Investigation of carbon steel corrosion rate in different acidic environments

Abstract

This study focused on evaluating the rate of carbon steel corrosion in one molarity of HNO3 H2SO4 and HCl in various acidic conditions. The twenty-day exposure of carbon steel specimens to acidic conditions was investigated and followed by the evaluation of corrosion penetration rate and mils per year. The results showed that the 1 M HNO3 solution was the most damaging to carbon steel due to its oxidizing character. Among the tested acidic media HNO3 was the most harmful followed by H2SO4 and HCl. Carbon steel metal's corrosion behaviour was affected by acid medium strength and exposure duration. Dissolving of carbon steel increased with increasing corrosive media severity and exposure time. Concept of passive behaviour in metals has been proposed as the primary reason for this effect. The corrosion penetration rate values for carbon steel used in the present investigation followed the order of HNO3 > H2SO4 > HCl when exposed to the three acidic environments. The maximum corrosion penetration rate values for carbon steel metal subjected to HCl H2SO4 and HNO3 were determined to be 0.008952 (2nd day) 0.03095 (1st day) and 0.039373 (1st day) respectively. In addition corrosion penetration rate values steadily dropped throughout the final days of immersion eventually becoming essentially constant in all acidic media. As a result of the greater impact of all the acidic media used in this investigation corrosion pitting occur on carbon steel consistently. By intensifying the acid medium these effects were exacerbated.