Influences of Air Environments on Fatigue Properties of Pre-corroded 2XXX Aluminum Alloy

The fatigue tests of pre-corroded 2XXX aluminum alloy specimens(Kt=1 and Kt=3) were carried out in lab air and wet air environments,the unilateral tolerance factor statistical analysis method was used to predict the values of fatigue life,the median fatigue life and reliability of 99% and 95% confidence levels of the fatigue life were obtained.The results show that the wet air deteriorates the fatigue property of pre-corroded 2XXX aluminum alloys.The fatigue life data of smooth specimens are scattered and the data become much scattered with the decrease of the stress level,while the fatigue life data of the notched specimens are more concentrated.The thin water film at aluminum alloy surface accelerating the crack growth and partial damage caused by atomic hydrogen are the major reasons of low fatigue life in wet air environment.