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http://dx.doi.org/10.7777/jkfs.2016.36.5.159

Evolution of Microstructure and Mechanical Properties of a Ni Base Superalloy during Thermal Exposure  

Kim, In-Soo (High tmeperature Materials Department, Kora Institute of materials Science)
Choi, Baig-Gyu (High tmeperature Materials Department, Kora Institute of materials Science)
Jung, Joong-Eun (High tmeperature Materials Department, Kora Institute of materials Science)
Do, Jeong-Hyeon (High tmeperature Materials Department, Kora Institute of materials Science)
Jung, In-Yong (High tmeperature Materials Department, Kora Institute of materials Science)
Jo, Chang-Yong (High tmeperature Materials Department, Kora Institute of materials Science)
Publication Information
Journal of Korea Foundry Society / v.36, no.5, 2016 , pp. 159-166 More about this Journal
Abstract
The microstructural evolution of a cast Ni base superalloy, IN738LC, has been investigated after long term exposure at several temperatures. Most of the fine secondary ${\gamma}^{\prime}$ particles resolved after 2000 hour exposure at $816^{\circ}C$. At higher temperatures of $871^{\circ}C$ and $927^{\circ}C$, secondary ${\gamma}^{\prime}$ resolved after 1000 hours of exposure, and cuboidal primary ${\gamma}^{\prime}$ grew with exposure time. During the thermal exposure, ${\sigma}$ phase formed at all tested temperatures, and ${\eta}$ phase was observed around interdendritic regions due to carbide degeneration. The influence of microstructural evolution during thermal exposure on the mechanical properties has been analyzed. The effects of ${\gamma}^{\prime}$ particle growth are more pronounced on the high temperature creep properties than on the room temperature tensile properties.
Keywords
Ni-base superalloy; Thermal exposure; Microstructure; Mechanical properties;
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  • Reference
1 R. A. Stevens and P. E. J. Flewitt, Mater. Sci. and Eng., "Intermediate regenerative heat treatments for exending the creep life of the superalloy IN-738", 50 (1981) 271-284.   DOI
2 E. Balikci, R. A. Mirshams and A. Raman, Mater. Sci. and Eng. A, "Fracture behavior of superalloy IN738LC with various precipitate microstructures", A265 (1999) 50-62.
3 N. El-Bagoury, M. Waly and A Nafal, Mater. Sci. and Eng. A, "Effect of various heat treatment conditions on microstructure of cast polycrystalline IN738CL alloy", A487 (2008) 152-161.
4 K. Banerjee, N. L. Richards and M. C. Chaturvedi, Metall. and Mater. Trans. A, "Effect of filler alloys on heat-affected zone cracking in preweld heat-treated IN738LC gas-tungstenarc welds", 36A (2005) 1881-1890.
5 Huang Xuebing, Kang Yan, Zhou Huihua, Zhang Yun and Hu Zhangqi, Mater. Letters, "Influence of heat treatment on the microstructure of a unidirectional Ni-base superalloy", 36 (1998) 210-213.   DOI
6 E. Lvova, J. of Mater. Eng. and Perform., "A comparision of aging kinetics of new and rejuvenated conventionally cast GTD-111 gas turbine blades", 16(2) (2007) 254-264.   DOI
7 R. S. Moshtaghin and S. Asgari, Mater. and Design, "Growth kinetics of ${\gamma}^{\prime}$ precipitates in superalloy IN738LC during long term aging", 24 (2003) 325-330.   DOI
8 R. S. Moshatghin and S. Asgari, J. of Alloys and compounds, " The effect of thermal exposure on the ${\gamma}^{\prime}$ characteristics in a Ni-base superalloy", 368 (2004) 144-151.   DOI
9 X. Li, N. Saunders and A. P. Miodownik, Metall. and Mater. Trans. A, "The Coarsening kinetics of ${\gamma}^{\prime}$ particles in Ni-based alloys", 33A (2002) 3367-3373.
10 R. A. Stevens and P. E. J. Flewitt, Acta Metll., "The dependence of creep rate on microstructure in a ${\gamma}^{\prime}$ strengthened superalloy", 29 (1981) 867-882.   DOI
11 E. Balikci, R. A. Mirshams and A. Raman, J. of Mater. Eng. and Perform., "Tensile strengthening in the nickel-base superalloy IN738LC", 9(3) (2000) 324-329.   DOI
12 C.-N. Wei, H.-Y. Bor and L. Chang, J. of Alloys and Comp., "The influence of carbon addition on carbide characteristics and mechanical properties of CM-681LC superalloy using fine-grain process" 509 (2011) 5708-5714.   DOI
13 L. R. Liu, T. Jin, N. R. Zhao, X. F. Sun, H. R. Guan and Z. Q. Hu, Mater. Sci. and Eng. A, "Formation of carbides and their effects on stress rupture of a Ni-base single crystal superalloy", A361 (2003) 192-197.
14 Choi BG, Kim IS, Kim DH and Jo CY, Mater. Sci. and Eng. A, "Temperature dependence of MC decomposition behavior in Ni-base superalloy GTD-111", A478 (2008) 329-335.
15 I. M. Lifshitz and V. V. Slyozov, J. Phys. Chem. Solids, "The kinetics of precipitation from supersaturated solid solutions", 19 (1961) 35-50.   DOI
16 C. Wagner, Z. Elektrochem., "Theroy of precipitate change by redissolution", 65 (1965) 581-591.
17 J. Tiley, G. B. Viswanathan, R. Srinivasan, R. Banerjee, D. M. Dimiduk and H. L. Fraser, Acta Mater., "Coarsening kinetics of ${\gamma}^{\prime}$ precipitates in the commercial nickel base superalloy Rene 88 DT", 57(8) (2009) 2538-2549.   DOI