Abstract: With the solution of 5%NaCl+0.5%(NH 4) 2SO 4(pH=3.0), 2024 and 7075 aluminium alloys were tested in a salt spray cabinet(one hour wet, one hour dry) and a periodical immersion cabinet respectively. The results obtained from the two tests showed similar corrosion kinetic laws. The simulation and acceleration of the salt spray test were better than those of the periodical immersion test. Based on the corrosion kinetic law obtained, a concept of \ Reference Corrosion Rate\" was proposed, which can be used to evaluate the corrosion extent and to estimate the time equivalence between the salt spray test and the atmospheric corrosion.

Key words: alum inium alloy, accelerated co rro sion test, co rro sion est imat ion