Abstract:An extensive investigation has been carried out on the friction stir welded lock joint consisted of a
2219MCS ring and a 2219C10S barrel, and the effect of the FSW pin length and AS location on the Hook defect, mechanical
property and fracture mode of the lock joint has been systematically analyzed in this paper. As the results indicated
that, there is a hook defect located in junction of the assembly interface and nugget zone, and the warping rate
and the migration amount of the junction when 2219C10S barrel located in AS location is greater than 2219MCS ring
located in AS. And the migration amount of the junction increased with the FSW pin length. The results of the tensile
tests indicated that the mechanical performance of the lock joint with the 2219MCS ring located in AS is better than
the 2219C10S barrel located in AS, and the mechanical properties reduced gradually with the increase of the FSW pin
length. As analyzed, the morphology of the hook defect and the migration amount are the main reasons for the change
of the mechanical properties with the AS location and FSW pin length. The optimized investigation results show that
the room temperature mechanical strength can be up to 300 MPa, the low temperature strength is 370 MPa, and the
ductility is all more than 3. 5%. The tensile failure mode of the FSWed lock joint is closely related to the AS location
of the 2219MCS ring or 2219C10S barrel.
