Behavior to wear and corrosion of steel with chromium silicon nitride coatings

Abstract

Chromium silicon nitride coatings were deposited via physical vapor deposition using a reactive sputtering magnetron, on steel specimens, with a chromium silicate target, purity of 99.5% and argon/nitrogen gas ratio (%) of 80/20. The coating characterization was carried out by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and nano hardness. The erosion-corrosion analysis was performed with a pin on disc tribometer, with a zircon pin, load of 1 N, applying three rotation speeds of the system (250 rpm, 400 rpm and 500 rpm) with an electrolyte composed of water, silica sand (0.05 mm, 0.1 mm and 0.15 mm) and 1% of sodium chloride. The electrochemical techniques used were resistance to polarization, electrochemical impedance spectroscopy and potentiodynamic polarization. The coating decreases the rate of substrate wear between 32% and 56%. The coefficient of friction decreases by almost 50% with the application of the film. Finally, the coating reduces by an order of magnitude the corrosion rate of steel in systems subject to wear and in 3 orders of magnitude in steel systems in static conditions, increasing the useful life of industrial facilities.