|About this Abstract
||2014 TMS Annual Meeting & Exhibition
||Multiscale Approaches to Hydrogen-assisted Degradation of Metals
||Embrittlement Measures in Fe-base Systems Appropriate to Multiscale Models
||William Gerberich, Eric Hintsala
|On-Site Speaker (Planned)
Using special non-electrochemical techniques, we show that relatively large amounts of hydrogen can be inserted into both body-centered (BCC) and face-centered cubic (FCC) crystal structures of interest to embrittlement. The fact that this is possible to accomplish in sub-micron systems will eventually allow scale effects to be established. For Fe-3%Si tested at mean strain rates of 1.8x10-5 to 0.11 s-1,, the shift in the ductile-brittle transition temperature (DBTT) is about 100 K for both compact-round tension samples and an analytical model. At an intermediate strain rate, the upward shift in DBTT for specimens without hydrogen to those with hydrogen is nearly 140 K. For an austenitic iron base alloy (Nitronic 50), even at room temperature and relatively fast strain rates of 0.01 s-1, brittle fracture is found in compression of sufficiently small nanopillars. First order estimates of the strain-energy release rate suggest the Griffith criterion is approached.
||Planned: Paper Selections