Papers by Author: Władysław Osuch

Abstract: Due to aggressive gases produced during combustion process of biomass, some elements of the power boiler should be covered with a material that possesses very high corrosion resistance (e.g. Inconel 625). This paper presents results of microstructural studies of Inconel 625 padding weld on waterwall elements (made of 13CrMo4-5 steel) for steam boiler designed for biomass combustion. The microstructural studies were carried out using Scanning- as well as Transmission Electron Microscopy methods. The padded weld layer exhibited dendritic structure. In the weld layer γ phase with an increased dislocation density and stacking faults was observed. In the base material (13CrMo4-5 steel) titanium nitrides, complex carbides and Laves phase enriched in niobium were observed.

Abstract: The electron tomography and transmission electron microscopy studies of the carbides in the 0.5Cr-0.5Mo-0.25V (13HMF) low-alloy steel after service during 160 000 h at 540 °C were carried out. Identification of the carbides was performed by means of electron diffraction analysis. Meso-scale tomography technique, mainly FIB/SEM tomography, was used for detailed characterization of spatial distribution and metrology of the carbides in 13HMF steel. The results achieved confirm the ability of FIB tomography to get 3D reconstruction of internal microstructure of steel as well as to obtain information about the shape and spatial distribution of carbides.