Device for underwater local dry process welding and welding method

Abstract

The invention provides a device for underwater local dry process welding and a welding method. The device comprises a welding gun and further comprises a drainage cover with one end opened and an annular magnetic conductive iron core. An exciting coil is wound around the outer portion of the magnetic conductive iron core, and the welding gun is inserted in the middle portion of the magnetic conductive iron core and penetrates the magnetic conductive iron core to be inserted in the drainage cover. The drainage cover covers at least part of a to-be-welded area on a workpiece, and the drainage cover is in sealed connection with the workpiece through a drainage sealing device. According to the device for underwater local dry process welding and the welding method, the arc form in the welding process can be effectively improved, arcs are contracted, accordingly, the infiltration capacity of molten drops at the end portion of a welding wire in the welding process can be improved, the weldingline structure is refined, molten drop transition is promoted, and accordingly the quality of a welding connector is improved. In addition, the device for underwater local dry process welding is simple in structure, low in manufacturing cost, capable of being applicable to multi-position welding operation and wide in project application range.

Description

technical field [0001] The invention relates to the field of welding, in particular to a device and welding method for underwater partial dry welding. Background technique [0002] With the development and utilization of marine resources, underwater welding has become an important technical means for the construction and maintenance of offshore engineering structures. However, due to the existence of water, the underwater welding process is much more complicated than land welding, and various problems that do not appear in land welding will occur, such as fast cooling speed, high hydrogen content in the weld, and poor weld formation. [0003] There are many kinds of underwater welding, which can be divided into wet welding, dry welding and partial dry welding in terms of working environment. Wet welding has the advantages of gradual change of equipment, flexible construction, and low price, but it is difficult to obtain better welded joints by wet welding. Dry welding has ...

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Problems solved by technology

[0004] However, there are still some deficiencies in underwater local dry welding: (1) In order to increase arc ionization, welding with large heat input is generally used, which will easily cause the weld structure to be thick and reduce the mechanical properties of the weld; (2) because the whole welding process is in water Complete, the cooling speed of the weld pool is too fast, the weld is not easy to spread, and it is easy to cause welding defects such as incomplete fusion and slag inclusion; (3) The molten drop is not easy to transfer to the base metal, and it is easy to form a large drop repulsive transition, resulting in arc instability

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