CORROSION PROBLEMS AND PHYSICAL-MECHANICAL MODELS OF STRUCTURAL MATERIALS FAILURE FOR POWER PLANT ENGINEERING

Abstract

Relevance of the research is caused by the need for increase of thermal and mechanical equipment life by reducing the metal losses caused by corrosion damage. Life extension and diagnostics of the structural materials state in power equipment are induced by the growing wear rate at operating electric power plants. In this relation, a thorough analysis of current mechanisms of oxide film formation and destruction, microcracking, evolution of microcracks with their further development and structural factors, affecting these mechanisms, is required. It will promote the preparation for transition to a qualitatively more informative and extensive level of research – nanoscale and even atomic, without which it is impossible to find dramatic solutions to the efficiency problems for materials used in manufacture of power equipment components and operated under high temperatures and pressure. The aim of the research is to analyze the problem to find reliable indicators of pre-corrosion failure, as well as to investigate the mechanisms of further corrosion of heating surfaces in steam generators and other heat exchange systems and obtain objective data about corrosion and heat resistance of steels for power plant engineering products, and also to develop the information basis for justification of objectives and methodology of studies in this area. Results of researching the problem. The authors have defined the mechanisms of corrosion failure affected by operational factors. Deeper insight of these factors pattern requires obtaining of observation results not only in the static state of the object, but the dynamic history as well.

Keywords

• steel
• stress corrosion cracking
• intergranular corrosion
• passive films
• grain size
• internal stress
• microstructure