Mechanical and microstructural/chemical degradation of coating and substrate in gas turbine blade

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:204642

Sugita, Y; Ito, M ^[1]; Sakurai, S ^[2]; Gold, C R; Bloomer, T E; Kameda, J ^[3]

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1. Chubu Electric Power Co. Inc., Nagoya (Japan)
2. Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.
3. Iowa State Univ. of Science and Technology, Ames, IA (United States). Center for Advanced Technology Development

The mechanical property degradation (295--1223 K) and microstructural/chemical evolution of CoNiCrAlY coatings and superalloy (Rene 80) substrates in gas turbine blades operated in- service have been studied using a small punch (SP) testing technique and scanning Auger microprobe. In SP tests, coating cracks continuously and discretely propagated at 295 K and higher temperatures, respectively. The ductile-brittle transition temperature of the coatings was increased during long time exposure of gas turbine blades to oxidizing environments while that of the substrate did not change. The low cycle fatigue life of the coatings at 295 K was also reduced in-service. Oxidation and sulfur segregation near the coating surface were found to be major causes of the mechanical degradation of the coatings.

• Research Organization: Ames Lab., IA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 204642
• Report Number(s): IS-M--837; CONF-951042--1; ON: DE96006799
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
36 MATERIALS SCIENCE
GAS TURBINES
MECHANICAL TESTS
PROTECTIVE COATINGS
RENE 80
TURBINE BLADES