Inhibitive effect of calcium gluconate and sodium molybdate on carbon steel

Abstract

There is an increasing demand for eco‐friendly inhibitors for use in cooling water systems. Both calcium gluconates and molybdate are eco‐friendly, non‐toxic chemicals. The corrosion inhibition of calcium gluconate and sodium molybdate on carbon steel in neutral aqueous media was evaluated by means of weight loss, electrochemical polarisation and impedance techniques. A synergistic effect was observed when these two eco‐friendly non‐toxic inhibitors were used in protecting carbon steel. A non‐linear relationship existed between the concentrations of the two inhibitors showing a synergistic effect.

Improvement in Corrosion Inhibition Efficiency of Molybdate-Based Inhibitors via Addition of Nitroethane and Zinc in Stimulated Cooling Water

“…Figure 10(a) shows crystal growth of iron oxide on the surface and its noncontinuous structure. In fact, the decrease in corrosion current densities and increase in polarization resistance when exposed to the previous inhibitors were due to the coverage of metal surface with more protective films [18] as shown in Figure 10. Also the surface roughness of mild steel exposed to solution SCW is much higher than mild steel exposed to solution SCW with the inhibitor 1000 M and optimized inhibitor.…”

“…The presence of C, Si, Mn, and Fe element can be observed in all figures. But the presence of Mo is only in Figures 11(b) and 11(c), indicating that molybdate oxide is formed on the surface of mild steel sample as stabilizer through its incorporation into the oxide film [18].…”

Synergistic inhibition of carbon steel corrosion in seawater by cerium chloride and sodium gluconate

“…Zinc gluconate is used for common cold treatment and for better wound healing. The efficiency and the mechanism of the corrosion inhibition by gluconates, either as single compound or in a mixture, have been described in a number of recent studies [2,[38][39][40][41][42][43][44][45]. A successful inhibition of carbon steel was obtained in the seawater or solutions containing different chloride concentrations by gluconate [1,2,40,[45][46][47][48][49].…”

Corrosion inhibition of carbon steel in various water types by zinc gluconate

“…Zinc gluconate is used for common cold treatment and for better wound healing. A number of recent studies have been carried out on the efficiency and the mechanism of the gluconate corrosion inhibition either as single compound or in a mixture [2,3,[7][8][9][10][11][12][13][14][15]. The efficiency of gluconate inhibition depends on inhibitor concentration, pH value and chemical composition of investigated solution, the nature of cations introduced in the solution as gluconate or already present in water and the state of the metal surface [11,16].…”

“…Gluconic acid and its salts (sodium, calcium and zinc gluconate) are known to be convenient corrosion inhibitors for carbon steel in many applications, particularly as scaling and corrosion inhibitors in cooling water systems [1][2][3][4][5][6]. They are environmentally suitable non-toxic compounds having also useful applications in medicine.…”