L. E. Karkina, A. R. Kuznetsov, I. N. Karkin

ULTIMATE THEORETICAL STRENGTH OF CEMENTITE IN THE (100), (010) AND (001) PLANES

Atomistic analysis of the ultimate theoretical strength of cementite in the (100), (010) and (001) planes has been performed using the molecular dynamics method. To characterize fracture, the decohesion energy, the Griffith surface energy for crack planes and the brittle fracture parameter in the Rice-Thompson model have been calculated. It is demonstrated that crack blunting may occur only in the (001) plane due to plastic strain relaxation at its top. The fracture parameter is either too large, or plastic relaxation of stresses at the crack tip is impossible in the (010) and (100) planes due to the location geometry of the studied cleavage planes and the easiest modes of plastic relaxation. The crack in the (100) and (010) planes opens in a brittle way.

References:

1. Shchastlivtsev V.M., Mirzaev D.A., Yakovleva I.L., Okishev K.Yu., Tabatchikova T.I., Khlebnikova Yu.V. Perlit v uglerodistykh stalyakh [Pearlite in Carbon Steels]. Ekaterinburg, UrO RAN Publ., 2006, 312 p. (In Russia).
2. Koreeda A., Shimizu K. Dislocations in cementite. Phil. Mag., 1968, vol. 17, iss. 149, pp. 1083–1086. DOI: 10.1080/14786436808223185.
3. Inoue A., Ogura T., Masumoto T. Deformation and fracture behaviours of cementite. Trans. JIM., 1976, vol. 17, pp. 663–672.
4. Inoue A., Ogura T., Masumoto T. Dislocation structure of cementite in cold-rolled carbon steels. J. Japan Inst. Metals., 1973, vol. 37, no. 8, pp. 875–882.
5. Inoue A., Ogura T., Masumoto T. Microstructures of deformation and fracture of cementite in pearlitic carbon steels strained at various temperatures. Met. Trans., 1977, vol. 8A, pp. 1689–1695.
6. Nishiyama Z., Kore’eda A., Katagiri S. Study of plane defects in the cementite by transmission electron microscopy. Trans. JIM., 1964, vol. 5, pp. 115–121.
7. Rice J.R., Thompson R. Ductile versus brittle behaviour of crystals. Phil. Mag., 1974, vol. 29, iss. 1, pp. 73–97. – DOI: 10.1080/14786437408213555.
8. Bitzek E., Kermode J.R., Gumbsch P. Atomistic aspects of fracture. Int. J. Fracture, 2015, vol. 191, iss. 1, pp. 13–30. – DOI: 10.1007/s10704-015-9988-2.
9. Terentyev D., He X. Properties of grain boundaries in BCC iron and iron-based alloys. An atomistic study. Open Report of the Belgian Nuclear Research Centre, SCK•CEN-BLG-1072, 2010, 70 p. ISSN 1379-2407.
10. Starikov S.A., Kuznetsov A.R., Karkina L.E., Sagaradze V.V. Ultimate theoretical strength of fcc Fe-Ni alloy polycrystals. Diagnostics, Resource and Mechanics of materials and structures, 2015, iss. 6, pp. 58–62. DOI: 10.17804/2410-9908.2015.6.058-062. Available at: http://dream-journal.org
11. Sun Y., Rice J.R., Truskinovsky L. Dislocation Nucleation Versus Cleavage in Ni₃AI and Ni. Mat. Res. Soc. Symp. Proc., 1991, vol. 213, pp. 243–248. DOI: 10.1557/PROC-213-243.
12. Kelly A., Tyson W., Cottrell A.H. Ductile and brittle crystals. Phil. Mag., 1967, vol. 15, iss. 135, pp. 567–586. DOI: 10.1080/14786436708220903.
13. Rosato V. Comparative behavior of carbon in bcc and fcc iron. Acta Metall., 1989, vol. 37, iss. 10, pp. 2759–2763. DOI: 10.1016/0001-6160(89)90310-6.
14. Daw M.S., Baskes M.I. Embedded atom method: derivation and application to impurities, surfaces and other defects in metals. Phys. Rev., 1984, vol. 29B, no. 12, pp. 6443–6453. DOI: 10.1103/PhysRevB.29.6443.
15. Johnson R.A., Dienes G.J., Damask A.C. Calculation of the energy and migration characteristics of carbon and nitrogen in α-iron and vanadium. Acta Metall., 1964, vol. 12, iss. 11, pp. 1215–1224. DOI: 10.1016/0001-6160(64)90105-1.
16. Levchenko E.V., Evteev A.V., Belova I.V., Murch G.E. Molecular dynamics simulation and theoretical analysis of carbon diffusion in cementite. Acta Mater., 2009, vol. 57, iss. 3, pp. 846–853. DOI: 10.1016/j.actamat.2008.10.025.
17. Kar'kina L.E., Kar'kin I.N., Kuznetsov A.R Atomistic simulation of stacking faults in (001), (010), and (100) planes of cementite. Physics of Metals and Metallography, 2014, vol. 115, iss. 1, pp. 85–97. DOI: 10.1134/S0031918X14010086.
18. Kar'kina L.E., Kar'kin I.N., Zubkova T.A. Atomistic simulation of stacking faults in cementite: Planes containing vector [100]. Physics of Metals and Metallography, 2014, vol. 115, iss. 8, pp. 814–829. DOI: 10.1134/S0031918X14080067.
19. Kar'kina L.E., Kar'kin I.N. Atomistic simulation of stacking faults in cementite: Planes containing vector [010]. Physics of Metals and Metallography, 2014, vol. 115, iss. 8, pp. 830–842. DOI: 10.1134/S0031918X14080079.
20. Kar'kina L.E., Zubkova T.A., Yakovleva I.L. Dislocation structure of cementite in granular pearlite after cold plastic deformation. Physics of Metals and Metallography, 2013, vol. 114, iss. 3, pp. 234–241. DOI: 10.1134/S0031918X13030095.

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