局部干法环境下GMAW横向焊接熔滴过渡特性

提出了一种水下结构件局部干法横向焊接方法，该方法通过对排水罩结构进行设计，使高压气体在排水的同时在排水罩内部形成向上流动的风场，利用风场对熔池的吹袭作用来抑制熔池下淌. 采用高速摄像技术研究了在侧向风场作用下GMAW焊的熔滴过渡特性. 结果表明，在短路过渡状态下，由于受到侧向风场的影响，更容易发生B型短路过渡. 在滴状过渡时，由于熔滴体积较大，侧向风场的支托作用不明显，熔滴沿焊丝倾斜向下过渡到熔池中. 在射流过渡时，侧向风场对电弧的影响较小，使熔滴略微向上偏斜，有助于减小熔池下淌程度，获得较好的焊缝成形质量. 研究结果对于水下结构件横向焊接质量控制有一定的参考价值.

Metal transfer characteristics in the GMAW horizontal welding process under local dry environment

A local dry underwater weld method was proposed in this paper for the underwater structures horizontal welding. Through designing the structure of waterproof chamber, a flowing up wind field was formed, and this wind field was used to reduce the molten pool dropping during horizontal welding process. A high speed camera was used to record the metal transfer process, then the characteristic of metal transfer of GMAW in the local dry environment was researched. The results show that B type short circuiting transfer more easily happened in the local dry welding environment. In the globular transfer status, due to the mass of droplet was relatively large, the lateral wind had less influence on the droplet. The droplet transfers into molten pool along downwards direction. In the spray transfer status, the lateral wind had less influence to the welding arc but make the droplet transfer into the molten pool slightly along a upward direction. It was beneficial to depress the molten pool dropping during horizontal welding process and improved the welding bead forming quality. The results had certain reference value to improve the horizontal welding quality.