| 摘要 |
PROBLEM TO BE SOLVED: To provide an aluminum alloy structural member having a resistance spot welding joint more excellent in fatigue strength than heretofore. SOLUTION: This aluminum alloy structural member has a resistance spot welding joint excellent in fatigue strength, in which resistance spot welding joint of an aluminum alloy the value of a surface defect is <=375μm and the value of an internal defect is <=850μm when these values are defined by a value of a square root of S (√S) where S stands for the cross sectional area of a projected surface given by projecting a weld defect on a surface which is vertical with respect to a load stress direction. The bottom surface of an impression has a shape of an arc, the ratio of the depth of the impression to the radius of the impression is <=0.045, and the ratio of the impression to a plate thickness is <=0.135. |
