焊透深度和前进侧位置对FSW 贮箱锁底接头性能的影响

开展了2219MCS 叉形环和2219C10S 短壳组成的锁底接头的搅拌摩擦焊工艺试验,详细分析了

搅拌针长度和前进侧位置对锁底接头Hook 型缺陷、力学性能、断裂方式的影响规律。结果表明:搅拌摩擦焊

锁底接头在短壳一侧存在Hook 型缺陷,短壳位于前进侧时的搭接界面上翘曲率和迁移量均大于叉形环位于

前进侧,且随着搅拌针长度的增加,搭接界面的向上迁移量逐渐增大。相同的焊透深度时,叉形环位于前进侧

的力学性能优于短壳位于前进侧;相同的前进侧位置时,随着焊透深度的逐渐增加,接头力学性能逐渐降低。

锁底接头搭接界面缺陷形貌及迁移量的变化是引起力学性能变化的主要原因。优化的试验结果显示,当焊透

深度和短壳板材厚度相同,且叉形环位于焊缝前进侧的力学性能最优,常温可达到300 MPa,低温可达到370

MPa,延伸率均超过3. 5%。锁底接头的拉伸断裂方式与焊缝前进侧位置密切相关。当短壳位于前进侧时,从

短壳一侧热力影响区断裂;当叉形环为前进侧时,从焊缝焊核区断裂。

Efect of FSW Pin Length and AS Location on MechanicalProperties of Lock Joint of Tank

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.