SU923683A1 - Method of producing multilayer vessels - Google Patents

Description

The invention relates to the manufacture of multilayer vessels operating under excessive internal pressure.

A known method of producing multilayer. vessels, including the installation of billets into one another with a gap, in which the filler is placed, under pressure, ensuring the tightness of the blanks [11.

The disadvantage of this method is its considerable complexity, as well as the fact that its operation is associated with the danger of sudden destruction by the pressure of the working environment.

The purpose of the invention is to reduce the complexity of manufacturing multi-layer vessels and increase their operational reliability.

This goal is achieved by the fact that in the method of manufacturing a multilayer ·. vessels, including the installation of billet one in DOWS with a gap, in which a filler is supplied, which provides tension, as a filler, use a material that increases its volume during phase transformations, place it in the gap - in a state of minimal volume, after which phase2

the transformation of the aggregate to its solid state.

At the same time as a placeholder

_ use a transition metal * and carry out the process of phase transformation by its hydrogenation. In addition, as a filler used or molten metal alloy, Ger, ₀ metiziruyut gap and ^ιυ th phase conversion process is performed while cooling the melt.

Shells tension is achieved for

due to the fact that in the gap between the shells place a material capable of

15 as a result of the phase transformation to increase its volume.

In the final state, the gap turns out to be filled with solid material, which, due to the increase in its volume under constrained conditions

exerts contact pressure on the outer th inner shell. In this case, the outer shell undergoes tensile stresses, and the inner shell undergoes compressive stresses, and the filler itself in the gap is under conditions of volumetric compression from the side of the shell surfaces that are in contact with it, since it itself tends to occupy a larger volume after phase transformation.

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As materials experiencing phase transformations, accompanied by an increase in the initial volume, can be used hydride-bonding materials: transition metals, their alloys and intermetallic compounds, such as, for example, titanium Zirconium, yttrium, niobium, hafnium, Fountain, lontan-nickel, lontan - iron, etc., which, when interacting with gaseous hydrogen, increase their initial volume by 15-20%. Depending on the nature of the metal, the temperature of its hydrogenation can be from 20 to 1000 ° C. For example, the nickel-lanthanum alloy is hydrogenated at 20–25 ° C, and yttrium — at 1000 ° C.

According to the proposed method, the process of hydrogenation is carried out after placing the hydride-forming metal in the form of a layer between the sides of the vessel, and then the vessel is placed in a hydrogen medium and heated. As a result, the formation of metal hydride in the gap with increasing its volume and shell are strained. · The process of formation of hydride all the time occurs when the solid state of the intermediate layer.

In addition, as materials having an increase in volume after crystallization (hardening), can be used such as, for example, silicon (whose volume change during melting to volume in the solid state is ΔΜ-3, 6%), gallium (d \ / - 3.2%), germanium (DU-5.0), tin (dU + 0.95 U, bismuth (d \ / - 3.35%), as well as, for example, bismuth-tin alloys, bismuth -galy

According to the proposed method, a melt of any of the above listed materials is poured into the gap between the shells, and then the melt crystallizes when it is cooled. In the final state, after crystallization, the walls in the vessel are strained.

The temperature mode of hydrogenation or crystallization, as well as the magnitude of the deformations of the shells, is determined in each particular case by the materials of the shells, the required magnitude of the stresses and the configuration of the shells. Mode of hydrogenation and. . crystallization for these materials is widely known in engineering and technological practice and does not cause difficulties in the implementation of the proposed method.

Example!. Take the pipe from two pipe blanks placed concentrically to each other. The material of pipe billets - St 121318N10T. The gap between the tube blanks is 2 mm. Accuracy of processing blanks in class 4. At. Soorke pipe header between them on landing with a gap placed zirconium pipe-- ’

Ku with a wall thickness of 1.9 mm. The collected three-layer pipe billet is placed in an autoclave, into which hydrogen is then injected. The mode of hydrogenation is as follows: the temperature is 600 ° C, the hydrogen pressure is 4 atm, the exposure time is 0.5-1.0 h. As a result, a three-layer pipe is obtained in which all the layers are connected to each other. An increase in the wall thickness of the intermediate tube during the hydrogenation process ensures that it fits snugly against the surface of the steel tubes.

PRI mme R 2. A three-layer pipe is made, such as, for example, in Example 1, to which the blanks are made of high-density graphite of the MPG-6 brand. The gap is pre-filled with silicon and, by that, siliconizes the walls of the tubes. Then melt technical silicon is poured into the gap at 1550 ° С. After sealing the gap with end caps, the billet is cooled to room temperature. The result is a strained three-layer pipe made of graphite, capable of operating at elevated temperatures and pressures.

Example A multi-layer vessel is made in the form of a cone with an inner surface of steel and an outer surface of titanium. An alloy of bismuth-gallium is poured into the gap between the tapered bushings at 250 ° C. Then the workpiece after sealing the gap is cooled to room temperature. Get a three-layer tapered tense sleeve.

As follows from the above examples, the proposed method can produce strained multilayer vessels from various materials and ’different configurations. The processing accuracy can be 4-5 classes, instead of 2-3 classes in a known way.

Techniques for implementing the method are simple and not time consuming.

Modes of hydrogenation and crystallization are also sufficiently known, can be analytically processed and therefore the final values of the stresses in the sides of the vessel can be calculated with an accuracy sufficient for their reliable operation.

The proposed method can be made cylindrical vessels, ^- spherical, conical and curved shape, which can be used in various branches of technology. In addition, the intermediate layer can simultaneously perform functions associated with changes in heat and electrical conductivity, radiation and chemical resistance, etc.

For the implementation of the proposed method uses the standard

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equipment: furnaces with heating in hydrogen, devices for casting melts, etc. In contrast to the known methods, it is not necessary to maintain a strictly predetermined temperature to create tension.

The simplicity of the method, the ability to use standard equipment, especially in the manufacture of vessels with melt pouring, and the possibility of producing vessels with melt pouring, and the possibility of manufacturing vessels of various configurations and lengths without high machining of the source shells on the mating surfaces, allow us to conclude that reducing the labor intensity of the vessel manufacturing process and the usefulness of the proposed method for the national economy.

Claims (3)

Claim 1. A method of manufacturing multilayer vessels, including the installation of billets into one another with zazrrom, which serves · a filler providing tension, characterized in that, in order to reduce the labor intensity of manufacturing multilayer vessels and increase their operational reliability, a material that increases its volume during phase transformations is used as a filler, is placed in a gap in a minimum volume state, and then phase transformation is performed aggregate to its solid state. 2. The method according to π. 1, characterized in that a transition metal is used as a filler and the process of phase transformation is carried out by hydrogenation. 3. Method pop.2, characterized in that a metal or alloy melt is used as a filler, the gap is sealed, and the phase transformation process is carried out with the melt cooled.