Recently, seven hundred twenty-five 4500 meters manned submersible framework manufacturing and bearing test and acceptance is completed, to fill the gaps in our submersible titanium alloy frame manufacturing field, provides the reference standard and basis for the submersible titanium alloy frame design, manufacture and test.
4500 meters deep manned submersible is a key project of national "863", in which the frame is the supporting framework of the submersible, both for the manned cabin, buoyancy and various equipment provides a mounting base, but also in lifting recovery, mother ship carrying, sitting sink to the bottom of the sea in the process under the submersible weight and 4500 meters depth under seawater stress. Manned submersible frame manufacturing is an important part of the whole project.
Titanium alloy submersible framework for domestic first developed, frame under the condition of under load is large and complex, structure dense welds, low rigidity structure, easy to produce welding deformation, so the technical index requirements are very strict, all the main weld requires full weld penetration (including a large number of fillet welding seam), the overall structure of the dimension precision demanding, it is necessary to meet the structural strength of the seam, but also control the structure welding deformation.
The technological problems encountered in the early stage of the project, project team members to a positive, cooperative and hard tackling, combined with its process characteristics, breaking the spear MIG welding, vacuum electron beam welding and heat treatment as a whole in a number of key technologies. In the case of full penetration of the frame body, the welding deformation of the frame is effectively controlled, which meets the requirements of the stringent technical requirements.

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