Effect of Microstructure Evolution on Corrosion Behavior of Friction Stir Welded Joint for 2195-T8 Alloy

CORROSION ◽  
10.5006/3567 ◽  
2020 ◽  
Vol 76 (12) ◽  
Author(s):  
B.Y. Hu ◽  
H. Zhang ◽  
L.Y. Liu ◽  
D.B. Liu ◽  
A.H. Feng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Galvanic Corrosion ◽  
Open Circuit ◽  
Nugget Zone ◽  
Friction Stir ◽  
Free Zone ◽  
Transmission Electron

Corrosion behavior of friction stir welded 2195-T8 Al-Cu-Li alloy has been studied. Immersion and electrochemical open-circuit potential (OCP) test were applied. The microstructure and precipitates evolution in different zones were investigated by scanning electron microscopy, stereoscope, and transmission electron microscopy. The corrosion tests showed that the sequence of corrosion resistance of each area of the joint is: welding nugget zone (WNZ) > base metal > heat affected zone (HAZ). The WNZ showed highest corrosion resistance due to the fine recrystallized grains, the dissolution of T1(Al2CuLi) phase, and the refined and evenly-distributed particles in this area. However, the HAZ had the lowest corrosion resistance due to the intergranular precipitates, deleterious precipitate-free zone (PFZ), S′ (Al2CuMg) phase, and the galvanic corrosion couples formed among T1, θ′, and PFZ.

CORROSION PROPERTIES OF CRYOROLLED AA2219 FRICTION STIR WELDED JOINTS USING DIFFERENT TOOL PIN PROFILES

2018 ◽  
Vol 25 (03) ◽  
pp. 1850071 ◽  
Author(s):  
K. KAMAL BABU ◽  
K. PANNEERSELVAM ◽  
P. SATHIYA ◽  
A. NOORUL HAQ ◽  
S. SUNDARRAJAN ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Welded Joints ◽  
Weld Nugget ◽  
Corrosion Properties ◽  
X Ray ◽  
Friction Stir ◽  
Transmission Electron ◽  
Aa2219 Alloy ◽  
Tool Pin

The purpose of this paper is to present the corrosion behavior of the Cryorolled (CR) material and its Friction Stir Welded joints. Due to the thermal cycles of Friction Stir Welding (FSW) process, the corrosion behavior of the material gets affected. Here, the cryorolling process was carried out on AA2219 alloy and CR material was joined by FSW process using four different pin tool profiles such as cylindrical, threaded cylindrical, square and hexagonal pin. The FSW joints were analyzed by corrosion resistance with the help of potentiodynamic polarization test with 3.5% NaCl solution. From the analysis, it is found that CR AA2219 material exhibits good corrosion resistance compared to the base AA2219 material, and also a hexagonal pin profile FSW joint exhibits high corrosion resistance. Among the weld joints created by four different tools, the lowest corrosion resistance was found in the cylindrical pin tool FSW welds. Further, the corroded samples were investigated through metallurgical investigations like OM, Transmission Electron Microscopy (TEM), Energy-Dispersive X-ray Spectroscopy (EDX) and X-Ray Diffraction (XRD). It was found that the amount of dissolution of Al2Cu precipitate was present in the weld nugget. The amount of dissolution of Al2Cu precipitate is higher in the weld nugget produced by hexagonal pin tool. This is due to the enhancement of the corrosion resistance.

Corrosion Resistance of Modified Silane Films Formed on AZ31 Magnesium Alloys

2011 ◽  
Vol 686 ◽  
pp. 21-25
Author(s):  
Xian Long Cao ◽  
Fu Sheng Pan ◽  
Hong Da Deng ◽  
Wei Cai
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Open Circuit ◽  
Chloride Ions ◽  
Cerium Nitrate ◽  
Az31 Magnesium Alloy ◽  
Sodium Chloride Solutions

This present work investigated the corrosion behavior of AZ31 magnesium alloy substrates pre-treated with bis-[triethoxysilylpropyl] tetrasulfide silane modified with cerium nitrate. The corrosion behavior of the pre-treated substrates in 0.005M sodium chloride solutions was assessed by potentiodynamic polarization, open circuit potential and electrochemical impedance spectroscopy (EIS). The results showed that the silane pre-treatments improved the corrosion resistance of the AZ31 magnesium alloy substrates in the presence of chloride ions. Especially the addition of cerium nitrate played an important role in reducing the corrosion activity.

scholarly journals Corrosion Behavior of Cold-Formed AA5754 Alloy Sheets

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 394
Author(s):  
Anna Dobkowska ◽  
Agata Sotniczuk ◽  
Piotr Bazarnik ◽  
Jarosław Mizera ◽  
Halina Garbacz
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Open Circuit ◽  
Alloy Sheet ◽  
Original Form ◽  
Coarse Particles ◽  
Electrochemical Polarization ◽  
Transmission Electron ◽  
Complex Process ◽  
Corrosion Mechanisms

In this work, the influence of bending an AA5457 alloy sheet and the resulting microstructural changes on its corrosion behavior was investigated. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to perform detailed microstructural analyses of the alloy in its original form and after bending. After immersion in naturally-aged NaCl under open-circuit conditions (0.5 M, adjusted to 3 by HCl), post-corrosion observations were made, and electrochemical polarization measurements were performed to investigate the corrosion mechanisms occurring on both surfaces. The results showed that the corrosion of AA5457 is a complex process that mainly involves trenching around coarse Si-rich particles, crystallographically-grown large pits, and the formation of multiple tiny pits around Si-rich nanoparticles. The experimental data showed that bending AA5457 changed the shape and distribution of Si-rich coarse particles, cumulated a higher dislocation density in the material, especially around Si-rich nanoparticles, and all of these factors caused that corrosion behavior of the AA5754 in the bending area was lowered.

scholarly journals Roles of Alloying Elements on the Corrosion Behavior of Amorphous W–Zr–(15–33)Cr Alloys in 1 M NaOH Solution

1970 ◽  
Vol 25 ◽  
pp. 93-100
Author(s):  
Raju Ram Kumal ◽  
Jagadeesh Bhattarai
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Chromium Content ◽  
Chemical Society ◽  
Immersion Test ◽  
Open Circuit ◽  
Corrosion Rates ◽  
Naoh Solution ◽  
Zirconium Metal

Roles of alloy-constituting elements on the corrosion behavior of the sputter-depositedamorphous W-Zr-(15-33)Cr alloys was studied in 1 M NaOH solution open to air at 25°Cusing corrosion tests and open circuit potential measurements. Zirconium and chromiummetals act synergistically with tungsten in enhancing the corrosion resistance of the sputterdepositedamorphous W-Zr-Cr alloys containing 15-33 at % chromium content so as toshow higher corrosion resistance than those of alloy-constituting elements in 1 M NaOHsolution. The corrosion rates of the amorphous W-Zr-(15-33)Cr alloys containing 9-33 at %tungsten are in the ranges of 2.0-5.0×10-3 mm.y-1 after immersion for 240 h in 1 M NaOHsolution which is about two orders of magnitude lower corrosion rates lower than that oftungsten and even slightly lower than that of the zirconium metal. The simultaneousadditions of zirconium and chromium metals in W-Zr-(15-33)Cr alloys are effective forennoblement of the open circuit potential of the tungsten metal.Keywords: W-Zr-Cr alloys, corrosion resistance, immersion test, open circuit potential, 1 MNaOH.DOI:  10.3126/jncs.v25i0.3312Journal of Nepal Chemical Society Volume 25, 2010 pp 93-100

Corrosion Behavior of Electroless Deposited Fe-Zn Coating

2011 ◽  
Vol 117-119 ◽  
pp. 81-84
Author(s):  
Xi Ran Wang ◽  
Jing Wu ◽  
Xin Gang Hu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Corrosion Current ◽  
Open Circuit ◽  
Nacl Solution ◽  
Positive Direction ◽  
Heat Treated ◽  
Heat Treated Temperature ◽  
Electronic Microscope

In this work, Fe-Zn coating on copper is obtained by electroless plating. The surface mor -phologies and composition of the coatings has been investigated using scanning electronic microscope (SEM) and energy dispersive spectroscopy(EDS). Corrosion behavior of Fe-Zn coating in3.5% NaCl solution is gaved a further insight. The impedance diagram indicates that corrosion resistance of coating is better. The open circuit potential of Fe-Zn coating is at about -1V. Self-corrosion potential of Fe-Zn coating in 3.5%NaCl solution shifts in the positive direction first and then shifts from -0.622V to -0.603V with increasing heat-treated temperature, while corresponding self-corrosion current decreases at first and then. increases Corrosion resistance of coating is the best when heat-treated temperature is 300°C.

scholarly journals The Corrosion Behavior of Sputter?deposited W?xTa Alloys in 0.5 M NaCl Solution

2013 ◽  
Vol 14 (1) ◽  
pp. 103-108
Author(s):  
Jagadeesh Bhattarai ◽  
Susil Baral
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Nacl Solution ◽  
High Corrosion Resistance ◽  
Positive Direction ◽  
Sputter Deposited

The corrosion behavior of the sputter–deposited amorphous and nanocrystalline W–xTa (x = 8–77) alloys was studied in 0.5 M NaCl solution open to air at 25°C using corrosion tests and electrochemical measurements. Tungsten and tantalum metals act synergistically in enhancing the corrosion resistance of the sputter–deposited W–xTa alloys and hence additions of 23 at. % of tantalum or more to the sputter–deposited W–xTa alloys were found to be effective to achieve significantly high corrosion resistance properties of the alloys than those of alloy– constituting elements. In particular, the corrosion rate of the W–60Ta alloy showed the lowest corrosion rate (that is, 2.0×10-3). The open circuit potential of the alloys shifted noble (positive) direction with immersion time. Addition of tantalum metal in W–xTa alloys is effective for ennoblement of the open circuit corrosion potential of the tungsten metal in 0.5 M NaCl solution open to air at 25°C. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 103-108 DOI: http://dx.doi.org/10.3126/njst.v14i1.8929

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

scholarly journals Corrosion Behavior and Galvanic Corrosion Resistance of WC and Cr3C2 Cermet Coatings in Madeira River Water

2021 ◽  
Author(s):  
Leonardo Augusto Luiz ◽  
Juliano de Andrade ◽  
Camila Melo Pesqueira ◽  
Irene Bida de Araújo Fernandes Siqueira ◽  
Gustavo Bavaresco Sucharski ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
River Water ◽  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Cermet Coatings ◽  
Madeira River

scholarly journals Investigation of Zirconium Effect on the Corrosion Resistance of Aluminum Alloy Using Electrochemical Methods and Numerical Simulation in an Acidified Synthetic Sea Salt Solution

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1982 ◽  
Author(s):  
Yong-Sang Kim ◽  
Jong Park ◽  
Byeong-Seon An ◽  
Young Lee ◽  
Cheol-Woong Yang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Galvanic Corrosion ◽  
Sea Salt ◽  
Al Alloy ◽  
Alloying Element ◽  
Intermetallic Particles ◽  
Transmission Electron ◽  
Corrosion Simulation

Corrosion resistance of Zr that has been added to an Al alloy (U1070) is higher than that of a commercial Al alloy (A1070). A decreasing number and size of Al3Fe intermetallic particles (IMPs) were observed by electron microprobe analysis and transmission electron microscopy. Based on the numerical corrosion simulation, it was confirmed that decreasing the number and size of IMPs was favorable for improving the corrosion resistance of the Al alloy due to the reduction of the galvanic effect. In addition, Al3Zr was found to be insignificant in promoting galvanic corrosion within the Al matrix. Thus, Zr is an advantageous alloying element for improving the corrosion resistance of the Al alloy.

Study of Corrosion Behavior of Conventional and Nanostructured WC-Co HVOF Sprayed Coats

2010 ◽  
Vol 64 ◽  
pp. 13-18 ◽  
Author(s):  
Shahin Khameneh Asl ◽  
Mohammad Reza Saghi Beyragh ◽  
Mahdi Ghassemi Kakroudi
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Heat Treating ◽  
Crystalline Phases ◽  
Chemical Test ◽  
Transmission Electron ◽  
Hvof Spray ◽  
Wear And Corrosion Resistance

Interest in nanomaterials has increased in recent years. This is due to the potential of size reduction to nanometric scale to provide properties of materials such as hardness, toughness, wear, and corrosion resistance. The current study is focused on WC-Co cermet coats, materials that are extensively used in applications requiring wear resistance. In this work, WC-17Co powder was thermally sprayed onto mild steel using High Velocity Oxy Fuel (HVOF) spray technique. The nanostructured specimen was produced from sprayed sample by heat-treating at 1100°C in a vacuum chamber. Their structures were studied by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Polarization and electrochemical impedance spectroscopy (EIS) tests were performed on the both types of coated samples in 3.5% NaCl solution. The amorphous phase in WC-17Co coating was transformed to crystalline phases by heat treatment at high temperatures. The heat treatment of these coatings at high temperature also resulted in partially dissolution of WC particles and formation of new crystalline phases. Generation of these phases produced the nanostructured coating with better mechanical properties. Comparative electro chemical test results showed that, the heat treatment could improve corrosion resistance of the nanostructured WC-17Co coat than the as sprayed coats.

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