Nondestructive Degradation Evaluation of Ferritic Steels for High Temperature Applications
The assessment of deterioration of ferritic steels as employed for power plant components with respect to creep, softening and embrittlement is achieved mainly by observation of changes in microstructure. The experience gathered in laboratory investigations is outlined. The obtained knowledge can be applied best in field work if metallography by replication techniques is performed. As a valuable supplement hardness measurements can and should be untertaken. Results from measurements of changes of other physical properties are as yet unable to adequately differentiate changes. Preliminary tests in a static magnetic field indicate some potential for a method based on measurements of reversible permeability.
KeywordsStatic Magnetic Field Ferritic Steel Stress Rupture Turbine Rotor Creep Cavity
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- /1/.Gooch, D.J., Townsend, R.D.: CEGB Remanent Life Assessment Procedures. EPRI, Conf. Life Extension and Assessment of Fossil Plants, 1986Google Scholar
- /2/.Hede, A., Aronsson, B.: Microstructure and Creep Properties of some 12%-Chromium Martensitic Steels, J. Iron and Steel Inst. 207 (1969) 1241–1251Google Scholar
- /3/.Irvine, K.J., Crowe, D.J., Pickering, F.B.: The Physical Metallurgy of 12%-Chromium Steels. J. Iron and Steel Inst. 195 (1960) 386–404Google Scholar
- /4/.Tipler, H.R., Hopkins, B.E.: The Creep Cavitation of Commercial and High-Purity Cr-Mo-V-Steels. Metal Science (1976) 47–56Google Scholar
- /5/.Clark, W.G., Metala, M.J.: Eddy Current Determination of Material Properties. EPRI, Conf. Life Extension and Assessment of Fossil Plants, 1986Google Scholar
- /6/.Relander, K., Geiger, T.: Gefügeänderungen in den warmfesten Stählen 13CrMo 44 and 10CrMo 9 10 bei langzeitigen Glühungen zwischen 550 und 780°C. Arch. Eisenhüttenwesen 37 (1966) 897–906Google Scholar
- /7/.Hartnagel, W. et al.: Determination of Residual Life of Turbine Components. COST 501, Progress Report 1983Google Scholar
- /9/.Equotip by PROCEQ, Zurich, SwitzerlandGoogle Scholar