Dual-phase stainless steel segmented construction method for chemical ship

Abstract

The invention discloses a dual-phase stainless steel segmented construction method for a chemical ship. The dual-phase stainless steel segmented construction method for the chemical ship comprises thefollowing steps that a carbon steel middle group and a stainless steel splicing plate are separately constructed, wherein the stainless steel splicing plate comprises a framework surface and a liquidcargo tank surface; the carbon steel middle group and the stainless steel splicing plate are combined; the stainless steel splicing plate is welded on the carbon steel middle group; an outfitting piece is arranged on the liquid cargo tank surface, and surface treatment is performed; and when the stainless steel splicing plate is welded on the carbon steel middle group, the framework surface is firstly welded, and then the liquid cargo tank surface is welded. The dual-phase stainless steel segmented construction method for the chemical ship has the beneficial effects that the number of stainless steel special jig frames and the arrangement of stainless steel segmentation special jig positions are reduced, the stainless steel segmented construction efficiency is improved, the welding efficiency and quality of stainless steel welding workers are further improved, the stainless steel welding deformation can be effectively controlled by fully utilizing the stainless steel deformation mechanism, so that the stainless steel segmented construction quality is improved.

Description

Technical field [0001] The invention belongs to the technical field of ship construction, and particularly relates to a method for constructing a chemical tanker duplex stainless steel section. Background technique [0002] The method of the present invention mainly researches and solves three background technologies: [0003] First, the duplex stainless steel section construction of chemical tankers is relatively special due to the special material of duplex stainless steel. In order to avoid the contact between stainless steel and other materials, most shipyards set up special workshops during the construction process, and the stainless steel section construction is similar to that of ordinary ships. The isolation is constructed in sections, and it is required to build on a special stainless steel tire frame. As stainless steel ship lines become more and more complex, shipowners have higher and higher requirements for the construction cycle. In order to ensure the progress of ma...

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Problems solved by technology

At the same time, duplex stainless steel is sensitive to temperature, and it is difficult to correct after welding deformation

The second is that duplex stainless steel contains about 50% ferrite, which also has brittleness at 475°C. Ferrite in duplex steel will precipitate high-chromium α phase when it is kept warm for a long time between 300-525°C. Sensitive, embrittlement of dual-phase steel, therefore, it is very difficult to control the temperature during welding, and it is easy to produce embrittlement on the back of welding (especially when it is heated twice) during double-sided welding of jigsaw panels

[0006] In the third aspect, during the manufacturing process of duplex stainless steel, the surface is very prone to various defects, especially brown spots, most of these brown spots are only found in the pickling process

It not only increases the construction cost of stainless steel sections, but also poses severe challenges to the layout requirements of tire positions

[0009] 2. The traditional stainless steel segmented stainless steel panel is first welded to the liquid cargo tank surface, and then welded to the frame surface, because the weld seam of the liquid cargo tank surface is heated twice (the first time it is welded by itself, and the second time is produced when the frame surface is welded. ), especially the second heating temperature is more difficult to grasp, and it is very easy to produce embrittlement on the surface of the weld, which is very harmful to the surface quality of the cargo tank

[0010] 3. In traditional stainless steel segmental construction, the inner shell longitudinals and stainless steel panels are first welded (using an automatic fillet welder). Even if local restraint welding is performed, it is impossible to control the deformation of the fillet weld or eliminate the stress of the fillet weld , after the restraint welding is removed, the deformation will appear immediately, and it is very difficult to deal with

[0011] 4. The traditional stainless steel segmental construction period is long, the surface of the liquid cargo tank is in contact with the tire frame for a long time, it is very difficult to protect the surface of the liquid cargo tank, and there are many defects on the surface of the liquid cargo tank, and it takes a lot of time to repair

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