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Corrosion resistance of SiMo- and SiCu-types of nodular cast iron in NaCl solution

Vaško Alan, Zatkalíková Viera, Kaňa Václav

System Safety : Human - Technical Facility - Environment

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2020

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Vol. 2, nr 1

191--198

EN

Nodular cast irons are used in a wide range of industrial applications, especially in the automotive industry. SiMo-type of nodular cast iron is suitable for high-temperature applications, for example the exhaust manifolds of the combustion engines; SiCu-type of nodular cast iron is used in various components of tribotechnical units. These automotive components often work in a corrosive environment. Therefore, the aim of this paper is to compare the corrosion resistance of two types of the nodular cast irons (SiMo-type and SiCu-type). Corrosion resistance was determined by the exposure immersion test at ambient temperature. Specimens of both types of nodular cast iron were immersed in 3.5 % NaCl solution (to simulate sea water) and gradually removed from the solution after 1, 2, 4 and 8 weeks. Subsequently, the weight loss (g) and the average corrosion rate (g m-2 day-1) were calculated. Experimental results show that nodular cast iron alloyed by Si and Mo has higher corrosion resistance than the nodular cast iron alloyed with Si and Cu. Moreover, the mechanical properties (evaluated by tensile test, impact bending test and hardness test) and fatigue properties of both types of nodular cast iron has been compared in the paper.

2

Roughness of 1.0721 steel after corrosion tests in 20% NaCl

Lipiński T.

Production Engineering Archives

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2017

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Vol. 15

27--30

EN

Non-alloy quality case-hardening steels are used for low-load components made on automatic machining centers (automatic lines). Because of the widespread use of these steel in open constructions, they are exposed to atmospheric corrosion. The study attempted to analyze the effect of 20% aqueous NaCl solution on the roughness of the steel as a result of corrosion. The steel roughness and corrosion wear were determined according to corrosion time.

3

Odporność na korozję elektrochemiczną wyciskanego stopu magnezu AZ31 z dodatkiem litu

Przondziono J., Hadasik E., Walke W., Lalik S., Dubiel M.

Hutnik, Wiadomości Hutnicze

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2015

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Vol. 82, nr 1

93--96

PL

W pracy przedstawiono wyniki badań korozji elektrochemicznej wyciskanego stopu magnezu AZ31 z dodatkiem 7,5% Li. Badania realizowano w roztworach o stężeniu 0,01÷2 M NaCl. Odporność na korozję elektrochemiczną oceniano w oparciu o rejestrację krzywych polaryzacji anodowej metodą potencjodynamiczną. Wykonano obserwacje powierzchni po ekspozycji stopu w roztworach NaCl w czasie 1÷5 dni. Realizowane je przy użyciu mikroskopu stereoskopowego Olympus SZX9 oraz mikroskopu świetlnego Olympus GX51.

EN

The study presents results of electrochemical corrosion tests of extruded magnesium alloy AZ31 with addittion of 7,5% Li. The tests were performed in solutions with concentration of 0,01÷2 M NaCl. Resistance to electrochemical corrosion was evaluated on the ground of registered anodic polarisation curves with potentiodynamic method. The surface of the alloy was observed after exposure to NaCl solutions for 1÷5 days. The tests were performed with application of stereomicroscope Olympus SZX9 and light microscope Olympus GX51.

4

Structure and corrosion resistance of aluminium AlMg2.5; AlMg5Mn and AlZn5Mg1 alloys

Kciuk M., Kurc A., Szewczenko J.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 41, nr 1-2

74-81

EN

Purpose: The aim of the work was the evaluation of corrosion resistance and structure of aluminium AlMg2.5; AlMg5Mn and AlZn5Mg1 alloys. Design/methodology/approach: The corrosion resistance tests of investigated alloys were carried out by means of potentiodynamic method registering anodic polarization curves in 3.5% NaCl solution at room temperature. Registering anodic polarization curves was conducted at the potential rate equal to 1mV/s. As the reference electrode was used saturated calomel electrode (SCE) and the auxiliary electrode was platinum electrode. Mechanical properties were evaluated on the basis of Vickers hardness test. The test was realized with the use of Hauser hardness tester. The observations of the surface morphology after corrosive tests were carried out using Digital Scanning Electron Microscope DSM 940 OPTON. Findings: The investigations of corrosion resistance of examined aluminium alloys shows that the highest corrosion resistance in 3.5% NaCl solution was observed for AlZn5Mg1 aluminium alloy. Practical implications: The obtained results can be used for searching the appropriate way of improving the corrosion resistance of analysed alloys because better corrosion resistance, lightweight of aluminium and its alloys makes them as most attractive for the steel replacement in shipbuilding. Originality/value: The corrosion behaviour in chloride solution of AlMg2.5; AlMg5Mn and AlZn5Mg1 alloys was investigated.

5

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

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2010

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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.

6

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

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2009

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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.