scholarly journals THE EFFECT OF Fe-ENRICH PHASE ON THE PITTING CORROSION RESISTANCE OF Al ALLOY IN VARIOUS NEUTRAL SODIUM CHLORIDE SOLUTIONS

2014 ◽  
Vol 7 (2) ◽  
Author(s):  
Gadang Priyotomo ◽  
I Nyoman Gede Putrayasa Astawa
Keyword(s):  
Corrosion Resistance ◽  
Sodium Chloride ◽  
Pitting Corrosion ◽  
Al Alloy ◽  
Chloride Solutions ◽  
Sodium Chloride Solutions ◽  
Pitting Corrosion Resistance ◽  
Neutral Sodium

scholarly journals Improvement of Pitting-Corrosion Resistance of Ultrafine-Grained 7475 Al Alloy by Aging

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 360
Author(s):  
Ewa Ura-Bińczyk
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Al Alloy ◽  
Subsequent Aging ◽  
Fine Grained ◽  
Transmission Electron ◽  
Pitting Corrosion Resistance ◽  
Ultrafine Grained ◽  
Ultrafine Grained Microstructure

The effect of aging on the resistance to pitting corrosion of ultrafine-grained 7475 aluminium (Al) alloy processed by hydrostatic extrusion (HE) is studied. Differences in the microstructure were investigated using secondary electron (SEM) and transmission electron microscopy (TEM). Corrosion tests were performed in 0.1 M NaCl, and characterization of corroded surface was performed. The results of this work show that the pitting susceptibility of ultra-fine grained 7475Al is related to the distribution of MgZn2 precipitates. After HE, the formation of An ultrafine-grained microstructure at the grain boundaries of ultrafine grains is observed, while subsequent aging results in the formation of MgZn2 precipitates in the grain interior. Grain refinement increases susceptibility to localized attack, while the subsequent aging improves the overall corrosion resistance and limits the propagation of corrosion attack.

Resistance to Pitting of Types 202 and 321 Steels to Sulfuric Acid and Sodium Chloride Solutions

CORROSION ◽  
1966 ◽  
Vol 22 (9) ◽  
pp. 257-260 ◽  
Author(s):  
R. LEBET ◽  
A. PIOTROWSKI
Keyword(s):  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Pitting Corrosion ◽  
Nickel Content ◽  
Cast State ◽  
Potential Region ◽  
Chloride Solutions ◽  
Sodium Chloride Solutions ◽  
Aisi Type ◽  
Lower Nickel

Abstract Anodic potentiokinetic polarization measurements were made of pitting corrosion of two stainless steels in 1 N sulfuric acid and 1 N sodium chloride solutions to compare then-resistance to this type of corrosive attack. One steel was approximately of the same analyses as AISI Type 321 (H18N9), the second a substitutional steel with lower nickel content containing manganese and nitrogen approximately of the same analyses as AISI Type 202 (OH17N4G8). The steels were investigated both in as-cast state and after the plastic deformation. Type H18N9 steel, in its passive potential region is somewhat less resistant to pitting, assuming that total corrosion volume is taken into account-However, the type of pits seems to be more dangerous in Type OH17N4G8 steel. A similar situation is observed with respect to the structure effect. Rolled alloys exhibit greater total pitting corrosion losses while those tested as-cast suffers less extensive over-pitting. Pits in as-cast materials are, however, deeper and larger.

Development of pitting corrosion of stainless steel 403 in sodium chloride solutions

2010 ◽  
Vol 46 (2) ◽  
pp. 196-204 ◽  
Author(s):  
K. V. Rybalka ◽  
V. S. Shaldaev ◽  
L. A. Beketaeva ◽  
A. N. Malofeeva ◽  
A. D. Davydov
Keyword(s):  
Stainless Steel ◽  
Sodium Chloride ◽  
Pitting Corrosion ◽  
Chloride Solutions ◽  
Sodium Chloride Solutions

Effect of Equal-Channel Angular Pressing on the Pitting Corrosion Resistance of Al Alloy

2006 ◽  
Vol 503-504 ◽  
pp. 487-492 ◽  
Author(s):  
In-Joon Son ◽  
Hiroaki Nakano ◽  
Satoshi Oue ◽  
Shigeo Kobayashi ◽  
Hisaaki Fukushima ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Equal Channel Angular Pressing ◽  
Pitting Corrosion ◽  
Formation Rate ◽  
Electrochemical Techniques ◽  
Mg Alloy ◽  
Al Alloy ◽  
Angular Pressing ◽  
Ecap Process ◽  
Pitting Corrosion Resistance

The effect of equal-channel angular pressing (ECAP) on the pitting corrosion resistance of Al and Al-Mg alloy was investigated by means of polarization curves in solutions containing 300 ppm of Cl- and by surface analysis. The potentials for pitting corrosion of Al and Al-Mg alloy were evidently shifted to the noble direction by using the ECAP process, indicating that this process improves resistance to pitting corrosion. This increase in resistance seems to be attributable to the increase in formation rate of Al oxide films due to the increase in grain boundary with ECAP. The pitting corrosion resistance of Al and Al-Mg alloy anodized galvanostatically in H2SO4 solution after ECAP was also investigated using electrochemical techniques. The pitting corrosion resistance of Al and Al-Mg alloy was remarkably improved by anodizing. However, the pitting corrosion resistance of anodized Al-Mg alloy was better without ECAP than with ECAP.

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