RU2433025C1 - Method of tube shells plating by explosion welding - Google Patents

Abstract

FIELD: technological processes. ^ SUBSTANCE: invention may be used for production of multilayer tube shells by explosion welding. The plated shell is installed in a massive matrix. Plastic material is installed between the external surface of the plated shell and the inner surface of the massive matrix. The plating shell is installed with a gap inside the plated shell, and an electric hydraulic generator is installed inside to develop impact waves. The generator comprises electrodes installed in a tight cylindrical body insulated along its inner surface and filled with fluid, in walls of which there are cumulative grooves with lining provided in them. Impact waves in the fluid are produced by development of a pulse high-voltage electric discharge between the electrodes. The plating and plated shells are exposed to cumulative jets formed by displacement of lining of cumulative grooves under action of impact waves. ^ EFFECT: method makes it possible to improve quality of welded joints and to reduce prime cost of works, at the same time it is environmentally safe since toxic explosives are not used. ^ 2 cl, 4 dwg

Description

The invention relates to methods for joining metals by explosion welding and can be used in mechanical engineering, metallurgy and other industries.

Explosion welding ("explosive cladding") is used to obtain a strong connection of two or more metal bodies during their collision. The acceleration of colliding bodies to the required speed is carried out, as a rule, under the influence of the explosion energy released during the detonation of explosives. Explosion welding is used for the manufacture of multilayer (most often bimetallic) sheets, strips, cylindrical products from a variety of metals and alloys.

A known method of cladding tube blanks by explosion welding, including installing a clad blank with a gap inside the clad blank, placing a hydraulic generator inside the clad blank and creating shock waves that affect the clad and clad blanks to produce a welded joint in contact areas (JP 58068490 A, 23.04. 1983, abstract). This method of cladding pipe billets by explosion welding is the closest analogue (prototype) to the proposed method.

The disadvantage of this method is not always the good quality of the welded joints.

The objective of the invention is to improve the quality of welded joints.

This goal is achieved by the fact that in the known method of cladding pipe billets by explosion welding, which includes installing a cladding workpiece with a gap inside the cladding workpiece, placing a hydraulic generator inside the cladding workpiece to create shock waves that affect the cladding and cladding workpieces to obtain a welded joint in contact zones , according to the invention, the plated workpiece is installed in a massive matrix between the outer surface of the plated workpiece and plastic material is placed in the morning surface of the massive matrix, and an electro-hydraulic generator is used to create shock waves, containing electrodes installed in a cylindrical body insulated over the entire inner surface and filled with liquid, in the walls of which cumulative recesses with lining located in them are made, while shock waves in a liquid is obtained by creating a pulsed high-voltage electric discharge between the electrodes, and the effect on the cladding and cladding the forging is carried out by cumulative jets formed by moving the lining of the cumulative recesses under the action of shock waves.

In addition, the shape, quantity and location in the housing of cumulative recesses with facings corresponds to a predetermined location of the contact zones when receiving a welded joint, taking into account the direction of propagation of cumulative jets.

Improving the quality of welded joints is achieved through the use of the cumulative effect of explosives (increasing the effect of the explosion by concentrating it in a given direction), which is achieved by using cumulative recesses and claddings located in the recesses in the electro-hydraulic generator. When an explosion is initiated, a high-speed cumulative jet is formed. The walls of the cladding slam toward each other, and as a result of their collision, the pressure in the material of the cladding increases sharply. The movement of the lining is similar to the flow of a liquid film - a jet is formed, moving at a speed of up to 10 km / s, which provides it with great strength.

As an electro-hydraulic generator of shock waves, it is possible to use, for example, a cumulative electro-hydraulic device for breaking and crushing solid materials (patent RU No. 2380161 C1, B02C 19/00, F42B 1/02, 05.23.2008).

The invention is illustrated by drawings, in which Figs. 1-4 show an application of the proposed method and the positions indicated: 1 - clad tube billet, 2 - massive matrix, 3 - plastic material, 4 - clad tube billet, 5 - electro-hydraulic shock wave generator , 6 - electrodes, 7 - liquid, 8 - body of an electro-hydraulic generator of shock waves, 9 - cumulative recesses, 10 - claddings, 11 - high-voltage pulse generator.

The method is as follows.

The plated tubular billet 1 is installed in a massive matrix 2. Between the outer surface of the plated tubular billet 1 and the inner surface of the massive matrix 2, plastic material 3 is placed, for example, asphalt, tar, sand, clay, rubber, etc. Inside the plated tubular billet 1, a plating is installed with a gap tube billet 4, and an electro-hydraulic shock wave generator 5 is placed inside the cladding tube billet 4, containing electrodes 6 installed in a sealed cylindrical liquid filled 7 ohm, isolated on the entire inner surface of the housing 8, in the walls of which cumulative recesses 9 with the facing 10 located in them are made. The shape, quantity and location of the cumulative recesses 9 with the facing 10 in the housing 8 is determined in accordance with the specified location of the contact zones upon receipt of the welded joint , considering the direction of distribution of cumulative jets.

Next, the electro-hydraulic generator of shock waves 5 through a high-frequency cable is connected to the output of the generator of high-voltage pulses 11.

After turning on the high-voltage pulse generator 11, a high voltage is applied to the discharge gap formed by the electrodes 6 of the electro-hydraulic shock wave generator 5, and a breakdown of the discharge gap occurs, accompanied by the formation of a conductive channel. An intense local heating of liquid 7 occurs in the discharge channel. In this case, the energy of superheated ionized gas and steam is concentrated in it. The rapid expansion of the discharge channel in the form of a vapor-gas cavity under the action of internal pressure creates compression waves and pressure pulses in the liquid 7. Due to the high pressure and rapid expansion of the discharge channel, shock waves are formed, which, moving, collapse the walls of the lining 10 towards each other. As a result of the collision of the walls, the pressure in the material of the linings 10 increases sharply. The movement of the linings 10 forms flows converging at a certain angle to the axes of the cumulative recesses 9, which pass into thin streams of liquid moving along the axes at very high speeds. As a result of this, the outer surface of the cladding tubular billet 4 enters into the contact zone with the inner surface of the cladding tubular billet 1, forming a welded joint.

The proposed method allows to improve the quality of welded joints.

Claims (2)

1. The method of cladding tube blanks by explosion welding, including installing a clad blank with a gap inside the clad blank, placing a hydraulic generator inside the clad blank and creating shock waves that affect the clad and clad blanks to produce a welded joint in contact zones, characterized in that the workpiece is installed in a massive matrix, between the outer surface of the plated workpiece and the inner surface of the massive matrix plastic material, and to create shock waves, an electro-hydraulic generator is used, containing electrodes installed in a sealed cylindrical body, insulated over the entire inner surface and filled with liquid, in the walls of which cumulative recesses with linings located in them are made, while shock waves in the liquid are obtained by creating a pulsed high-voltage electric discharge between the electrodes, and the impact on plating and plating blanks is carried out by cumulative uyami formed by moving the cumulative facing recesses under the action of shock waves. 2. The method according to claim 1, characterized in that the shape, quantity and location in the housing of cumulative recesses with facings corresponds to the specified location of the contact zones when receiving a welded joint, taking into account the direction of propagation of cumulative jets.

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