Corrosion Behavior of Hastelloy C-276 in Hydrochloric and Sulfuric Acid

This research was conducted to determine the corrosion rate by varying the concentration of the solution against hydrochloric acid and sulfuric acid. The method used is open circuit potential (OCP) and Tafel plot. Based on the research conducted, Hastelloy C-276 was more prone to get oxidized in sulfuric acid rather than hydrochloric acid. It can be seen from the OCP value of sulfuric acid was much more negative than that of hydrochloric acid as of-1.5 V for 0.5 M sulfuric acid and-0.2 V for hydrochloric acid. The corrosion rate of Hastelloy C-276 in sulfuric acid was also higher compared to same alloy in hydrochloric acid. At the most concentrated solution, 0.5 M, the corrosion rate of sulfuric acid reached 0.39 mmpy and as for corrosion cate in hydrochloric acid, only at 0.16 mmpy. It is thought that there was a difference of passive film composition for both solutions. Keywords: Hastelloy C-276, Corrosion, Hydrochloric acid, Sulfuric acid.