CONCLUSIONS In eutectoid steels, the microstructural changes produced by the cold drawing process affect the macroscopic behavior with regard to environmentally assisted cracking in general and hydrogen assisted cracking (or hydrogen embrittlement) in particular. In heavily drawn steels, the microscopic fracture mode is a kind of very deformed tearing topography surface, the deformation axis coincident with the cold drawing direction. This topography is produced as a consequence of the macroscopic crack deflection with mode II propagation. A proportional relationship was found between the different hydrogen damage topographies (HDT): the very deformed TTS really observed in heavily drawn steels could be virtually obtained by deforming the micrograph of the pure TTS (associated with the hot rolled material) in the direction of cold drawing. Acknowledgements The financial support of this work by the Spanish CICYT (Grant MAT97-0442) and Xunta de Galicia (Grant XUGA 11802B97) is gratefully acknowledged. In addition, the authors wish to express their gratitude to EMESA TREFILERIA S.A. (La Coruña, Spain) for providing the steel used in the experimental programme. REFERENCES 1. Parkins, R.N., Elices, M., Sánchez-Gálvez, V. y Caballero, L. (1982). Corros. Sci. 22, 379. 2. Lancha, A.M. (1987). Ph. D. Thesis, Complutense University of Madrid. 3. Toribio, J. and Ovejero, E. (1998). Int. J. Fracture 90, L21. 4. Toribio, J. and Ovejero, E. (1999). Scripta Mater 40, 943. 5. Toribio, J. and Ovejero, E. (1997). Mater. Sci. Engng. A234-236, 579. 6. Toribio, J. and Ovejero, E. (1998). J. Mater. Sci. Lett. 17, 1037. 7. Toribio, J. and Ovejero, E. (1998). Scripta Mater. 39, 323. 8. Toribio, J. and Ovejero, E. (1998). Mech. Time-Dependent Mater. 1, 307. 9. Thompson, A. W. and Chesnutt, J.C. (1979). Metall. Trans. 10A, 1193. 10. Costa, J.E. and Thompson, A.W. (1982). Metall. Trans. 13A, 1315. 11. Toribio, J., Lancha, A.M. and Elices, M. (1991) Scripta Metall. Mater. 25, 2239. 12. Toribio, J., Lancha, A.M. and Elices, M. (1992) Metall. Trans. 23A, 1573.
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