Characteristics of Fusion-Welded Joints Made Using Martensitic Steel after 100,000 Hours in Service

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Abstract:

The paper presents the results of tests of mixed fusion-welded joints consisting of superheater pipes of grades T91 and HCM12A(T122) after 100,000 hours in service in a BB-1150 boiler welded to new pipes (in “as-delivered” condition) of grades T91 and VM12-SHC. The state of the microstructure and properties of the used tube material after long term service are characterized. The paper describes fusion welding conditions and parameters, and evaluates the quality of the created butt joints. The results of tests of the macro-and microstructure of the joints and their mechanical properties are presented. It was determined that the welding process intensifies further degradation of the tested materials to a small extent only. This work was performed under the Strategic Research Project No SP/E/1/67484/10 supported by the National Centre for Research and Development.

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Periodical:

Solid State Phenomena (Volume 246)

Pages:

177-182

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Online since:

February 2016

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[1] G. Moskal, A. Hernas, J. Pasternak, Structural stability and properties of weld joints of new creep-resistant steel grades with 9 or 12% Cr contents applied in operation of power generations sector over 30 000h, in: J. Lecomte-Beckers, M. Carton, F. Schubert and P.J. Ennis (Eds. ), Materials for Advanced Power Engineering 2006, Proceedings of the 8th Liege Conference Part III, 2006, pp.1357-1368.

Google Scholar

[2] A. Hernas, G. Moskal, K. Przegaliński, Degradation of T91 and HCM12(A) steels after 70000 hours exposure in boiler [in Polish], Power Engineering (Journal of Polish Electrician Association - in Polish) 19 (2009) 69-72.

Google Scholar

[3] K. Rodak, A. Hernas, Scaning transmission electron microscopy studies on the microstructure of high chromium steel after long time exposition, Solid State Phenom. 212 (2013) 25-28.

DOI: 10.4028/www.scientific.net/ssp.212.25

Google Scholar

[4] C.G. Panait, W. Bendick, A. Fuchsmann, A.F. Gourgues-Lorenzon, J. Besson, Study of the microstructure of the Grade 91 steel after more than 100, 000 h of creep exposure at 600 °C, Int. J. Pres. Ves. Pip. 87 (2010) 326–335.

DOI: 10.1016/j.ijpvp.2010.03.017

Google Scholar

[5] K. Rodak, A. Hernas, V. Vodárek, Microstructural characterization of second phases in X10CrMoVNb9–1 and 12CrMoWCuVNb steels after long steam exposure time at 550°C, submitted to: Int. J. Mater. Res. (2015).

DOI: 10.3139/146.111258

Google Scholar

[6] H.K. Danielsen, J. Hald, Influence of Z-Phase on Long-term Creep Stability of Martensitic 9 to 12 % Cr Steels, VGB PowerTech 5 (2009) 68-73.

Google Scholar

[7] M. Łomozik, A. Hernas, M. Zeman, Effect of welding thermal cycles on the structure and properties of simulated heat-affected zone areas in X10CrMoVNb9-1 (T91) steel at a state after 100, 000 h of operation, Mat. Sci. Eng. A-Struct. 637 (2015).

DOI: 10.1016/j.msea.2015.04.009

Google Scholar