Condensate Corrosion Behavior of Type 409 Stainless Steel in Simulated Automotive Muffler Environments

摘要

The cyclic method of hot exhaust gas-oxidation and condensates immersion has been adopted tosimulate the internal service conditions of automotive mufflers. The condensation corrosion of 409stainless steel was investigated during the immersion by using electrochemical measurement andsurface analysis techniques. Due to the existence of defects, the oxidation and corrosion productslayers on the specimen surfaces play an unimportant role in the condensate corrosion. During thecyclic processes, small pits will form gradually and result in relatively steady active corrosion forspecimens in the condensate solutions. Trace SO2 in the hot exhaust gas only exerts slight inhibition oncondensate corrosion through the initial oxidation process, but it almost has no influence oncondensate corrosion anymore with the progress of cyclic process. The evolution of condensatecorrosion is discussed in detail.