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1
Content available remote Porównanie odporności korozyjnej powłok cynkowych otrzymanych w kąpielach z dodatkiem Al, Ni, Pb, Bi i Sn
Kania Henryk, Saternus Mariola, Kudláček Jan, Zoubek Michal
Ochrona przed Korozją
|
2022
|
nr 7
203--215
PL
W artykule przedstawiono wyniki badań wpływu dodatków Al, Ni, Pb, Bi i Sn do kąpieli cynkowej na mikrostrukturę i odporność na korozję powłok cynkowych. Obserwowano mikrostrukturę w dużych powiększeniach (SEM) na powierzchni i przekroju poprzecznym powłok oraz określono skład chemiczny w mikroobszarach. Odporność powłok na korozję została zbadana porównawczo w obojętnej mgle solnej (PN EN ISO 9227) i wilgotnej atmosferze zawierającej związki siarki (PN EN ISO 6988). Określono parametry elektrochemiczne korozji powłok. Stwierdzono, że powłoki otrzymane w kąpielach zawierających dodatki Pb, Bi oraz BiSn wykazują niższą odporność na korozję w porównaniu z powłokami otrzymanymi w kąpieli Zn-AlNi. Badania strukturalne ujawniły występowanie w powłoce wydzieleń Pb, Bi oraz stopu BiSn. Stwierdzono, że wydzielenia te mają bardziej elektrododatni potencjał niż cynk, co sprzyja powstawaniu dodatkowych ogniw korozyjnych.
EN
The article presents the results of research on the influence of Al, Ni, Pb, Bi and Sn additives in a zinc bath on the microstructure and corrosion resistance of zinc coatings. The microstructure at high magnifications (SEM) was revealed on the surface and cross-section of the coatings, and the chemical composition in micro-regions was determined. The corrosion resistance of the coatings was tested comparatively in neutral salt spray (PN EN ISO 9227) and in a humid atmosphere containing sulfur compounds (PN EN ISO 6988). The electrochemical corrosion parameters of the coatings were determined. It was found that the coatings obtained in the baths containing Pb, Bi and BiSn additives showed lower corrosion resistance compared to the coatings obtained in the Zn-AlNi bath. The microstructural tests showed the occurrence of Pb, Bi and BiSn alloy precipitates in the coating. These precipitates have a more electropositive potential in relation to zinc, which favors the formation of additional corrosion cells.
2
Content available Influence of seawater salinity on corrosion of hull structural steel
Zagożdżon Paweł, Starosta Robert
Journal of KONES
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2019
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Vol. 26, No. 2
189--195
EN
Hulls of ships are often made of steel, which are produced under the supervision of classification societies. Usually, the hull steel of ordinary strength category A is used for the ship's shell (the yield strength is 235 MPa and the impact strength 27 J at 20ºC). Vessels sail in sea areas with various levels of salinity and thus with different corrosiveness. The average salinity of the seas is taken as 3.5% content of sodium chloride. This article presents the results of corrosion tests of S235 JRG1 steel in an aqueous solution in which the mass fraction of sodium chloride was: 0.7%, 1.4%, 2.2%, 2.8%, 3.5% and 4.2%. Corrosion tests were performed using the potentiodynamic method. As parameters characterizing the corrosion properties of the tested steel, the corrosion current density and corrosion potential were assumed. Statistically significant influence of seawater salinity on the corrosion properties of hull structural steel of ordinary strength of category A was found. The highest value of the corrosion current density was observed in the solution containing 3.5% NaCl mass fraction was observed. In seawater with a sodium chloride content in the range of 0.7 to 3.5%, an increase in the value of the corrosion current density was observed, along with the increasing share of NaCl. In seawater with higher salinity, the corrosion rate was reduced. The corrosion potential of S235JRG1 steel decreases with the NaCl content in the corrosive solution. The susceptibility of this material to corrosion in seawater increased.
3
Content available Electrochemical Corrosion of Magnesium Alloy AZ31 with Additive Lithium
Przondziono J., Hadasik E., Szala J.
Archives of Metallurgy and Materials
|
2017
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Vol. 62, iss. 4
2359--2363
EN
The purpose of performed tests was evaluation of resistance to electrochemical corrosion of extruded magnesium alloy AZ31 with additive of 4.5% Li. Corrosion tests were performed in 0.01-2.0 M NaCl solutions. Potentiodynamic tests enabled to register polarisation curves. With application of stereoscopic microscope Nikon SMZ745T and electron scanning microscope Hitachi S-4200, the surface of the alloy was observed after immersion tests performed in 1-6 days. Results of performed tests prove explicitly deterioration of corrosion properties of the alloy with the increase of molar concentration of NaCl solution. It can be seen that corrosion process is intensive and that intensity increases with the increase of solution concentration and extension of exposure time.
4
Content available remote Effect of chemical composition and plastic deformation on corrosion properties of highMn austenitic steels in alkaline solution
Kozłowska A., Grajcar A
Archives of Materials Science and Engineering
|
2016
|
Vol. 77, nr 1
31--39
EN
Purpose: The aim of the paper is to compare the corrosion properties of two high-Mn austenitic steels with various Al and Si additions in 0.1M NaOH solution using a potentiodynamic method. Design/methodology/approach: The steels used for the investigation were thermomechanically rolled in 3 passes. The final thickness of about 2 mm was obtained at a temperature of 850°C. Three groups of samples were prepared: thermomechanically rolled, thermomechanically rolled and additionally annealed at 900°C for 20 min, thermomechanically rolled and additionally cold deformed in static tensile test to total elongation of 36%. Corrosion resistance of investigated steels was examined using the potentiodynamic method. The metallographic inspection of corrosion damage included scanning electron microscope observations. The chemical analyses of the corrosion pits were carried out using EDS techniques. Findings: It was found that X4MnSiAlNbTi27-4-2 and X6MnSiAlNbTi26-3-3 steels were characterized by relatively high corrosion resistance in 0.1M NaOH solution independently of their state. EDS analysis revealed that corrosion pits nucleated preferentially at nonmetallic inclusions such as MnS and AlN. Results of potentiodynamic tests showed that cold deformation had the highest influence on decreasing the corrosion resistance of investigated steels. Thermomechanically treated and supersaturated specimens showed lower values of corrosion current density and consequently less amount of corrosion damage. Research limitations/implications: To investigate in more detail the corrosion behaviour of high-manganese austenitic steels, the impedance spectroscopy investigations will be carried out. Practical implications: The knowledge of the corrosion resistance of high-Mn steels has a significant effect on their industrial application in the automotive industry. Originality/value: The corrosion resistance of two high-manganese austenitic steels with different initial microstructures was compared in alkaline solution.
5
Content available remote Porównanie odporności korozyjnej różnych powłok cynkowych wyznaczanej w komorach klimatycznych i metodą potencjodynamiczną
Szłapa I., Jędrzejczyk D., Hajduga M., Węgrzynkiewicz S.
Ochrona przed Korozją
|
2014
|
nr 4
129--135
PL
W badaniach porównawczych przedstawionych w pracy zastosowano cztery metody oceny odporności korozyjnej powłok cynkowych. Wnioski formułowano na podstawie wyników testu prowadzonego w komorze solnej w mgle obojętnej NaCl (wg PN-EN ISO 9227), testu w komorze klimatycznej (VDA 621-415), testu Kesternicha (DIN 50018/2,0 SO2) oraz badania metodą potencjodynamiczne w 5% NaCl. Testy przeprowadzono na próbkach wykonanych ze stali DC01, na które powłoka cynkowa została naniesiona przy zastosowaniu następujących metod: galwanicznej (PN-EN ISO 4042), ogniowej (PN-EN ISO 10684) oraz płatkowej (PN-EN ISO 10683). Zakres badań obejmował ocenę odporności korozyjnej, gdzie kryterium limitującym czas protekcji było pojawienie się korozji białej oraz czerwonej. Stwierdzono, że powłoka cynkowa z nową pasywacją grubowarstwową najdłużej chroni stalowe podłoże w środowisku NaCl, a powłoka Zn płatkowego jest najbardziej odporna na działanie zmiennych warunków termicznych i wilgoci. Powyższe wnioski zostały również potwierdzone za pomocą metody potencjodynamicznej.
EN
This paper presents corrosion resistance of construction elements covered with different metallic (zinc) protective coatings. The following methods of zinc coating were applied: galvanic (PN-EN ISO 4042), hot-dip (PN-EN ISO 10684) and lamellar (PN-EN ISO 10683). All samples with the Zn coating were analyzed metallographically. The structure and continuity of the Zn coating were evaluated. Next, the corrosion resistance of Zn coatings was investigated. Samples were placed in the salt chamber with neutral NaCl (PN-EN ISO 9227), climatic chamber (VDA 621-415) and KESTERNICH (DIN 50018/2,0 SO2) chamber. It is clear that the zinc coating with new passivation thick layer protects the steel base material in the NaCl environment and zinc flake coating is the most resistant to variable thermal conditions and moisture. Research carried out using the potentiodynamic method confirmed these results.
6
Content available Effect of finishing on the corrosion properties of flame sprayed Ni-5%Al and Ni-5%Al-Al2O3 coatings
Charchalis A., Starosta R.
Journal of KONES
|
2014
|
Vol. 21, No. 4
29--36
EN
The Ni-5%Al alloy and Ni-5% Al-Al2O3 composite coatings were obtained by a flame spraying method, “Casto- Dyn DS 8000” torch was used. The coatings onto a substrate made of austenitic stainless steel (X5CrNi18-10) were sprayed. The coatings were subjected to turning, burnishing and grinding. The evaluation of corrosion properties were based on the measurements of direct current (potentiodynamic method) and the alternating current (EIS method). Corrosion tests were performed in a 3.5% sodium chloride solution. On the basis of studies, the effect of finishing type on the corrosion properties of flame sprayed coatings has been demonstrated. The lowest corrosion current density was found for Ni-5%Al coatings after burnishing, icorr value equal to 0.76 μA/cm2, and the charge transfer resistance was 31063 Ω/cm2. The lowest resistance to corrosion of grinded Ni-5%Al-Al2O3 composite coatings was observed. These coatings were characterized by the following parameters of corrosion process: icorr = 14.01 μA/cm2, Rct = 3260 Ω/cm2. Burnishing caused increased corrosion resistance of both coatings. Due to reduced roughness and waviness are obtained reduction of the area of the actual burnished coatings compared to turned coatings. Thus, it is resulting in reduced values of corrosion current density. After finishing treatment, the thermally sprayed Ni-5%Al-15%Al2O3 coatings characterized by lower corrosion resistance compared to the alloy coating. The presence of the reinforcing phase in the coating promotes the increase of the porosity. Burnishing does not cause a significant change in porosity of the coating. The flame sprayed coatings on nickel-based have a tendency to localized corrosion in seawater environment.
7
Content available remote Badania własności elektrochemicznych warstw krzemionkowych stosowanych na wyroby medyczne przeznaczone do kontaktu z krwią
Basiaga M., Popik P, Paszenda Z., Pochrząst M.
Przegląd Elektrotechniczny
|
2013
|
R. 89, nr 12
374-377
PL
W pracy zaprezentowano wyniki badań własności elektrochemicznych warstw krzemionkowych wytworzonych na stali Cr-Ni-Mo przeznaczonej do kontaktu z krwią. Badane próbki poddano szeregowi metod obróbki powierzchniowej: szlifowanie, polerowanie elektrolityczne, pasywacja chemiczna, naniesienie warstw krzemionkowych przy wykorzystaniu zanurzeniowej techniki zol-żel. W celu określenia własności elektrochemicznych powłok SiO2 przeprowadzono badania odporności korozyjnej metodami: potencjodynamiczną oraz impedancyjną.
EN
The paper presents the results of the electrochemical properties of silica layers produced on Cr-Ni-Mo steel intended for contact with blood. The samples were subjected to a series of surface preparation methods: grinding, electrolytic polishing, chemical passivation, sol-gel silica coatings by means of dipping. For the evaluation of electrochemical properties of SiO2 layers of corrosion resistance tests were carried out by means of potentiodynamic and impedance methods.
8
Content available Badania własności elektrochemicznych stentów wieńcowych
Hyla A., Walke W.
Aktualne Problemy Biomechaniki
|
2013
|
z. 7
75--80
PL
W pracy przeprowadzono ocenę właściwości elektrochemicznych stentu wieńcowego wykonanego ze stali austenitycznej Cr-Ni-Mo. W celu zasymulowania warunków występujących w środowisku naczyń krwionośnych człowieka badania przeprowadzono w sztucznym osoczu w temperaturze T = 37 ± 1°C i pH = 7,0 ± 0,2. Badania odporności korozyjnej przeprowadzono w oparciu o rejestrację krzywych polaryzacji anodowej oraz metodę Sterna. Dla oceny zjawisk zachodzących na powierzchni badanego stentu zastosowano również metodę elektrochemicznej spektroskopii impedancyjnej (EIS – Electrochemical Impedance Spectroscopy). Analizie poddano stenty przed i po procesie rozprężenia. W celach porównawczych badania wykonano również dla próbek pobranych ze stali Cr-Ni-Mo w stanie przesyconym o właściwościach mechanicznych odpowiadających stali wykorzystanej do produkcji stentów.
EN
The study includes the evaluation of electrochemical properties of coronary stent made ​​of Cr-Ni-Mo austenitic stainless steel. In order to simulate the conditions found in the human vascular environment studies were carried out in the artificial plasma at a temperature of T = 37 ± 1°C and pH = 7.0 ± 0.2. Corrosion resistance tests were carried out on the basis of registration of the anodic polarization curves and the method of Stern. In order to assess developments on the surface of a stent the method of electrochemical impedance spectroscopy was used. Stents were analyzed before and after expansion. For comparative purposes, tests were also performed to samples of the Cr-Ni-Mo in the supersaturated state of the corresponding mechanical properties of steel used for the production of stents.
9
Content available remote Influence of cold rolling on the corrosion resistance of austenitic steel
Kurc A., Kciuk M., Basiaga M.
Journal of Achievements in Materials and Manufacturing Engineering
|
2010
|
Vol. 38, nr 2
154-162
EN
Purpose: The paper analyzes the effects of plastic deformation in cold working process on the corrosion resistance, micro-hardness and mechanical properties of austenitic stainless steel X5CrNi18-10. Design/methodology/approach: Corrosion resistance of X5CrNi18-10 steel was examined using weight and potentiodynamic methods. In the weight method, the specimens were immersed in the prepared solution for 87 days. The evaluation of the corrosion behaviour of investigated steel in the potentiodynamic method was realized by registering of anodic polarization curves. The VoltaLabŽ PGP 201 system for electrochemical tests was applied. The tests were carried out at room temperature in electrolyte simulating artificial sea water (3.5% NaCl). Registering of anodic polarization curves was conducted at the potential rate equal to 1 mV/s. As the reference electrode the saturated calomel electrode (SCE) was applied, the auxiliary electrode was platinum electrode. Mechanical properties were evaluated on the basis of the static tensile and Vickers micro-hardness test. The observations of the surface morphology after corrosive tests were carried out using Scanning Electron Microscope SUPRA™25. Findings: According to the results of potentiodynamic analyses it was found that plastic deformation in a cold working of austenitic steel grade X5CrNi18-10 affected to lower its corrosion resistance in 3.5% NaCl solution, what has an essential meaning in industrial applications of this group of materials. Research limitations/implications: The microscope observations of the surface samples subjected to corrosion resistance test in 3.5% NaCl solution permitted to evaluate types and the rate of corrosion damages. Practical implications: The obtained results can be used for searching the appropriate way of improving the corrosion resistance of a special group of steels. Originality/value: The corrosion behaviour in chloride solution of a Cr-Ni austenitic stainless steel was investigated.
10
Content available remote Corrosion behaviour of Fe-Mn-Si-Al austenitic steel in chloride solution
Opiela M., Grajcar A., Krukiewicz W.
Journal of Achievements in Materials and Manufacturing Engineering
|
2009
|
Vol. 33, nr 2
159-165
EN
Purpose: The aim of the paper is to investigate the corrosion behaviour of the new-developed high-manganese austenitic steel in 0.5n NaCl solution. Design/methodology/approach: The steel used for the investigation was thermomechanically rolled and solution heat-treated from a temperature of 850°C. Corrosion resistance of investigated steel was examined using weight and potentiodynamic methods. In the weight method, the specimens were immersed in the prepared solution for 24h. In the potentiodynamic method, anodic polarization curves with a rate of potential changes of 1 mV/s in the anodic direction were registered. After the current density being equal 1 mA/cm2 was achieved, the direction of polarization has been changed. Basing on the registered curves, the pitting potential, repassivation potential, polarization resistance and corrosion current were determined. Findings: It was found that the steel is characterized by a partially recrystallized austenitic microstructure with numerous annealing twins and slip bands. According to the results of potentiodynamic analyses it was found that the samples of examined steel show poor corrosion resistance in the NaCl solution. The observed corrosion pits are related to the chemical composition. It is connected with the high dissolution rate of Mn and Fe atoms in NaCl solution. Fractographic analyses of samples revealed corrosion products on their surface in a form of pits with diversified size. Research limitations/implications: To investigate in more detail the corrosion behaviour of high-manganese steel, the investigations should include steels with a wider Al concentration. Practical implications: The obtained results can be used for searching the appropriate way of improving the corrosion resistance of a modern group of high-manganese austenitic steels. Originality/value: The corrosion behaviour in chloride solution of a new-developed Fe-Mn-Si-Al steel was investigated.
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