A new class of corrosion inhibitors of mild steel in hydrochloric acid solutions

The effect of a new class of corrosion inhibitors namely 4-methoxy chalcone (A 1 ) and dichalcone (A 2 ) on the corrosion of mild steel in 1.0 M HCl has been investigated by various techniques. Results obtained reveal that A 2 stimulates corrosion.The inhibition by the other compound increased with increasing additive concentration. The maximum inhibition efficiency reached 81% at 10 - 4 M. It has been shown that A 1 acts as a mixed type inhibitior and its adsorption on steel surface obeys the Temkin isotherm model. The effect of temperature on the corrosion behaviour of steel indicated that inhibition efficiency decreases with the rise of temperature in the range 298-338 K. The apparent activation energy for steel has been determined.