In general, Inconel alloys exhibit good resistance to hydrochloric acid in various concentrations at room temperature. However, as the temperature increases, the corrosion resistance of Inconel may decrease.
For instance, Inconel 625, a nickel-chromium-molybdenum alloy, has excellent corrosion resistance to hydrochloric acid at room temperature and can withstand concentrations up to 37% HCl. However, at elevated temperatures, such as boiling hydrochloric acid, the corrosion resistance of Inconel 625 decreases, and it becomes susceptible to pitting and crevice corrosion.
Inconel 718, another nickel-chromium alloy, shows similar corrosion resistance to hydrochloric acid as Inconel 625. It is resistant to concentrations up to 20% HCl at room temperature but experiences increased corrosion at higher temperatures.
It is important to note that the corrosion behavior of Inconel in hydrochloric acid can be influenced by additional factors such as the presence of impurities, dissolved oxygen, and flow conditions. Therefore, it is recommended to consult corrosion data and conduct compatibility tests under specific operating conditions to ensure the suitability of Inconel in hydrochloric acid environments.
