Evaluating the Corrosion Behaviour of Borided Carbon Steel C35

Abstract

In this work, an evaluation of corrosion resistance of boride layers formed on carbon steel C35 in different solutions of H₂SO₄, HCl, HNO₃, NaCl and NaOH was carried out. Boriding treatment was applied on C35 carbon steel using Ekabor powder at 950 °C for 4 h. The corrosion behaviour was analyzed by the weight loss method after total immersion tests in different solutions at variable times from 24 hours to 6 months. The corrosion rate has been determined by electrochemical method using the polarization curves. Results obtained show that boriding treatment improved significantly the corrosion resistance of C35 steel in some acidic environments. The corrosion resistance of boride C35 steel is higher compared with that of untreated C35 steel, and the corrosion potentials E_cor of boride C35 steel are more electropositive than those of untreated C35 steel in some solutions.

Keywords:
boriding; corrosion resistance; weight loss method; electrochemical method