Influence research of ultrasonic processing on nature of plastic deformation on mesoscale level steel samples ST3/sup 0/

Abstract

The method of ultrasonic forging allows creating on a surface a hardened layer, which does not have a marked interface with a substrate. The presence of such a layer on a surface should not result in considerable effects of localization, but at the same time, due to high-density of defects in a near-surface layer in control of homogeneous development of plastic deformation as a whole according to specimen. Low-carbon steel ST3/sup 0/ was used. Hardening the surface was conducted on the one hand of a specimen under conditions of ultrasonic burnishing. Under used treatment conditions the depth of study of a near-surface layer revealed according to analysis of a microhardness, amounted to 180 microns. The tests for single-axis static stretching were conducted on the test facility "IMASH 20-7" with speed of stretching of 0.05 mm/min. With the usage of an optical and television measuring complex "TOMSC-1", the principle of operation which one is based on computer processing of the optical images of a surface, fields of vectors of displacement were plotted. The analysis of distribution of vectors of displacement constructed at overseeing for a surface of a lateral face was conducted. The character of plastic deformation at a mesoscale level was investigated.