Effects of Mn content on resistance to corrosion fatigue and to stress corrossion cracking of Al-Mg casting alloys

Abstract

Studies were made of the effects of Mn content (0.2, 0.4 and 0.6%) on mechanical properties, the resistance to corrosion fatigue, and the resistance to stress corrosion cracking of Al-Mg casting alloys.
The results obtained were summarized as follows:
(1) The strength of Al-Mg alloys increased, but the elongation decreased with increasing Mg and Mn contents.
(2) The corrosion resistance of Al-3.56.5%Mg casting alloys was very high. In particular, their susceptibility to stress corrosion cracking was much lower than that of Al-10%Mg casting alloys.
(3) The corrosion resistance of Al-3.5%Mg alloys increased, but that of Al-6.5%Mg alloys decreased with increasing Mn content.