A study of the LCF characteristics of the Ni-based superalloy IN738LC
Tóm tắt
In this study, low cycle fatigue (LCF) tests of IN738LC were conducted under high-temperature conditions. The tests were performed with various mechanical strain amplitudes and the relationship between strain amplitude and fatigue life was obtained. In addition, an equation for LCF life prediction was derived from the test results. After obtaining a strain-life diagram from the LCF test results, additional LCF tests were conducted according to the extent of damage. The LCF tests were taken at various degrees of damage in order to observe the change in mechanical properties the severity of damage. For this purpose, indentation tests were conducted and the relationship between hardness and damage was obtained. To nondestructively assess the low cycle fatigued IN738LC, the subharmonic nonlinearity parameter was first introduced because of the high attenuation properties of IN738LC. Until now, the subharmonic technique has been applied only to crack evaluation problems. This technique is presented as an effective tool for assessing low cycle fatigued IN738LC in this paper.
Tài liệu tham khảo
Wright, I. G. and Gibbons, T. B., “Recent Developments in Gas Turbine Materials and Technology and their Implications for Syngas Firing,” International Journal of Hydrogen Energy, Vol. 32, No. 16, pp. 3610–3621, 2007.
Evans, W., Screech, J., and Williams, S., “Thermo-Mechanical Fatigue and Fracture of INCO718,” International Journal of Fatigue, Vol. 30, No. 2, pp. 257–267, 2008.
Brooks, J. W. and Bridges, P. J., “Metallurgical Stability of Inconel Alloy 718,” Superalloys, Vol. 88, pp. 33–42, 1988.
Electric Power Research Institute, “Gas Turbine Blade Superalloy Material Property Handbook,” Topical Report, Product ID: 1004652, 2001.
ASTM International, “Standard Test Methods for Tension Testing of Metallic Materials,” ASTEM E8, 2002.
ASTM International, “Standard Test Method for Strain-Controlled Fatigue Testing,” ASTEM E606, 2005.
Fleury, E. and Ha, J., “Thermomechanical Fatigue Behaviour of Nickel base Superalloy IN738LC Part 2-Lifetime Prediction,” Materials Science and Technology, Vol. 17, No. 9, pp. 1087–1092, 2001.
Hwang, K. T., Kim, J. H., Yoo, K. B., Lee, H. S., and Yoo, Y. S., “Low-Cycle Fatigue in Ni-Base Superalloy IN738LC at Elevated Temperature,” Transactions of the Korean Society of Mechanical Engineers A, Vol. 34–10, pp. 1403–1409, 2010.
Kim, D. H., Kim, K. G., Kim, J. H., Lee, Y. S., and Park, W. S., “Prediction of Low Cycle Fatigue Life for Inconel 617 using Strain Energy Method,” Proc. of the KSME Autumn Conference, pp. 285–290, 2004.
Oh, J. H., Choi, I. Ch., Shin, G. S., Lee, D. B., Kim, S. J., and Jang, J. I., “The State-of-the-Art of Nickel-Based Superalloy Development for Advanced Ultra-supercritical Fossil Power Plant Boilers,” Trends in Metals & Materials Engineering, Vol. 24, No. 2, pp. 27–33, 2011.
Yoo, K. B., Kim, D. S., Yun, W. N., and Kim, J. S., “An Increase of Repair Cycle of used Component in Gas Turbine,” Trends in Metals & Materials Engineering, Vol. 24, No. 2, pp. 34–43, 2011.
“Engineering Development Report for Evaluation of the Degradation of Material for Gas Turbine,” Changwon Univ, pp. 28–30, 2002.
Joshi, N. R. and Green, R. E., “Ultrasonic Detection of Fatigue Damage,” Engineering Fracture Mechanics, Vol. 4, No. 3, pp. 577–583, 1972.
Kenderian, S., Berndt, T. P., Green, R. E., and Djordjevic, B. B., “Ultrasonic Monitoring of Dislocations during Fatigue of Pearlitic Rail Steel,” Materials Science and Engineering: A, Vol. 348, No. 1–2, pp. 90–99, 2003.
Kang, T., Kim, H. H., Song, S. J., and Kim, H. J., “Characterization of Fatigue Damage of AL6061-T6 with Ultrasound,” NDT & E International, Vol. 52, No. pp. 51–56, 2012.
Frouin, J., Sathish, S., Matikas, T. E., and Na, J. K., “Ultrasonic Linear and Nonlinear Behavior of Fatigued Ti–6Al–4V,” Journal of Materials Research, Vol. 14, No. 4, pp. 1295–1298, 1999.
Cantrell, J. H. and Yost, W. T., “Nonlinear Ultrasonic Characterization of Fatigue Microstructures,” International Journal of Fatigue, Vol. 23, Suppl. 1, pp. 487–490, 2001.
Han, X., Li, W., Zeng, Z., Favro, L., and Thomas, R., “Acoustic Chaos and Sonic Infrared Imaging,” Applied Physics Letters, Vol. 81, No. 17, pp. 3188–3190, 2002.
Solodov, I., Wackerl, J., Pfleiderer, K., and Busse, G., “Nonlinear Self-Modulation and Subharmonic Acoustic Spectroscopy for Damage Detection and Location,” Applied Physics Letters, Vol. 84, No. 26, pp. 5386–5388, 2004.