Changes in Material Properties of Used Gas Turbine Blade Made of Single- Crystal Superalloy

가스터빈 단결정 블레이드 사용품의 특성변화

  • Received : 2010.06.04
  • Accepted : 2010.09.28
  • Published : 2010.12.01


The material properties of gas turbine components change during the daily start/stop thermal cycle because of exposure to the hot combustion gas. Recently, single-crystal Ni-based superalloys have been used to manufacture many hot-gas components for gas turbines. However, the user needs to depend on the manufacturer for maintenance issues because of the lack of data required for predicting blade life and material degradation. In this study, we investigate the time-dependent degradation of first-stage blades at various operating facilities to collect the basic data for life assessment and damage analysis. The blade material is a single-crystal Ni-based superalloy, CMSX-4, and the EOH (equivalent operating hours) are 25,000 and 52,000, respectively. We prepared the test specimen directly from used blades and carried out mechanical tests and microstructural observations.


Gas Turbine;Used Blade;Material Property;Super Alloy;Single Crystal


  1. Swaminathan, V. P., Cheruvu, N. S., Klein, J. M. and Robinson, W. M., 1998, "Microstructure and Property Assessment of Conventionally Cast and Directionally Soilidified Buckets Refurbished After Long-Term Service,” International Gas Turbine & Aeroengine Congress & Exhibition Proceedings, 98-GT-510, Sweden.
  2. Lvov, E. and Norsworthy, D., 2000, "Influence of Previous Service History on the Microstructure of Rejuvenated Superalloy Gas Turrbine Blades After Their Return to Service,” 4th International RRAC Conference, Welding and Repair Technology for Power Plants, Florida.
  3. Sajjadi, S. A., Nategh, S. and Guthrie, R. I. L., 2002, "Study of Microstructure and Mechanical Properties of High Performance Ni-Base Superalloy GTD-111,” Material Science Engineering A, 325, pp. 484-489.
  4. Viswanathan, R., 1989, "Damage Mechanisms and Life Assessment of High-Temperature Components,” ASM International, pp. c.
  5. Kameda, J., Bloomer, T. E., Sugita,Y., Ito, A. and Sakurai, S., 1997, "High Temperature Environmental Attack and Mechanical Degradation of Coatings in Gas Turbine Blades,” Material Science Engineering A, 229, pp. 42-44.
  6. Yoo, K. B. and Lee, H. S., 2009, "Degradation Characteristics of CMSX-4 Gas Turbine Blade with Operation Hours,” Proc. of the 23rd Conference on Advanced Structural Materials, pp. 296-307.