Влияние наноструктурирующей деформационно-термической обработки на особенности деформирования и разрушения закаленной стали 50 при статическом и циклическом нагружении

Abstract

Straining and fracture features upon static and cyclic loading of quenched grade 50 steel (with 0.51 wt.% of C) subjected to nanostructurizing deformation-thermal treatment, which includes frictional treatment and optimized tem-pering at temperature of 350°С have been investigated. It is established that combined nanostructurizing treatment alters the character of development of a plastic yielding upon loading and makes it more uniform. This is expressed in disappearance of the yield point elongation at the early stage of deformation upon static tension and in suppression of formation of a deformation relief caused by action of shear and rotary deformation modes in volume of a material upon cyclic tension. At that in spite of appearance of cracks the hardened by means of deformation-thermal treatment surface layer of grade 50 steel doesn't completely fracture (doesn’t flake) throughout the process of cyclic loading and keeps high ability to resist contact mechanical action.