Effect of nanostructuring frictional treatment on the properties of high-carbon pearlitic steel. Part II: mechanical properties

In this second part of the work, the mechanical properties, features of deformation and fracture under static and contact fatigue loading of the high-carbon (1.03 wt% C) steel with a fine-lamellar pearlitic structure have been studied before and after frictional treatment with a sliding indenter. It has been found that the frictional treatment practically does not affect the mechanical properties of the steel under static tension. A method of contact fatigue testing for estimating the contact endurance of thin hardened surface layers has been proposed, which consists in performing contact fatigue tests according to a pulsing non-impact “sphere-to-surface” contact scheme under conditions of repeated elastic-plastic deformation with different maximum loads. It has been established that the frictional treatment increases the fracture resistance of the steel surface under contact fatigue loading, if contact damages are localized in the thin surface layer with maximum hardness and high values of microindentation based parameters. However, the hardened surface layer can endure heavy contact loads until failure and fractures only when contact damages cover the entire layer.