition - till 190 000 hours and after heat treatment reprocessing, for all observed components in the entire profile of the wall thickness. Great attention was paid to metallographic evaluation of the creep damage also. The results of test were compared with the supposed properties of the undegraded material in origin state.

• Periodical: Materials Science Forum (Volume 782)
• Pages: 325-330
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.782.325
• Online since: April 2014
• Authors: Martin Kraus, Vratislav Mareš, Jaroslav Bystrianský
• Keywords: Creep Damage, Destructive Testing, Long-Term Exposition, Pressure Circuit

References

[1] J. Betten, Creep Mechanics, 2nd edition. Berlin: Springer-Verlag Berlin Heildelberg, October 7, 2008. Print., 361 p, ISBN 978-3-540-85050-5.

[2] M. Życzkowski (Ed), Creep in Structures, 4th IUTAM Symposium, Cracow, September 1990, Springer-Verlag Berlin Heildelberg 11/2012, 708 p, ISBN: 978-3-642-84457-7.

DOI: 10.1007/978-3-642-84455-3

[3] R. Viswanathan, Damage Mechanisms and Life Assessment of High-Temperature Componentns, ASM International, Metals Park Ohio, Second Printing 1992, 440 p, ISBN-10-0871703580.

[4] P. Seliger, U. Gampe, Life Assessment of Creep Exposed Components, New Challenges for Condition Monitoring of 9Cr Steels, Life Assessment of 9Cr Steel Components OMMI (Vol. 1, Issue 2) August 2002, Acces. from: www. omni. co. uk/PDF/Articles/50pdf.

[5] ČSN 41 5128 - Steel 15 128 Cr-Mo-V, ČNI Praha, 1986(in Czech).

[6] Residual Life Assessment and Microstructure, prepared by ECCC-WGS1. 1, AC/MC/93 [Issue1]2005, Accessible from http: /www. ommi. co. uk/etd/eccc/advancedcreep/V6i1x. pdf.

[7] VGB-TW 507: Microstructure Rating Charts for Evaluating the Microstructure and Creep Damage of High-Temperature Steels for High-Pressure Piping and Boiler Components, 2nd Edition, (2005).

[8] W. Arnswald, R. Blum, B. Neubauer, K. E. Poulsen, Application of Structural Surface Examination for the testing of power plant components subjected to creep stress, reprinted from VGB Kraftwerkstechnik, July (1979).

[9] P. Auerkai, K. Borggren, J. Salonen, Reference micrographs for evaluation of creep damage in replica inspections report NT TR 170, Nordtest, February 1992, accessible from: http: /www. nordtest. info/images/documents/nt-technical reports.

[10] Z. Štorkán, Material structure evaluating using replicas following the life of heat equipment, In: TLAK 2011, CDMS Praha, May 2011, p.105 – 110 (in Czech).

[11] J. Bystrianský, M. Kraus, R, Bonček, S. Vejvoda, Program of destructive testing of long-term exposed structural materials in terms pressure circuit conventional power plant, In: Kotle a energetická zařízení (Boilers and Power Equipment), Brno, March 2011 (in Czech).