Browsing Institutt for maskinteknikk og produksjon by Title
Now showing items 1829-1848 of 4068
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Hydrogen permeation in 13% Crsuper martensitic stainless steel and API X70 pipeline steel
(Doktoravhandlinger ved NTNU, 1503-8181; 2010:208, Doctoral thesis, 2010)Hydrogen permeation measurements have been carried out on 13% Cr super martensitic stainless steel (SMSS), API X70 steel and type HBQ Coreweld under cathodic charging conditions at temperatures from 5°C to 80°C. In addition, ... -
Hydrogen stress cracking and crack initiation in precipitation hardened Ni-alloys
(Journal article; Peer reviewed, 2018)The two different precipitation hardened nickel alloys, Alloy 718 and Alloy 725, were tested in its as received condition. Their susceptibility to hydrogen stress cracking was examined by the use of stepwise increasing ... -
Hydrogen susceptibility of an interstitial equimolar high-entropy alloy revealed by in-situ electrochemical microcantilever bending test
(Peer reviewed; Journal article, 2019)Hydrogen effect on an interstitial CoCrFeMnNi high-entropy alloy was investigated by micro-cantilever bending tests with pre-notched plane as a case study. Results showed sharp mode I cracks on plane bisecting two planes ... -
Hydrogen uptake and diffusivity in steel armor wires with different chemical composition, carbide distribution, grain size, and degree of deformation
(Peer reviewed; Journal article, 2021)In this study, six flexible pipe steel armor wires used in oil and gas transportation are characterized, and their hydrogen diffusion coefficients and hydrogen uptakes are measured using an electrochemical hydrogen permeation ... -
Hydrogen uptake during active CO2-H2S corrosion of carbon steel wires in simulated annulus fluid
(Peer reviewed; Journal article, 2022)The hydrogen uptake of five carbon steel wires exposed to a corrosive CO2/H2S environment where protective film formation was not favorable was measured. The hydrogen uptakes decreased with the accumulation of retained ... -
Hydrogen-Assisted Cracking Investigated by In Situ Electrochemical Micro-Cantilever Bending Test
(Doctoral theses at NTNU;2018:212, Doctoral thesis, 2018)Most high strength and high performance alloys experience a premature rupture and loss in the ductility when exposed to hydrogen. The interaction of hydrogen with dislocations and other microstructural defects such as ... -
Hydrogen-Assisted Fatigue Crack Growth in Ferritic Steels
(Doctoral theses at NTNU;2019:251, Doctoral thesis, 2019) -
Hydrogen-assisted fatigue crack growth in ferritic steels – a fractographic study
(Journal article; Peer reviewed, 2018)Fatigue crack growth (FCG) behavior of a Fe-3wt.%Si ferritic alloy under different environmental conditions using in-situ electrochemical (cathodic) hydrogen (H) charging has been investigated. Three frequencies have been ... -
Hydrogen-enhanced cracking revealed by in situ micro-cantilever bending test inside environmental scanning electron microscope
(Journal article, 2017)To evaluate the hydrogen (H)-induced embrittlement in iron aluminium intermetallics, especially the one with stoichiometric composition of 50 at.% Al, a novel in situ micro-cantilever bending test was applied within an ... -
Hydrogen-enhanced fatigue crack growth in a single-edge notched tensile specimen under in-situ hydrogen charging inside an environmental scanning electron microscope
(Journal article; Peer reviewed, 2019)Fatigue crack growth (FCG) test was done on a pre-cracked single-edge notched tensile (SENT) specimen with oligocrystalline ferritic structure. Innovative in-situ hydrogen (H)- charging by plasma inside an environmental ... -
Hydrogen-enhanced grain boundary vacancy stockpiling causes transgranular to intergranular fracture transition
(Journal article; Peer reviewed, 2022)The attention to hydrogen embrittlement (HE) has been intensified recently in the light of hydrogen as a carbon-free energy carrier. Despite worldwide research, the multifaceted HE mechanism remains a matter of debate. ... -
Hydrogen-enhanced intergranular failure of sulfur-doped nickel grain boundary: In situ electrochemical micro-cantilever bending vs. DFT
(Peer reviewed; Journal article, 2020)Intergranular failure of nickel (Ni) single grain boundaries (GBs) owing to the segregation of sulfur (S), hydrogen (H), and their co-segregation has been investigated by employing micro-cantilever bending tests and density ... -
Hydrogen-induced degradation behavior of nickel alloy 625, studied using multiscale in-situ experiments
(Doctoral theses at NTNU;2023:435, Doctoral thesis, 2023)Nickel-based alloys are widely used in the oil and gas industries as safety critical components owing to its high strength and corrosion resistance properties. However, they are susceptible to hydrogen embrittlement (HE), ... -
Hydrogen-material interactions on austenitic and super duplex stainless steels
(Doctoral theses at NTNU;2022:120, Doctoral thesis, 2022)The interaction between hydrogen and structural materials has been intensively studied for many years. In this PhD thesis the effect of hydrogen on the mechanical properties of two stainless steels has been investigated ... -
Hydrological Analysis of Tekeze Hydropower System in the Current and Future Climate
(Master thesis, 2015)Climate change is expected to intensify the already high hydrological variability and energy production in various regions of the world. This research work investigates the runoff and energy production in the current and ... -
Hydrological Assessment of Water Resources in Bergen - Climate Change Impacts
(Master thesis, 2015)Bergen Waterworks is reliant on steady loads of precipitation to meet the drink- ing water demand. Accordingly, the system is vulnerable to drought events and seasonal changes in inflow. Climate change impact analysis, as ... -
Hydrological data for small hydropower plants
(Master thesis, 2014)During last years extensive development of small hydropower plants has taken place, and many of that plants are frequently located in small catchments. Mainly there is no runoff data for these small catchments, because ... -
Hydrological forecasting in catchments with glaciers
(Master thesis, 2015)The runoff forecast is crucial in Norway because the country bases most of its electricity from hydropower. The hydrological model has thus been improved for years in order to foresee the runoff in the best possible way. ... -
Hydrological modelling in east Gojjam Region, Ethiopia
(Master thesis, 2011)The Blue Nile River is known for its huge hydropower potential. Future sustainable planning and management of the river system require advanced approaches in hydrological analysis. Rainfall-runoff models are one of the ... -
Hydrological Modelling of the Ilabekken Catchment, and Flood Simulations of Ilabekken using HEC-HMS and HEC-RAS
(Master thesis, 2015)As the global climate is changing, the local climate in Trøndelag is expected to be wetter and more extreme in the future. Flooding and erosion are huge challenges in Norway, leading to severe damages each year which lead ...