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| Effect of Urea on Condensates Corrosion of Stainless Steels in Simulated Automotive Exhaust Environments |
| WANG Shidong, HAN Peihong, MA Rongyao, LI Moucheng, SHEN Jianian |
| Institute of Materials, Shanghai University, Shanghai 200072, China |
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Abstract The high-temperature exhaust gas oxidation-acidic condensates immersion cyclic test was used to simulate diesel exhaust after-treatment environments. After oxidation at 400 ℃ in simulated exhaust gas environments with or without urea, the corrosion behavior of 304 and 439 stainless steels was investigated in the condensate solutions. The electrochemical test results indicate that 304 stainless steels oxidized in the presence or absence of urea show passive corrosion characteristics in the condensate solutions, whereas 439 stainless steels oxidized under both conditions tend to active corrosion. Corrosion product films on the specimen surfaces may be damaged during the oxidation and immersion cycles, which give rise to the formation of some pits on the specimens. As urea is added into the exhaust gas, it can promote the oxidation processes of both 304 and 439 stainless steel. As a result, the general corrosion processes of both stainless steels are accelerated by the urea addition, but the localized corrosion processes are inhibited to a certain extent.
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Cite this article:
WANG Shidong,HAN Peihong,MA Rongyao,LI Moucheng,SHEN Jianian. Effect of Urea on Condensates Corrosion of Stainless Steels in Simulated Automotive Exhaust Environments. Journal of Chinese Society for Corrosion and protection, 2013, 33(1): 41-46.
URL:
https://www.jcscp.org/EN/ OR https://www.jcscp.org/EN/Y2013/V33/I1/41
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