Ultrasonic impact peening technique for improvement the constant amplitude corrosion-fatigue interaction

The fatigue behavior of 6061-T6 aluminum alloy under constant amplitude loading was investigated in air for as-received and pre-corroded specimens in 3.5% NaCl corrosive solution for 77 days. Constant corrosion-fatigue tests have been done with and without ultrasonic peening treatment under rotating bending load at stress ratio (R= -1) and room temperature (RT= 25 °C). The experimental results presented that the tests of fatigue life on pre-corroded specimens with and without ultrasonic peening revealed a significant reduction in life related with the presence of corrosion defects before cyclic loading. In state of unpeened specimens the constant S-N fatigue strength curve was decreased by 4.5% due to immersed the specimens in corrosive 3.5% NaCl solution for 77 days, while in state of ultrasonically peened specimens the reduction of S-N curve decreased to 2.2% due to the beneficial effect of this treatment for increasing the corrosion-fatigue life. The improvement of fatigue life and corrosion-fatigue life of specimens when applying of ultrasonic peening treatment was 8.69% and 2.3% respectively. Copyright © 2018 International Energy and Environment Foundation All rights reserved.