Corrosion of metals and alloys. Accelerated corrosion test for intergranular corrosion susceptibility of austenitic stainless steels

2015 ◽  
2013 ◽  
Vol 842 ◽  
pp. 275-278 ◽  
Author(s):  
Jian Ming Wang ◽  
Xiao Dan Meng ◽  
Ying Ying Bai ◽  
Guo Feng Ma ◽  
Yan Liu ◽  
...  

The effect of artificial aging on the corrosion properties of 6063 Al alloy was investigated by optical microscope, field emission scanning electron microscope and accelerated corrosion test. Accelerated corrosion test revealed that the alloy was susceptible to intergranular corrosion (IGC) in the artificial aged conditions according to the surface corrosion morphology, and the IGC resistance was reduced as the aging time was prolonged, resulting from more Mg2Si grain boundary precipitates formed. However, the corroded cross-sections showed that the IGC was very local. Additionally, the surface corrosion morphology also showed that pitting corrosion took place, resulting from galvanic corrosion between (FeMn)3Si12Al15 particles and matrix Al.


2014 ◽  
Vol 1046 ◽  
pp. 50-53
Author(s):  
Chun Lin He ◽  
Yan Liang ◽  
Ying Ying Bai ◽  
Guo Feng Ma ◽  
Jian Ming Wang ◽  
...  

The effect of artificial aging on the corrosion resistance of 2024 Al alloy was investigated by field emission scanning electron microscope (FE-SEM) and accelerated corrosion test. For comparison, the solution treatment followed by air-cooled and water-quenched samples were also researched. Accelerated corrosion test revealed that the corrosion resistance of the alloy strongly depended on artificial aging times, and the weight gain of the aged alloy increased first and then decreased with increasing the aging times, and a maximum value was found at peak aged condition. The air-cooled sample had the highest weight gain while the water-quenched one had the lowest weight gain among all the samples. The corrosion morphologies showed that pitting and localized intergranular corrosion were the main corrosion forms for the air-cooled and aged 2024 Al alloys. However, only pitting corrosion took place on the water-quenched samples. The pitting and intergranular corrosion resulted from galvanic corrosion between secondary particles and matrix Al, and between grain boundary precipitates and matrix Al, respectively.


2014 ◽  
Vol 1046 ◽  
pp. 54-57 ◽  
Author(s):  
Chun Lin He ◽  
Xiao Dan Meng ◽  
Guo Feng Ma ◽  
Jian Ming Wang ◽  
Zhao Fu Du ◽  
...  

The effect of artificial aging on the corrosion properties of 6063 Al alloy was investigated by optical microscope, field emission scanning electron microscope (FE-SEM) and accelerated corrosion test. Accelerated corrosion test revealed that the corrosion resistance of the alloy strongly depended on artificial aging times, and the corrosion weight gain curve of the aged alloy was greatly in agreement with that of hardness vs. aging times, showing that the lowest corrosion resistance was exhibited at peak aged condition. It is found that pitting is the main corrosion form for the 6063 aluminum alloy aged with different times at 210°C, and slight intergranular corrosion is also found at peak hardness. It is believed that pitting results from galvanic corrosion between Al9Fe2Si2 particles and matrix Al while intergranular corrosion results from galvanic corrosion between Mg2Si and matrix Al.


CORROSION ◽  
1982 ◽  
Vol 38 (6) ◽  
pp. 327-330 ◽  
Author(s):  
T. M. Devine ◽  
B. J. Drummond

Abstract The procedure for developing an accelerated corrosion test which would aid in assessing the sensitization resistance of low chromium ferritic stainless steels is described. Immersion corrosion tests were conducted on Fe-Cr binary alloys in boiling acidified Cu-CuSO4 solutions. Reducing the H2SO4 concentration of the standard ASTM A262E solution results in a reduction in the minimum chromium content required for passivation. In a boiling solution containing 0.5 w/o H2SO4 + 6 w/o CuSO4 + Cu chips, alloys with > 12 w/o chromium are passive and alloys with < 12 w/o chromium undergo general attack. The 0.5 w/o H2SO4 solution is shown to be useful in evaluating the time-temperature-sensitization behavior of a 12 w/o chromium ferritic stainless steel.


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