scholarly journals Effects of LaAlO3 and La2O2S inclusions on the initialization of localized corrosion of pipeline steels in NaCl solution

2020 ◽  
Vol 177 ◽  
pp. 151-156 ◽  
Author(s):  
Yanhui Hou ◽  
Gang Xiong ◽  
Linli Liu ◽  
Guangqiang Li ◽  
Nele Moelans ◽  
...  
Keyword(s):  
Localized Corrosion ◽  
Nacl Solution ◽  
Pipeline Steels

Mechanism of Yttrium composite inclusions on the localized corrosion of pipeline steels in NaCl solution

Micron ◽  
2020 ◽  
Vol 130 ◽  
pp. 102820 ◽  
Author(s):  
Yanhui Hou ◽  
Tengfei Li ◽  
Guangqiang Li ◽  
Changgui Cheng
Keyword(s):  
Localized Corrosion ◽  
Nacl Solution ◽  
Pipeline Steels

Radial Spreading of Localized Corrosion-Induced Selective Leaching on α-Brass in Dilute NaCl Solution

CORROSION ◽  
10.5006/0611 ◽  
2013 ◽  
Vol 69 (5) ◽  
pp. 468-476 ◽  
Author(s):  
Mattias Forslund ◽  
Christofer Leygraf ◽  
Changjian Lin ◽  
Jinshan Pan
Keyword(s):  
Localized Corrosion ◽  
Selective Leaching ◽  
Nacl Solution ◽  
Radial Spreading

scholarly journals Assessment of nickel titanium and beta titanium corrosion resistance behavior in fluoride and chloride environments

2013 ◽  
Vol 83 (5) ◽  
pp. 864-869 ◽  
Author(s):  
Elisa J. Kassab ◽  
José Ponciano Gomes
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Fluoride Concentration ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
General Corrosion ◽  
Nacl Solution ◽  
Galvanic Coupling ◽  
Beta Titanium

ABSTRACT Objective: To assess the influence of fluoride concentration on the corrosion behavior of nickel titanium (NiTi) superelastic wire and to compare the corrosion resistance of NiTi with that of beta titanium alloy in physiological solution with and without addition of fluoride. Materials and Methods: NiTi corrosion resistance was investigated through electrochemical impedance spectroscopy and anodic polarization in sodium chloride (NaCl 0.15 M) with and without addition of 0.02 M sodium fluoride (NaF), and the results were compared with those associated with beta titanium. The influence of fluoride concentration on NiTi corrosion behavior was assessed in NaCl (0.15 M) with and without 0.02, 0.04, 0.05, 0.07, and 0.12 M NaF solution. Galvanic corrosion between NiTi and beta titanium were investigated. All samples were characterized by scanning electron microscopy. Results: Polarization resistance decreased when NaF concentration was increased, and, depending on NaF concentration, NiTi can suffer localized or generalized corrosion. In NaCl solution with 0.02 M NaF, NiTi suffer localized corrosion, while beta titanium alloys remained passive. Current values near zero were observed by galvanic coupling of NiTi and beta titanium. Conclusions: There is a decrease in NiTi corrosion resistance in the presence of fluoride. The corrosion behavior of NiTi alloy depends on fluoride concentration. When 0.02 and 0.04 M of NaF were added to the NaCl solution, NiTi presented localized corrosion. When NaF concentration increased to 0.05, 0.07, and 0.12 M, the alloy presented general corrosion. NiTi corrosion resistance behavior is lower than that of beta titanium. Galvanic coupling of these alloys does not increase corrosion rates.

Corrosion of High Zn Content Al-Zn-Mg-Cu Alloy in 3.5 wt.% NaCl Solution

2014 ◽  
Vol 703 ◽  
pp. 21-28
Author(s):  
Fan Qing Ran ◽  
Zi Yong Chen ◽  
Li Hua Chai
Keyword(s):  
Corrosion Process ◽  
Localized Corrosion ◽  
Nacl Solution ◽  
X Ray ◽  
Second Stage ◽  
Cu Alloy ◽  
Zn Content ◽  
The Matrix ◽  
Two Stages ◽  
Scanning Electron

In this paper, the polished specimens of high Zn content Al-Zn-Mg-Cu alloy after various aging treatments were immersed in 3.5 wt.% NaCl for up to 240 mins. The development of corrosion was monitored using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). There are two stages during the corrosion process, the first stage of attack started with localized corrosion of trenching around the Al-Zn-Mg-Cu particles. In the second stage the pitting corrosion appeared at the grain boundaries, and then developed into intergranular corrosion. This phenomenon is related to the potential difference between the matrix and the precipitates.

scholarly journals Effect of Microstructure on the Localized Corrosion and Stress Corrosion Behaviours of Plasma-Electrolytic-Oxidation-Treated AA7075 Aluminum Alloy Forging in 3.5 wt. %NaCl Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
A. Venugopal ◽  
Rajiv Panda ◽  
Sushant Manwatkar ◽  
K. Sreekumar ◽  
L. Ramakrishna ◽  
...  
Keyword(s):  
Stress Corrosion ◽  
Plasma Electrolytic Oxidation ◽  
Tensile Tests ◽  
Localized Corrosion ◽  
Nacl Solution ◽  
Uncoated Sample ◽  
Electrolytic Oxidation ◽  
Metallographic Observation ◽  
The One ◽  
Plasma Electrolytic

The influence of metallurgical heterogeneities such as coring and intermetallic phases on the corrosion and stress corrosion cracking behaviours of AA7075 aluminium alloy forging was examined in 3.5 wt. % NaCl solution with and without plasma electrolytic oxidation coating. Electrochemical test results demonstrated significant improvement in the corrosion resistance of the alloy after PEO coating. Stress corrosion results show that the metallurgical heterogeneities resulted in a loss in elongation of the uncoated sample in NaCl (11.5%) when compared to the one tested in air (12.9%). The loss in elongation of the uncoated sample was shown to be due to localized corrosion-assisted mechanical cracking rather than true stress corrosion based on preexposure tensile tests followed by posttest metallographic observation of the stress corrosion tested samples. This was further confirmed by the fractographic examination of the failed samples, which exhibited a typical ductile cracking morphology for all the coated and uncoated specimens.

Inhibition of localized corrosion of Ni–Ti superelastic alloy in NaCl solution by hydrogen charging

2015 ◽  
Vol 639 ◽  
pp. 365-372 ◽  
Author(s):  
Ken’ichi Yokoyama ◽  
Yuki Hirata ◽  
Toshiaki Inaba ◽  
Kenichiro Mutoh ◽  
Jun’ichi Sakai
Keyword(s):  
Localized Corrosion ◽  
Nacl Solution ◽  
Hydrogen Charging

Influence of Cl- on Corrosion Behavior of AZ91 Magnesium Alloy in Simulating Acid Rain

2011 ◽  
Vol 686 ◽  
pp. 181-185
Author(s):  
Wan Qiu Zhou ◽  
Wei Tang ◽  
Da Yong Shan ◽  
En Hou Han ◽  
Wei Ke
Keyword(s):  
Magnesium Alloy ◽  
Acid Rain ◽  
Corrosion Behavior ◽  
Localized Corrosion ◽  
Passive State ◽  
Nacl Solution ◽  
Az91 Magnesium Alloy ◽  
Β Phase ◽  
Α Phase ◽  
Az91 Magnesium

Initial corrosion behavior of AZ91 magnesium alloy in simulating acid rain containing Cl-is investigated by SEM/EDX and electrochemical method. The results show that corrosion of magnesium alloy in diluted NaCl solution was localized corrosion, and the attack only occurred around the scattered AlMn particle which induced the departure of AlMn from metal matrix. HSO3-in acid rain induced the dissolution of corrosion in α phase, β phase was not be corroded and presented in passive state. The corrosion of magnesium alloy in simulating acid rain containing Cl-was mainly induced by HSO3-, and the existence of Cl-accelerated the corrosion process.

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