Corrosion behaviors of (Cr,Fe)3Si/Cr13Fe5Si2 composite coating under condition of synergistic effects of electrochemical corrosion and mechanical erosion

The aim of this paper was to study the corrosion behaviors of the (Cr,Fe)3Si/Cr13Fe5Si2 composite coating under condition of synergistic effects of electrochemical corrosion and mechanical erosion. The (Cr,Fe)3Si/Cr13Fe5Si2 composite coating was prepared on 316L stainless steel surface by double glow plasma technique. The electrochemical corrosion behaviors of the (Cr,Fe)3Si/Cr13Fe5Si2 composite coating under static state and hydrodynamic conditions were characterized by potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) and compared with those of Hastelloy C-2000 alloy and AISI 316L stainless steel. In static 3.5% NaCl solution, the corrosion resistance of the (Cr,Fe)3Si/Cr13Fe5Si2 composite coating was comparable to that of Hastelloy C-2000 alloy, but higher than that of AISI 316L stainless steel. However, under liquid impingement and liquid-solid impingement conditions, corrosion behaviors of the (Cr,Fe)3Si/Cr13Fe5Si2 composite coating were prominently superior to that of the reference materials. After 20 h liquid-solid impingement test, the mass loss measurements indicated that the (Cr,Fe)3Si/Cr13Fe5Si2 composite coating exhibited the lowest coupling effects of erosion and corrosion.