Morphological and electrochemical study of the effect of electrolyte corrosion based on potassium chloride and urea fertilizers on SAE 1020 structural steel substrates covered with titanium dioxide films grown by sputtering in a double cathodic cage

ABSTRACT

Films of titanium and carbon-doped titanium were deposited on SAE 1020 steel substrates and glass substrate using the double cathodic cage sputtering technique to verify their influence on structural physical properties, hardness, and corrosion rates in saturated fertilizer environment. Hydrogen was used as atmosphere only inside on reactor, in a flow of 200 sccm, at a temperature of 260 ° C, with a pressure of 0.7 Torr, for a time of 06 hours. Using confocal microscopy, it was possible to measure the thickness of the films deposited on the substrate surfaces. Electrochemical tests were used to polarize and identify the corrosion rates of the samples. The Scanning Electron Microscopy and Dispersive Energy Spectroscopy provided data on the homogeneity of the film and structural characteristics and its morphology. Hardness measurements were obtained with instrumented nanoindentation. In general, the films obtained had gains in corrosion resistance due to the film grown up to 597.71 ± 151 nm, resulting in a reduction in the corrosion rate in positive potentials. The samples obtained hardness gains above 17% in the titanium film identified in the SEM, presenting itself as an advantageous alternative for application in working environments with fertilizers.

Keywords
Titanium; Fertilizers; Polarization; nanohardness; Confocal Microscopy