Žárupevnost a mikrostruktura heterogenních svarů typu P91/P23

Abstract

Diploma thesis is focused on creep resistance and microstructure of heterogeneous welded joints. Types of the steel which are discussed in theoretical and also in experimental part are high-alloyed P91 steel and low-alloyed P23 steel. These steels are used in energy industry. This thesis is aimed at requirements which creep resistant steels used in that sector should have. It further deals with creep characteristics and microstructure evolution in creep resistant steels during long - term creep exposition and degradation of heterogeneous welded joints during creep. Failure locations in heterogeneous welds of P23 and P91 steels, depending on the creep conditions, were studied in experimental part. It was observed that besides failure in partially decarburized area, failure in other areas of cross weld specimens, depending on the creep exposition parameters, may also occur.