Corrosion Behavior of Some Materials in 0.5 M Ammonium hydroxide Solution

Abstract

The present work has the purpose of studying metallographic aspects and corrosion resistance of three materials used in ammonia stripping plants. The corrosion process was evaluated by gravimetric tests and potentiodynamic method. Materials tested were Al 1050 (99.5%Al), stainless steel AISI 316Ti and low alloy steel P235TR2. To determine gravimetrically the rate of penetration, samples were immersed in corrosive environment for 294 days and weighed periodically. As test solution 0.5 M ammonium hydroxide (specific for coke industry) was used in a three electrode open cell with material tested as working electrode (WE), a platinum electrode as counter electrode (CE) and an Ag/AgCl electrode as reference electrode (RE).