Materials, Design and Corrosion Effects on Exhaust-System Life

A description is given of contemporary exhaust-system metal-deteriorating conditions, and their relation to exhaust component failure mode and likelihood, based on materials and design considerations. Exhaust-component durability is discussed, and specific failure sites and metal corrosion-oxidation conditions identified.

Localized, external corrosion is shown to be an important source of metal-failure in exhaust-system components. Internal, muffler-condensate corrosion is likely to produce the most rapid rate of metal-thickness decrease, and component failure. The effect of the catalytic convertor on internal corrosion is discussed.

Exhaust-component steels' corrosion oxidation resistance depends both on the metallic coating, and the internal and external exhaust-system operating environment. Traditional steel usage in exhaust-systems may change, due to current and future requirements of reduced-weight and/or extended life.