Investigation On The Corrosion Inhibitor For Metal In Acid Solution

Corrsion has always been one of the major problems in modern industry and manufacture. Adding corrosion inhibitor is a generally applied technique in material protection for its advantage of high efficiency and easy control. With the enhancement of the environnmental consciousness, the research of inhibitor which is non-toxic, pollution-free, biodegradable, has become an important research aspect. Tween-40, phytic acid, PASP and Na2WO4are nontoxic corrosion inhibitors. The research on the effect of their inhibition efficiency and synergism is rarely reported on steel in acid. In this paper we discussed the corrosion inhibition ability of tween-40and phytic acid to A3steel in HC1and PASP and Na2WO4to A3steel in H2SO4with weight loss method and electrochemical technique. The synergistic effects of them were also studied through methods mentioned above. The primary content in this article includes:1. the corrosion inhibition ability of tween-40and phytic acid to A3steel in HC1The inhibition efficiencies of single tween-40and phytic acid increase with the increase of density. The inhibition efficiency increase after the match tween-40with phytic acid, and the maximum value of corrosion efficiency achieves88%. The synergistic effect of complex of them is stable, not affected much by temperature. The adsorption energy of tween-40on A3steel follows langmiur isotherm, which is mainly physical adsorption. The adsorption energy of phytic acid is deviated langmiur isotherm, which is mainly chemical adsorption. The adsorption energy of their complex follows langmiur isotherm, which is mainly chemical adsorption.The complex of tween-40and phytic acid and single of them can inhibitate reaction of cathode and anode, but the inhibition of cathode is primary. But the complex of tween-40and phytic acid has bigger synergistic effects than single. 2. the corrosion inhibition ability of PASP and Na2WO4to A3steel in H2SO4The inhibition efficiencies of single PASP and Na2WO4increase with the increase of density. The inhibition efficiency increase after the match PASP with Na2WO4, and the maximum value of corrosion efficiency achieves92%. The synergistic effects of complex of them is stable, not affected much by temperature.The adsorption energy of PASP on A3steel follows langmiur isotherm, which is mainly physical adsorption. The adsorption energy of Na2WO4follows Frumking isotherm, which is mainly chemical adsorption. The adsorption energy of their complex is deviated langmiur isotherm, which is mainly chemical adsorption.PASP can inhibitate reaction of cathode, Na2WO4can inhibitate reaction of anode. The complex of PASP and Na2WO4has synergistic effects on both cathode and anode, but the inhibition of anode is primary.The study proves that:as a secure and nontoxic inhibitor, complex of tween-40with phytic acid, PASP with Na2WO4has a good synergistic effect.