scholarly journals CORROSION BEHAVIOUR OF TEMPERED 42CrMo4 STEEL

2021 ◽  
Vol 55 (3) ◽  
Author(s):  
Sunčana Smokvina Hanza ◽  
Lovro Štic ◽  
Lovro Liverić ◽  
Vedrana Špada
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behaviour ◽  
Microstructural Characterization ◽  
Open Circuit ◽  
Medium Carbon Steel ◽  
42Crmo4 Steel ◽  
Double Quenching ◽  
Quenched And Tempered Steel ◽  
Quenching And Tempering ◽  
Tempered Steel

Low-alloy 42CrMo4 steel (AISI 4140) is a medium carbon steel, commonly used as a quenched and tempered steel. Because of its good mechanical properties, high tensile strength and toughness, 42CrMo4 is one of the widely used and investigated steels. In order to increase ductility even more, in addition to standard quenching and tempering, steel is often hardened by double quenching and tempering and austempering. The aim of this paper was to investigate the corrosion behaviour of 42CrMo4 steel after quenching and tempering, double quenching and tempering and austempering. For this purpose, microstructural characterization and electrochemical investigation after different hardening processes were performed. Microstructure of specimens was observed using optical microscopy and scanning electron microscopy. Open circuit potential and potentiodynamic polarization measurements of tempered specimens were carried out using computer-controlled potentiostat with three electrode set-up in 0.6 M NaCl naturally aerated solution. It was concluded that applied heat treatment processes increase the corrosion resistance of 42CrMo4 steel in comparison to normalized steel. In comparison to quenched and tempered steel, double quenching and tempering, as well as austempering, do not significantly change corrosion resistance of steel.

Electrochemical Determination of the Corrosion Resistance of Ag-Pd Dental Alloys

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Daniel Mareci ◽  
Igor Cretescu ◽  
Neculai Aelenei ◽  
Julia Claudia Mirza Rosca
Keyword(s):  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Artificial Saliva ◽  
Surface Film ◽  
Electrochemical Determination ◽  
Open Circuit ◽  
Electrochemical Characteristics

The electrochemical behavior of a three Ag-Pd alloys used in dental prosthetics construction for crowns and bridges was studied in artificial saliva using the polarization curves and electrochemical impedance spectroscopy (EIS). The corrosion resistance was evaluated by means of the corrosion currents value and by coulometric analysis. The open circuit potential of Ag-Pd are attributed to dealloying followed by surface enrichment with Ag and the possible formation of an insoluble AgCl surface film on the respective alloy surfaces. Our results have shown that these alloys have a somewhat good corrosion resistance in artificial saliva. When increasing the content of Cu, corrosion resistance decreases. The passivation of all samples occurred spontaneously at the open circuit potential. The electrochemical properties of the spontaneously passivated electrodes at the open circuit potential were studied by EIS. The polarization resistance (Rp) and the electrode capacitance (Cdl) were determined. The polarisation resistance of all the samples increases with the immersion time. The polarization resistances are largest and decrease when increasing the content of Cu. Cu reduces the Ag-Pd alloy corrosion resistance. The present study, thought limited, has shown that electrochemical characteristics can be use to identify such alloys. Knowledge of the in vitro corrosion behaviour of these alloys may lead to better understanding of any biologically adverse effects in vitro.

Corrosion Behaviour of Duplex Treated EN 42CrMo4 Steel by Gas Nitriding and TiAlN PAPVD Deposition

2016 ◽  
Vol 1138 ◽  
pp. 159-164
Author(s):  
Ramona Monica Buzdugan ◽  
Mircea Dan ◽  
Iosif Hulka ◽  
Monica Dome ◽  
Anamaria Feier ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Linear Polarization ◽  
Corrosion Behaviour ◽  
Nacl Solution ◽  
Gas Nitriding ◽  
Duplex Treatment ◽  
42Crmo4 Steel

A Duplex treatment consisting in gas nitriding followed by PAPAVD deposition of TiAlN has been proposed as a solution for improving the corrosion behaviour of EN 42CrMo4 steel. The corrosion resistance in 3.5% NaCl solution was evaluated by linear polarization. It was found that the Duplex treated samples exhibited better corrosion resistance and that the corrosion rate decreased significantly from 0.069 mm an-1 (untreated samples) to 0.008 mm an -1 (Duplex treated).

Microstructural characterization and corrosion behaviour of ultrasound-assisted synthesis of Ni–xCo–yTiO2 nanocomposites in alkaline environments

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nady ElSayed ◽  
Mohamed M. El-Rabiei ◽  
Mosaad Negem
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Microstructural Characterization ◽  
Alkaline Media ◽  
Face Centered Cubic ◽  
X Ray ◽  
Ultrasound Waves ◽  
Mechanical Stirring ◽  
Alkaline Environments

Abstract Electroplated protective thin film is highly promising materials for advanced applications such as high corrosion resistance and energy conversion and storage. This work is to investigate the effect of Co content and TiO2 on the corrosion resistance of Ni–xCo–yTiO2 nanocomposites in alkaline media. The nanocrystalline Ni–xCo–yTiO2 composites were electroplated using the sulfate-gluconate bath containing the suspended TiO2 nanograins under ultrasound waves and mechanical stirring. The microstructure and corrosion behavior of the electroplated Ni–xCo–yTiO2 nanocomposites have been investigated via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The XRD pattern of the electroplated Ni–Co matrices with 1–75% of cobalt arranged in face-centered cubic (FCC) system, while the electroplated Ni–Co matrices of further Co% more than 76% converted to hexagonal closed-package (HCP) crystal system. The surface of the Ni–xCo–yTiO2 nanocomposites after immersion in 1.0 M KOH electrolytes was investigated via SEM, atomic force microscopy and EDX. The results displayed that the rate of corrosion of the different composites decreased by combining Ni, Co and the inclusion of TiO2. The improved corrosion resistance of Ni–47Co–3.77TiO2 composites is due to the formation of Ni/Co oxy/hydroxide layer and rebelling effect of OH− by TiO2 sites, which reduces the attacking effect of OH−, O2, and H2O, and notably retards the overall corrosion processes.

Corrosion Behaviour of a Laser-MIG hybrid welding-brazing Joint of 6061 Aluminium Alloy to SUS304 Stainless Steel

CORROSION ◽  
10.5006/3866 ◽  
2021 ◽  
Author(s):  
ruilin liu ◽  
Yunqi Liu ◽  
Zheng Lei ◽  
Hui Tang ◽  
Shaoxiong He ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Weld Metal ◽  
Aluminium Alloy ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Salt Spray ◽  
Chemical Properties ◽  
Open Circuit ◽  
Hybrid Welding

Lightweight steel-aluminium structures have broad application prospects because of their lowering weight characteristics, however, the corrosion of welding-brazing joints in steel-aluminium structures is less concerned or studied. In this paper, the corrosion behaviour of the Laser-MIG hybrid welding-brazing joints of steel-aluminium is investigated through the tests and analysis of salt spray, immersion and electrochemistry. The salt spray and immersion tests show that obvious galvanic corrosion occurs at the welded joints, in which the aluminium side is seriously corroded while the steel side is not corroded. The OCP values of the aluminium alloy and the weld metal are similar (approximately -0.48 V), and the stainless steel has a higher OCP value of -0.33 V. The corrosion resistance of the weld metal is lower than aluminium- as well as steel-base materials. The corrosion resistance of the joints is controlled by the aluminium alloy part of the two metals based on the open-circuit potential and EIS analysis. A possible corrosion process schematic for the physical/chemical properties of a welding-brazing joint immersed in a sodium chloride solution is proposed according to electrochemical impedance spectroscopy.

scholarly journals Corrosion Resistance of Multilayer Coatings Deposited by PVD on Inconel 718 Using Electrochemical Impedance Spectroscopy Technique

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 521 ◽  
Author(s):  
Citlalli Gaona-Tiburcio ◽  
Marvin Montoya-Rangel ◽  
José A. Cabral-Miramontes ◽  
Francisco Estupiñan-López ◽  
Patricia Zambrano-Robledo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Inconel 718 ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Open Circuit ◽  
Inconel 718 Alloy ◽  
Transfer Resistance ◽  
Crn Coatings

AlCrN/TiSi, AlCrN/TiCrSiN and AlCrN/AlCrN + CrN coatings were deposited on Inconel 718 alloy by physical vapour deposition (PVD). The corrosion behaviour of uncoated and coated specimens was evaluated using electrochemical impedance spectroscopy (EIS) at open circuit potential in a 3.5 wt.% NaCl and 2 wt.% H2SO4 solutions. The EIS data acquired were curve fitted and analysed by equivalent circuit models to calculate the pore resistance, the charge transfer resistance and the capacitance. The Nyquist diagrams of all systems showed one part of the semicircle which could relate that reaction is a one step process, except for the AlCrN/TiCrSiN and AlCrN/AlCrN + CrN coatings in H2SO4 solution, for which two semicircles related to active corrosion in substrate alloy were found. However, from the Bode plots, it was possible to identify two the time constants for all systems exposed to NaCl and H2SO4 solutions. According to electrochemical results, the corrosion resistance of the AlCrN/TiSiN coating was better in the NaCl solution, whereas the AlCrN/AlCrN + CrN coating show better performance in the Sulphuric Acid solutions.

Corrosion Behaviour of AISI 304 Austenitic Stainless Steel Fabricated by Equal-Channel Angular Pressing

2011 ◽  
Vol 194-196 ◽  
pp. 411-415 ◽  
Author(s):  
Guo Xing Chen ◽  
Yan Gao ◽  
Shu Hui Wu ◽  
Jin Li Hu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Austenitic Stainless Steel ◽  
Grain Refinement ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Open Circuit ◽  
Aisi 304 ◽  
Angular Pressing ◽  
Average Size

In this essay, the effects of grain refinement on corrosion behavior and hardness of equal-channel-angular-pressed (ECAPed) AISI 304 austenitic SS were studied. Finer grains with average size of 5μm in the specimen were obtained after four ECAPed passes compared with as-received one with grain size in range of 55μm Strain-induced grain refinement process can increase grain boundary and dislocation. Thus, the corrosion resistance of ECAPed AISI 304 austenitic SS would be improved.The refined microstructure achieves more positive open circuit potential (OCP) and lower corrosion current density in polarization corrosion tests.Through this process, austenitic stainless steel with better performance in corrosion resistance can be gained.

Corrosion Behaviour of High Pressure Die-Cast and Semi-Solid Cast AZ91, AM60 and AM50 Alloys

2012 ◽  
Vol 192-193 ◽  
pp. 231-237 ◽  
Author(s):  
Simone Umberto Mariani ◽  
Anna da Forno ◽  
Massimiliano Bestetti
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Corrosion Resistance ◽  
Open Circuit Potential ◽  
Corrosion Behaviour ◽  
Open Circuit ◽  
Corrosive Media ◽  
Die Cast ◽  
Cast Alloys ◽  
Semi Solid

A comparison of corrosion resistance of die-cast and semi-solid cast AZ91, AM60 and AM50 magnesium alloys was performed in different corrosive media by measurement of the open circuit potential, potentiodynamic scans and weight loss tests. Before testing, a heat treatment was carried out onto semi-solid cast alloys. Electrochemical measurements have shown that the semi-solid cast alloys have a different corrosion rate compared to the die-cast ones. The results could be correlated to the different microstructures of the samples produced by the different processes.

A Study on the Corrosion and Mechanical Properties of an Al6063 Reinforced With Egg Shell Ash and Rice Husk Ash

2018 ◽  
Author(s):  
Nosa Idusuyi ◽  
Peter Ozaveshe Oviroh ◽  
Adetoye Henry Adekoya
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Corrosion Behaviour ◽  
Low Cost ◽  
Microstructural Characterization ◽  
Industrial Applications ◽  
Casting Technique ◽  
Egg Shell

Aluminium based metal matrix composites (MMCs) have received considerable attention in the last decade for its potential industrial applications. One of the challenges encountered using Aluminium based MMCs is understanding the influence of the reinforcement particles on the corrosion resistance and mechanical properties. In this study the corrosion behaviour and mechanical properties of Al6063 reinforced with egg shell ash and rice husk ash were investigated. Waste Egg Shell Ash (ESA) and Rice Husk Ash (RHA) 212 μm in size were used to produce the composites with 10 wt% of reinforcements via stir casting technique. The RHA and ESA were added in the ratios of 10:0, 7.5:2.5, 5:5, 2.5:7.5, 0:10. Unreinforced Al6063 was used as baseline material. Immersion tests, potentiodynamic polarization techniques, tensile tests, optical microscopy (OM) and scanning electron microscopy (SEM) were used to characterize the composites. The results showed that reinforcing with 7.5 wt% RHA + 2.5 wt% ESA provided the highest resistance to corrosion. Generally, a reduction in the corrosion rates were observed for the reinforced composites as the wt% of RHA increased. Porosity levels of the composites reduced with an increase in the percentage of ESA in the matrix. Microstructural characterization using SEM and OM revealed a distribution of pits on the composite surfaces which was more severe with increasing RHA percentage. The UTS (ultimate tensile stress) results revealed that the composite containing 10 wt% RHA had the maximum value of 161 MPa. The results demonstrate that rice husk ash and eggshell ash can be useful in producing low cost Aluminium composites with improved corrosion resistance and tensile properties.

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