The effects of tungsten (W) additions (0, 0.1, 0.5 and 1 wt.%) on the hydrogen embrittlement behaviour of microalloyed steels were systematically investigated by means of slow strain rate tests on circumferentially notched cylindrical specimens, and the mechanism of hydrogen-induced embrittlement was discussed. W addition is found to increase the activation energy of hydrogen desorption. Micros...

One of the basic mechanisms of radiation embrittlement of steels and welds is due to matrix damage. Embrittlement results in a raise in the ductile-to-brittle transition temperature, which is normally used as indicator of the degradation status of the material. Other methods different than mechanical tests can be used to follow embrittlement like small punch test, non-destructive measurements o...

A new methodology is developed for the prediction of RPV embrittlement that utilizes a combination of domain models and nonlinear estimators including neural networks and nearest neighbor regressions. The Power Reactor Embrittlement Database is used in this study. The results from newly developed nearest neighbor projective fuser indicate that the combined embrittlement predictor achieved about...

Gold embrittlement of solder joints has been written about for at least four decades [1 – 3]. Nevertheless, gold embrittlement related solder joint failures have been analyzed in this laboratory as recently as July 2009. Gold embrittlement can be avoided by careful solder joint design and knowledge of the causes of this condition. The purpose of this paper is to provide a detailed account of ma...

The chemomechanical degradation of metals by hydrogen is widely observed, but not clearly understood at the atomic scale. Here we report an atomistic study of hydrogen embrittlement of grain boundaries in nickel. All the possible interstitial hydrogen sites at a given grain boundary are identified by a powerful geometrical approach of division of grain boundary via polyhedral packing units of a...

Owing to their glassy nature, metallic glasses demonstrate a toughness that is extremely sensitive to the frozen-in configurational state. This sensitivity gives rise to "annealing embrittlement," which is often severe and in many respects limits the technological advancement of these materials. Here, equilibrium configurations (i.e., "inherent states") of a metallic glass are established aroun...

Intrinsically ductile metals are prone to catastrophic failure when exposed to certain liquid metals, but the atomic-level mechanism for this effect is not fully understood. We characterized a model system, a nickel sample infused with bismuth atoms, by using aberration-corrected scanning transmission electron microscopy and observed a bilayer interfacial phase that is the underlying cause of e...

Most works on liquid metal embrittlement up to 1960 are compiled by Rostoker et al. (1) They stated that grain boundary diffusion is not an origin of embrittlement, since its rate, in general, is too small. However, Waterhouse et al. (2), performing the experiment on 70/30 brass wetted with mercury, suggested that dissolution of zinc from grain-boundaries into mercury accelerates the degree of ...

The study on temper embrittlement and hydrogen embrittlement of a test block from a 3Cr1Mo1/4V hydrogenation reactor after ten years of service was carried out by small punch test (SPT) at different temperatures. The SPT fracture energy Esp (derived from integrating the load-displacement curve) divided by the maximum load (Fm) of SPT was used to fit the Esp/Fm versus-temperature curve to determ...

Mikrovlnné žiarenie frekvencie 2,45 GHz bolo použité na vzorkách uhlia z rôznych anglických lokalit, na ich tepelnú predúpravu pred rozpojovaním. Získané údaje poukazujú na vplyv mikrovlnnej tepelnej úpravy na relatívnu meliteľnosť uhlia. Výrazná redukcia ( 20 –40 % ) relatívnej energie mletia bola zaznamenaná už po pomerne krátkom čase pôsobenia mikrovlnného žiarenia (3 –8 min). Vplyv mikrovln...