Blar i NTNU Open på forfatter "Iannuzzi, Mariano"
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Cathodic protection by distributed sacrificial anodes - Performance at elevated temperature and in mud
Johnsen, Roy; Iannuzzi, Mariano; Ryen, Audun; Årtun, Lars (Journal article; Peer reviewed, 2018)Thermal Spray Aluminum (TSA) can be used to reduce anode demand or to extend anode life on projects with long design lives (i.e., 40 to 50 years). However, for subsea structures, TSA has not been used to replace the ... -
Crevice corrosion of solution annealed 25Cr duplex stainless steels: Effect of W on critical temperatures
Torres Rodriguez, Cristian; Johnsen, Roy; Iannuzzi, Mariano (Peer reviewed; Journal article, 2021)In this work, the influence of tungsten on the crevice corrosion resistance of three super duplex stainless steels (SDSS) containing 0.0, 0.6, and 2.1 wt.% W was determined. The PD-GS-PD technique was used to estimate the ... -
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 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 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 ... -
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 ... -
Hydrogen uptake and diffusivity in steel armor wires with different chemical composition, carbide distribution, grain size, and degree of deformation
Skilbred, Ellen Synnøve; Kappes, Mariano; Iannuzzi, Mariano; Johnsen, Roy (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 ... -
Influence of tungsten on passivity breakdown and repassivation of 25CR super duplex stainless steel
Torres Rodriguez, Cristian; Kappes, Mariano A; Johnsen, Roy; Iannuzzi, Mariano (Journal article; Peer reviewed, 2018)Super duplex stainless steels are ferritic-austenitic stainless steels with 25 wt% Cr and a pitting resistance equivalent (PRE) ≥ 40. Even though other elements, such as Cr and Mo, have been studied in much more detail ... -
Integrated cathodic protection (CP) sensor network development of the CP sensor
Wold, Kristian; Johnsen, Roy; Iannuzzi, Mariano; Årtun, Lars (Journal article; Peer reviewed, 2018)This paper describes a new CP monitoring approach to quantify the health of the CP system in real-time with spatial resolution. Spatial resolution is achieved by an integrated sensor network distributed across a Subsea ... -
Pitting and Crevice Corrosion of Super Duplex Stainless Steels in Seawater - Effect of Tungsten
Bjørge Haugan, Eirik (Master thesis, 2015)The need for low cost and lighter materials with higher mechanical and chemical properties has lead to more frequently usage of SDSS because of their increased mechanical and superior corrosion properties compared to other ... -
The Role of Tungsten on the Phase Transformation Kinetics and its Correlation with the Localized Corrosion Resistance of 25Cr Super Duplex Stainless Steels
Torres Rodriguez, Cristian; Hazarabedian, Maria Sofia; Quadir, Zakaria; Johnsen, Roy; Iannuzzi, Mariano (Peer reviewed; Journal article, 2020)Super Duplex Stainless Steels (SDSS) have excellent corrosion resistance due to their high concentration of alloying elements like Cr, Mo, and N. There is still, however, disagreement on the role of tungsten in the corrosion ... -
Susceptibility to Hydrogen Induced Stress Cracking of centrifugal cast 25Cr Duplex Stainless Steel
Gjelseng, Linn Cecilie (Master thesis, 2017)Testing of the susceptibility towards hydrogen induced stress cracking (HISC) for five 25\%Cr super duplex stainless steels (SDSS) under cathodic protection (CP) in seawater has been conducted. The materials were from pipes ... -
Use of the Critical Acidification Model to Estimate the Influence of W in the Localized Corrosion Resistance of 25Cr Super Duplex Stainless Steels
Torres Rodriguez, Cristian; Iannuzzi, Mariano; Johnsen, Roy (Peer reviewed; Journal article, 2020)Two super duplex stainless steels (SDSS) with different W content, namely UNS S32750 (W-free) and UNS S39274 (2.1 wt.% W), were tested in simulated crevice corrosion environments to determine the influence of W on their ...