RU121760U1 - HORIZONTAL BORESEED STEEL PIPE - Google Patents

Abstract

1. Hexagonal boron steel pipe, characterized in that it is welded with a laser-welded seam located in the middle part of one of the pipe faces parallel to its rib, and the connection of the ribs is made with an outer radius of curvature of 20 ± 1.75 mm. ! 2. A hexagonal pipe according to claim 1, characterized in that its outer "turnkey" dimension is 257 ± 2.0 mm and the wall thickness of the edges is 6 ± 2.0 mm. ! 3. The hexagonal pipe according to claim 1, characterized in that it and the welded seam are made of boron steel containing carbon, chromium, boron, titanium, vanadium, silicon, manganese, aluminum, nickel, phosphorus and iron with the following content of components, wt .%: carbon 0.02-0.06; chromium 13.0-16.0; boron 1.3-3.6; titanium 2.3-6.5; vanadium 0.15-0.35; silicon not more than 0.5; manganese not more than 0.5; aluminum not more than 0.5; nickel not more than 0.5; phosphorus not more than 0.03, iron - the rest.

Description

The utility model relates to the field of production of pipes by welding, namely, welded pipes of a special shape for products of nuclear equipment with increased requirements for neutron absorption, in particular, equipment for storing spent nuclear fuel.

The closest in technical essence and the achieved technical result is a cover hex pipe with a turnkey size of 257 mm and a wall thickness of 6 mm made of ChS82 grade boron steel with a boron content of 1.3-1.8 wt.%. Known pipe for the manufacture of nuclear fuel storage equipment obtained by profiling seamless hot-rolled conversion pipes.

(RU 2317866, B21B 21/04, published 02.27.2008)

The disadvantages of the known pipe is its relatively high cost, due to the complexity of the manufacturing technology: obtaining a pipe billet and its conversion into a hexagonal pipe. In addition, with the existing production technology, the pipe may have obvious or latent defects, especially in the area of junction of faces, which requires constant quality control of the workpiece at the stages of redistribution, as well as repair of identified defects and repetition of technological operations. This ultimately reduces the reliability of both the pipe itself and the equipment in which it is used.

The objective and technical result of the utility model is a hexagonal tube made of boron steel with a reduced level of defectiveness in the area of the connection of faces and an increase in the reliability of its operation.

The technical result is achieved by the fact that the hexagonal pipe made of boron steel is made welded with a laser-welded seam placed in the middle part of the pipe face parallel to its edge, and the connection of the ribs is made with an outer radius of curvature of 20 ± 1.75 mm.

The technical result is also achieved by the fact that the external dimension of the turnkey pipe is 257 ± 2.0 mm with a wall thickness of the faces of 6 ± 2.0 mm, and the pipe and weld are made of boron steel containing carbon, chromium, boron, titanium , vanadium, silicon, manganese, aluminum, nickel, phosphorus and iron in the following ratio of components, wt.%: carbon 0.02-0.06; chrome 13.0-16.0; boron 1.3-3.6; titanium 2.3-6.5; vanadium 0.15-0.35; silicon not more than 0.5; manganese not more than 0.5; aluminum no more than 0.5; nickel no more than 0.5; phosphorus is not more than 0.03, the rest is iron.

The utility model can be illustrated in Figure 1, where:

1 - pipe face;

2 - weld;

3 - pipe edge.

Getting pipes according to a utility model are as follows. According to standard technology, their boron steel slab was rolled on rolls until the required size of 6 ± 2.0 mm was reached. Used boron steel containing carbon, chromium, boron, titanium, vanadium, silicon, manganese, aluminum, nickel, phosphorus and iron in the following ratio of components, wt.%: Carbon 0,037; chromium 13.8; boron 1.73; titanium 3.65; vanadium 0.24; silicon 0.41; manganese 0.32; 0.26 aluminum; nickel 0.21; phosphorus 0.007, sulfur 0.003, iron the rest. After rolling, sheet straightening on roller units, edge processing and precise cutting were carried out. Then, on a press brake, a six-sided pipe profile was formed with an external turnkey size of 257 ± 2.0 mm and an outer radius of curvature of the connection of the ribs of 20 ± 1.75 mm. The edges were welded using laser welding, and the seam was placed in the middle of the pipe face parallel to its edge. The composition of the weld metal did not differ from the composition of the boron steel used. After machining, the pipe was subjected to heat treatment.

The use of boron steel for the manufacture of a hexagonal pipe according to a utility model makes it possible to use it in structures of the nuclear industry that require increased neutron absorption due to the presence of boron in the steel composition. Placing a weld in the middle part of the pipe face parallel to its edge and its formation by laser welding with subsequent heat treatment does not reduce the boron content in the weld, reduce its uniform distribution in the weld volume, noticeable internal stresses in the pipe volume and loss of corrosion resistance. The formation of the outer radii of curvature of the connection of the ribs 20 ± 1.75 mm using the plate-bending technology also does not lead to the occurrence of defects and noticeable internal stresses in the rib areas of the pipe and the loss of corrosion resistance.

According to a utility model, the obtained hexagonal pipe had no defects in the area of joining faces and the weld, as well as differences in the chemical composition of the pipe and the weld. This provides resistance to intergranular corrosion and the reliability of the welded pipe under the influence of neutron radiation and moisture.

Claims (3)

1. A hexagonal tube made of boron steel, characterized in that it is made welded with a seam obtained by laser welding, placed in the middle part of one of the faces of the pipe parallel to its edge, and the connection of the ribs is made with an outer radius of curvature of 20 ± 1.75 mm. 2. The hexagonal pipe according to claim 1, characterized in that its external "turnkey" size is 257 ± 2.0 mm and the wall thickness of the faces is 6 ± 2.0 mm. 3. The hexagonal pipe according to claim 1, characterized in that it and the weld are made of boron steel containing carbon, chromium, boron, titanium, vanadium, silicon, manganese, aluminum, nickel, phosphorus and iron in the following components, wt %: carbon 0.02-0.06; chrome 13.0-16.0; boron 1.3-3.6; titanium 2.3-6.5; vanadium 0.15-0.35; silicon not more than 0.5; manganese not more than 0.5; aluminum no more than 0.5; nickel no more than 0.5; phosphorus no more than 0.03, iron - the rest.