Browsing NTNU Open by Author "Johnsen, Roy"
Now showing items 21-40 of 80
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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 (Conference object, 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 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 (Conference object, 2010) -
Effect of tungsten on the precipitation kinetics and localized corrosion resistance of super duplex stainless steels
Bernås, Mia; Westermann, Ida; Johnsen, Roy; Torres Rodriguez, Cristian; Jernberg, Anders; Qvale, Atle H; Iannuzzi, Manuela (Journal article; Peer reviewed, 2018)Although extensively used in oil and gas production due to their excellent combination of mechanical properties and corrosion resistance, 25Cr super duplex stainless steels (SDSSs) are susceptible to the precipitation of ... -
Environmental Embrittlement Revisited by In-Situ Miniature Fracture Testing Approach
Deng, Yun (Doctoral theses at NTNU;2019:25, Doctoral thesis, 2019) -
Environmentally assisted degradation of spinodal copper alloy C72900
Johnsen, Roy; Lange, Torstein; Stenerud, Gaute; Olsen, Jim Stian (Journal article; Peer reviewed, 2018)In this work, a spinodal Copper alloy – C72900, was tested to investigate the resistance against environmentally assisted degradation. The material was tested according to ISO 15156-3 Level V in sour H2S solution and to ... -
Erosion Resistance of Composite Materials Exposed to a Mixture of Water and Sand
Johansen, Jostein (Master thesis, 2014)In the oil and gas industry, components used in the drill mud handling system suffer from erosive wear. Drill mud containing a fairly large fraction of sand moving at high speed, creates harsh conditions with respect to ... -
Examination of the Effect on Tungsten on the Corrosion Properties of 25% Cr Super Duplex Stainless Steel by Advanced Electrochemical Techniques
Rodríguez, Cristian Torres (Doctoral theses at NTNU, 2020:329, Doctoral thesis, 2020)In this thesis, the effect of Tungsten (W) on localized corrosion resistance of 25Cr super duplex stainless steel (SDSS) was investigated. Firstly, the effect of W on precipitation kinetics of intermetallic phases in SDSS ... -
FRICTION AND WEAR OF COATINGS FOR SUBSEA GATE VALVES OPERATING AT HIGH TEMPERATURE AND PRESSURE
Wesmann, Johan Andre Riis (Doctoral thesis at NTNU;2016:161, Doctoral thesis, 2016)Gate valves for subsea oil and gas operation work under harsh conditions. Proper design ensures the valves functional integrity over the designed lifetime of the valve. The design of the valve includes material choice ... -
HISC in Super Duplex Stainless Steels: A study of the relation between microstructure and susceptibility to hydrogen induced stress cracking
Andersen, Kjetil (Master thesis, 2013)Testing of susceptibility to hydrogen induced stress cracking (HISC) in two 25% Cr Super Duplex Stainless Steels (SDSS) has been carried out. These were a forged material and a hot isostatically pressed (HIP) material with ... -
Hydrogen Embrittlement of 25Cr duplex stainless steel exposed to well fluid with H2S - effect of cold working and product form
Ollestad, Svein (Master thesis, 2017)It is known that cold deformation may have detrimental effects on resistance against SulphideStress Cracking/Stress Corrosion Cracking and Hydrogen Induced Stress Cracking. Thoughit is clear that cold deformation should ... -
Hydrogen embrittlement suceptibility of steel armour wires for flexible pipes
Skilbred, Ellen Synnøve; Lotz, Signe Aarthun; Johnsen, Roy (Peer reviewed; Journal article, 2020)Flexible pipes are frequently used both as flowlines and risers in the oil and gas industry. A flexible pipe has a complex structure consisting of layers of polymer and metallic materials. The armor wire layers – shielded ... -
Hydrogen induced stress cracking of alloy 718: Effects of chemical composition and microstructure
Haaland, Adrian Christian (Master thesis, 2014)This master thesis have examined the effect of variations in composition and microstructure on the HISC susceptibility of Inconel-718. 6 different Inconel-718 variants with different compositions and heat treatments were ...