Assessment on the Effecs of Sodium Salts of Tungstate and Nitrite as Green Inhibitor for the Corrosion of Cr–5Ni–53W Alloy in 0.5 M NaCl Solution

Abstract

Corrosion inhibition effect of sodium salts of tungstate and nitrite on the sputter-deposited ternary Cr–5Ni–53W alloy was investigated in 0.5 M NaCl solution open to air at 25±1 °C using corrosion test, inhibition mechanism and corrosion potential measurement. The use of sodium salts of both the tungstate and nitrite enhanced the corrosion resistance properties of the ternary alloy in 0.5 M NaCl solution, mostly due to tungstate and nitrite ions adsorption on the surface of the alloy by physical adsorption, not by the chemisorption. As a result the corrosion rate of the Cr–5Ni–53W alloy was found to be significantly decreased with increasing the concentration of tungstate and nitrite ions in 0.5 M NaCl solution. Sodium tungstate and sodium nitrite act as an anodic corrosion inhibitor for the ternary Cr–5Ni–53W alloy in 0.5 M NaCl solution at 25±1 °C.

Keywords: green inhibitor, immersion tests, electrochemical measurements, Cr–5Ni–53W alloy, tungstate, nitrite