Transmission, Distribution & Storage

The aim of this work is the evaluation of the hydrogen effect on the J-integral parameter. It is well-known that the micro alloyed steels are affected by Hydrogen Embrittlement phenomena only when they are subjected at the same time to plastic deformation and hydrogen evolution at their surface. Previous works have pointed out the absence of Hydrogen Embrittlement effects on pipeline steels cathodically protected under static load conditions. On t Read More

In the present work the effect of artificial ageing of AA2024-T3 on the tensile mechanical properties and fracture toughness degradation due to corrosion exposure will be investigated. Tensile and fracture toughness specimens were artificially aged to tempers that correspond to Under-Ageing (UA) Peak-Ageing (PA) and Over-Ageing (OA) conditions and then were subsequently exposed to exfoliation corrosion environment. The corrosion exposure time was Read More

Safe and long term operation of nuclear reactors is one of the most discussed challenges in nuclear power engineering. The radiation degradation of nuclear design materials limits the operational lifetime of all nuclear installations or at least decreases its safety margin. This paper is a review of experimental PALS/PLEPS studies of different nuclear reactor pressure vessel (RPV) steels investigated over last twenty years in our laboratories. Positron annihil Read More

Hydrogen embrittlement (HE) is a critical issue that affects the reliability of hydrogenation reactors. The hydrogen diffusivity/trap characteristics of 2.25Cr-1Mo-0.25V steel are important parameters mainly used to study the HE mechanism of steel alloys. In this work the hydrogen diffusivity/trap characteristics of heat-treated (annealed) and untreated 2.25Cr-1Mo-0.25V steel were studied using an electrochemical permeation method. The microstructures o Read More

To understand the effect of surface machining on the resistance of AISI 316L to SCC (stress–corrosion cracking) in marine environments we tested nuts surface-machined by different methods in a seawater-spraying chamber. Two forms of cracks were observed: on the machined surface and underneath it. On the surface cracks connected with the pitting sites were observed to propagate perpendicular to the hoop-stress direction identifying them as stre Read More

Hydrogen storage is a materials science challenge because for all six storage methods currently being investigated materials with either a strong interaction with hydrogen or without any reaction are needed. Besides conventional storage methods i.e. high pressure gas cylinders and liquid hydrogen the physisorption of hydrogen on materials with a high specific surface area hydrogen intercalation in metals and complex hydrides and storage of hy Read More

Hydrogen interaction with metal atoms is of prime focus for many energy related applications like hydrogen storage hydrogen evolution using catalysis etc. Although hydrogen binding with many main group alkaline and transition metals is quite well understood its binding properties with lanthanides are not well reported. In this article by density functional theory studies we show how a rare earth metal cerium binds with hydrogen when decorated over a h Read More

DFT calculations at B3LYP/6-31g(dp) with the D3 version of Grimme’s dispersion are performed to investigate the application of TM-encapsulated Mg12O12 nano-cages (TM= Mn Fe and Co) as a hydrogen storage material. The molecular dynamic (MD) calculations are utilized to examine the stability of the considered structures. TD-DFT method reveals that the TM-encapsulation converts the Mg12O12 from an ultraviolet into a visible optical active m Read More

Smart energy hubs (Smart Hubs) equipped with Vehicle-to-Grid (V2G) charging photovoltaic (PV) energy generation and hydrogen storage capabilities are an emerging technology with potential to alleviate the impact of electric vehicles (EV) on the electricity grid. Their operation however is characterised by intermittent PV energy generation as well as uncertainties in EV traffic and driver preference. These uncertainties when combined with the need t Read More

Hydrogen embrittlement (HE) of metals has remained a mystery in materials science for more than a century. To try to clarify this mystery tensile tests were conducted at room temperature (RT) on a 316 stainless steel (SS) in air and hydrogen of 70 MPa. With an aim to directly observe the effect of hydrogen on ordering of 316 SS during deformation electron diffraction patterns and images were obtained from thin foils made by a focused ion beam from t Read More