| Title |
Investigation of the Degradation Behaviors of a Gas Turbine Burner made of an Inconel 738LC Superalloy |
| Authors |
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) |
| DOI |
https://doi.org/10.3365/KJMM.2013.51.3.159 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
gas turbine; alloys; degradation; microstructure; intergranular crack |
| 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. |