SU925596A1 - Method of producing bimelallic tube plates - Google Patents

Description

(5) METHOD OF MANUFACTURING BIMETALLIC PIPE GRIDS

one

The invention relates to the field of welding and can be used in public goods branches that manufacture heat exchangers with bimetallic tube sheets.

The closest to the invention to the technical essence is the method of making bimetallic tube sheets, which is used for plating the tube sheet, reaming the holes, installing the tubes in them, disassembling the pipe ends and welding them to the tube sheet.

However, with this method, depending on the method of obtaining the bimetal and the diameter of the tube plates from 20 to 5% of the cladding layer, it goes to waste, since the cladding corrosion-resistant layer is needed only in the preformed area, i.e. on the bridges and the tube grid sealing field, the consumption of cladding material is significant, for example,

In order to obtain a cladding layer with the required chemical composition, the cladding should be carried out in no less than three layers, and in case of induction heating due to the shrinkage of the molten metal, the cladding layer is 2-2 times thicker than S. In addition, specialized sites are required to obtain a bimetal.

The aim of the invention is to reduce the consumption of scarce and expensive corrosive resistant materials.

Claims (2)

For the method of making bimetallic tube grids, which are used for cladding the tube grid, drilling out holes, installing pipes in them, fitting the pipe ends and welding them to the tube grid, the cladding is carried out in two steps: first the clad layer is applied onto the sealing field of the tube sheet, and after drilling the hole, installing the tubes in them, disassembling their ends, the cladding layer is applied onto the bridges in the process of welding the tubes to the tube sheet. FIG. 1 shows a tube plate obtained by a known method in FIG. 2 - application of the cladding layer on the sealing field; FIG. 3 welding scheme with simultaneous surfacing of the cladding layer. The manufacturing method is implemented as follows. A corrosion-resistant cladding layer is deposited on the sealing surface of the tube sheet. The surfacing is performed by an AV, a tomato under a flux layer of an AN-B using a ribbon electrode made of MNM5-1 alloy or by an argon-arc method using welding wire St. MNZHKT5-1-0, 2-0, 2. Surfacing mode: Welding current 850-900 A; Voltage at arc 3 –3 V; Welding speed 10 m / h; The thickness of the electrode tape is 2.0 mm, the width of the electrode tape is 20.0 mm. Surfacing mode argon-arc method: Welding current A; Welding speed m / h j Welding wire diameter mm Then, the holes are drilled, the tubes are inserted into the tube bars and the ends are disassembled. After that, the pipes are welded and the cladding layer is overlaid by lintels of tube sheets. The welding and surfacing is carried out by the argon-arc method using a non-consumable electrode using a welding rod of the type ST MNZHKT5-1-0.2-0.2 on the welding current 120-1 0 A, with one seam. Applying the cladding layer before drilling the holes only on the sealing field and then surfacing on the lintels with simultaneous welding of pipes makes it possible to exclude the operation of drilling out the expensive corrosion-resistant material together with the metal of the tube grid, and also to eliminate the independent operation of the preliminary surfacing of the cladding layer. The proposed method allows to obtain bimetallic tube grids with a lower consumption of scarce and expensive corrosion-resistant materials and without creating specialized sections, to weld in one layer, because of the narrow jumpers (3-5 mm) and the framing of the pipe ends, in the formation of a weld Improve not only the material being deposited, but also the material of corrosion-resistant pipes containing up to 28 nickel and reduce the cost of tube grids. Claims The method of manufacturing bimetallic tube sheets, which is used to clad a tube grid, drill holes in it, install pipes in them, disassemble the tube ends and weld them to the tube grid, characterized in that the chain reduces the consumption of scarce and expensive corrosion-resistant materials, cladding is performed in two stages: first, a cladding layer is applied to the sealing field of the tube sheet, and after drilling the holes, installing pipes in them and disassembling their ends uyuschy layer was applied to webs in the welding process, the pipes to the tubesheet. Sources of information taken into account during the examination 1. Kalinina AP and others. Features of welding small-diameter pipes with tube sheets in the manufacture of heat exchangers. Chem. and neorg. mechanical engineering, 1978, № 10, p. 24-26 (prototype).  ff ff / rffflyfffi ft / v fffmrffi - eoffjfoffeff oa e / f f / fff / ff r / ffffftf y e eeff ZV. / gon 0fff.l