PENGARUH PENAMBAHAN INHIBITOR, KONSENTRASI LARUTAN DAN TEMPERATUR TERHADAP LAJU KOROSI PADA MATERIAL STAINLESS STEEL 316L
Corrosion is a decrease in the quality of metals due to chemical reactions between the metal and the surrounding compounds. The problem of corrosion was found in the pre-treatment process in the pipeline system of an industry engaged in the production of Sodium Tripolyphosphate in one area in East Java. The type of fluid that flows in this process is 32°C phosphoric acid. The temperature of the fluid is very influential on the rate of corrosion. The pre-treatment process uses 316L Stainless Steel material in the piping system. Based on these problems, the addition of inhibitors is needed as a corrosion inhibitor. There are two types of inhibitors used, namely coffee extract inhibitor and NaNO2. Beside the type of inhibitor, concentration and temperature are also varied. Potentiostat test is used to determine the corrosion rate that occurs in 316L Stainless Steel. The results of tests that have been done show that the lowest corrosion rate value is by using NaNO2 inhibitors with a concentration of 200 ppm at a temperature of 35°C that is equal to 0.027441 mm/year while the lowest corrosion rate value for coffee extract inhibitors is 0.050521 mm/year mm/year at 35°C with a concentration of 300 ppm. From these results it can be concluded that the best corrosion protection method is obtained by adding NaNO2 inhibitors because it has the lowest corrosion rate.