AMPP Store - Individual Conference Papers

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Effect of Plastic Strain on Hydrogen Absorption of Low Alloy Carbon Steel for Linepipe

Product Number: 51323-19139-SG

Author: Taishi Fujishiro, Yusaku Tomio, Taro Muraki, Takuya Hara

Publication Date: 2023

$20.00

In the oil and gas industry, oil country tubular goods and linepipes are exposed to the wet H2S environment (sour environment) in some cases. The presence of H2S promotes hydrogen entry into steel due to the catalytic action of H2S. The absorbed hydrogen enhanced by H2S affects hydrogen embrittlement.

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Effect of Pre-pits on Localized Corrosion and Sulfide Stress Cracking Resistance of Duplex Stainless Steel UNS S32205 in Upstream Production Environments

Product Number: 51324-21031-SG

Author: Guru Prasad Sundararajan; V.T. Aruna; Marc E. Wilms; Navashree Surendran

Publication Date: 2024

$40.00

Components in upstream Oil and Gas production such as flowlines, storage vessels or injector pipelines which are made of duplex stainless steel UNS S32205 can undergo localized corrosion such as pitting or crevice corrosion when exposed to oxygen during shutdowns or turn arounds. Such unintended exposure to oxygen is related to poor maintenance or improper preservation and would normally require replacement of equipment. Further use of such pitted components can be considered but requires re-assessment of the pre-corroded material. Open-circuit Potential (OCP) and repassivation potentials (Erp) were measured on UNS S32205 in simulated flowline brines containing 150,000 mg/L Cl- at 110oC with pCO2 of 4.1 bara. The effect of pre-pits on bare and girth welded UNS S32205 was determined by creating artificial pits at OCP under oxygenated brine conditions and then switching the gaseous environment to sweet (CO2) conditions with continuous OCP monitoring. It was found that in oxygen-free CO2 production environments, existing pits did not grow. Sulfide Stress Cracking (SSC) resistance of pre-pitted solution annealed UNS S32205 specimens was determined through Slow Strain Rate Testing (SSRT) and Ripple Load Testing (RLT) at 90oC in concentrated chloride solutions. An electrochemical method was applied to create a single pit on the gauge surface. Comparison of SSRT and RLT results showed that SSRT is too aggressive for determining the pH2S limits. RLT of both pristine and pre-pitted UNS S32205 in concentrated chlorides with up to 0.3 bara pH2S did not show rupture, while selective attack of the ferrite phase was found (pit-depth < 30µm). RLT of notched UNS S32205 specimens were compared to that of pre-pitted specimens. Implications of these results on the limits recommended in ISO15156 / NACE MR0175 are discussed.

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Effect of Pressure and Thermal Cycling on Long-Term Oxidation in Supercritical CO2

Product Number: 51319-12750-SG

Author: Bruce Pint

Publication Date: 2019

$20.00

Next generation concentrating solar power (CSP) plants may employ supercritical CO2 (sCO2) for the power block to achieve 50% electrical efficiency at 700°C. The goal of this project was to develop a long-term (100 kh) lifetime model for sCO2 compatibility using 10-15 kh laboratory exposures. Nickel-base alloys 740H 282 and 625 and Fe-base austenitic alloy 25 were evaluated in 500-h cycles at 1 and 300 bar and 1-h and 10-h cycles in 1 bar industrial grade CO2. All of the alloys have shown low mass gains in 500-h cycles after 10000 h exposures similar to exposures in laboratory air. However alloy 25 showed accelerated mass gain after ~1500 h of cumulative exposure in 10-h cycles at 700° and 750°C and 1-h cycles at 750°C. The Cr-rich oxide broke down allowing Fe-rich oxide formation. Characterization of the reaction products as a function of time will be presented. Research sponsored by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Solar Energy Technology Office.

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Effect Of Relative Humidity And Galvanic Couples On Stress Corrosion Cracking Of High-Strength Aluminum Alloys

Product Number: 51322-18015-SG

Author: L. Agnew, B. Clark, V. Avance, F. Friedersdorf

Publication Date: 2022

$20.00

High-strength aerospace aluminum alloys, such as AA7075-T651, are susceptible to environmental assisted cracking (EAC) under the right combinations of stress, environment, and microstructure. EAC presents a serious risk to structures and equipment operated in corrosive conditions. Studies of EAC in aluminum alloys have highlighted the importance of both anodic dissolution and hydrogen embrittlement to EAC initiation and propagation.^1–4 The EAC response of alloys under variable atmospheric conditions is of particular importance for assessing material performance for aerospace applications.

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Effect of Residual Copper, Nickel, and Chromium on the Corrosion Resistance of Carbon Steel in Hydrofluoric Acid Alkylation Services

Product Number: 51393-93623-SG

Author: H.H. Hashim, W.L. Valerioti,

Publication Date: 1993

$20.00

Carbon steel is the main construction material in HYDROFLUORIC ACID (HF) alkylation units. Carbon Steel has good corrosion resistance to anhydrous HF (AHF) below 160 degrees fahrenheit (71 C). The corrosion resistance is due to the formation of an inorganic iron fluoride scale on the carbon steel surface that protects the steel from futher corrosion. The presence of an adherent and continuous scale is essential in keeping the corrosion rate at a minimum.

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Effect Of Residual Strain On Short Time Oxidation Kinetics In PWR Simulated Primary Water

Product Number: ED22-17127-SG

Author: Rachel E. Turfitt, John A. Savchik, Bryan A. Webler, Kevin B. Fisher

Publication Date: 2022

$20.00

Type 304 stainless steel is commonly used in pressurized water reactor (PWR) primary circuits, where it is exposed to high temperature, high pressure water. Combination of material and environment influence the oxidation behavior in these systems. In addition to oxidation of the surface, 304 is also susceptible to stress corrosion cracking and corrosion fatigue, which are both types of environmentally assisted cracking, or EAC. EAC is a function of prior material condition, environment, and stress induced during exposure.

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Effect of Salt Concentration on CO2 Uniform Corrosion

Product Number: 51319-13026-SG

Author: Fazlollah Madani Sani

Publication Date: 2019

$20.00

Hydrocarbon extracted from oil and gas wells is typically accompanied by the production of brines. Salt concentration or salinity is a general characteristic of brines that can vary from 1000 to 400000 mg/l. The effect of salt concentration on uniform CO2 corrosion has been studied in the past however most of these studies have been performed at low salt concentrations usually between 1 to 3 wt.% NaCl. Moreover no true mechanistic study of corrosion has been done to cover the higher ranges of salt concentration. In this study CO2 uniform corrosion of an API X65 carbon steel was studied by weight loss (WL) linear polarization resistance (LPR) and potentiodynamic polarization methods in a range of NaCl concentration from 0 to 20 wt.%. The WL and LPR results both showed a maximum in the corrosion rate at 1 wt.% NaCl. The polarization curves showed that the key change due to higher salt concentrations was in the cathodic limiting current.Keywords: CO2 uniform corrosion carbon steel high salt concentration weight loss linear polarization resistance potentiodynamic polarization

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Effect Of Salt Concentration On Uniform H2S Corrosion Rate Of Pipeline Steel At 100 Ppm H2S(G) And 20Oc

Product Number: 51322-17982-SG

Author: Fazlollah Madani Sani, Bruce Brown, Srdjan Nesic

Publication Date: 2022

$20.00

Large amounts of water can be produced during extraction of hydrocarbons from underground reservoirs.¹ It is well understood that produced waters usually contain high amounts of dissolved salts, up to 28 wt.%.² In addition to salts, dissolved corrosive gases (CO₂ and H₂S) are present in produced water, which make the mixture a complex corrosive environment for metallic parts and equipment used throughout the production process.

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Effect of Sample Configuration on Autoclave Experiment in Dense Phase CO2 with Impurities

Product Number: 51324-21137-SG

Author: Xi Wang; Gaoxiang (Garret) Wu; Yoon-Seok Choi; Srdjan Nesic

Publication Date: 2024

$40.00

Corrosion plays an important role in the integrity management of the CO2 transport pipeline, since carbon steels, the most common material utilized for pipeline construction, are susceptible to corrosion in the presence of impurities, such as water, SO2, and NO2. Autoclave tests have been used to examine the corrosion susceptibility and severity in this condition. However, studies have shown a range of corrosion rates in similar experimental conditions, and there are no standard methods for laboratory corrosion testing in dense phase CO2 with impurities. In this study, the impact of sample configuration, one of the parameters that can affect the results of the corrosion experiment, is investigated. Autoclave experiments were conducted in dense phase CO2 with O2, SO2, NO2, H2S, CH4, and H2O where the samples were placed either vertically or horizontally. Furthermore, horizontal samples were placed in different locations of the autoclave. The results showed that corrosion was observed on both sides of the vertical samples, while top side of each horizontal sample corroded more compared to the bottom side in some conditions. For horizontal samples, the corrosion rates could increase with the location from top to bottom of the autoclave depending on the combination of impurities.

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Effect of Sensitization on the Corrosion Resistance of a New and Advanced Version of Alloy N08825

Product Number: 51319-12729-SG

Author: Julia Botinha

Publication Date: 2019

$20.00

Alloy UNS N08825 is a nickel-iron-chromium alloy with additions of molybdenum copper and titanium. The alloy was designed for applications in the chemical process industry as well as in oil and gas industry.UNSN08825 shows an excellent corrosion behavior in sour service environment and a high resistance to stress corrosion cracking and sulfide stress cracking. However due to its low molybdenum content of 3 wt.% alloy UNSN08825 has limited resistance to pitting and crevice corrosion in chloride containing environments.A new advanced version of UNS N08825 which will be called in this paper UNS N08825 CTP with higher molybdenum content was developed to improve its corrosion resistance. Previous corrosion tests showed an increased critical pitting temperature of the new alloy. Based on these data further corrosion tests were performed.An important factor that has a detrimental influence on the corrosion behavior is the sensitization of the material. To simulate the real life application of this alloy different heat treatments were performed especially under critical temperatures where detrimental phases occur. Pitting corrosion intergranular corrosion and susceptibility to hydrogen embrittlement were investigated within the testing program as well as stress corrosion cracking (SCC) resistance.This paper will present an overview of the corrosion behavior of this new and improved version of UNS N08825 which was called Alloy 825 CTP.

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Effect of service conditions on the corrosion of Nickel-Aluminum Bronze (NAB) and Copper-Nickels (CuNi) in seawater

Product Number: 51319-13337-SG

Author: Dominique Thierry

Publication Date: 2019

$20.00

Nickel-Aluminum Bronze (NAB) and Copper-Nickel alloys (CuNi) are commonly used in seawater environment in raison of their strength combined with a good corrosion resistance and a high resistance to biofouling. However localized corrosion failures have been reported often attributed to abnormal service conditions. The effect of several service condition parameters on the localized corrosion of NAB and CuNi alloys 90/10 and 70/30 have been investigated in natural seawater. It includes flow conditions (flowing quiescent and stagnant) chlorination sulphide pollution and crevice geometries. Both indoor and outdoor exposures (biodeposit promoting conditions) have been tested in temperate and in tropical seawaters. The global stability of the protective oxide layer of the tested copper-based alloys was mainly affected by sulphide pollution in aerated seawater (general corrosion). Under the tested conditions localized corrosion under-biodeposit clearly appeared as the critical failure for the tested alloys. The conditions in which biodeposit appeared critical for copper-nickel alloys was investigated. The current for cathodic protection of NAB in natural seawater have also been investigated as function of flow rate.

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Effect of Shielding and Backing Gases on Mechanical and Corrosion Properties of Alloy N08935 Welds

Product Number: 51324-20854-SG

Author: Deepjyoti Mukherjee; Conrad Liebsch; Thomas Hündgen; Björn Helmersson; Ravi Vishnu

Publication Date: 2024

$40.00

The newly developed super-austenitic alloy, N08935, combines the best features of a high performance austenitic stainless steel and Ni-based alloys. The alloy has a nickel content of 35 wt.%, which is relatively higher than the usual austenitic steels but lower than conventional Ni-base alloys. With a high resistance to localized and uniform corrosion, it is a good alternative when standard highly alloyed austenitic 6Mo or super-duplex stainless steels do not suffice, and a cost-efficient alternative is desired to Ni-base alloys such as Alloy 625. Due to an excellent corrosion resistance and high mechanical strength, the potential use of alloy N08935 extends to chemical, petrochemical, Oil & Gas equipment, and acidic environments. However, the true test of the suitability of a material is if the weldments also measure up to the performance standards of the base material. The present study examines this concern. In this work, the GTAW (TIG) method will be used to weld 2 mm thick sheets autogenously and with Ni-based filler metal ERNiCrMo-13. The tests were performed for a combination of different shielding and backing gases with and without additions of nitrogen. The welds were evaluated according to SS-EN ISO 15614-1:2017 and additionally the corrosion properties were evaluated using the ASTM G48 standard method E. The aim of this paper is to compare the different combinations of shielding and backing gases to present proper welding recommendations for alloy N08935.

Individual Conference Papers

Association for Materials Protection and Performance