scholarly journals Evaluation of Structure and Corrosion Behavior of FeAl Alloy after Crystallization, Hot Extrusion and Hot Rolling

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2041
Author(s):  
Janusz Cebulski ◽  
Dorota Pasek ◽  
Bartosz Chmiela ◽  
Magdalena Popczyk ◽  
Andrzej Szymon Swinarew ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Hot Rolling ◽  
Cast Alloy ◽  
Rolling Direction ◽  
Extrusion Direction ◽  
Electrochemical Corrosion ◽  
Hot Extrusion ◽  
Corrosion Current ◽  
Plastic Working ◽  
Ingot Axis

The paper presents the results of tests on the corrosion resistance of Fe40Al5Cr0.2TiB alloy after casting, plastic working using extrusion and rolling methods. Examination of the microstructure of the Fe40Al5Cr0.2TiB alloy after casting and after plastic working was performed on an Olympus GX51 light microscope. The stereological relationships of the alloy microstructure in the state after crystallization and after plastic working were determined. The quantitative analysis of the structure was conducted after testing with the EBSD INCA HKL detector and the Nordlys II analysis system (Channel 5), which was equipped with the Hitachi S-3400N microscope. Structure tests and corrosion tests were performed on tests cut perpendicular to the ingot axis, extrusion direction, and rolling direction. As a result of the tests, it was found that the crystallized alloy has better corrosion resistance than plastically processed material. Plastic working increases the intensity of the electrochemical corrosion of the examined alloy. It was found that as-cast alloy is the most resistant to corrosion in a 5% NaCl compared with the alloys after hot extrusion and after hot rolling. The parameters in this study show the smallest value of the corrosion current density and corrosion rate as well as the more positive value of corrosion potential.

The influence of hot extrusion deformation on microstructure evolution, tensile properties and corrosion behavior of Mg–3Al–0.5Mn–0.5Sr alloy

2020 ◽  
Vol 10 (3) ◽  
pp. 325-336
Author(s):  
Xia Shen ◽  
Tiancai Xu ◽  
Boxin Li
Keyword(s):  
Tensile Strength ◽  
Corrosion Resistance ◽  
Yield Strength ◽  
Tensile Properties ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Corrosion Current ◽  
Tensile Tests ◽  
Original Structure ◽  
Corrosion Morphology

A novel microalloyed Mg–3Al–0.5Mn–0.5Sr (AMJ300) alloy was designed and prepared. Then the original structure of as-cast alloy was optimized by hot extrusion. The influence of extrusion on microstructure, corrosion and tensile properties of as-cast AMJ300 alloy were studied by OM, SEM, EDS, XRD, TEM, electrochemical workstation and tensile tests. The results indicated that α-Mg, Al8Mn5 and Al4Sr phases constitute the AMJ300 alloy. Furthermore, the microstructure of alloy was further refined after extrusion, which indicates that the microstructural evolution during extrusion was governed by dynamic recrystallization. The fine and close of structure and the morphology change of intermetallic compounds greatly improved the corrosion resistance of AMJ300 alloy. The results of corrosion rate, corrosion current and corrosion morphology showed that the corrosion resistance of as-cast alloy could be significantly improved by extrusion. The main corrosion products of AMJ300 alloy in 3.5 wt.% NaCl solution was Mg(OH)2. After extrusion, the tensile properties of AMJ300 alloy was significantly improved. The tensile strength reached 349 MPa, the yield strength reached 229 MPa, and the elongation reached 13.2%. Compared with the as-cast alloy, the tensile strength, the yield strength and the elongation increased by 218.1%, 248.9% and 173.7% respectively

scholarly journals Effect of Cooling Rate at the Eutectoid Transformation Temperature on the Corrosion Resistance of Zn-4Al Alloy

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1703
Author(s):  
Marzena M. Lachowicz ◽  
Robert Jasionowski
Keyword(s):  
Corrosion Resistance ◽  
Cooling Rate ◽  
Cast Alloy ◽  
Corrosion Current ◽  
Electrochemical Studies ◽  
Eutectoid Transformation ◽  
Nacl Solution ◽  
Α Phase ◽  
Initial Stage ◽  
Alloy Microstructure

The main purpose of this work was to experimentally determine the effect of the cooling rate during the eutectoid transformation on the corrosion resistance of a hypoeutectic Zn-4Al cast alloy in 5% NaCl solution. This was considered in relation to the alloy microstructure. For this purpose, metallographic and electrochemical studies were performed. It was found that the faster cooling promoted the formation of finer (α + η) eutectoid structures, which translated into a higher hardness and lower corrosion current density. In the initial stage of corrosion processes the eutectoid structure in the eutectic areas were attacked. At the further stages of corrosion development, the phase η was dissolved, and the α phase appears to be protected by the formation of corrosion products.

Corrosion Resistance of Rare Earth Modified Chromizing Coating on P110 Oil Casing Tube Steel by Pack Cementation

2009 ◽  
Vol 79-82 ◽  
pp. 1075-1078
Author(s):  
Nai Ming Lin ◽  
Fa Qin Xie ◽  
Tao Zhong ◽  
Xiang Qing Wu ◽  
Wei Tian
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Steel Substrate ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Pack Cementation ◽  
Tube Steel ◽  
X Ray ◽  
Immersion Corrosion ◽  
P110 Steel

The rare earth (RE) modified chromizing coating was obtained on P110 oil casing tube steel (P110 steel) substrate by means of pack cementation technique to enhance the resistance against corrosion of P110 steel. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) were employed to research microstructure, composition distribution and phase constitution of the chromizing coating. The effect of minor addition of RE on the microstructure of chromizing was discussed. Corrosion resistance of chromizing coating was investigated and compared with that of bare P110 steel via electrochemical corrosion and immersion corrosion in simulated oilfield brine solution, respectively. The results showed that a uniform, continuous and compact coating was formed on P110 steel. The coating with RE addition was more compact than that of the coating added no RE, and a small amount of RE addition could promote the chromizing procedure notably. From SEM and EDX investigation, it had been confirmed that the coating was composed of two different layers, an out layer and an inner layer; the coating mainly contains Fe and Cr; the concentration of Cr decreased as the distance from the surface increased, yet Fe presented the inverse trend. XRD analysis indicated the coating was built up by (Cr, Fe)23C6 referring to the out layer, (Cr, Fe)7C3, Cr7C3 and α-(Cr, Fe) corresponding to the inner layer. Electrochemical corrosion consequence was obtained as follows: the self-corroding electric potential of chromizing coating was higher, and the corrosion current density was lower than that of bare P110 steel, which revealed that chromizing coating had better anti-corrosion performance; immersion corrosion results demonstrated the mass loss of chromized P110 steel was lower, and this meant that chromizing coating had a better corrosion resistance than that of bare P110 steel on the experimental condition. A compact (Cr, Fe)xCy coating can be fabricated by pack cementation technique. As a result of minor RE addition, microstructure and corrosion resistance of the chromizing coating are improved obviously.

Ceria Coatings Prepared by Sol-Gel Approach on AZ91 Magnesium Alloy

2017 ◽  
Vol 898 ◽  
pp. 1369-1380 ◽  
Author(s):  
Hui Min Han ◽  
Dan Tong Wang ◽  
Hua Qian Yu ◽  
Min Zuo ◽  
Li Hong Wang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Sol Gel ◽  
Electrochemical Corrosion ◽  
Chemical Conversion ◽  
Corrosion Current ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

The ceria coatings on AZ91 substrates were successfully synthesized by chemical conversion and the corrosion resistance of AZ91 samples with and without ceria coatings were evaluated by means of electrochemical corrosion in 3.5 wt.% NaCl solution. According to the parameters derived from the polarization date, the Icorr (the corrosion current density) values of the coated samples are smaller than that of bare one, indicating that the corrosion resistance of AZ91 alloys has been improved to some extent. The influence of fluoridated pretreatment, inter-layer heat treatment, sintering temperature and the layer of films on the performance of ceria coatings were also investigated. It was found that the inter-layer heat treatment has no influence on improving the anticorrosion resistance of AZ91 alloy. In comparison with the bare one, the Icorr of optimal sample is about 0.0219mA/cm2, which decreases by two orders of magnitude, indicating that the ceria coatings could significantly improve the corrosion resistance of AZ91 magnesium alloy.

scholarly journals Effect of Current Density on the Performance of Ni–P–ZrO2–CeO2 Composite Coatings Prepared by Jet-Electrodeposition

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 616
Author(s):  
Zhaoyang Song ◽  
Hongwen Zhang ◽  
Xiuqing Fu ◽  
Jinran Lin ◽  
Moqi Shen ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Current Density ◽  
Composite Coatings ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
X Ray Diffraction ◽  
X Ray ◽  
Jet Electrodeposition ◽  
Electrochemical Corrosion Resistance

The objective of this study was to improve the surface properties, hardness, wear resistance and electrochemical corrosion resistance of #45 steel. To this end, Ni–P–ZrO2–CeO2 composite coatings were prepared on the surface of #45 steel using the jet-electrodeposition technique by varying the current density from 20 to 60 A/dm2. The effect of current density on the performance of the composite coatings was evaluated. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) were applied to explore the surface topography, elemental composition, hardness and electrochemical corrosion resistance of the composite coatings. The results showed that with the increase in the current density, the hardness, wear resistance, and electrochemical corrosion resistance tends to increase first and then decrease. At a current density of 40 A/dm2, the hardness reached a maximum of 688.9 HV0.1, the corrosion current reached a minimum of 8.2501 × 10−5 A·cm−2, and the corrosion potential reached a maximum of −0.45957 V. At these values, the performance of the composite coatings was optimal.

Effect of High-Intensity Pulsed Ion Beam Irradiation on the Electrochemical Corrosion Behavior of AZ31 Magnesium Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 571-574
Author(s):  
Peng Li
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Current Density ◽  
Ion Beam ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Electrochemical Corrosion Behavior ◽  
Shot Number

HIPIB irradiation experiment is carried out at a specific ion current density of 1.1 J/cm2 with shot number from one to ten in order to explore the effect of shot number on electrochemical corrosion behavior of magnesium alloy. Surface morphologies, microstructure and corrosion resistance of the irradiated samples are examined by scanning electron microscopy (SEM), transmission electron microscope (TEM) and potentiodynamic polarization technique, respectively. It is found that HIPIB irradiation leads to the increase in open circuit potential, corrosion potential and breakdown potential, and the decrease in the corrosion current density and the corrosion rate as compared to the original sample. The improved corrosion resistance is mainly attributed to the grain refinement and surface purification induced by HIPIB irradiation.

Enhancement Corrosion Resistance of (3–Glycidoxylpropyl)- Silsesquioxane Hybrid Films and its Validation by Gas-Molecule Diffusion Coefficients Using MD Simulation

2009 ◽  
Vol 610-613 ◽  
pp. 190-197
Author(s):  
Gang Xie ◽  
Peng Wang ◽  
Li Jiang Hu
Keyword(s):  
Corrosion Resistance ◽  
Diffusion Coefficients ◽  
Md Simulation ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Hybrid Films ◽  
Self Diffusion ◽  
Three Samples ◽  
Unit Cells ◽  
Electrochemical Corrosion Resistance

Based on silsesquioxanes (SSO) derived from hydrolytic condensation of (–glycidoxylpropyl) trimethoxysilane (GPMS) and tetraethoxysilane (TEOS), two hybrid films, f-GPMS-TEOS-SSO (f-GTS) modified with 10 wt-% TEOS and f-GTS modified with 50 wt-% DGEBA (f-GTSD), were prepared. The anticorrosion properties (corrosion potential, Ecorr, and corrosion current density, Icorr) of the bare aluminum alloy (AA) and the two films on AA were tested by electrochemical measurements with typical potentiodynamic polarization curves. The Icorr values of three samples were significantly different with the order of f-GTSD<f-GTS<AA， which implies that the DGEBA addition in the f-GTSD coating indeed enhances the electrochemical corrosion resistance. Two different 3D-amorphous cubic unit cells, cell(f-GTS) and cell(f-GTSD), as models were employed to investigate self-diffusion coefficients by MD simulation for the NO2, SO2 and H2O molecules. All the three self-diffusion coefficients of NO2, SO2 and H2O diffusing in cell(f-GTSD) were less than the coefficients in cell(f-GTS), which validates the corresponding anticorrosion-experiment results. Two reasons that the addition of DGEBA in the system of f-GTS lead to the decrease of the gas self-diffusion coefficient compared to the f-GTS system were discussed.

Effects of alkaline zinc bath formulations on electrochemical corrosion behavior of electrogalvanized coatings

CORROSION ◽  
10.5006/3760 ◽  
2021 ◽  
Author(s):  
Thanyalux Wanotayan ◽  
Tongjai Chookajorn ◽  
Sirikarn Sattawitchayapit ◽  
Piya Khamsuk ◽  
Kanokwan Saengkiettiyut ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Electrochemical Impedance ◽  
Texture Coefficient ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Plating Bath ◽  
Zinc Plating ◽  
Electrochemical Corrosion Behavior ◽  
Zinc Coatings

The effects of alkaline non-cyanide zinc plating bath formulation on the plating characteristics and deposit properties are investigated. Scanning electron microscope and X-ray diffractometer are used to study the surface morphology and texture of the zinc deposits respectively. Uniform and compact coatings with a dominant (110) texture are obtained for all of the bath formulations. Nevertheless, significant differences in surface morphology and relative preferences for the (110) and (100) planes were found to result from the concentrations of zinc and sodium hydroxide in the bath. Electrochemical impedance spectroscopy and potentiodynamic polarization scan were employed to evaluate the corrosion resistance. The coatings with a moderate Zn (8-11 g/L) and controlled NaOH (120 g/L) contents show good corrosion resistance, with the corrosion current and corrosion rate being the lowest at 8 g/L of Zn and 120 g/L of NaOH. The ratio of texture coefficient, morphology, and compressive residual stress from different bath composition contribute to the corrosion resistant property. The findings from this work should provide useful information of electrogalvanized zinc coatings with enhanced corrosion resistance.

The Preparation of Coatings with Codepositon Plating on A3 Steel and its Corrosion Resistance

2010 ◽  
Vol 150-151 ◽  
pp. 1034-1038
Author(s):  
Shang Dong Chen ◽  
Ting Sun ◽  
Hong Nian
Keyword(s):  
Corrosion Resistance ◽  
Polarization Resistance ◽  
Polarization Effect ◽  
Corrosion Potential ◽  
Steel Substrate ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Plain Carbon Steel ◽  
Cathode Polarization ◽  
Electrochemical Corrosion Behavior

A new method for preparation of coatings with codeposition plating on the ordinary A3 steel and heat treatment later. Research the coatings on electrochemical corrosion behavior variation in Q-sun. Results show that corrosion potential shuffle, corrosion current density reduced nearly two number magnitudes value, polarization resistance increased, the cathode polarization effect enhanced obviously in polarization curves, and self-corrosion current reduced, impedance increased twenty times in alternating current impedance atlas than A3 steel substrate without coatings. It was indicated that the coating improve effectively the corrosion resistance of plain carbon steel.

scholarly journals Influence of Element Penetration Region on Adhesion and Corrosion Performance of Ni-Base Coatings

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 895
Author(s):  
Xiuqing Fu ◽  
Zhenyu Shen ◽  
Xinxin Chen ◽  
Jinran Lin ◽  
Hongbing Cao
Keyword(s):  
Corrosion Resistance ◽  
Laser Scanning ◽  
Adhesion Force ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Scratch Test ◽  
Laser Scanning Confocal Microscopy ◽  
Scanning Confocal Microscopy ◽  
Steel Substrates ◽  
Sic Coatings

In this study, Ni–P/Ni–P–SiC coatings were prepared on pretreated 45 steel substrates by scanning electrodeposition. Prior to the electrodeposition, the substrates were subjected to two types of pretreatments: polishing and sandblasting. The 3D morphology of the pretreated substrates was characterized by laser scanning confocal microscopy. The micromorphology and section morphology of the coating surface were characterized by field emission scanning electron microscopy. The section element composition was characterized using an EDS energy spectrum analyzer. The adhesion and corrosion resistance of 15 coatings were analyzed using an automatic scratch tester and CS350 electrochemical workstation. The results showed the presence of an element penetration region between the coating and the substrate. The sandblasting pretreatment and SiC nanoparticle addition helped widen the penetration region of the elements. The Ni–P–SiC coating prepared by scanning electrodeposition on the sandblasted substrate exhibited the thickest penetration region, up to 28.39 µm. A scratch test conducted on this coating showed that it exhibits the best adhesion force, up to 36.5 N. In electrochemical corrosion experiments, its corrosion potential was found to be the highest, reaching −0.30 V, and the corrosion current density was the lowest, reaching 8.45 × 10−7 A·cm−2. The presence of the element penetration region increased the coating adhesion and improved the corrosion resistance.

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