The corrosion features of 20# carbon steel, the base material of sour water stripper, in NH₄Cl solution were examined in this research. The anatomical samples of the corroded parts were characterized by an X-ray diffractometer and other analytical tools. It was found to be a localized perforation caused by pitting, and the corrosion product was FeCl₂. 20# steel was subjected to electrochemical testing using Tafel polarization and Electrochemical impedance spectroscopy. The studies showed that the 20# steel’s cathodic depolarization reaction rate speeds as density rises, and that the concentration polarization gets more marked as temperature rises. The corrosion rate of 20# steel is the fastest when temperature hits its highest point of 80°C, measuring 4.7142 mm/a. When density rose from 5 to 20%, corrosion rate grew from 1.6378 to 7.2430 mm/a.