Corrosion Fatigue Properties of Joined Materials for the Automotive Industry

摘要

A prototype that allows fatigue corrosion to be performed on joined panels in cyclic corrosion tests has been developed. Preliminary tests were performed on magnesium alloy (AM50) adhesively bonded to aluminum alloy (AA6016), on cold rolled carbon steel clinch-bonded with hot-dip galvanized carbon steel and on electro galvanized (EG) steel clinched to aluminum alloy (AA5182). Results were obtained after exposure to the Renault cyclic corrosion test (ECC1) with and without simultaneous fatigue loading. Fatigue loading was applied with a load ratio R of 0, i.e. repeated tension, a frequency of 0.025 Hz and a maximum load of 15% to 24% of the tensile strength. After exposure, the residual tensile strength was compared to reference tensile strength obtained before any exposure. The failure mode and the corrosion in the overlap area were also evaluated. Preliminary results showed that the damaging effect of corrosion was increased by the simultaneous fatigue loading.