Abstract
Based on results obtained from the project electron beam welding of 9-12 % Cr steel the correlation between microstructure and mechanical properties of welded joints will be investigated in detail. Therefore, the evolution of the microstructure in the heat affected zone will be investigated with regard to grain size, precipitates distribution and formation of detrimental phases. Particularly, the influence of δ-Ferrite size and fraction on the properties of the welded joints is of great interest. Further on, the creep behaviour and the microstructural evolution during creeping will be studied.