抄録
The axial fatigue tests were performed using the dissimilar friction stir welds of aluminum alloy A6061-T6 (Al) and SS400 (Steel) and the fatigue behavior was investigated. The welding conditions of the Al/Steel weld were set to be the rotational speed of 800 rpm and the traveling speed of 50mm/min. The tensile strength of Al/Steel weld was 192MPa and that of Al/Al similar weld was 240MPa. The fatigue limit of Al/Steel weld was 80MPa and that of Al/Al weld was 120MPa. In the Al/Steel weld, fatigue cracks were initiated from the interface of Al and Steel and they propagated in the stir zone (SZ) to failure. On the other hand, in the Al/Al weld, fatigue cracks initiated from the thermo-mechamcally affected zone (TMAZ), where the hardness drop was the largest, by the slip deformation.
