Observations of Corrosion Product Formation and Stress Corrosion Cracking on Brass Samples Exposed to Ammonia Environments

Davalos-Monteiro, Raul

doi:10.1590/1980-5373-mr-2018-0077

Cited by 13 publications

(3 citation statements)

References 7 publications

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“…It is evident that NH 4 + plays an important role in the acceleration of pitting of B30 copper–nickel alloy. Davalos-Monteiro (2019) immersed copper tubes in different concentrations of ammonia solution and found that the higher the concentration of ammonia, the faster the corrosion rate of copper tubes. NH 4 + is easily hydrolyzed to produce NH 3 , which in turn reacts with available Cu+ ions to produce copper–ammonia complexes, which promote the dissolution of Cu (reaction 7), making the surface of the alloy brittle ( Shalaby et al, 1999 ; Agarwal, 2002b ).…”

Section: Discussionmentioning

confidence: 99%

Mechanism underlying the acceleration of pitting corrosion of B30 copper–nickel alloy by Pseudomonas aeruginosa

Sun

et al. 2023

Front. Microbiol.

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Despite its excellent corrosion resistance, B30 copper–nickel alloy is prone to pitting, particularly when exposed to microorganisms. The mechanism underlying the acceleration of pitting in this alloy is not fully understood. In this study, the acceleration of pitting corrosion in B30 copper–nickel alloy caused by a marine microorganism named Pseudomonas aeruginosa (P. aeruginosa) was investigated using surface analysis and electrochemical techniques. P. aeruginosa significantly accelerated the pitting in B30 copper–nickel alloy, with a maximum pitting depth of 1.9 times that of the abiotic control and a significant increase in pitting density. This can be attributed to extracellular electron transfer and copper–ammonia complex production by P. aeruginosa, accelerating the breakdown of the passivation film.

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Section: Discussionmentioning

confidence: 99%

Mechanism underlying the acceleration of pitting corrosion of B30 copper–nickel alloy by Pseudomonas aeruginosa

Sun

et al. 2023

Front. Microbiol.

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“…Temperatures at the base plate of the burner were also used. It is emphasized that no further temperature measurements were available due to corrosion problems experienced in the thermocouples of the high-pressure optical combustor (HPOC) section used for the experiments, a consequence of the high ammonia concentration (i.e., well-known to impact material integrity [45]).…”

Section: Methodsmentioning

confidence: 99%

Numerical Predictions of a Swirl Combustor Using Complex Chemistry Fueled with Ammonia/Hydrogen Blends

et al. 2020

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Ammonia, a chemical that contains high hydrogen quantities, has been presented as a candidate for the production of clean power generation and aerospace propulsion. Although ammonia can deliver more hydrogen per unit volume than liquid hydrogen itself, the use of ammonia in combustion systems comes with the detrimental production of nitrogen oxides, which are emissions that have up to 300 times the greenhouse potential of carbon dioxide. This factor, combined with the lower energy density of ammonia, makes new studies crucial to enable the use of the molecule through methods that reduce emissions whilst ensuring that enough power is produced to support high-energy intensive applications. Thus, this paper presents a numerical study based on the use of novel reaction models employed to characterize ammonia combustion systems. The models are used to obtain Reynolds Averaged Navier-Stokes (RANS) simulations via Star-CCM+ with complex chemistry of a 70%–30% (mol) ammonia–hydrogen blend that is currently under investigations elsewhere. A fixed equivalence ratio (1.2), medium swirl (0.8), and confined conditions are employed to determine the flame and species propagation at various operating atmospheres and temperature inlet values. The study is then expanded to high inlet temperatures, high pressures, and high flowrates at different confinement boundary conditions. The results denote how the production of NOx emissions remains stable and under 400 ppm, whilst higher concentrations of both hydrogen and unreacted ammonia are found in the flue gases under high power conditions. The reduction of heat losses (thus higher temperature boundary conditions) has a crucial impact on further destruction of ammonia post-flame, with a raise in hydrogen, water, and nitrogen through the system, thus presenting an opportunity of combustion efficiency improvement of this blend by reducing heat losses. Final discussions are presented as a method to raise power whilst employing ammonia for gas turbine systems.

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“…Although there are many findings reported in the literature on corrosion resistance of brass alloy, only a little information is available which covers the crystal structure in correlation with hardness and electrical resistivity [17-22]. The aim of the current study is to determine the effects of carbon ions implantation on the surface of brass alloy and the consequent changes in microstructure and hardness with special emphasis on the characterisation of surface damage and electrical resistivity using four different carbon ion doses.…”

Section: Introductionmentioning

confidence: 99%

Surface characterisation of brass alloy in the correlation of hardness and electrical resistivity by carbon ion implantation

Shahnawaz

Nawaz

2021

Materials Science and Technology

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Material modification, as per demand of era, has been explored by several groups in different areas focusing its engineering prospect for better performance. Carbon ion implantation, using four different doses, has been done on α-brass (64% Cu; 36% Zn) to see its effects on hardness, microstructure and electrical resistivity. Carbon ions distorted the crystalline surface, increased defect density and hardened the surface by 13.2%. The crystallite size was found decreased by 41.15%, which in turn caused a significant increase in electrical resistivity, i.e. 234.8%. Overall, the lattice parameter found increased from 3.680 to 3.688 Å. SEM morphology exhibited nonuniform agglomerations in the form of pits, cracks, voids, cavities, craters, particulates, droplets and petals like structures at the surface by carbon ion implantation.

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Observations of Corrosion Product Formation and Stress Corrosion Cracking on Brass Samples Exposed to Ammonia Environments

Cited by 13 publications

References 7 publications

Mechanism underlying the acceleration of pitting corrosion of B30 copper–nickel alloy by Pseudomonas aeruginosa

Mechanism underlying the acceleration of pitting corrosion of B30 copper–nickel alloy by Pseudomonas aeruginosa

Numerical Predictions of a Swirl Combustor Using Complex Chemistry Fueled with Ammonia/Hydrogen Blends

Surface characterisation of brass alloy in the correlation of hardness and electrical resistivity by carbon ion implantation

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