Potentiodynamic corrosion behavior and microstructural features of gas tungsten constricted arc (GTCA)-welded superalloy 718 joints

2021 ◽  
Vol 63 (12) ◽  
pp. 1116-1123
Author(s):  
Tushar Sonar ◽  
Visvalingam Balasubramanian ◽  
Thiruvenkatam Venkateswaran ◽  
Dhenuvakonda Sivakumar ◽  
Sergey Konovalov
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Laves Phase ◽  
Phase Precipitation ◽  
Phase Development ◽  
Gas Tungsten ◽  
Superior Corrosion Resistance ◽  
Current Pulsation ◽  
Better Than ◽  
Frequency Current

Abstract The gas tungsten constricted arc welding (GTCAW) process was used to join thin Su-718 alloy sheets to minimize alloying segregation and Laves phase precipitation in the fusion zone (FZ). The potentiodynamic corrosion behavior of GTCAW Su-718 alloy joints was studied and correlated to the microstructural features of welds. The potentiodynamic corrosion test was done in a 3.56 wt.-% NaCl solution to determine the corrosion rate of Su-718 alloy joints. The optical microscopy (OM) technique was used to analyze the microstructure of corroded weldments. The scanning electron microscopy (SEM) technique was used to study the Laves phase development in FZ. The SEM X-ray energy dispersive spectroscopy (EDS) technique was used to for elemental mapping of FZ. The corrosion resistance of Su-718 joints is inversely proportional to the precipitation of Laves phase in FZ. The GTCA welded Su-718 alloy joints disclosed superior corrosion resistance for the joints with lower Laves phase precipitation. It is correlated to the refining of FZ microstructure, which aids in minimizing the Laves phase precipitation. The joints with higher Laves phase precipitation revealed inferior corrosion resistance. It is attributed to coarsening of FZ microstructure, which raises the alloying segregation and leads to depletion of alloying elements in FZ. The dendritic core regions showed severe corrosion compared to the interdendritic regions. The corrosion resistance of GTCA welded Su-718 joints is better than that of CC-GTAW and PC-GTGAW joints and comparable to that of EBW and LBW joints. It refers to the arc constriction and high frequency current pulsation.

The Influence of Sn Addition on the Corrosion Behavior of Mg-5Al-1Zn Alloy

2009 ◽  
Vol 620-622 ◽  
pp. 153-156 ◽  
Author(s):  
Kyung Chul Park ◽  
Byung Ho Kim ◽  
Jong Jin Jeon ◽  
Yong Ho Park ◽  
Ik Min Park
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Volume Fraction ◽  
Secondary Phases ◽  
Nacl Solution ◽  
High Hydrogen ◽  
Hydrogen Overvoltage ◽  
Mg2sn Phase ◽  
Superior Corrosion Resistance

In the present work, the effect of Sn addition on the corrosion behavior of Mg–5Al–1Zn alloys was investigated. Microstructure, potentiodynamic polarization and immersion tests were carried out in 3.5% NaCl solution of pH 7.2 to estimate the corrosion behavior of AZ51 alloys with and without Sn addition. Mg17Al12 and Mg2Sn phases were mainly precipitated in inter-dendrite structures. With increasing the Sn content, the volume fraction of the Mg2Sn phase was increased and coarsening tendency was observed. The corrosion resistance was increased by Sn addition. Especially, the AZ51-5wt.%Sn alloy characterized the superior corrosion resistance among the four alloys. The Sn is known for a high hydrogen overvoltage and the secondary phases effectively formed the network structure, resulting in a drastically decreasing corrosion rate of AZ51 alloy.

Study on Corrosion Resistance of Cr-Containing P110 Steel

2013 ◽  
Vol 740 ◽  
pp. 608-611 ◽  
Author(s):  
Ming Hua Liang ◽  
Zhi Yong Pan ◽  
Xiang Zhang
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Local Corrosion ◽  
Effect Of Temperature ◽  
Corrosion Rates ◽  
P110 Steel ◽  
Better Than

The influence of Cr on corrosion behavior of P110 steel was studied in the simulated CO2 environment. The result demonstrated that the Cr cant change the effect of temperature on P110 steel. The corrosion rates of the two kinds of materials reached the peak at 90°C. The temperature has dual effects on corrosion, which caused the adhesive and productivity of corrosion product formed up 90°C are better than that formed below 90°C; The adding of Cr in the P110 steel can prohibit the local corrosion to occur.

Hot Corrosion Behavior of Sputtered Fe-Y Alloy Coatings with Different Y Contents

2011 ◽  
Vol 391-392 ◽  
pp. 1263-1267
Author(s):  
Guang Yan Fu ◽  
Jing Yu Chen ◽  
Qun Liu ◽  
Yong Su
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Alloy Coating ◽  
Good Adhesion ◽  
Corrosion Scale ◽  
Measurement Results ◽  
The Matrix ◽  
Better Than

Three Fe-Y alloy coatings with differernt kinds of Y contents were prepared on stainless steel by magnetron sputtering. The hot corrosion behavior of sputtered alloy coatings with Na2SO4 deposits at 800 °C was investigated by discontinuous weigh measurement. Results show that the sputtered Fe-Y alloy coatings exhibit good adhesion with the matrix of stainless steel, and the hot corrosion kinetic curves of the specimens approximately follow the parabolic rate law. The Fe oxides are the main substances in the corrosion scale, and the hot corrosion rate of the three Fe-Y alloy coatings increases as the Y content increases. Therefore, the hot corrosion resistance of Fe-15Y alloy coating is better than that of Fe-20Y or Fe-30Y alloy coating.

Corrosion Behavior of Die-Cast and Thixocast AXJ530 Magnesium Alloy in Chloride Medium

2006 ◽  
Vol 15-17 ◽  
pp. 449-454 ◽  
Author(s):  
Sofiene Amira ◽  
M. Shehata ◽  
Dominique Dubé ◽  
R. Tremblay ◽  
Edward Ghali
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Noise ◽  
Noise Analysis ◽  
Nacl Solution ◽  
Chloride Medium ◽  
Die Cast ◽  
Immersion Technique ◽  
Superior Corrosion Resistance

The corrosion behavior of AXJ530 magnesium alloy in 3.5% NaCl solution at 25°C and pH 7.25 has been studied. Die-cast and thixocast specimens were tested using constant immersion technique, potentiodynamic polarization measurements and electrochemical noise analysis. The microstructure of cast specimens and their surface aspect after corrosion tests were analysed and compared. The results show that thixocast specimens have the best corrosion resistance. Their superior corrosion resistance can be attributed mainly to the presence of large pre-existing α-Mg grains.

Corrosion of Valve Steels in Combustion Gases of Diesel Engines under Thermal Shock Conditions

2012 ◽  
Vol 323-325 ◽  
pp. 327-332 ◽  
Author(s):  
Zbigniew Grzesik ◽  
Krzysztof Adamaszek ◽  
Zbigniew Jurasz ◽  
S. Mrowec
Keyword(s):  
Corrosion Resistance ◽  
Thermal Shock ◽  
Corrosion Behavior ◽  
Diesel Engines ◽  
Chromium Concentration ◽  
Fuel Oil ◽  
Chromia Scale ◽  
Combustion Gases ◽  
Better Than ◽  
Component Addition

The corrosion behavior of four valve steels (X33CrNiMn23-8, X50CrMnNiNbN21-9, X53CrMnNiN20-8 and X55CrMnNiN20-8) in combustion gases of fuel oil, containing different bio-component concentrations of (5 and 10 wt. %) has been studied under thermal shock conditions. It has been found that the addition of bio-components to the fuel oil decreases the corrosion resistance of all steels under investigation, this effect being the stronger, the higher was the concentration of bio-component addition. It has been shown, that in spite of bio-component addition, the X33CrNiMn23-8 steel containing the highest chromium concentration, behaved much better than three remaining steels due to the formation of the highly protective chromia scale.

Effects of Nano-Al2O3p on Hot Corrosion Resistance of NiCoCrAlY Cladded Coatings

2013 ◽  
Vol 670 ◽  
pp. 65-69 ◽  
Author(s):  
H.Y. Wang ◽  
Dun Wen Zuo ◽  
X.F. Li ◽  
M.D. Wang ◽  
Y.P. Yu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Laser Cladding ◽  
Hot Corrosion ◽  
Influencing Mechanism ◽  
The One ◽  
Super Alloy ◽  
Better Than

Three NiCoCrAlY cladded coatings reinforced by different contents of nano- Al2O3p and one without nano-Al2O3p were prepared on a Ni-base super alloy using laser cladding technique. Hot corrosion of the NiCoCrAlY coatings in Na2SO4/K2SO4 (75:25, wt. /wt.) mixture was performed at 1050 °C in static air. The effects and influencing mechanism of nano-Al2O3p on the hot corrosion behavior of the coatings were discussed. Results indicate that the hot corrosion resistance of the coatings with nano-Al2O3p is better than that of the one without nano-Al2O3p, among which the one with 1.0 wt. % nano-Al2O3p presented the best hot corrosion resistance. The improvement of the hot corrosion resistance is largely due to the refinement of the microstructure after adding nano-Al2O3p.

EFFECT OF SCANDIUM ON THE CORROSION BEHAVIOR OF THE CASTING Al-Cu ALLOYS IN NACL SOLUTION

2009 ◽  
Vol 23 (06n07) ◽  
pp. 978-983 ◽  
Author(s):  
WENGUI ZHAO ◽  
JINGUO WANG ◽  
JINGQI HOU ◽  
QICHUAN JIANG
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Measurement ◽  
Immersion Test ◽  
Nacl Solution ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Sc Addition ◽  
Equiaxed Grains ◽  
Better Than

Corrosion behavior of the casting Al - Cu alloys with and without Sc addition was studied by both the immersion test and electrochemical measurement methods. The results show that pitting corrosion was found on the surfaces of these alloys in 3.5 wt .% NaCl solution, while the corrosion resistance of the Al - Cu alloys with Sc is better than that of the Al - Cu alloy without Sc . With increasing Sc content, the corrosion resistance of the present Al - Cu alloys varies significantly, and the 0.1 wt .% Sc alloy has the best corrosion resistance. Also, the corrosion potential of the present alloys with Sc is shifted positively compared with that of the alloy without Sc by electrochemical measurement, indicating that the alloys with Sc have better corrosion resistance. The microstructures of the Al - Cu alloys change from the coarse grains to the fine equiaxed grains due to Sc addition, which is responsible for the reduced susceptibility to corrosion and the enhanced corrosion resistance of the present alloys.

Corrosion Behavior of Anodic Films Formed on Aluminium 7A04 Alloy in Boric/Sulphuric Mixed Acid and in Chromic Acid

2011 ◽  
Vol 399-401 ◽  
pp. 95-98
Author(s):  
Shan Deng ◽  
Lei Xu ◽  
Qiu Ze Li ◽  
Xing Min Huang ◽  
Shu Lin Liang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Film ◽  
Corrosion Behavior ◽  
Copper Sulfate ◽  
Chromic Acid ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Anodic Films ◽  
Mixed Acid ◽  
Better Than

The corrosion behavior of the anodic oxide film on aluminium 7A04 alloy is investigated in current paper, where the different anodic oxide films are prepared. Morphology observation on different anodic films is carried out by using laser confocal microscopy (LCM) and copper sulfate test. Meanwhile, the electrochemical properties are evaluated through using electrochemical impedance spectroscopy (EIS). The LCM observation shows that the anodic oxide film formed in boric/sulphuric mixed acid is uniform with porous appearance, while the anodic oxide film formed in chromic aid is nonporous one but defective. The copper sulfate test results show that the corrosion regions almost developed from micropores in strong corrosive media. The evaluation of EIS in NaCl solution demonstrates that the corrosion resistance of specimen with anodic oxide film is much better than that without film. Furthermore, the corrosion resistance of anodic film formed in boric/sulphuric mixed acid is better than that formed in chromic acid.

The Corrosion Behavior of Ni-P/SiC Composite Coating

2011 ◽  
Vol 291-294 ◽  
pp. 215-218 ◽  
Author(s):  
Gui Rong Yang ◽  
Wen Ming Song ◽  
Xian Ming Sun ◽  
Ying Ma ◽  
Yuan Hao
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Acid Solution ◽  
Composite Coating ◽  
Corrosion Behavior ◽  
Alkaline Solution ◽  
Chemical Deposition ◽  
Increasing Temperature ◽  
Electroless Ni ◽  
Better Than

The Ni-P/SiC composite coating was prepared by chemical deposition technique. The corrosion behavior of electroless Ni-P/SiC composite coating was investigated. The results show that the corrosion resistance of electroless composite coating decreased with the increasing SiC concentration in bath solution. There were some little pores among the composite coating and the pores would increased with the increasing SiC content among the coating, which made the corrosion resistance decreased. The corrosion rate increased with the increasing temperature of corrosion liquid. The corrosion resistance was improved for T gradient electroless Ni-P/SiC composite coating comparing with the single electroless composite coating whether the corrosion solution was acid solution or alkaline solution. The corrosion rate were less than 5 mg/cm2for all specimens in alkaline solution, which indicated that the corrosion resistance of electroless composite coating was better than that in acid solution.

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