Investigation on corrosion behaviors of aluminum alloy in NaCl and EXCO solution

Abstract

Purpose – The purpose of this paper is to investigate the corrosion behaviors of 2A12 aluminum alloy in NaCl and EXCO solution, and establish the relationship between the corrosion depth and the time. Design/methodology/approach – Alternate immersion corrosion test chamber was used to perform the corrosion test. The corrosion mediums were 3.5 percent NaCl solution and EXCO solution (NaCl 234 g/L, KNO3 50 g/L, 68 percent HNO3 6.8 mL/L). The surface morphology was studied using the digital microscope. Findings – The average corrosion rate of aluminum alloy in NaCl solution decreased gradually at the initial stage and then went to a plateau value. The average corrosion rate of aluminum alloy in EXCO solution increased first, then showed a downward trend. The empirical function D=At B was verified. Originality/value – The results could provide a reference for the establishment of accelerated environmental spectrum in the laboratory and give instructions on the application of aluminum alloy in alternated dry and wet environment.