High Temperature Corrosion and Corrosion Protection
The research projects in the section „High Temperature Corrosion and Corrosion Protection” of IEK-2 relate to the performance, degradation and protection of high temperature metallic materials. The main research interests include high temperature oxidation, high temperature corrosion in mixed gas environments, modelling of corrosion processes, corrosion life prediction and application of surface analysis techniques in corrosion science. The research topics are linked to materials behaviour in a variety of practical applications such as fossil fuel fired boilers, steam and gas turbines, plants in chemical industries and Solid Oxide Fuel Cells.
A major aim of the research activities is the development of new metallic construction materials and coating systems and their characterization with respect to the behaviour during isothermal and cyclic exposure in a wide temperature range in simulated service environments, containing e.g. oxygen, water vapour, hydrogen, carbon dioxide and/or sulphur dioxide.
Materials classes which are presently being studied include martensitic/ferritic/austenic steels and nickel base alloys for applications in power generation, different types of metallic and ceramic coating systems as well as FeCrAl type alloys for application in heating elements and catalyst carriers.
The research projects comprise fundamental investigations (including the use of isotopes) for elucidating corrosion mechanisms as well as long term studies for obtaining design relevant data
For quantitative assessment of corrosion attack, thermogravimetric studies are combined with extensive characterization methods of the alloys/coatings and corrosion products. Thereby a number of conventional analysis methods such as light optical microscopy, scanning and transmission electron microscopy (SEM, TEM) and x-ray diffraction (XRD) are combined with surface analytical methods specifically adopted for corrosion research such as Sputtered Neutrals Mass Spectrometry (SNMS), Laser Raman-Spectroscopy (LRS) and Glow Discharge Optical Emission Spectroscopy (GDOES).
Modelling studies include the description of growth mechanisms of Cr2O3 and Al2O3 surface scales, oxidation induced diffusion processes and precipitate dissolution/formation in the metallic substrates as well as predicting the life time of (thin walled) components and coating systems.