Vol.3, No2, 2003, pp. 85-92
UDC 620.17:62-988

Microstructural parameters, obtained based on kinetic theory of strength (model Zhurkov), are used to estimate the time-to-fracture of a material subjec-ted to high-temperature creep. The input parameter, necessary for the residual life estimation by computer, is the creep resistance for a given service time. Since the creep resistance decreases with time in operation due to microstructure degradation, it is essential to use microstructural parameters in order to statisti-cally define the changes in the creep resistance, which, in turn, enables to follow the physical signifi-cance of these changes. Due to a considerable dT scattering, their processing by regression analysis of the physically significant parameters is a problem, that has not been satisfactorily solved yet. The present work describes one approach to general solution of considered problem. The residual life, as the basis for the integrity assessment, has been determined for the component, taken from a power plant after determined service time under known operating conditions.

Keywords: low-alloyed steel, creep, long-term strength, microstructure