Kinetics of damage accumulation in pearlitic rail steels under contact fatigue

Resumo

The kinetics of damage accumulation in specimens of rail steels with the pearlitic structure manufactured by various companies has been studied in contact fatigue tests. The parameters of damage to the steels, such as the number, dimensions, and area of defects, the angular coefficients of cumulative size statistical distributions of the defects, as well as the velocity of propagation and the attenuation coefficient of ultrasonic waves, have been assessed. New criteria have been proposed to characterize the evolution of damage under contact fatigue. A linear interrelation between the number of surface defects and the number of subsurface defects in the zone of contact has been established, which can serve as a basis for continuously monitoring the condition rail steels and for assessing their current and remaining service lives.