Blar i NTNU Open på forfatter "Johnsen, Roy"
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Distributed CP Sensor - Design and Operation Sequence Optimization
Wold, Kristian Wingan (Master thesis, 2017)Focus on reducing cost and improve efficiency has been key aspects in the oil and gas industry the recent years. New technology and new ideas that can improve efficiency and reduce cost should be more than welcome for ... -
Distributed Sacrificial Anode (DSA) - Properties in Mud and at Elevated Temperatures in Seawater
Ryen, Audun (Master thesis, 2017)Cost savings with regards to optimizing the Cathodic Protection (CP) design has over the last 50 years not been considered as a major opportunity so far. Sacrificial anodes combined with organic coatings is the main corrosion ... -
Distributed Sacrificial Cathodic Protection - A New Cost Effective Solution to Prevent Corrosion on Subsea Structures
Quale, Geir (Master thesis, 2016)Over the last 50 years, only minor changes have been made to the cathodic protection (CP) design, whereas optimization has not been considered as a cost saving opportunity to date. For subsea structures, sacrificial anodes ... -
Effect of a time-dependent magnetic field on the corrosion of Ni-Al bronze
Krogstad, Hedda Nordby; Johnsen, Roy; Coey, Michael (Journal article; Peer reviewed, 2018)Nickel-aluminum bronze (NAB) was anodically polarized in a solution of 3.5 wt% NaCl and exposed to a time-dependent magnetic field (TDMF) with an amplitude of 180 mT. The effect of a TDMF on the anodic behavior of NAB has ... -
Effect of a uniform magnetic field on corrosion of Ni-Al bronze in 3.5wt% NaCl
Krogstad, Hedda Nordby; Johnsen, Roy; Coey, Michael (Journal article; Peer reviewed, 2018)Following the observation of enhanced corrosion of parts of a seawater-immersed permanent magnet motor made from Ni-Al bronze, a laboratory study of the effect of uniform magnetic field on the corrosion of this alloy in a ... -
Effect of Cathodic Polarization on the Susceptibility to Hydrogen Embrittlement in 5xxx, 6xxx and 7xxx Series Aluminium Alloys
Veium, Kjetil Fossland (Master thesis, 2015)Aluminium is an interesting material for use in subsea applications due to the combination of low weight, good corrosion resistance and superior low temperature properties. So far, the use of aluminium alloys in offshore ... -
Effect of different microstructural features on the hydrogen embrittlement susceptibility of alloy 718
Stenerud, Gaute; Wenner, Sigurd; Olsen, Jim Stian; Johnsen, Roy (Journal article; Peer reviewed, 2018)Due to its high strength and acceptable corrosion resistance, Alloy 718 is a viable material for the use in subsea applications. The alloy's susceptibility to hydrogen embrittlement is however limiting its viability. In ... -
Effect of hydrogen on dislocation nucleation in alloy 718
Stenerud, Gaute; Johnsen, Roy; Olsen, Jim Stian; He, Jianying; Barnoush, Afrooz (Journal article; Peer reviewed, 2017)In situ electrochemical nanoindentation has been used to study the effect of hydrogen on the nanomechanical response of Alloy 718. Observations show that hardness increase as a result of hydrogen charging. Also, the hydrogen ... -
Effect of hydrogen on the embrittlement susceptibility of Fe-22Mn-0.6C TWIP steel revealed by in-situ tensile tests
Wang, Dong; Lu, Xu; Wan, Di; Guo, Xiaofei; Johnsen, Roy (Peer reviewed; Journal article, 2020)The hydrogen embrittlement (HE) behavior on a Fe–22Mn-0.6C twinning-induced plasticity (TWIP) steel was investigated by tensile tests with in-situ scanning electron microscope observation combined with electron backscatter ... -
EFFECT OF MICROSTRUCTURE AND SURFACE FINISH ON LOCALIZED CORROSION PERFORMANCE OF SUPER DUPLEX STAINLESS STEEL IN SEAWATER
Næss, Monika (Master thesis, 2014)Corrosion resistant alloys (CRAs) used in subsea pressure-retaining components must be compatible with production fluids and resistant to pitting and crevice corrosion in seawater. Whereas materials selection in production ... -
Effect of Microstructure and Temperature on HydrogenDiffusion and Trapping in X70 grade Pipeline Steel and itsWeldments
Skjellerudsveen, Magnus; Akselsen, Odd Magne; Olden, Vigdis; Johnsen, Roy; Smirnova, Anna (Chapter, 2010) -
Effect of microstructure on the corrosion resistance of duplex stainless steels: Materials performance maps
Bernås, Mia; Westermann, Ida; Johnsen, Roy; Lauritsen, Christian; Iannuzzi, Mariano (Journal article; Peer reviewed, 2017)Although super duplex stainless steels (25Cr SDSS) are extensively used in oil and gas production due to their excellent combination of mechanical properties and corrosion resistance they are susceptible to the precipitation ... -
Effect of nickel in solid solution on the hydrogen embrittlement resistance of low alloy steels
Husby, Hans (Doctoral theses at NTNU;2018:231, Doctoral thesis, 2018)The ever-increasing demand and consumption of energy in the world is depleting conventional oil and gas reserves. Nickel alloying improves mechanical and technological properties of low alloy steels (LAS), but is limited ... -
Effect of nickel on hydrogen permeation in ferritic/ pearlitic low alloy steels
Husby, Hans; Iannuzzi, Mariano; Johnsen, Roy; Mariano, Kappes; Barnoush, Afrooz (Journal article; Peer reviewed, 2018)Nickel offers several beneficial effects as an alloying element to low alloy steels. However, it is, in the oil and gas industry, limited by part 2 of the ISO 15156 standard to a maximum of 1 wt% due to sulfide stress ... -
Effect of Nickel on the Hydrogen Stress Cracking Resistance of Ferritic/Pearlitic Low Alloy Steels
Husby, Hans; Wagstaff, Philip Haakon; Iannuzzi, Mariano; Johnsen, Roy; Kappes, Mariano A (Journal article; Peer reviewed, 2018)Nickel additions to low alloy steels improve mechanical and technological properties. However, Part 2 of ISO Standard 15156 limits the nickel content to a maximum of 1 wt% in oil and gas environments containing H2S because ... -
Effect of Plastic Deformation and Microstructure on Hydrogen Diffusion in Steel
Hope, Malin Sofie Berglund (Master thesis, 2015)This work has been part of the ROP (Repair Contingency of Pipelines) project executed by SINTEF, where Vigdis Olden is project lead. The main content of this report is the execution of hydrogen permeation tests on Fe3wt.%Si ... -
The effect of plastic deformation on hydrogen diffusion in nickel Alloy 625
Lu, Xu; Díaz, Andrés; Ma, Jun; Wang, Dong; He, Jianying; Zhang, Zhiliang; Johnsen, Roy (Peer reviewed; Journal article, 2022)Recently, several hydrogen-assisted failures have been reported on different nickel alloys used in the subsea oil and gas industries. It is thus essential to correlate hydrogen uptake and diffusion behavior with stress ... -
Effect of production/process parameters on corrosion properties of AM AISI 316L
Maicas Esteve, Héctor (Master thesis, 2021)The evolution of new techniques for processing materials is being of interest for the current industry. Some scientific researchers have focused their studies on knowing more about them, and the results show a promising ... -
The effect of surface roughness and topography on the organic coating/steel interface stability
Hagen, Catalina H. Musinoi (Doctoral theses at NTNU;2020:304, Doctoral thesis, 2020)The study in this thesis, focused on the effect of surface roughness and topography on the organic coating/steel interface stability in humid air and corrosive conditions. A strong correlation between roughness, Rz, and ... -
Effect of tensile stress on hydrogen permeation in 13% Cr supermartensitic stainless steel
Smirnova, Anna; Johnsen, Roy; Nisancioglu, Kemal (Chapter, 2010)