PSI - Issue 59

Jesús Toribio et al. / Procedia Structural Integrity 59 (2024) 104–111 Jesús Toribio / Procedia Structural Integrity 00 ( 2024) 000 – 000

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2. Compressive residual stresses improve the SCC behaviour and increase the failure load in aggressive media by delaying either the metal dissolution (in the case of LAD) or the hydrogen entry (in the case of HAC). 3. Hydrogen effects in the pearlitic microstructure are manifested in the form of tearing topography surface or TTS, a sort of hydrogen-assisted micro-damage (HAMD) region. 4. The Rice's model of residual stress distribution in the vicinity of a crack tip is able to explain the mechanical behaviour of pre-cracked samples in aggressive environments by estimating the stress level and the plastic zone size. 5. The comparison between the sizes of the plastic zone and of the TTS zone (HAMD region) demonstrates the hydrogen transport by diffusion is predominant over hydrogen transport by dislocations in pearlite. 6. Epilogue: A Tribute to Thomas Stearns Elio t’s “ And All Is Always Now ” This paper is aimed towards an elucidation of the important role of diffusion in the hydrogen transport in pearlite, with implications in hydrogen assisted cracking (HAC). In this framework, and considering the role of history in HAC, it recalls the verse of the Spanish Poet Antonio Machado ― Hoy es siempre todavía ‖, and also T.S: Eliot’s ― And All is Always Now ‖ References Costa, J.E., Thompson, A.W., 1982. Hydrogen cracking in nominally pearlitic 1045 steel. Metallurgical Transactions 13A, 1315-1318. Dadfarnia, M., Martin, M. L., Nagao, A., Sofronis, P., Robertson, I. M., 2015. Modeling hydrogen transport by dislocations. Journal of the Mechanics and Physics of Solids 78, 511-525. Gortemaker, P.C.M., de Pater, C, Spiering, R.M.E.J., 1981. Near- crack tip finite strain analysis. In: ―Advances in Fracture Research– ICF5", D. Francois (Ed.). Pergamon, Oxford, pp. 151-160. ISO 7539-6, 1989. Preparation and use of pre-cracked specimens. ISO 7539-7, 1989. Slow strain rate testing. Parkins, R.N., 1993. Slow strain rate testing-25 years experience. ASTM STP 1210, 7-21. Rice, J.R., 1967. Mechanics of crack tip deformation and extension by fatigue. ASTM STP 415, 247-309. Thompson, A.W., Chesnutt, J.C., 1979. Identification of a fracture mode: the tearing topography surface. Metallurgical Transactions 10A, 1193 1196. Tien, J., Thompson, A. W., Bernstein, I. M., Richards, R. J., 1976. Hydrogen transport by dislocations. Metallurgical Transactions 7A, 821-829. Toribio, J., 1992. Fractographic evidence of hydrogen transport by diffusion in pearlitic steel. Journal of Materials Science Letters 11, 1151-1153. Toribio, J., 1993. The use of precracked and notched slow strain rate specimens. ASTM STP 1210, 105-122. Toribio, J., 1996. Hydrogen-plasticity interactions in pearlitic steel: a fractographic and numerical study. Materials Science and Engineering A219, 180-191. Toribio, J., 1997. Fracture mechanics approach to hydrogen assisted microdamage in eutectoid steel. Metallurgical and Materials Transactions 28A, 191-197. Toribio, J., 2012. Time-dependent triaxiality effects on hydrogen-assisted micro-damage evolution in pearlitic steel. ISIJ International 52, 228 233. Toribio, J., Kharin, V., 2015. A generalised model of hydrogen diffusion in metals with multiple trap types. Philosophical Magazine 95, 3429 3451. Toribio, J., Lancha, A. M., 1993. Effect of cold drawing on susceptibility to hydrogen embrittlement of prestressing steell. Materials and Structures 26, 30-37. Toribio, J., Lancha, A. M., 1996. Effect of cold drawing on environmentally assisted cracking of cold-drawn steel. Journal of Materials Science 31, 6015-6024. Toribio, J., Lancha, A.M., Elices, M., 1991a. Characteristics of the new tearing topography surface. Scripta Metallurgica et Materialia 25, 2239 2244. Toribio, J., Lancha, A.M., Elices, M., 1991b. Hydrogen embrittlement of pearlitic steels: Phenomenological study on notched and precracked specimens. Corrosion 47, 781-791. Toribio, J., Lancha, A.M., Elices, M., 1992. The tearing topography surface as the zone associated with hydrogen embrittlement processes in pearlitic steel. Metallurgical Transactions 23A, 1573-1584. Toribio, J., Vasseur, E., 1997. Hydrogen-assisted micro-damage evolution in pearlitic steel. Journal of Materials Science Letters 16, 1345-1348. Van Leeuwen, H.P., 1974. The kinetics of hydrogen embrittlement: a quantitative diffusion model. Engineering Fracture Mechanics 6, 141-161.