Slow strain rate tests were performed on quenched and tempered AISI 4340 steel to measure the extent of hydrogen embrittlement caused by electroplating with zinc-cobalt alloys. The effects of bath composition and pH were studied and compared with results for electrodeposited cadmium and zinc-10%nickel. It was found that Zinc-1%cobalt alloy coatings caused serious hydrogen embrittlement (EI 0.63...

Calculations indicate that the introduction of hydrogen into the body–centred cubic and face-centred cubic allotropes of iron in both cases reduces the {100} surface energy. The reduction is rather small in magnitude so this mechanism cannot present the major cause of the well–known hydrogen embrittlement phenomenon. Consistent with the theory of grain boundary embrittlement in iron, carbon is ...

in this paper, effect of hydrogen diffusion on 2.25cr-1mo steel with ferritic-bainitic and martensitic microstructure has been investigated. hydrogen embrittlement of this steel was investigated by doing experimental such as delayed fracture and slow strain rate tests. result of this research was showed that the steel with martensitic  microstructure strongly affected by hydrogen diffusion and ...

P. Vaňová, J. Sojka. VŠB Technical u niversity of O strava, FMME, Ostrava, Czech Republic This paper is dealing with hydrogen embrittlement of austenitic-ferritic 2205 duplex steel using the slow strain rate test (SSRT). The original material was subjec ted to heat treatment under 700 °C during 5 hours and f ollowing aircooling with the aim of pr ovoking sigma phase pr ecipitation and embrittle...

Hydrogen embrittlement of metals is widely observed, but its atomistic origins remain little understood and much debated. Combining a unique identification of interstitial sites through polyhedral tessellation and first-principles calculations, we study hydrogen adsorption at grain boundaries in a variety of face-centered cubic metals of Ni, Cu, γ-Fe, and Pd. We discover the chemomechanical ori...

Impurities segregated to grain boundaries of a material essentially alter its fracture behavior. A prime example is sulfur segregation-induced embrittlement of nickel, where an observed relation between sulfur-induced amorphization of grain boundaries and embrittlement remains unexplained. Here, 48x10(6)-atom reactive-force-field molecular dynamics simulations provide the missing link. Namely, ...

Intermediate-depth earthquakes (30-300 km) have been extensively documented within subducting oceanic slabs, but their mechanics remains enigmatic. Here we decipher the mechanism of these earthquakes by performing deformation experiments on dehydrating serpentinized peridotites (synthetic antigorite-olivine aggregates, minerals representative of subduction zones lithologies) at upper mantle con...

Hydrogen diffusion is the main problem for corrosion fatigue in corrosive environment. In order to analyze the phenomenon, it is needed to understand their behaviors specially the hydrogen behavior during the diffusion. So, Hydrogen embrittlement and prediction its behavior as a main corrosive part of the fractions, needed to solve combinations of different equations mathematically. The main po...

Impurity elements, which have very low bulk concentrations in metals, often segregate to grain boundaries where their concentrations can be greatly enriched. As a results of this segregation, the grain boundaries are often weakened so that they become preferred paths for brittle fracture. This paper presents the results of fully quantum mechanical cluster calculations which have been applied to...

The essential facts about the nature of the hydrogen embrittlement of steels have now been known for 140 years. It is diffusible hydrogen that is harmful to the toughness of iron. It follows, therefore, that the harmful influence of diffusible hydrogen can be mitigated by preventing its entry into steel or by rendering it immobile once it penetrates the material. This review deals with the meth...