PSI - Issue 28

Jesús Toribio et al. / Procedia Structural Integrity 28 (2020) 2444–2449 Jesús Toribio et al. / Procedia Structural Integrity 00 (2020) 000–000

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6. Conclusions The following conclusions have been obtained in this numerical research dealing with hydrogen embrittlement and notch tensile strength of sharply-notched specimens of pearlitic steels under axial tensile loading under the steady-state regime): The global amount of hydrogen entering the sample increases with the level of remote stress or externally-applied load, and the concentration profile shows a strong gradient and a peak in the close vicinity of the notch tip, the depth of such a peak also increasing for growing load. Results show how the boundary value of hydrogen concentration increases markedly with the remote stress (externally applied load) and slightly decreases with the notch depth, i.e., the equilibrium boundary value of hydrogen concentration is slightly higher for shallow sharp notches. The point of maximum hydrostatic stress shifts by increasing the load from the notch tip to the axis of the bar and its depth is an increasing function of the notch depth itself. However, such a characteristic point does not reach the specimen axis in the analyzed geometries. References Hardie, D., Liu, S., 1996. The Effect of Stress Concentration on Hydrogen Embrittlement of a Low Alloy Steel. Corrosion Science 38, 721-733. Jewett, RP., Walter, RJ., Chandler, WT., Frohmberg, RP., 1973. Hydrogen Environment Embrittlement of Metals (NASA CR-2163), NASA: Hamptom VA, USA. Lillard, RS., Enos, DG., Scully, JR., 2000. Calcium Hydroxide as a Promoter of Hydrogen Absorption in 99.5% Fe and a Fully Pearlitic 0.8% C Steel During Electrochemical Reduction of Water. Corrosion 56, 1119-1132. Toribio, J., 1992. Fractographic Evidence of Hydrogen Transport by Diffusion in Pearlitic Steel. Journal of Materials Science Letters 11, 1151-1153. Toribio, J., 1993. Role of Hydrostatic Stress in Hydrogen Diffusion in Pearlitic Steel. Journal of Materials Science 28, 2289-2298. 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., 2018. HELP versus HEDE in Progressively Cold-Drawn Pearlitic Steels: Between Donatello and Michelangelo . Engineering Failure Analysis 94, 157-164. Toribio, J., Ayaso, FJ., 2004. Optimisation of Round-Notched Specimen for Hydrogen Embrittlement Testing of Materials. Journal of Materials Science Letters 39, 4675-4678. Toribio, J., Elices, M., 1992. The Role of Local Strain Rate in the Hydrogen Embrittlement of Round-Notched Samples. Corrosion Science 33, 1387-1395. Toribio, J., Lancha, AM., Elices, M., 1991. Macroscopic Variables Governing the Microscopic Fracture of Pearlitic Steels. Materials Science and Engineering A145, 167-177. Toribio, J., Vasseur, E., 1997. Hydrogen-Assisted Micro-Damage Evolution in Pearlitic Steel. Journal of Materials Science Letters 16, 1345-1348. Van Leeuwen, HP., 1974. The Kinetics of Hydrogen Embrittlement: A Quantitative Diffusion Model. Engineering Fracture Mechanics 6, 141-161. Wagenblast, H., Wriedt, HA., 1971. Dilation of Alpha Iron by Dissolved Hydrogen at 450º to 800ºC. Metallurgical Transactions 2, 1393-1397. Walter, RJ., Chandler, WT., 1971. Influence of Hydrogen Pressure and Notch Severity on Hydrogen-Environment Embrittlement at Ambient Temperatures. Materials Science and Engineering 8, 90-97. Wang, M., Akiyama, E., Tsuzaki, K., 2005a. Crosshead Speed Dependence of the Notch Tensile Strength of a High Strength Steel in the Presence of Hydrogen. Scripta Materialia 53, 713-718. Wang, M., Akiyama, E., Tsuzaki, K., 2005b. Effect of Hydrogen and Stress Concentration on the Notch Tensile Strength of AISI 4135 Steel. Materials Science and Engineering A398, 37-46. Wang, M., Akiyama, E., Tsuzaki, K., 2007. Effect of Hydrogen on the Fracture Behavior of High Strength Steel During Slow Strain Rate Test. Corrosion Science 49, 4081-4097. Ayas, C, Deshpande, VS., Fleck, NA., 2014. A Fracture Criterion for the Notch Strength of High Strength Steels in the Presence of Hydrogen. Journal of the Mechanics and Physics of Solids 63, 80-93.