MODIFICATION OF SURFACE LAYERS STRUCTURE AND PROPRIETIES IN ORDER TO ENSURE THE COROSION RESISTANCE IN DIFERENT MEDIUMS UTILISING SURFACE SILICON ENRICHING

摘要

The paper advances the results from the researches on the increased performance in some components of devices and equipment employed in the chemistry and oil industry, that are required to feature high corrosion resistance both at the ambient and the high temperatures. The researches are focused on the silicon-based thermal-chemical treatments (surface silicon enriching) of the low carbon steel parts used in the paper industry, desalinization systems and ammonia (secondary product resulted from the coke processing in the steel factory-SIDEX S.A.) processing regenerators. The experimental study of the silicon treatment conditions (environment, temperature, duration etc.) of the component parts made it possible to find some optimum technologies for making corrosion resistance parts at different temperatures in acids (H_2SO_4, HCL, HNO_3) of various concentrations in the sea water. The micro-structural aspects of the silicon surface depending on the technological parameters of the silicon process and the chemical composition of the steel subject to this treatment as well the corrosion behavior in different media.