Study of corrosion layers using backscattering ions

The backscattering technique was applied to materials of steam generator pipes of fossil fired plants in order to study the corrosion layers with respect to elemental amounts and depth structure. The samples were taken from plants and also from treatment in a laboratory device for the simulation of material stress. Using 7.6 MeV He-ions the oxide layer of a sample of a long time operated steam generator pipe was analyzed. Further three samples heated in a laboratory device in air show the initial state of corrosion. A damaged pipe of a coal fired plant was also investigated using 2 MeV He-ions in order to determine the elemental amounts in the oxide layer and in the ash layer at the fire side. The results allowed to draw conclusions for further plant operations.