Modifikovaná Z-fáze v moderních žáropevných austenitických ocelích

Abstract

The goal of this thesis is a detailed description of modified Z – phase in moder austenitic heat – resistant steels. Theoretical part deals with the problematic of precipitation processes and different phases specifications in austenitic steels. In the practical part microstructural examination of provided samples from steel Super 304 H with long – term creep exposition has been carried out and put into evaluation. The existence, size and chemical composition of modified Z – phase has been of interest. The results have been compared to the published studies results of the precipitation processes in HR3C steel. It has been confirmed that the residual percentage of vanadium in studied steels influences precipitation processes in said steels and thus it would be desirable to include the percentage of vanadium in chemical composition in their commercial information.