CORROSION RESISTANCE OF DIFFUSION COATINGS INVOLVING CHROMIUM AND SILICON ON 45 STEEL

In this work, the diffusive chromosilicide coatings were applied to steel 45 by a gas method in a specially designed installation, which had a reaction chamber of a new design. The process was carried out for 6 hours in a closed reaction environment at the pressure of the active gas phase and a temperature of 1323K. Ferrosilicon, chromium, and carbon tetrachloride powders were used as starting reagents for applying diffusion coatings. Corrosion resistance of chromosilicid diffusion coatings was studied in solutions of hydrochloric, phosphoric, acetic, citric, and nitric acids, in a 3% solution of sodium chloride. It was shown that diffusive chromosilicide coatings applied to carbon steels increase the corrosion resistance in the tested solutions by 2.2 to 750.0 times. It is possible to increase the corrosion resistance of diffusion coatings due to the introduction of inorganic substances (ammonium molybdate) and their combinations with organic substances. The introduction of corrosion inhibitors into aggressive acid solutions increases the protective effect of coatings by 5.0-136.0 times. It is shown that chromosilicide coatings can be recommended for the protection of machine parts operating in various aggressive environments.