Blar i NTNU Open på forfatter "Johnsen, Roy"
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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 ... -
Effects of chloride, sulfate and pH on the corrosion of tensile wires in grouted tendon ducts in Herøysundet bridge
Myhre, Bettina Horn (Master thesis, 2022)Over lang tid har korrosjon av armering skapt problemer for betong strukturer og det er lagt ned mye forskning for å forstå hva som forårsaker det. Effektene av faktorer som pH-nivå, aggressive ioner, karbonatisering, stål ... -
Environmenally assisted cracking revisited via novel miniature fracture mechanics approach in environmental scanning electron microscope
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 ... -
Evaluation of microstructural and environmental effects on the hydrogen uptake and desorption in high-strength carbon steels: A thermal desorption spectroscopy study
Karimi, Shabnam; Taji, Iman; Palencsar, Simona; Dugstad, Arne; Hajilou, Tarlan; Barnoush, Afrooz; Verbeken, Kim; Johnsen, Roy; Depover, Tom (Peer reviewed; Journal article, 2023)The hydrogen uptake in three high-strength carbon steels is studied after exposure to three different environments: an aqueous solution with CO2 bubbling, CO2/H2S bubbling, and cathodic charging without external gassing. ... -
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 ... -
Experimental comparison of gaseous and electrochemical hydrogen charging in X65 pipeline steel using the permeation technique
Koren, Erik Aas; Hagen, Catalina Hoem Musinoi; Wang, Dong; Lu, Xu; Johnsen, Roy; Yamabe, Junichiro (Peer reviewed; Journal article, 2023)Herein, hydrogen uptake and diffusivity in X65 pipeline steel were investigated using the permeation technique under different hydrogen charging conditions. Hydrogen charging was performed using hydrogen gas at different ... -
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 ... -
Growth Kinetics of Calcareous Deposits on Thermally Sprayed Aluminum Coatings in Natural Seawater
Johnsen, Roy; Hornus, Edgar; Vouilloz, Francisco; Long, Yu; Salasa, Mobin; Iannuzzi, Mariano; Andersen, Kjetil; Krosness, Ola (Peer reviewed; Journal article, 2022)The formation of calcareous deposits on thermally sprayed aluminum (TSA)-coated surfaces immersed in natural seawater and connected to a cathodic protection system is a recurring issue. There is at present limited knowledge ... -
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 and corrosion evaluation of Alloy 725 alloyed with B and Cu
Taji, Iman (Doctoral theses at NTNU;2023:40, Doctoral thesis, 2023)The need to achieve materials with higher strength and better corrosion resistance results in producing new alloys. Nickel base alloys are among the materials which have been subjected to several studies related to producing ... -
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 Additive Manufactured Components made from Alloy 625 and 25Cr Super Duplex Stainless Steel
Egeland, Mathias (Master thesis, 2022)Denne masteroppgaven har som mål å bidra til økt forståelse rundt hvordan 3D-printede komponenter produsert ved selektiv lasersmelting (SLM) blir påvirket av hydrogensprøhet (HISC). Både 25Cr super duplex rustfritt stål ... -
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 ... -
Hydrogen Induced Stress Cracking of Inconel 625 - Effect of Production Method, Heat Treatment and Cold Working
Thorstensen, Eivind Bruun (Master thesis, 2016)The following work has examined the effect of heat treatment, production method and cold working (CW) on the hydrogen induced stress cracking (HISC) susceptibility of Inconel 625 (UNS N06625). This was done by hydrogen ... -
Hydrogen Induced Stress Cracking of Inconel 718 under Cathodic Polarization - Effects of Hydrogen on the Initiation and Propagation of Cracks
Knarbakk, Kristian (Master thesis, 2015)This work has examined the susceptibility to hydrogen induced stress cracking (HISC) of Inconel 718 (UNS N07718) by stepwise tensile loading tests with in situ cathodic polarization. Specifically, the effect of hydrogen ... -
Hydrogen Induced Stress Cracking of Spheroidal Graphite Cast Iron
Djupvik, Veronika (Master thesis, 2020)Abstract will be available on 2023-06-17 -
Hydrogen Induced Stress Cracking Resistance of Nickel Alloy ATI 830
Heimsæter, Martin (Master thesis, 2018)The following activities shall be included in the project: ATI 830 1. Document microstructure and mechanical properties for the received alloy. 2. Execute the test program given in Attachment 1. 3. Execute a literature ...