PSI - Issue 23

Petr Král et al. / Procedia Structural Integrity 23 (2019) 287–292 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 7. Fracture surfaces of Ni-Cr-W alloy tested at (a) 1173 K and 50 MPa, (b) 1373 K and 10 MPa.

4. Summary The investigation of microstructure changes of Ni-Cr-W based superalloy occurring during creep testing showed the gradual coarsening and dissolution of secondary M 23 C 6 carbides with increasing creep temperature. The analyses of creep data revealed low values of creep damage tolerance factor λ suggesting that creep damage is influenced by intergranular fracture mode. Acknowledgements The authors acknowledge financial support for this study provided by the Ministry of Industry and Trade of the Czech Republic within the framework programme MPO ČR Trio under the Project FV 10699. The research infrastructure IPMinfra supported by the Ministry of Education, Youth and Sports of the Czech Republic through the project No. LM2015069 was used. References Reed R. C., 2006. The Superalloys Fundamentals and Applications. Cambridge University Press, Cambridge, UK. Tawancy, H.M., Klarstrom, D.L., Rothman, M.F., 1984. Development of a new nickel-base superalloy. J. Met. 36, 58-62. Liu, Y., Hu, R., Li, J.S., Kou, H.C., Li, H.W., Chang, H., Fu, H.Z., 2009. Hot working characteristic of as-cast and homogenized Ni – Cr – W superalloy. Mater. Sci. Eng. A 508, 141-147. Lee, H.J., Kim, H., Kim, D., Jang, C., 2015. Microstructure evolution of a Ni – Cr – W superalloy during long-term aging at high temperatures. Mater. Character. 106, 283-291. Djerdjare, B., Lebaili, S., Lay, S., 2008. Microstructural study of (Co – Ni – Fe) based alloys. Mater. Sci. Eng. A 475, 336-342. Reddy, G.V.P., Harini, P., Sandhya, R., Rao, K.B.S., Paretkar, R.K., 2010. On dual-slope linear cyclic hardening of Hastelloy X. Mater. Sci. Eng. A 527, 3848-3851. Chomette, S., Gentzbittel, J.M., Viguier, B., 2010. Creep behaviour of as received, aged and cold worked INCONEL 617 at 850 °C and 950 °C. J. Nucl. Mater. 399, 266-274. Xu, Z., Jiang, L., Dong, J., Li, Z., Zhou, X., 2015. The effect of silicon on precipitation and decomposition behaviors of M6C carbide in a Ni – Mo – Cr superalloy. J. Alloys and Compounds 620, 197-203. Ashby, M.F., Dyson,B.F, 1984. Creep damage mechanics and micromechanisms, in “ Advances in Fracture Research ” . In: Valluri, S.R. et al. (Eds.). Pergamon Press, Oxford, 3-30. Dyson, B. F., Gibbons, T.B., 1987. Tertiary creep in nickel-base superalloys: analysis of experimental data and theoretical synthesis. Acta Metall. 35, 2355-2369. Sklenička, V., Kuchařová, K., Kvapilová, M., Král, P., Dvořák, J., 2017. Combination of Experiments and Continuum Damage Mechanics Approach for Prediction of Creep Fracture in an Advanced 9%Cr Steel. Solid State Phenomena 258, 591-594.