INVESTIGATION OF PHOSPHONIC ACID AND PROPARGYL ALCOHOL INHIBITORS IN HYDROCHLORIC-ACID MEDIA

The inhibitory effects of propargyl alcohol and diethylene- triamine-p entakis (methylenephosphonic) acid were studied on carbon steel in aer ated 5% HCl solution at 60 degrees C by the Planned Interval Test tech nique. According to the results, the effectiveness of the propargyl al cohol is higher than that of the phosphonic acid. The effect of the mi xtures of the two inhibitors is not superior to the effect of the prop argyl alcohol. The minor increase in inhibitor efficiency in shorter t est duration caused by the phosphonic acid shows that it promotes the adsorption of the protective species. However, during longer exposure times it causes pitting corrosion.