Structural changes in low alloy cast steel Cr-Mo-V after long time creep service

AbstrAct Purpose: of this publication is to present the changes of the structure in the power station boiler and turbine components made of low cast steel Cr-Mo-V after long time creep service. Design/methodology/approach: The material of the research studies has been obtained from Polish power stations. All examined elements have exceeded their assessed life of 100.000 hours. The microstructures of the elements have been observed using a scanning electron microscope. The investigation of the development of the precipitation processes has been done by X-ray diffraction phase analysis. Findings: The microstructures and phase compositions of the residues, obtained from the elements, depend on life exhaustion extent. Practical implications: The presented method can be used for evaluation and qualification of structural changes in power station boiler and turbine components operating in creep conditions. Originality/value: The observed changes in the structure and in the precipitation composition are applied to evaluation of the condition of the components in further industrial exploitation.