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1

Research of bactericide-inhibitor properties of new compositions based on gossypol resin and chloroprene

Gurbanov Guseyn R., Gasimzade Aysel V., Alikishiyeva-Balamiyeva Samira F.

Nafta-Gaz

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2025

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R. 81, nr 1

58--66

EN

Five new compositions with conventional names A-1, A-2, A-3, A-4, and A-5 were prepared using different ratios of chloroprene and gossypol resin reagents, and their corrosion-inhibitory properties were investigated. The sulfate-reducing bacteria Desulfomicrobium genus and Desulfovibrio desulfuricans species were employed in the study. The effects of the A-series compositions on the bacteria were observed over a 15-day period, during which concentrations of 50, 100, 150, and 200 g/t were tested. Analysis of the results from numerous experiments revealed that the A-3 composition exhibited the highest bactericidal effect among the A-series compositions. Specifically, the bactericidal effect of the A-3 composition at a concentration of 200 g/t was found to be 99%. Under laboratory conditions, the effect of the new A-series compositions on the rate of electrochemical corrosion in formation water containing hydrogen sulfide was investigated. The corrosion rate was determined using the gravimetric method over a six-hour period. Based on the determined corrosion rate, the corrosion protection effect of the new compositions was calculated. The corrosion protection effects of the tested compositions in the order A-1, A-2, A-3, A-4, and A-5 were found to be 98%, 99%, 99%, 92%, and 90%, respectively, at the optimal consumption rate of 200 g/t. Therefore, the results of numerous experiments conducted under laboratory conditions provide evidence suggesting that the A-series compositions possess corrosion-inhibitory properties.

PL

Pięć nowych mieszanin o konwencjonalnych nazwach A-1, A-2, A-3, A-4 i A-5 przygotowano przy użyciu różnych proporcji odczynników chloroprenu i żywicy gossypol, a następnie zbadano ich właściwości antykorozyjne. W badaniu wykorzystano bakterie redukujące siarczany z rodzaju Desulfomicrobium i gatunku Desulfovibrio desulfuricans. Wpływ mieszanin serii A na bakterie obserwowano przez okres 15 dni, podczas których testowano stężenia 50, 100, 150 i 200 g/t. Analiza wyników licznych eksperymentów wykazała, że mieszanina A-3 wykazywała najwyższe działanie bakteriobójcze spośród mieszanin serii A. W szczególności stwierdzono, że działanie bakteriobójcze mieszaniny A-3 w stężeniu 200 g/t wynosi 99%. W warunkach laboratoryjnych zbadano wpływ nowych mieszanin serii A na szybkość korozji elektrochemicznej w wodzie złożowej zawierającej siarkowodór. Szybkość korozji określono metodą grawimetryczną w okresie sześciu godzin. Na podstawie wyznaczonej szybkości korozji obliczono efekt ochrony antykorozyjnej nowych mieszanin. Stwierdzono, że efekty ochrony przed korozją badanych mieszanin w kolejności A-1, A-2, A-3, A-4 i A-5 wynoszą odpowiednio 98%, 99%, 99%, 92% i 90% przy optymalnym zużyciu 200 g/t. Wyniki licznych eksperymentów przeprowadzonych w warunkach laboratoryjnych dostarczają zatem dowodów sugerujących, że mieszaniny serii A posiadają właściwości antykorozyjne.

2

Investigation of the efficiency of multifunctional compositions against corrosion and salt precipitation

Adygezalova Mehpara B.

Nafta-Gaz

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2025

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R. 81, nr 1

48--57

EN

One of the most important tasks facing petroleum engineers today is the implementation of comprehensive measures to prevent corrosion and salt precipitation processes in the storage and transportation system of high-paraffin oils. In order to prolong the service life of oil field facilities, this article presents the results of laboratory research on a multifunctional compound composition with high efficiency against salt precipitation and electrochemical corrosion. Analyzing the results of numerous research works revealed that a concentration of 100 mg/l of composition M-5 exhibited high efficiency against both corrosion and salt precipitation in alkaline and neutral formation waters and in different solvent media (kerosene and diesel fuel). In case of kerosene solvent medium, in hard formation water the corrosion rate was 0.0087 g/m2 · h (efficiency 98%), salt precipitation was 0.41 g/l (efficiency 93%); in alkaline formation water, the corrosion rate was 0.0625 g/m2 · h (efficiency 92%), salt precipitation was 0.42 g/l (efficiency 90%); in neutral formation water, the corrosion rate was 0.1024g/m2 · h (efficiency 90%), salt precipitation was 0.32 g/l (efficiency 91%). These indicators were also evaluated o in diesel fuel medium, where in hard formation water the corrosion rate was 0.0129 g/m2 · h (efficiency 99.9%), salt precipitation was 0.12 g/l (efficiency 98%); in alkaline formation water the corrosion rate was 0.0234 g/m2 · h (efficiency 97%), salt precipitation was 0.29 g/l (efficiency 93%); in neutral formation water the corrosion rate was 0.0819 g/m2 · h (efficiency 92%), salt precipitation was 0.72 g/l (efficiency 98%).

PL

Jednym z najważniejszych zadań stojących obecnie przed inżynierami z sektora naftowego jest wdrożenie kompleksowych środków zapobiegających procesom korozji i wytrącania się soli w systemie magazynowania i transportu ropy wysokoparafinowej. W celu przedłużenia żywotności instalacji na polach naftowych, w niniejszym artykule przedstawiono wyniki badań laboratoryjnych nad wielofunkcyjną kompozycją związków wykazujących wysoką skuteczność przeciwdziałania wytrącaniu się soli i korozji elektrochemicznej. Analiza wyników licznych prac badawczych wykazała, że kompozycja M-5 o stężeniu 100 mg/l wykazuje wysoką skuteczność zarówno przeciwko korozji, jak i wytrącaniu się soli w alkalicznych i neutralnych wodach złożowych oraz w różnych mediach rozpuszczalnikowych (nafta i olej napędowy). W przypadku rozpuszczalnika naftowego, w twardej wodzie złożowej wskaźnik korozji wynosił 0,0087 g/m2 · h (98% skuteczność), a wytrącanie soli wynosiło 0,41 g/l (93% skuteczność). Z kolei dla alkalicznej wody złożowej wskaźnik korozji wyniósł 0,0625 g/m2 · h (92% skuteczność), a wytrącanie soli 0,42 g/l (90% skuteczność). W neutralnej wodzie złożowej wskaźnik korozji wyniósł 0,1024g/m2 · h (90% skuteczność), a wytrącanie soli 0,32 g/l (91% skuteczność). Wskaźniki te zostały również zbadane dla oleju napędowego i wyniosły: w twardej wodzie złożowej wskaźnik korozji wyniósł 0,0129 g/m2 · h (99,9% skuteczność), wytrącanie soli 0,12 g/l (98% skuteczność), w alkalicznej wodzie złożowej wskaźnik korozji wyniósł 0,0234 g/m2 · h (97% skuteczność), wytrącanie soli 0,29 g/l (skuteczność 93%), natomiast w neutralnej wodzie złożowej wskaźnik korozji wyniósł 0,0819 g/m2 · h (92% skuteczność), wytrącanie soli 0,72 g/l (98% skuteczność).

3

Możliwości zabezpieczenia stalowych elementów konstrukcyjnych i materiałów lekkiej obudowy według wytycznych DAFA

Brytan Zbigniew, Tański Tomasz, Węglarz Roman

Izolacje

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2024

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T. 29, nr 10

58--62

PL

Artykuł porusza kwestie zabezpieczenia stalowych elementów konstrukcyjnych i materiałów lekkiej obudowy. Autorzy scharakteryzowali korozję elektrochemiczną i chemiczną oraz podali typowe powłoki metaliczne stosowane jako zabezpieczenie korozyjne na wyrobach metalowych. Opisali sposoby dodatkowego zabezpieczenia stalowych elementów lekkiej obudowy za pomocą powłoki organicznej.

EN

The article discusses the issues of securing steel elements construction and lightweight housing materials. The authors characterized electrochemical and chemical corrosion and reported typical metallic coatings used as corrosion protection on metal products. They described additional methods securing the steel elements of the lightweight casing with organic coating.

4

Influence of Starch Admixtures and Silver Colloids Stabilised with Starch Hydrolysates on the Course of Electrochemical Potential Difference of Reinforcing Steel in High-chloride Environment

Sybis Marta, Sybis Michał, Konował Emilia

Civil and Environmental Engineering Reports

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2024

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Vol. 34, no. 2

141--156

EN

The purpose of the conducted study was to verify whether the use of concrete admixtures with modified starches and starches modified with stabilised silver colloids affects the course of electrochemical potential difference, and hence corrosion, of reinforcing steel in a chloride environment. In the tests, cross-linked starches and products of acid hydrolysis of starch (dextrins) were used as admixtures. The 1-molar aqueous solution of sodium chloride was used as an aggressive environment. The tests consisted of measuring the potential difference generated in the reinforcement corrosion cell on the surface for a period of 60 days and then assessing the risk of corrosion. The effect of the addition of starch derivatives on the properties of cement paste was investigated through a one-way ANOVA analysis of variance followed by post hoc tests. The test results showed that the use of concrete admixtures with cross-linked starches positively affects the passivation of the steel. The likelihood of reinforcing steel corrosion when using distarch phosphate, acetylated distarch phosphate and acetylated distarch adipate admixtures is less than 5%. The results obtained showed an improved effect on the passivation of reinforcing steel in cement composites. Additionally, concrete samples may have microbicidal properties.

5

Effects of Y2O3 on Microstructure and Corrosion Properties of Laser Cladding Composite Coatings on 304 Stainless Steel Substrate

Yu Jinling, Zhentai Zheng, Li Shuai, Guo Donghui, Chang Liang

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

447--453

EN

Ni625/WC composite coatings added with different amounts of Y2O3 were prepared on the surface of 304 stainless steels by laser cladding. This study focused on the microstructure characteristics, microhardness, and corrosion performances of Ni625/WC composite coatings. The results showed that Y2O3 can effectively improve the corrosion resistance of the composite coatings. The microstructure from the bottom to the surface of composite coatings consists of plane crystal, cellular crystal, columnar crystal and equiaxed crystal. The Y2O3 content of optimum composite coating was 1.0%. Its microhardness was three times that of matrix material. In addition, the corrosion current density of the composite coating was only 2% of Ni625/WC coating, which was attributed to the good properties of Y2O3 and appropriate Y2O3 refined microstructure.

6

Seismic behavior of high-rise reinforced concrete walls with flange subjected to corrosion under low cyclic loading: an experimental research and numerical model

Yang Lu, Zheng Shan-Suo, Zheng Yue, Liu Hua, Wu Hong-Lin, Zhang Zhi-Wei

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 4

art. e261, 1--27

EN

As a result of chloride ion erosion, corrosion of steel bars in coastal or deicing salt environments deteriorates reinforced concrete’s (RC) structural performance. At present, there were few studies involving both chloride ion erosion and shear walls with flange, which made it difficult to evaluate the performance of corroded shear wall structures in coastal environ ments. Consequently, seven high-rise RC shear walls with flange were tested by electrochemical chloride erosion (ECE) and low cyclic loading in this paper, and the influences of key parameters such as corrosion degree, axial compression ratio and reinforcement ratio of longitudinal reinforcement on the hysteretic characteristics of corroded shear walls with flange were investigated. This article assesses the seismic behavior of specimens by analyzing corrosion morphology and dam age processes of concrete and rebars. In addition, scrutiny is placed on failure modes, bearing capability, deformability, and energy-dissipating capacity. Subsequently, according to the failure characteristics and test data, a numerical modeling analysis method based on fiber elements was proposed and validated to obtain the seismic response prediction of corroded shear walls with flange. Finally, based on the built numerical model, the effects of other parameters on the seismic property of corroded shear walls with flange were discussed.

7

Investigating the influence of NaCl concentration on the electrochemical corrosion behavior of metal oxide reinforced magnesium matrix composites

Gnanavelbabu A., Vinothkumar E., Ross Nimel Sworna, Rai Ritu, Kuntoğlu Mustafa

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e113, 2023

EN

This research examines the impact of different NaCl concentrations on the corrosion performance of AZ91D nanocomposites enhanced with nano metal oxides such as Zinc oxide (ZnO), Manganese oxide (MnO), and Titanium oxide (TiO2) through an electrochemical test method. The proposed materials were fabricated using a stir-squeeze casting process paired with an ultrasonication setup. In an argon gas-protected system, T6 heat treatment conditions were applied to these casted composites. The electrochemical corrosion results revealed that the ATO nanocomposite at 2.5% of NaCl concentration achieved lower corrosion current density (Icorr) (1.456 × 10–7 A/cm2) and higher corrosion potential (Ecorr) (− 1.08 V) owing to the formation of Mg2TiO3 precipitates, which act as a corrosion protective layer as well as reduce the corrosion rate. Based on the nyquist plot, the alloy and nanocomposites electron transfer rate were varied in the following sequence of AZD < AMO < AZO < ATO. The corroded samples Scanning Electron Microscope (SEM) and 3D profile image show ATO composites have minimum amount of crevice corrosion and peaks formation than other materials. Results from EDAX and elemental mapping confirm the presence of Mg2TiO3 precipitates on the ATO nanocomposite.

8

Investigations on the Microstructure and Corrosion Performance of Different WC-Based Cermet Coatings Deposited by High Velocity Oxy Fuel Process onto Magnesium Alloy Substrate

Jonda Ewa, Łatka Leszek, Maciej Artur, Khozhanov Aleksandr

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no. 2

25--35

EN

In the field of surface engineering, thermal spraying is very wide adopted in many branches of the industry. The main reasons of such situation are its flexibility as well as cost effectiveness. Among others, High Velocity Oxy Fuel (HVOF) technique is dedicated for spraying hardmetal and cermet coatings, especially for wear- and corrosion resistance. Such type of coating could be a promising candidate as protective layer for magnesium alloys elements. These materials need a strong improvement in the corrosion protection as well as on the field of wear resistance in order to be widely used in the industry. In this work, different WC-based coatings, namely: (i) WC-Co, (ii) WC-Co-Cr and (iii) WC-Cr3C2-Ni manufactured by HVOF spraying, were investigated. The form of all feedstock materials was agglomerated and sintered powder. All coatings were sprayed with the same technological parameters, especially spray distance which was equal to 400 mm on the AZ91 magnesium alloy substrate. The main aim of the studies was to investigate the influence of the powder material on the corrosion resistance of obtained coatings. The manufactured coatings were examined in terms of its microstructure, using scanning electron microscope (SEM) and corrosion performance, which was assessed in the electrochemical corrosion investigations in 3.5% NaCl solution by Tafel method. The study showed that the corrosion resistance increasing in such order: AZ91 < WC-Cr3C2-Ni < WC-Co < WC-Co-Cr. It should be stressed that WC-Cr3C2-Ni coating exhibits very low corrosion performance, which could be effected by relatively high porosity (c.a. 3 vol.%) and because of that the more complex composition promotes creation of many corrosion cells.

9

Influence of multi extrusion die process on mechanical and chemical behavior of 2024-T3 alloy

Razooqi Ahmed Ibrahim, Abbas Naseer M., Ghazi Sara Saad

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 3

163--170

EN

In this paper, a cold multi-pass extrusion process for a 15mm in diameter solid 2024-T3 aluminum alloy rod was carried out using three dies to obtain three different diameters of 14mm, 13mm, and 12mm. The microstructure, hardness, and corrosion behavior were investigated before and after the extrusion process. Load-Displacement data were recorded during each extrusion process. The electrochemical corrosion test was made in a 3.5 wt.% NaCl solution using potentiostat instrument under static potentials test. Corrosion current was recorded to determine the corrosion rate for specimens. The results showed that the extrusion load increased with the number of extrusion passes, which is also seen in hardness test results. In addition, the corrosion rate decreased with the increase in the number of extrusion passes. This is due to severe plastic deformation, which generates a fine grain structure of (AlCu) and (AlCuMg) components.

10

Evaluation of the corrosion resistance of spark plasma sintered stainless steel 316L matrix composites with zirconium diboride in sulfuric acid

Stępień Michał, Sulima Iwona, Hyjek Paweł, Kowalik Remigiusz

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e127

EN

The infuence of the zirconium diboride content and the method of initial material preparation on the corrosion properties of the composite on the 316L stainless steel matrix were determined. The powders were prepared in a Turbula mixer and a planetary mill. The corrosion properties were estimated on the basis of electrochemical tests, including open-circuit potential measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy. The presence of the ceramic phase changes the corrosion resistance of the tested materials due to porosity, which afects the corrosion mechanism. The standard potentiodynamic tests do not reveal poor corrosion resistance of porous materials, and only 24 h tests reveal accurate corrosion resistance of composite materials. Composites cannot go into a stable passive state because of the penetration of electrolytes into the pores and tend to oxidize systematically. 24-h corrosion tests indicate that samples prepared in a planetary mill show better corrosion resistance than those prepared in a Turbula mixer.

11

Ewentualna korozja elektrochemiczna szyn na szlaku kolejowym zelektryfikowanym prądem stałym

Dąbrowski Józef

Przegląd Komunikacyjny

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2021

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R. 76, nr 5

3--9

PL

W artykule opisano budowę zelektryfikowanego prądem stałym szlaku kolejowego. Zwrócono uwagę izolowanie elementów wiodących prąd trakcyjny w sieci zasilającej i powrotnej oraz na różnicę znaczenia tych izolacji. Podano przyczyny występowania prądów błądzących i ich charakter w dowolnym przekroju poprzecznym torowiska na szlaku. Wykazano warunki konieczne do ujawnianie się procesów elektrochemicznych na szynach torów szlakowych. Wykazano, że lokalnie na szlaku występują procesy galwanizacyjne – nakładania jonów elektrolitu glebowego na powierzchnię szyn i korozji elektrochemicznej – ubytku materiału szyn. Przy ruchu zelektryfikowanych pociągów na szlaku niezbędna jest wilgoć i styk szyn ze słabo odwodnionym podparciem stopki lub z tłuczniem – podsypką torowiska.

EN

The article describes the construction of a railway line electrified with direct current. Attention is paid to the isolation of the elements leading to the traction current in the supply and return network, and to the difference in significance of these insulations. The reasons for the occurrence of stray currents and their nature in any cross-section of the track on the trail are given. The necessary conditions for the disclosure of electrochemical processes on the rails of the track tracks were shown. It has been shown that the galvanization processes occur locally on the trail - the application of soil electrolyte ions on the surface of the rails and electrochemical corrosion - the loss of the rails material. During the movement of electrified trains on the route, moisture is necessary and the contact of the rails with the poorly drained support of the foot or with the ballast - track ballast.

12

Wpływ dodatków stopowych bizmutu i ołowiu na odporność korozyjną powłok cynkowych zanurzeniowych – Analiza stereologiczna i odporność korozyjna

Komorowski Leszek, Królikowska Agnieszka, Gałajda Zofia

Ochrona przed Korozją

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2021

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nr 12

396--404

PL

Na odporność korozyjną powłok zanurzeniowych wpływa wiele czynników takich jak temperatura, czas cynkowania, gatunek użytej stali, sposób chłodzenia, ale przede wszystkim skład chemiczny stopu cynkowniczego. Z historycznego punktu widzenia ołów używany był do ochrony wanny cynkowniczej oraz poprawienia właściwości lejnych stopu cynkowniczego. Uznanie ołowiu za toksyczny spowodowało użycie bizmutu jako jego zamiennika. Wpływ dodatków stopowych na odporność korozyjną powłok cynkowych na stalach o różnej reaktywności w kąpielach z dodatkiem ołowiu i bizmutu testowano w komorze solnej oraz technikami elektrochemicznymi. Za pomocą elektronowej mikroskopii skaningowej (SEM) analizowano grubości powłok oraz dystrybucję tych dodatków stopowych w powłokach, a także morfologię powłok. Zaobserwowano wpływ dodatków stopowych na przyspieszenie szybkości korozji powłok. Dodatki stopowe powodowały występowanie lokalnych procesów korozyjnych.

EN

The corrosion resistance of immersion coatings is the result of many factors such as temperature, time of galvanizing, the type of steel used, the cooling method, but above all the chemical composition of zinc melt. Historically, lead was used to protect the zinc bath and to improve the funnel properties of the zinc bath. The recognition of lead as toxic led to the use of bismuth as its substitute. The influence of alloy additives on the corrosion resistance of zinc coatings on steels with different lead and bismuth baths was tested in a salt chamber and by electrochemical techniques. The thickness of the coatings and the distribution of these alloy additives in the coatings as well as the phase distribution were analyzed using scanning electron microscopy (SEM). The influence of alloy additives on the acceleration of the corrosion rate of coatings was observed. Alloying additives induced the occurrence of localized corrosion processes.

13

Głębokościowa charakterystyka odporności korozyjnej azotowanego stopu Ti6Al4V

Jagielska-Wiaderek Karina

Ochrona przed Korozją

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2021

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nr 2

34--37

PL

W pracy przedstawiono elektrochemiczną ocenę odporności korozyjnej azotowanego stopu tytanu Ti6Al4V. Badania korozyjne wykonano w 0,5M roztworze siarczanowym zakwaszonym do pH = 2 wykreślając krzywe potencjokinetyczne na różnych głębokościach warstwy wierzchniej. Grubość powstałej warstwy wierzchniej oceniono na podstawie badań strukturalnych oraz zmiany mikrotwardości na przekroju poprzecznym obrobionego powierzchniowo materiału. Stwierdzono, że przeprowadzona obróbka azotująca poprawia odporność korozyjną oraz znacznie utwardza powierzchnie badanego materiału. Uzyskana warstwa wierzchnia posiada budowę strefową przy czym najwyższą odporność korozyjną jak i najwyższą mikrotwardość wykazuje najbardziej zewnętrzna strefa azotków.

EN

The paper reports the electrochemical assessment of the corrosion resistance of the titanium alloy Ti6Al4V. Corrosion tests were carried out in a 0.5M sulphate solution acidified to pH = 2, while plotting potentiometric curves at varying depths of the top layer. The thickness of the produced top layer was assessed based on structural examination and change in microhardness over the cross-section of the surface treated material. It has been found that the nitriding treatment improves the corrosion resistance and considerably hardens the surface of the material under study. The obtained top layer exhibits a zonal structure, with the greatest corrosion resistance and the highest microhardness being shown by the outermost nitride zone.

14

Problemy korozyjne struktury połączenia metalizacyjnego poszycia statku powietrznego - wybrane problemy

Ciężak Patryk, Gębura Andrzej, Szawłowski Sergiusz, Kwiatkowski Tadeusz, Handzel Kacper, Paszek Sławomir, Marcinkowska Maria, Kowalczyk Henryk, Olkowicz Klaudia

Journal of KONBiN

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2021

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Vol. 51, iss. 4

91--105

PL

Artykuł ujmuje kompleksowo problemy korozyjne związane ze strukturą obwodów powrotnych wojskowych statków powietrznych o metalowej konstrukcji kadłuba. Autorzy opisują problemy związane z wykorzystaniem kadłuba jako obwodu powrotnego prądu elektrycznego, w szczególności z przewodami minusowymi łączącymi kadłub z zaciskami minusowymi odbiornika lub źródła, rzadko poruszane w literaturze naukowej z uwagi na "trywialność" zagadnienia. Aby zmniejszyć błąd pomiarowy, autorzy do pomiarów rezystancji poszycia kadłuba wykorzystują metodę techniczną o natężeniu prądu probierczego zwiększanego proporcjonalnie do pola powierzchni i stopnia sfałdowania powierzchni stykowej.

EN

The article comprehensively describes corrosion problems related to the structure of ground-return circuits of military aircraft with metal fuselage structure. The authors describe problems related to the usage of the fuselage as a ground-return circuit of electric current, especially with negative circuits connecting the fuselage with negative terminals of the receiver or the source, rarely discussed in the scientific literature due to the triviality of the problem. Given the necessity to reduce the measurement error, the authors use a technical method for measuring the resistance of the fuselage fabric covering with the intensity of test current increased in proportion to the surface area and the degree of folding the contact surface.

15

Practical information on electrochemical corrosion of water pipelines

Dąbrowski Wojciech, McGarity Arthur E.

Instal

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2021

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nr 1

32--34

EN

Some aspects of drinking water ductile iron pipeline's electrochemical corrosion are discussed in this paper. We include: the impact of water parameters on its corrosivity, the relationships between the cement mortar lining and head loss to flow, pipeline diameter, and the total alkalinity of water, lifetime of the cement mortar lining. The discussion is lim ited strictly to some practical remarks with little theoretical background.

PL

Opisano wybrane aspekty elektrochemicznej korozji przewodów wodociągowych. Dyskusja ta dotyczyła: oceny korozyjności wody na podstawie jej parametrów fizyczno-chemicznych, wpływu wyprawy cementowej rurociągów na opory przepływu, związków pomiędzy jakością wody i oporami przepływu oraz trwałością wyprawy.

16

Structure and electrochemical behaviour of weldments of titanium Grade 1 in a bromine-containing solution

Ilieva M.D., Ferdinandov N.V., Gospodinov D.D., Radev R.H.

Archives of Materials Science and Engineering

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2021

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Vol. 112, nr 1

5--12

EN

Purpose: The presented research aims to determine the microstructural changes in weldments of commercially pure titanium Grade 1 after welding by hollow cathode arc discharge in vacuum and related changes in the corrosion behaviour of the weldments. Design/methodology/approach: Macro and microstructure of weldments were studied using optical microscopy. Corrosion behaviour of untreated Grade 1 and heat-affected zone of weldments of Grade 1 was investigated using electrochemical testing, including open circuit potential measurements and potentiodynamic polarisation. As an aggressive environment, 1 M KBr water solution was used. Findings: Welding by hollow cathode arc discharge in vacuum leads to the formation of a coarse Widmanstätten structure in the heat-affected zone. This imperfect structure results in a passive layer with worsened protective properties, thus increasing the corrosion rate of weldments by up to two orders of magnitude compared to Grade 1 in as-received condition. The passive layer on the welded surfaces did not allow Grade 1 to acquire a stable corrosion potential during potenitodynamic polarization. Research limitations/implications: Titanium and its alloys are passivating metallic materials, and their corrosion resistance depends on the properties of a thin protective surface layer. Changes in the underlying metal microstructure can affect the passivation behaviour of titanium and the properties of this layer. Welding by hollow cathode arc discharge in vacuum alters the microstructure of heat-affected zone, thereby causing Widmanstätten microstructure to form. As the passive layer over that microstructure has worsened protective properties, we suggest additional heat treatment after welding to be applied. Future experimental research on this topic is needed. Originality/value: Welding by hollow cathode arc discharge in vacuum is a welding method allowing weldments to be done in a clean environment and even in space. In the specialised literature, information on the structure and corrosion resistance of weldments of commercially pure titanium Grade 1 welded by hollow cathode arc discharge in vacuum is missing. The present research fills in a tiny part of this gap in our knowledge.

17

Electrochemical Corrosion Evaluation of Copper-Alloyed Ductile Cast Irons

Brito P., Pereira W., Santos W., Gomes H.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 2

26--30

EN

In the present work, different Cu-alloyed model ductile irons with ferritic (0%Cu-0.09%Mn), mixed ferritic-pearlitic (0.38%Cu-0.40%Mn) and pearlitic (0.69%Cu-0.63%Mn) microstructure were produced and analyzed in terms of their electrochemical corrosion behavior in a 3.5wt.%NaCl aqueous solution containing naturally dissolved oxygen at room temperature (25°C). The remaining elements such as Si and Mg were kept at balanced levels in an attempt to minimize variations in graphite size and distribution among different samples. The corrosion resistance was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization. Microstructure analysis of the cast alloys confirmed similarity in the graphite morphology among the different cast samples and the expected variations in the metallic matrix. In the absence of passivation, it was found that the addition of copper led to an increase in corrosion resistance, which could be attested by higher values polarization resistance and corrosion potential.

18

Corrosion properties of Mg-Zn-Ca-(Cu, Au) metallic glasses in artificial physiological fluid

Cesarz-Andraczke Katarzyna, Nowosielski Ryszard, Babilas Rafał

Archives of Civil and Mechanical Engineering

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2019

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Vol. 19, no. 3

716--723

EN

The Mg-Zn-Ca-(Cu,Au) alloys were considered as resorbable materials for orthopedic short- term implants. The aim of this paper was to determine the influence of Au and Cu addition on corrosion properties of Mg69Zn25Ca5Au1, Mg69Zn25Ca5Au0.5Cu0.5 and Mg69Zn25Ca5Cu1 metallic glasses. The analysis of corrosion results allowed to describe the influence of 0.5 and 1 at.% of Au and Cu on the corrosion resistance in artificial physiological fluid. The Mg69Zn25Ca5Au0.5Cu0.5 and Mg69Zn25Ca5Cu1 metallic glasses exhibit lower corrosion resis-tance in comparison with Mg69Zn25Ca5Au1 alloy. The increase of Cu content caused the increase of hydrogen evolution volume and the high cathodic activity. The Mg69Zn25Ca5Au1 metallic glass shows the decrease of hydrogen evolution volume and manifests the low corrosion current density and the high polarization resistance, indicating the high corrosion resistance.

19

Środowiskowe i klimatyczne warunki pracy aparatury rozdzielczej i sterowniczej nn i SN – wybrane aspekty

Kiszło S.

Wiadomości Elektrotechniczne

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2017

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R. 85, nr 9

32--35

PL

W artykule przedstawiono normalne i specjalne warunki pracy aparatury rozdzielczej. Podano przykłady narażeń środowiskowych. Omówiono zjawisko korozji elektrochemicznej. Przedstawiono próby urządzeń w oblodzeniu i wilgotne gorąco.

EN

The article presents normal and special service conditions switchgear and controlgear. Give for example environmental pollution. Characterization phenomenon electrochemical corrosion. Presents devices for low and high temperature and humidity test.

20

Studies on the Corrosion Resistance of Laser-Welded Inconel 600 and Inconel 625 Nickel-Based Superalloys

Łyczkowska K., Michalska J.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 2A

653--656

EN

The paper presents the results of the electrochemical corrosion tests of Inconel 600 and Inconel 625 laser-welded superalloys. The studies were conducted in order to assess the resistance to general and pitting corrosion in 3.5% NaCl solution. It was found that Inconel 600 possesses good corrosion resistance, however Inconel 625 is characterized by a greater resistance to general and also to pitting corrosion of the weld as well as the base metal.