عنوان مقاله [English]
Effectiveness of furfural as an organic inhibitor in 5 percent hydrochloric acid which is used in acid pickling of steel was evaluated. Lungmuir, Frumkin and Flory-Huggins isotherms [1, 2] were used to determine the parameters of effective adsorption, free energy and entropy of adsorption. Furfural indicated an inhibition less than 17 percent in concentrations of 0.001 mole per liter for a duration of two hours at temperatures of 50, 60 and 70 degrees centigrade. Steel was protected up to 90 percent in concentration of 0.08 mole per liter at temperature of 70 degrees centigrade in 5 percent hydrochloric acid solution. Adsorption of furfural on the steel surface obeyed lungmuir isotherm.