明确了搅拌摩擦焊技术应用于贮箱锁底环缝需要解决的关键问题。首先对熔焊锁底接头结构进行了搅拌摩擦焊工艺适应性设计,取消了背部焊漏槽和正面焊接坡口。结果表明:当叉形环位于焊缝前进侧,搅拌针长度与短壳板材厚度相当时锁底接头力学性能最优。锁底接头超声相控阵分析结果表明:存在于装配界面与焊核交界处的信号显示可以不当作缺陷信号判读。提出了采用立式帽装方式实现锁底环缝的装配焊接方案,并研制了可以保证锁底环缝装配间隙、错边、环缝平面度、贴合度以及叉形环大端周长的成套工装。实现了搅拌摩擦焊技术在Φ3 350 mm贮箱锁底环缝上的工程化应用,无损检测结果、形位尺寸符合设计要求。 Clarified the key problems to be solved when the friction stir welding technology is applied to the lock of the tank bottom. First of all, the structure of friction welded bottom joint was subjected to the friction stir welding process adaptability design, the back welding groove and the front welding groove were eliminated. The results show that when the fork ring is located on the advancing side of the weld and the length of the pin is equal to the thickness of the short shell plate, the mechanical properties of the locking joint are optimal. Ultrasonic phased array analysis of the lock-in connector shows that the signals present at the interface between the assembly interface and the weld nugget can not be interpreted as defect signals. The assembly and welding scheme of the lock ring girth lock with the vertical cap is proposed. The welding scheme of the lock girth lock, the wrong edge, the flatness of the girth ring, the fit degree and the large end circumference of the fork ring are also developed Kit. The engineering application of friction stir welding technology in Φ3 350 mm tank bottom lock ring was realized. The results of non-destructive testing and shape size conform to the design requirements.