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Vol.51, No.3, 159 ~ 169, 2013
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| Title |
| Investigation of the Degradation Behaviors of a Gas Turbine Burner made of an Inconel 738LC Superalloy |
| 홍현욱 Hyun Uk Hong , 박경미 Kyung Mi Park , 김희수 Hee Soo Kim , 김인수 In Soo Kim , 최백규 Baig Gyu Choi , 조창용 Chang Yong Jo , 우타관 Ta Kwan Woo , 이재현 Je Hyun Lee |
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| Abstract |
| The microstructure and mechanical property degradation of a gas turbine SEV burner made of the nickel-based superalloy Inconel 738LC were investigated with increasing operation times in the range of 24000-65000 equivalent number of operating hours (EOH). The original cuboidal shape of γ? particles with a size of 400-500 nm became spherical with a diameter larger than 1 μm. The γ? coarsening kinetics conformed well to the LSW model suggesting that the variation of r³as a function of exposure time is linear. In the hottest zone of the SEV burner operated for 65000 EOH, a continuous film of carbides along the grain boundaries was observed as a result of the transformation of MC carbide to M_23C_6＋γThis continuous film of M_23C_6 carbides provided a preferential site for intergranular crack initiation and propagation during tensile testing, and reduced accordingly the alloy ductility, whereas it was favorable to tensile strength. |
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| Key Words |
| gas turbine, alloys, degradation, microstructure, intergranular crack |
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