ABSTRACT
Correlations between Accelerated Laboratory Corrosion Tests and Atmospheric Corrosion Station Tests on Copper
Yang Min (Material Science)
Supervised by Associate Prof. Wang Zhenyao
This work presents results obtained on copper coupons exposed in Shenyang outdoor industrial area. Meanwhile, the results are obtained on copper coupons in accelerated laboratory corrosion tests with three solutions: 0.01mol/L(NH4)2SO4+0.01mol/LNaCl+ 0.01mol/LNaHSO3, 0.01mol/L(NH4)2SO4, 0.03mol/L(NH4)2SO4.The behavior of corrosion of copper in this work was studied through mass loss, surface observation and products analysis. The aim is to identify the corrosion layer composition using several analytical techniques and also to analyze some effects on the corrosion behavior of copper. The correlations between accelerated laboratory corrosion tests and atmospheric corrosion station tests on copper are established allowing the possibility of predicting long-term atmospheric corrosion behavior based on accelerated corrosion tests only.
In laboratory tests and Shenyang outdoor test, it is shown that the corrosion process of copper could be described by a formulary of M=C+V*T in which M presents mass loss, and T presents exposure time. It is shown that the corrosion rate of copper is approximately same in the corrosion process and protective properties of copper products are not obtained. In addition, the equation has been established when the same mass loss was reached of copper in outdoor and accelerated tests respectively. This equation could predict exposure time in long-term outdoor tests based on exposure time obtained in accelerated corrosion tests.
In laboratory tests and Shenyang outdoor test, local corrosion dominated on surface of
copper. The products formed on copper in laboratory tests and Shenyang outdoor test are
mainly CuO, Cu2O and copper sulfate, and Cu2O is formed in the whole corrosion process. Considering the corrosion products, corrosion behavior in all accelerated laboratory tests in this work could simulate that in Shenyang outdoor test.
Considering the simulation, the accelerated test with mixed solution has the worst simulation, and test with higher concentration solution is better than it with lower concentration solution, evaluated by corrosion morphology, products and elements on corroded surface.
Keywords: copper, atmospheric corrosion, correlations, accelerated laboratory tests
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