Corrosion Inhibition of Steel in Lithium Bromide Brines

The inhibiting effect of phosphomolybdenic acid (PMA) on the corrosion of steel (St3) in 65% lithium bromide solution has been studied in a temperature range from 80 to 230°C and at pH 5.0–8.5. Corrosion and electrochemical studies showed that the efficiency of PMA as a corrosion inhibitor increases with an increase in temperature and pH of the LiBr brine. The ambiguous behavior of PMA in solutions at low temperatures and pH was analyzed. A blend of PMA with a low-temperature inhibitor (IFK) was suggested. It was shown that these inhibitors manifest synergism and the composition has high inhibiting properties at elevated temperatures. The effect of PMA on the effective activation energy of the corrosion process was analyzed.