Abstract
Stress corrosion cracking (SCC) and corrosion fatigue (CF) experiments were performed on the test specimens in three directions (L, LT, ST) of rolled 7075 aluminum alloy. The results obtained are as follows.
(1) The SCC life time of the test specimen in ST direction could be estimated from the applied stress, the tensile strength, and the activation energy which is determined by changing the temperature of corrosive solution and immersing the test specimen in LT direction.
(2) There was a combined effect of SCC and CF in CF experiments for the test specimen in LT direction, because the total accumulated damage factor was smaller than one when the linear damage summation method was applied to the experimental result of CF at 5min. stress hold time. This effect was confirmed on the fracture surface of the test specimen.
(3) However, the effect was not observed either in the CF experimental result or on the fractograph for the specimen in L direction tested at room temperature and 30min. stress hold time, nor for the specimen in ST direction tested at 70°C and 5min. stress hold time.
