An Innovative Method for the Prediction of Hydrogen Embrittlement in Steel

Hydrogen embrittlement is among the more common forms of environmentally assisted cracking found in failed components made from high-strength steel alloys. There are numerous ways that hydrogen can enter the steel lattice and, under load, causeembrittlement. This embrittlement can lead to subcritical crack growth, a possible cause of premature catastrophic failure of the component. Traditional numerical analysis techniques do no account for such a complex phenomena. We propose a finiteelement-based method for the prediction of hydrogen embrittlement in steels, and the calculation of critical stress intensity factors based on such embrittlement. We propose a multi-scale modeling approach, with the lowest level of modeling being at thelevel of the microconstituents, including the embrittled steel region. The cohesive surface finite element method is used to predict the actual stress intensity factor for the onset of critical crack growth. This approach accounts for thethermo-micromechanical and chemical states of the steel over time, including the diffusion of hydrogen through the steel. (P-020588) Steel is among the most, if not the most, common of engineering materials. Hydrogen embrittlement is a significant problem for designers that employ steel in environments where hydrogen may be present. As such, a user-friendly computationally efficientmethod for prediction of hydrogen embrittlement in steels would have broad application across a wide range of industries, military and commercial. Any industry that utilizes steel machines and devices, and particularly those who design and manufacturethem, would be interested in utilizing this tool as a design, maintenance, and prognostics device. Thus, this program could find wide audience in the commercial automotive, aviation, space and power industries, to name just a few, as well as having broadapplication potentially across the entire military spectrum.