The electric power plant technology for the utilization of heavy fuel oil rich in sulphur, vanadium and asphaltenes poses very particular difficulties for plant design and materials selection. The combustion system plays a key role in the performance of power plants. The case study reported in
this paper considers the accelerated degradation of air nozzles or air swirlers. The components wereoperated during one year in a 350 MW boiler. The particular features of corrosion behavior ofSA213TP304, SA213TP446 and A297GrHH are presented. Optical, metallographic and microprobe evidence revealed that materials degradation mechanisms were all promoted by the very high operating temperature resulting from flame contact. Under this condition, a materials approach to solve the
problem was not encouraged because it is difficult to find a material resistant to such a condition. Solution to the problem must be directed to solve the flame contact problem. Design and operating conditions are considered as involved in the root cause of accelerated wastage of combustion system components.
Kevwords: Oxidation, corrosion, carburization, high temperature, combustion system, air nozzles, air swirlers, stainless steel, fuel oil, boilers, asphaltene.