Investigation of the Incubation Mechanisms in Metal Dusting Atmospheres

A significant number of plants within the petro-chemical industry is severely affected by the Metal Dusting phenomenon. Steam cracker as well as steam reformer units operating between 450°C and 900°C suffer by this special type of corrosive attack by a process atmosphere consisting mainly of carbon monoxide, hydrogen and water vapor. Those highly reducing and carburizing atmospheres lead to massive pitting corrosion which, once initiated, may proceed very rapidly leading to severe damages of plant components and, thus, loss of production. This may often occur after several thousend hours of operation time where the material subsurface composition and structure change during the incubation period and their influence on the Metal Dusting onset still remained unclear. Consequently, this project aims at a microstructural investigation of the initially protective oxide scale on the material surface to identify the parameters which cause defects and finally the failure of the protective effect.