Igor Konovalenko

Effect of Long Term Operation on Degradation of Material of Main Gas Pipelines

The mechanisms of metal damage in the pipe of the main pipeline are investigated, the main reasons for their appearance are found and analysed. The main results are obtained by joint use of metallography, indentation, method for processing and analysis of digital images.

Investigation of Statically Deformed Aluminum Alloy Surface

The peculiarities of the accumulation of structural and mechanical defects on the surface of the D16chT aluminum alloy under significant plastic strains are analyzed. The peculiarities of the surface strain hardening are found, and the geometrical parameters of the relief formations are described. The relationship between multiple cracking and specimen deformation is established. It is proved that the deformation relief parameters can be used to assess damage of the D16chT alloy under static deformation.

Defectometry Analysis of Surface Condition Damaged with Corrosion Pitting

The dismantled tubes of the steam-boiler operated by the “Kalush Heat and Power Plant” were investigated. Defects of various nature, pitting of the indefinite shape were found during the examination. Since pitting is a deepening in the material and contains dark products of the corrosion process. It looks like a darkened area that stands out against the light background of the non-damaged surface in the optical images. The efficiency of such processing for identification of the corrosion defects is analyzed. The suitability of the proposed methods for the calculation of Shannon entropy of the surface analyzed was tested, as well as for determining the area and number of pitting defects.

Analysis of surface relief evolution of polycrystalline aluminum alloy under static deformation

The peculiarities of using the surface as a damage sensor of the A2024 aluminum alloy under significant plastic strains are analyzed. Physical and mechanical regularities in the spatial self-organization of the structural and mechanical defects are found, and their relationship with the pore formation and deformation processes inside the material is established. It is proved that the surface relief formation can be used as the engineering parameter of the A2024 aluminum alloy damage under static deformation.