Physical and Chemical Conditions of Complex Saturation Carbon Steel 45 by Silicon and Chrome in Medium of Chlorine

Abstract

The package of the applied programs with base of the thermodynamic data was used and the theoretical analysis of physical and chemical conditions of complex saturation carbon steel by silicon and chrome in medium of chlorine in the closed reactionary space was carried out at the lowered pressure of a gas phase. The influence of structure of initial components of a sating mix on equilibrium structure gas and condensed of phases of process chromosilicided is revealed. It was theoretically proved that the opportunity of simultaneous application of chrome and silicon on a surface of steel and appearance on steel in medium of chlorine complex diffusion layers is experimentally confirmed based on chrome and silicon. Simultaneous saturation of steel 45 chrome and silicon in chlorine atmosphere for 6 hours at a temperature of 1323 K and a pressure of 10² Pa of the gas phase was carried out in this work. The X-ray diffraction studies, it was found that under the assumed conditions of saturation on the steel surface 45 formed diffusion layer thickness of 90–100 microns, which corresponds to the phase of the corresponding chromium carbides Cr₂₃C₆ and Cr₇C₃, doped silicon (outer coat coatings) and a solid solution of chromium and silicon in α-iron (an inner coatings layer). Using micro X-ray analysis, it was found that the outer zone of the coating of chromium carbide Cr₂₃C₆ contains up to 52.87 atomic % chromium, except that it dissolves a small amount of silicon (0.15 % atm.) and iron (up to 15.73 % at.). Located directly underneath the zone based on α- iron which contains 9.87–5.55 % at. chromium, 8.15–3.89 % at. silicon 72.47–84.69 % at. iron.