Chemical Removal of Lead Corrosion Products

Restoration treatment, specimen preparation or mass loss measurements on coupons made of lead require a reliable process of dissolution of corrosion products. In this study, several types of model corrosion products with compositions representative of those found on real objects were prepared and characterized. Ten solutions were then thoroughly tested in interval cleaning experiments, regarding the efficiency of removal of the corrosion products, corrosivity towards bare lead, and remnants left on the surface. The solution recommended in the current version of the ISO 8470 standard was found to be improper for the cleaning of both historical artefacts and corrosion coupons due to its inability to remove sulfide corrosion products and the risk of surface contamination and staining. A solution of 20% hydrochloric acid is the best choice for the preparation of lead coupons before exposure or for evaluation of mass loss of exposed samples because its somewhat higher corrosivity towards metallic lead is tolerable for these applications. Rochelle salt solution was found to be optimal for the cleaning of historical artefacts free of sulfide corrosion products due to the lowest corrosivity. None of these alternative solutions leave remnants on the surface and they are efficient at laboratory temperature.

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Leaching of Am-241 from a Radioactive Waste Glass Corroded in the Presence of Stainless Steel Corrosion Products and/or Bentonite

MRS Proceedings ◽

10.1557/proc-112-565 ◽

1987 ◽

Vol 112 ◽

Author(s):

Masaki Tsukamoto ◽

Inga-Kari Björner ◽

Hilbert Christensen ◽

Hans-Peter Hermansson ◽

Lars Werme

Keyword(s):

Stainless Steel ◽

Radioactive Waste ◽

Mass Loss ◽

Total Mass ◽

Corrosion Behaviour ◽

Steel Corrosion ◽

Waste Glass ◽

Corrosion Products ◽

Total Mass Loss ◽

Elemental Mass

AbstractThe release of Am-241 during corrosion of the radioactive waste glass, JSS-A, has been studied in the presence of corrosion products and/or uncom-pacted bentonite. The corrosion behaviour of Am-241 has been analyzed using gamma spectrometry. Adsorption of Am-241 on bentonite is observed in all cases. The contents of Am-241 in centrifuged leachates are in most cases less than 1/100 of total values. The normalized elemental mass loss of Am increases initially with corrosion time, and the values in the presence of bentonite and corrosion products are larger than those in the presence of bentonite alone. This tendency is in agreement with results previously found for other elements. The release of Am is low, only about 10–20 % of the corresponding total mass loss.

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Investigation of Corrosion Resistance Enhancement for Biodegradable Magnesium Alloy by Ball Burnishing Process

International Journal of Automation Technology ◽

10.20965/ijat.2020.p0175 ◽

2020 ◽

Vol 14 (2) ◽

pp. 175-183 ◽

Cited By ~ 1

Author(s):

Chenyao Cao ◽

Jiang Zhu ◽

Tomohisa Tanaka ◽

Dinh Ngoc Pham ◽

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...

Keyword(s):

Corrosion Resistance ◽

Mass Loss ◽

Immersion Test ◽

Corrosion Products ◽

Mg Alloys ◽

Surface Finishing ◽

Human Organism ◽

Corrosion Mechanism ◽

Ball Burnishing ◽

Treated Sample

Magnesium and magnesium-based alloys are considered ideal materials for implants in orthopedic treatment because their stiffness is close to that of human bones, and they can be absorbed gradually in the human organism. However, a major issue in their actual application is that the corrosion speed of Mg alloys is very high in aggressive environments such as the human fluids. In previous studies, many approaches have been attempted to enhance the corrosion resistance of Mg alloys. In this research, ball burnishing, a mechanical surface finishing process, is applied to improve the corrosion resistance of Mg alloys by changing its surface properties. The influence of the burnishing parameters on the corrosion resistance is investigated, and the corrosion of a treated and non-treated sample are compared. The test material used is the AZ31 Mg alloy. Firstly, a comprehensive review of the effect of burnishing on the final microstructures is reported. The influence of burnishing on grain size, work-hardened layer thickness, crystal orientation, and residual stress of the sample is discussed. Secondly, by conducting an especially designed long-term immersion test, the mass loss and surface evolution of each sample are evaluated. The experimental results indicate that, under proper processing conditions, the mass loss of the treated sample (8.8 mg) can be reduced to 36% of the non-treated one (24.2 mg). To elucidate the mechanism behind corrosion resistance enhancement by burnishing, the samples treated with the optimal processing parameters found are immersed in an aggressive solution for 1, 3, 5, and 7 days. From the results of mass loss measurement and surface structure characterization, it was found that, among pitting, general, and intergranular corrosion, pitting corrosion is the dominant corrosion mechanism. The holes enlarge because pits combine together, representing the greatest portion of mass loss. The main mechanism enhancing corrosion resistance is the size reduction of the grains on the surface induced by ball burnishing, causing a denser distribution of corrosion products in the immersion test. These corrosion products protect the material underneath accelerated corrosion.

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Raman Spectroscopy of Mackinawite FeS in Anodic Iron Sulfide Corrosion Products

Journal of The Electrochemical Society ◽

10.1149/2.1151606jes ◽

2016 ◽

Vol 163 (6) ◽

pp. C333-C338 ◽

Cited By ~ 49

Author(s):

Georgi Genchev ◽

Andreas Erbe

Keyword(s):

Raman Spectroscopy ◽

Iron Sulfide ◽

Corrosion Products ◽

Sulfide Corrosion

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Characteristics of sulfide corrosion products on 316L stainless steel surfaces in the presence of sulfate-reducing bacteria

Materials Science and Engineering C ◽

10.1016/j.msec.2005.09.108 ◽

2006 ◽

Vol 26 (4) ◽

pp. 624-629 ◽

Cited By ~ 44

Author(s):

Jizhou Duan ◽

Baorong Hou ◽

Zhigang Yu

Keyword(s):

Stainless Steel ◽

316L Stainless Steel ◽

Sulfate Reducing Bacteria ◽

Corrosion Products ◽

Sulfate Reducing ◽

Sulfide Corrosion ◽

Steel Surfaces ◽

Reducing Bacteria

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Postharvest durability of tomatoes with PVA covering

Horticultura Brasileira ◽

10.1590/s0102-053620200208 ◽

2020 ◽

Vol 38 (2) ◽

pp. 160-165

Author(s):

Manuella Candéo ◽

Maria Helene G Canteri ◽

Dayana Carla de Macedo ◽

Evaldo T Kubaski ◽

Sergio M Tebcherani

Keyword(s):

Mass Loss ◽

Soluble Solids ◽

Postharvest Quality ◽

Soluble Solids Content ◽

Total Soluble Solids ◽

Red Color ◽

Solids Content ◽

Alternative Solutions

ABSTRACT Plastic packaging from petroleum derives used in the food industry represents serious environmental problems. Alternative solutions to these problems consist of the development of biodegradable packaging, such as films and edible coatings including the polyvinyl alcohol (PVA). In this research we evaluated the effect of the PVA application by two different techniques aiming to increase shelf life of ripe tomatoes, cultivar Carmen. The methodology of this study consisted in covering tomatoes with a PVA solution and also with PVA impregnated tracing paper. The different fruit lots were kept in polystyrene trays for 19 days on a laboratory bench at a controlled temperature of 25±3ºC. The fruit analyzes were compared to the control fruits without any treatment, being evaluated firmness, pH, titratable total acidity, mass loss, total soluble solids content, water activity and color determination of fruit surface. Among the different treatments, the PVA coating applied directly to the fruits contributed to control the firmness and the mass loss, as well as this treatment influenced the total soluble solids content, the luminosity and the red color of fruits with statistical difference compared to the control and covered with tracing paper (with or without PVA). The PVA coating solution applied directly on the fruits contributed to maintain the postharvest quality of the ripe tomatoes.

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Metallographic Documentation of the Degradation of Iron and Nickel Based Alloys in HCl and H2S Containing Environments, between 480 – 680 °C

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.405.26 ◽

2020 ◽

Vol 405 ◽

pp. 26-32

Author(s):

Alexander Schmid ◽

Gregor Mori ◽

Roland Haubner

Keyword(s):

Mass Loss ◽

Chromium Oxide ◽

Nickel Content ◽

Testing Temperature ◽

Multilayered Structure ◽

Corrosion Products ◽

Nickel Sulphide ◽

Gas Atmosphere ◽

Chromium Oxide Layer ◽

Cracking Process

Corrosion behavior of the alloys 1.7386 (P9), 1.4462, 1.4841, 1.4959 (Alloy 800HT) and 2.4816 (Alloy 600) was tested for 24, 72 and 240 h between 480 – 680 °C. The testing gas atmosphere contained 3.8 vol. % HCl, 200 ppm H2S and CO, CO2 and N2. It simulated conditions present in a thermal cracking process for post-consumer plastics. Samples were analyzed by metallography, SEM/EDX and XRD after corrosion experiments. Additionally, their mass loss during the test was evaluated. A multilayered structure of corrosion products grew on the samples during the corrosion experiments. The composition of the corrosion products depended not on the material, but on the testing temperature. At 680 °C chromium sulphide formed the outer layer, followed by a chromium oxide layer. Below these two layers a chlorine containing layer was observed. At 480 °C mainly nickel sulphide was detected, besides chromium oxide and iron- and chromium chloride. Especially at higher testing temperatures FeCl2 was not observed directly on the samples, but as colorless crystals at the colder parts of the testing equipment. At 680 °C the mass loss of the samples decreased with increasing nickel content. However, this effect changed entirely at lower testing temperatures. At 480 °C 1.7386 and 2.4816 showed nearly the same mass losses.

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Effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water

Environmental Chemistry ◽

10.1071/en15156 ◽

2016 ◽

Vol 13 (4) ◽

pp. 602 ◽

Cited By ~ 15

Author(s):

Ding-Quan Ng ◽

Yi-Pin Lin

Keyword(s):

Drinking Water ◽

Distribution Systems ◽

Lead Concentration ◽

Ph Value ◽

Galvanic Corrosion ◽

Corrosion Products ◽

Lead Contamination ◽

Lead Corrosion ◽

Effects Of Ph ◽

Lead Release

Environmental context Galvanic corrosion has been recently reported as the main cause of lead contamination in drinking water in urban cities. Conditions that can deter or promote galvanic corrosion, however, are not well understood. Fundamental investigations exploring the mechanisms and processes involved in galvanic corrosion in drinking water could help to implement proper corrective measures to safeguard public health from lead contamination. Abstract This study investigates the effects of pH value, chloride and sulfate concentrations on galvanic corrosion between lead and copper in drinking water. We hypothesised that galvanic corrosion would occur immediately when a lead–copper couple is first formed and that the release of lead would be suppressed by the subsequent formation of lead corrosion products. Therefore, unlike previous long-term studies using harvested lead pipes, batch experiments employing high-purity lead and copper (99.9%) wires under stagnant and completely mixed conditions were conducted for a 7-day period to test our hypotheses. It was found that enhanced lead release was indeed observed after the lead–copper couple was formed and the lead profiles after 48h were strongly influenced by lead corrosion products formed in the system. Under stagnant conditions, reducing pH and increasing either chloride or sulfate concentrations promoted lead release, leading to the formation of lead corrosion products such as cerussite and hydrocerussite as experiments proceeded. The effect of chloride concentration on total lead concentration measured in the aqueous phase was similar to that of sulfate at the same molar concentration, showing that the chloride-to-sulfate mass ratio may not provide a good indication for total lead concentration in water. This study provides essential information on fundamental mechanisms and processes involved in galvanic corrosion in drinking water and may be used to explain related phenomena observed in real drinking-water distribution systems.

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