Imperial College London
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DrEmilioMartinez-Paneda

Faculty of Engineering, Department of Civil and Environmental Engineering

Visiting Reader
 
 
 
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Contact

 

+44 (0)20 7594 8188e.martinez-paneda Website

 
 
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Location

 

249Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Martinez-Paneda:2016:10.1016/j.actamat.2016.07.022,
author = {Martinez-Paneda, E and Niordson, CF and Gangloff, RP},
doi = {10.1016/j.actamat.2016.07.022},
journal = {Acta Materialia},
pages = {321--332},
title = {Strain gradient plasticity-based modeling of hydrogen environment assisted cracking},
url = {http://dx.doi.org/10.1016/j.actamat.2016.07.022},
volume = {117},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Finite element analysis of stress about a blunt crack tip, emphasizing finite strain and phenomenological and mechanism-based strain gradient plasticity (SGP) formulations, is integrated with electrochemical assessment of occluded-crack tip hydrogen (H) solubility and two H-decohesion models to predict hydrogen environment assisted crack growth properties. SGP elevates crack tip geometrically necessary dislocation density and flow stress, with enhancement declining with increasing alloy strength. Elevated hydrostatic stress promotes high-trapped H concentration for crack tip damage; it is imperative to account for SGP in H cracking models. Predictions of the threshold stress intensity factor and H-diffusion limited Stage II crack growth rate agree with experimental data for a high strength austenitic Ni-Cu superalloy (Monel®K-500) and two modern ultra-high strength martensitic steels (AerMet™100 and Ferrium™M54) stressed in 0.6 M NaCl solution over a range of applied potential. For Monel®K-500, KTH is accurately predicted versus cathodic potential using either classical or gradient-modified formulations; however, Stage II growth rate is best predicted by a SGP description of crack tip stress that justifies a critical distance of 1 μm. For steel, threshold and growth rate are best predicted using high-hydrostatic stress that exceeds 6 to 8 times alloy yield strength and extends 1 μm ahead of the crack tip. This stress is nearly achieved with a three-length phenomenological SGP formulation, but additional stress enhancement is needed, perhaps due to tip geometry or slip-microstructure.
AU  - Martinez-Paneda,E
AU  - Niordson,CF
AU  - Gangloff,RP
DO  - 10.1016/j.actamat.2016.07.022
EP  - 332
PY  - 2016///
SN  - 1359-6454
SP  - 321
TI  - Strain gradient plasticity-based modeling of hydrogen environment assisted cracking
T2  - Acta Materialia
UR  - http://dx.doi.org/10.1016/j.actamat.2016.07.022
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000383005300031&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - https://www.sciencedirect.com/science/article/pii/S1359645416305183
UR  - http://hdl.handle.net/10044/1/73414
VL  - 117
ER  -
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