Internal and external corrosion of exhaust systems for passenger vehicles - Test procedures, laboratory and field results

Exhaust systems fulfill a variety of tasks and their durability, their mass and their costs are of particular importance. Within the framework of furt her quality improvements a minimum lifetime of 3 to 5 years is aimed for, d epending on the vehicle type. The mass of the exhaust system should be redu ced by 20 to 25% without any substantial increase in the cost to performanc e ratio. The technical concept for muffler systems which fulfill these cond itions is examined in this paper. Special attention is given to corrosion, particularly as a result of the effects of exhaust condensate and to the co nstructional design possibilities fur the prevention of corrosion. In spite of all the efforts made it has not been possible up to now to simu late the wet corrosion stability of a complete exhaust system in the labora tory. For this reason the practical testing of the corrosion stability of e xhaust systems on test stretches and in traffic cannot be dispensed with.