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Influence of the H2 Impurity on the Fatigue Crack Growth and Fracture in a Dense Phase CO2 Pipeline

Product Number: 51324-20721-SG

Author: B Bezensek; S Hopkin; J Sonke; F Gui; C Taylor

Publication Date: 2024

$40.00

Transport of dense phase CO2 by pipelines needs to account for possible degradation mechanisms arising due to H2 impurity which can be present in (typically) the 0.75 ~ 1 mol% range depending on the specification used. H2 gas can affect fatigue and fracture properties even at low partial pressures and hence the integrity. In this study a complementary experimental and computational modeling program was undertaken. API 5L X65 grade material samples were used for comparable testing in pure H2 gas at low partial pressure H2 and in dense phase CO2 at 100 barg with H2 impurity added in a 2 mol% and 4 mol% increments (i.e. partial pressures of 2 barg and 4 barg). The test results show effect of the H2 impurity in the dense phase CO2 accelerated fatigue crack growth and reduced fracture toughness. These findings are supported by computational simulation using density functional theory and molecular dynamics. A scoping integrity assessment for a dense phase CO2 pipeline with H2 impurity at 2 mol% shows the measured accelerated fatigue crack growth only affects large pressure cycles (pressure range in excess of 70 bar for OD/WT pipelines of ~30). The fatigue life is significantly shortened compared to the pure CO2 pipeline and this is mainly driven by the reduced fracture toughness at low partial pressure H2. The fatigue damage is proportional to the maximum operating pressure (as it increases the pressure range). For a postulated 50-year design life a safe pipeline design window considering a range of conservative inputs (material properties, integrity operating window, geometry, postulated defect size etc.) a safe operating pressure of 2900 psig (200barg) was found for a new build pipeline using modern materials. For a repurposed vintage material pipeline the safe operating pressure was set at 2200 psig (150 barg). An ECA incorporating the deleterious effect of H2 should be conducted to confirm the above postulate unless the project falls within the limits of the conservative inputs (material properties, integrity operating window, geometry, postulated defect size etc.), from a fracture mechanics perspective, of the four case studies that form the basis of this overall study. Other impurities if exceeded their safe threshold may create water drop out and acid formation. It is imperative that the project specifications err on the side of caution and restrict the impurities to safe limits until further understanding of the complex interaction mechanisms is developed.

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Influence of the Hardening Phases on the Hydrogen Embrittlement Susceptibility of Ni-Alloys based on UNS N07718

Product Number: 51320-14667-SG

Author: Julia Botinha, Bodo Gehrmann, Helena Alves

Publication Date: 2020

$20.00

The Alloy UNS(1) N07718 is among the most used alloys in the oil and gas industry. Due to the presence of the alloying elements niobium, aluminum and titanium, this alloy is precipitation hardenable by the formation of the phases Gamma’ and Gamma’’. Although presenting excellent strength properties and good resistance in sour gas applications, this material is known to be susceptible to hydrogen embrittlement and most field failures are related to this limiting property.

The use of Alloy 718 (UNS N07718) for oil & gas applications is regulated by the API(2) 6ACRA1 standard and it is available in three different grades, the 120K, with minimum 120 ksi yield strength, the 140K, with minimum 140 ksi yield strength, and the 150K, with minimum 150 ksi yield strength. Previous studies showed that, due to the different hardening heat treatment parameters, each of the available grades presents a different precipitation behavior in terms of distribution and amount of precipitates, and the obtained microstructure is directly related to the resistance of the material to hydrogen embrittlement.

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Influence of the Soil Moisture Level and Differential Aeration Cell on the Corrosion Rate of Carbon Steel and Zinc Coated Steel

Product Number: 51324-20694-SG

Author: Erwan Diler; Philippe Verpoort; Souhail Amami; Ansbert De Cleene; Benoit Emo

Publication Date: 2024

$40.00

Soil is a complex media involving solid particles, gas and liquid phases. Among the many soil parameters influencing the corrosion rate, beyond the pH and resistivity, disregards the microbial activity, the moisture level and the related oxygen diffusion is usually pointed out as a key parameter. Depending on the soil texture and related ability to retain water, as well as the ground water level, differential aeration corrosion cells (DACC) might appear. Such phenomenon locally affects the corrosion rate and distribution by galvanic action. This phenomenon is particularly relevant for large metallic pieces such as buried pipes, tubular piles, and sheet piles. In this study, an experimental setup composed of 30 coupons in carbon steel or zinc coated steel was exposed in two different soils to a vertical gradient of moisture level. The setup allows measuring the corrosion potential and galvanic current of each coupon, before and after their interconnection. The obtained results highlight i) the influence of the moisture level and oxygen diffusion on the corrosion potential for both carbon steel and zinc, and ii) quantify the differential aeration corrosion cells. The results are compared to coupons exposed for 1 year in the same environment, with and without DACC.

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Influence Of The Surface Condition On The Pitting And SCC Resistance Of Alloy UNS N07718 Produced Via Selective Laser Melting

Product Number: 51321-16949-SG

Author: Madison Woolridge; Christoph Wangenheim; Helmuth Sarmiento Klapper

Publication Date: 2021

$20.00

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Influence Of Thermomechanical Processing On Mechanical Properties And Corrosion Resistance Of Super Duplex Stainless Steel UNS S32750.

Product Number: 51322-17613-SG

Author: Clara Herrera, Merlin Seifert

Publication Date: 2022

$20.00

Duplex stainless steels (DSSs) are based on the Fe-Cr-Ni system and are constituted of 30 to 70 % ferrite and austenite. They combine high tensile strength, good toughness, weldability, and excellent corrosion resistance including stress-corrosion cracking and resistance to localized corrosion.^1-3 DSSs can be classified according to the Pitting Resistance Equivalent Number (PREN = Cr + 3.3 Mo + 16 N) in lean duplex (PREN= 22-27), standard (PREN = 28-38), super duplex (PREN = 38-45) and hyperduplex (PREN > 45).

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Inhibiting localized corrosion of carbon steel pipelines in sour service

Product Number: 51323-18833-SG

Author: Anupom Sabhapondit, Aboubakr M Abdullah, Nicholas Laycock, Manoj Gonuguntla, Shimjith Madayi, Tom Bos

Publication Date: 2023

$20.00

Use of corrosion inhibitors (CI) to protect metallic equipment, especially carbon steel pipelines from corrosion has long been an established, effective, economic, and hence globally accepted technique. The oil and gas industry has been using CIs to protect the pipelines under various exposure conditions including sour and sweet services . Complete understanding of corrosion mechanisms under sour conditions and protecting pipeline steel under such conditions has always been a challenging task due to the complexity of such systems.

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Inhibiting Nucleation Corrosion in Liquid Hydrocarbons

Product Number: 51324-21232-SG

Author: Moshood Adewale; Hitesh Bagaria; Nimeshkumar Patel; Tatiana Barbosa; Osvaldo Antonio Heredia Cancino

Publication Date: 2024

$40.00

Dewpoint corrosion is a well-known phenomenon in flue gas stacks and refinery overheads, where fine water droplets condense from the vapor upon cooling, and the acid gases in the vapors diffuse into water droplets to form a highly corrosive low pH liquid. We have identified a similar mechanism in hydrocarbon liquids, which we call as “nucleation corrosion” (C2023-19463). Liquid hydrocarbons often have dissolved water (DW), which does not promote corrosion even in the presence of corrosive species (e.g., organic acids, H2S). Upon cooling, the DW nucleates as nanometer-sized water droplets and acids present in the liquid partition into the water droplets decreasing pH to cause aggressive nucleation corrosion. In this study the methods to mitigate nucleation corrosion are investigated with an emphasis on studying the impact of different types of chemical inhibitors on this newly discovered mechanism. An interesting example of the impact of the test method on inhibitor selection is shown. Finally, a case study highlighting nucleation corrosion in a refinery distillation overhead reflux line is presented.

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Inhibition of Calcium Phosphate Scale on Heat Exchangers-Relation Between Laboratory Test Results and Tests on Heat Transfer Surfaces

Product Number: 79220

Author: S. Kubo, T. Takahasi, H. Morinaga, H. Ueki

Publication Date: 1979

$20.00

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Inhibition of Crevice Corrosion of Ni-Cr-Mo Alloys by Sulfate, Nitrate and Molybdate

Product Number: 51323-18936-SG

Author: Eduardo Sáenz González, Martín A. Rodríguez, Edgar C. Hornus

Publication Date: 2023

$20.00

Nickel base alloys with high chromium and molybdenum contents are very resistant to chloride-induced localized corrosion, even at relatively high temperatures. These alloys include the Ni-Cr-Mo(W) or
“C” family of alloys and the novel Ni-Mo-Cr alloy HYBRID-BC1 (UNS N10362). Alloy 22 (UNS N06022) stands out due to its versatility: chromium and molybdenum contents were selected to optimize its corrosion behavior in oxidizing and reducing conditions. Alloy 625 (UNS N06625) has outstanding thermal ageing resistance and a longer in-service experience. The

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Inhibition of Formation of Magnesium Hydroxide by Polymers: The Role of Molecular Architecture

Product Number: 51321-16710-SG

Author: P. D. Natsi; P. G. Koutsoukos

Publication Date: 2021

$20.00

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Inhibition of Microbial Induced Corrosion of Concrete using Admixture and Surface Applied Corrosion Inhibitors

Product Number: 51323-18768-SG

Author: Behzad Bavarian, Koushik Kosanam, Lisa Reiner, Pranav Meddhali

Publication Date: 2023

$20.00

The life-cycle of concrete structures used in waste water systems should consider all factors that might cause a structural system to perform unacceptably at any point during its lifetime. This includes the progressive and sustained loss of load capacity caused by operational or environmental factors. In general terms, deterioration can be defined as a loss of structural load capacity with time as a result of the action of external agents causing chemical attacks or material weakening due to these environmental interactions.

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Inhibitor Exhaustion From Aerospace Primers

Product Number: 51322-18158-SG

Author: James F. Dante

Publication Date: 2022

$20.00

Once a coating system has been breached, protection is afforded by the availability of inhibitors at the defect site. The onset of subsequent corrosion, therefore, is a function of inhibitor release rate, the ratio of inhibitor to aggressive ions, and consumption of inhibitor in the vicinity of the defect. The parameters affecting each of these processes must be understood in order to appropriately model the onset of corrosion for either a first principles or an empirical approach. The influence of coating properties and environmental conditions on inhibitor exhaustion is discussed below.

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Association for Materials Protection and Performance