LIFE ASSESSMENT OF HIGH PRESSURE STEAM PIPING BEND WORKING UNDER CONDITIONS OF CREEP DAMAGE

1 JUNEK Michal
Co-authors:
1 JANOVEC Jiří
Institution:
1 CTU in Prague, Faculty of Mechanical Engineering, Karlovo náměstí 13, Praha 2, Czech Republic, EU
Conference:
24th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, June 3rd - 5th 2015
Proceedings:
Proceedings 24th International Conference on Metallurgy and Materials
Pages:
546-552
ISBN:
978-80-87294-58-1
ISSN:
2694-9296
Published:
12th January 2015
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
96 views / 23 downloads
Abstract

For many years, low alloy CrMo(V) creep-resistant steels are applied for parts in the construction of energy and chemical structural units working under creep conditions (temperature about 550 °C and pressure about 15 MPa). These steels most often include creep-resistant steel 13CrMo4-4 (ČSN 15 121), 14MoV6-3 (ČSN 15 128), 10CrMo9-10 (ČSN 15 128). The main problem of steam pipe-lines made of these creep-resistant steels is a residual lifetime, because these parts are at presence in most Czech power plants at the end of their designed lifetime (2,5 . 105 hours).This article deals with a lifetime assessment of one steam piping bend made of ČSN steel 15 128 (14MoV6-3) which was operated in conditions of creep damage in Czech fossil fuel power plant until its creep deformation obtained a limit of 1 percent. The overall condition of the bend was assessed using replica and cross section metallography including electron microscopy and by evaluation of mechanical properties in as-received state and after additional laboratory ageing at 600 °C for up to 5 000 hours in air conditions. As the final result, the residual lifetime by using mathematical approaches and standards was estimated.

Keywords: low alloy creep-resistant steels, creep, life assessment of steam pipe-lines, microstructure rating charts, laboratory ageing

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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