THE EFFECT OF TEMPERATURE AND CHLORIDE ION CONCENTRATION ON PITTING CORROSION AND CRITICAL PITTING TEMPERATURE OF UNS S31603

• Main Author: Julie Aulia - 13714035, Catia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26215
• Institution: Institut Teknologi Bandung

<p align="justify">This experiment simulates a pitting corrosion on UNS S31603 with a variation of temperature and concentration of chloride ions through immersion testing based on ASTM G48 Method E to determine Critical Pitting temperature. Solution containing FeCl3.6H2O, HCl, and reagent water was used. The test were carried out at a temperature 10oC, 20oC, 25oC, 30oC, and 35oC with variation of chloride ion concentration 2M; 2.25M; and 2.5M. The immersion was performed for 24 hours for each specimen with a stirring speed of 300rpm. <br /> <br /> The test results show that the temperature and concentration of chloride ions can influence the formation of pitting corrosion on UNS S31603 specimens. An increase in temperature will increasing the reaction rate so that the number of the number of pit increases. An increase in the concentration of chloride ions can accelerate the dissolution of passive layer on the specimen’s surface, so beside increase of the number of pits and increase of depth, there is also certain phenomenon where the pits gradually interconnected each other due to the adjacent pits position. The concentration of chloride ions can also affect the Critical Pitting Temperature, CPT, which with increasing concentration of chloride ions can decrease the CPT of UNS S31603 specimens up to 10oC.<p align="justify">