621.789At present, methods for thermal strengthening which are based on the action of high specific energies on relatively small volumes of metal followed by fast cooling are very widespread. As a result, one observes the formation of two structural zones, namely, the zone of secondary hardening (region with a white layer) and the zone of increased pickling (or thermal influence) with the structure of high-rate tempering.The temperature of heating of a surface, its plastic strain, and rates of change of these parameters in the process of pulse treatment have a significant effect on the formation of white layers. In this case, the redistribution of chemical elements in the surface layer occurs. For a rate of strain in the range 10-102 sec -1, the intensity of transfer of tagged atoms in the solid phase is greater than the diffusion mobility in the liquid state by a factor of 102-103 [1-31.Despite the short time of the process, chemical elements pass considerable distances. In [4,5], a high rate of mass transfer and an increase in the content of elements in the white layer produced by using various methods of surface strengthening are established. The mass transfer of elements proceeds from a technological medium and from subsurface layers of a detail. Under the action of high temperatures and pressures, the medium decomposes into atoms, which diffuse into surface layers along juvenile surfaces.The aim of this work is to determine the mass transfer of chemical elements from technological medium (a saturated aqueous solution of magnesium and calcium chlorides) into surface layers of metals in the process of frictional strengthening. Local X-ray spectral investigations were carried out with an MS-46 microprobe from "CAMECA" (France) [6][7][8]. The chemical composition was determined in the mode of the probe with U = 20 kV and I = 13 nA. The diameter of the electron beam was 1 ~tm, being the same on the microsection, on the surface of the specimen, and in its depth. The experimental results were processed by the ZOND program [9] which includes corrections for the atomic number, absorption, and fluorescence.We establish that the mass transfer of magnesium, calcium, chlorine, and carbon into the surface layer of metal occurs during the process of frictional treatment of Armco iron with the use of a saturated aqueous solution of magnesium and calcium chlorides (see Fig. 1). Near the surface, the contents of magnesium, chlorine, and calcium are, respectively, 0.16%, 0.1%, and 0.02%. The content of carbon in the surface layer is about 0.6% and decreases as depth increases. At a depth of 30 ~m, carbon is practically absent. In our opinion, carbon is transferred, mainly, from the material of a strengthened disk. Indeed, only the compound Ca(HCO2) 3 contains carbon in the medium, but its concentration is negligible. The maximum content of all elements mentioned above is recorded near the surface. As the depth increases, their content decreases.. At a depth of 50 gm, these elements are absent. This confirms the fact that the m...
