MEASURING THE PRE-HEATING TEMPERATURE OF THE PLATES SURFACE WITH IMPACT GAS IN THE WELDING GAP DURING EXPLOSION WELDING

A technique for measuring the heat flux from the shock-compressed gas in front of the point of contact to the surface of the colliding plates has been developed. The experimental values of the heat flux are obtained, which are in satisfactory agreement with theoretical calculations. For the first time experimentally proved a significant effect of preheating of plates before collision for various materials. The effect consists in heating the surface of the plates, depending on their dimensions and properties, up to 1000 ° C and above.

THE ASPECTS OF ALMG6 ALUMINIUM ALLOY DEFORMATION UNDER EXPLOSIVE WELDING

The paper presents the results of a study of the features of the deformation of the main plate made of AlMg6 in the process of explosion welding (with corrosion-resistant steel 08Cr18Ni10Ti). It was found that the end and edge sections of the main plate undergo severe deformation, as evidenced by the constructed maps of the distribution of residual deformations over the plate area. With an increase in the detonation velocity, an intensification of the deformation process occurs, which leads to the appearance of cracks and local spalling of plate fragments. In addition, the results of measurements of the elongation of the main plate showed that a noticeable longitudinal deformation of the plate begins approximately at a distance equal to 2/3 of the total length of the plate. The measured value of the beginning of elongation (240 ± 10 mm) with an accuracy of 95% converges with the calculated value (229 mm).

FEATURES OF FORMING THE VT1-0+AMG5 JOINT DURING EXPLOSION WELDING WITH THE INFLUENCE OF ACOUSTIC VIBRATIONS

The work is devoted to the study of the influence of the introduction of acoustic vibrations during explosion welding of the VT1-0 + AMg5 pair. A comparative study of joints obtained by the conventional method of explosion welding and explosion welding with the effect of acoustic vibrations in various welding modes has been carried out. The results of the study of the microstructure and mechanical properties allow us to speak about the positive effect of the introduction of acoustic vibrations during welding VT1-0 + AMg5, which consists in expanding the weldability area and reducing the volume of the melted metal in the joint zone. It is also shown in the work that the nature of surface preparation before welding can have a significant effect on the strength of the joint.

Simulation of New Multilayer Waveguides by Explosion Welding

The possibility of obtaining multilayer cylindrical waveguides by explosion welding is investigated. The fact that the technological welding scheme has a significant impact on the shaping of workpieces and the value of edge effects was established. The studies demonstrated that the nature of wave formation during the manufacture of multilayer cylindrical waveguides from a homogeneous material by explosion welding using a central rod is identical to the wave formation when welding flat multilayer compositions on a rigid base.

Research of the stress-strain state of a workpiece under the double bending by the pulse loading

The object of research is the technology of metal processing by high-speed and high-energy methods, plastic deformation of layered metal compositions. Theoretical studies are based on the main provisions of the theory of joining metals in the solid phase, the theory of plasticity, explosion welding technology, plastic deformation of layered metal compositions, and their heat treatment. The main problem of creating layered metal compositions using explosion energy, including wear and corrosion resistant, electrical, materials with high ballistic resistance, etc., is that they have not yet taken their rightful place in the range of modern structural and functional materials. This can be explained by the limited application of this process, as well as the lagging behind the theory and experimental base in the field of joining various metals in the solid phase and providing the necessary performance properties according to the needs of modern industry. The process of deformation of the cladding blank during the explosion welding is considered. The process of the workpiece collision is considered in three stages: the movement of the element of the cladding workpiece before the collision, its inertial movement and deformation. The equations of motion and equilibrium of the elements of the workpiece are described. A joint solution of the equations of plasticity and equilibrium of the blank element in the double inflection zone is presented. The work is devoted to solving the problem of increasing the level of production and economic indicators of the manufacture of layered metal compositions through the development of methods for calculating and optimizing the technological parameters. Explosion welding, as the most versatile, promising, and economical method, which still has many possibilities for the application of mathematical modeling and process optimization, has been investigated for the production and subsequent processing of the main groups of industrial metal compositions. This makes it possible to solve the problem of replacing traditional materials with layered metal compositions. The results obtained are important from the point of view of the application of cost-effective materials with high mechanical, operational, and technological properties.

The influence of the technological cycle of production on the change in the physical and mechanical characteristics of bimetal with a butt welded joint in the cladding layer

The goal of the study is to consider the effect of explosion welding, heat treatment and cold straightening (gagging) in production of 09G2S + 08Kh13 bimetal with a butt welded joint in the cladding layer on the evolution of residual internal stresses. The impact of technological operations on the change in the level of residual stresses in a bimetallic material with a welded butt joint in the cladding layer was carried out using a non-destructive method of the magnetic memory of metals (MMM). This method is based on the use of the intrinsic stray magnetic field formed in the zones of increased dislocation density. The results revealed the special features of the location of zones with maximum values of the stress field gradient (dH/dx) and their evolution upon production of 09G2S + 08Kh13 bimetal with a butt welded joint in the cladding layer. An increase in the level of residual stresses in the cladding layer occurs after manual electric arc welding of 2 parts of the cladding layer made of 08Kh13 steel. It is shown that after explosion welding the level of residual stresses change. The stress relaxation occurs in the zone of weld in the cladding layer. At the same time, an increase in the level of residual stresses is observed in the main and cladding layer of the bimetal. To reduce the high level of residual stresses, we used the subsequent heat treatment of the obtained bimetallic samples in two different modes. The optimal heat treatment mode (heating to 720 ± 20°C, holding for 2 h, cooling with a furnace) which excluded the crack formation in the cladding layer upon mechanical straightening of bimetal was specified for 09G2S + 08Kh13 bimetal sample with a butt welded joint in the cladding layer.

X-RAY STUDIES OF COMPOSITE MATERIAL STEEL 20 - STAINLESS STEEL 50CR15MO2V AFTER EXPLOSION WELDING AND NORMALIZATION

The results of studies of the characteristics of the fine structure of a bimetal made of stainless steel 50Kh15M2F and carbon steel 20 after explosion welding and subsequent heat treatment in the joint zone are presented. It was found that normalization at temperatures above 900 ° C leads to a martensitic transformation in steel 50Cr15Мo2V, which is accompanied by an increase in hardness and the development of a fine structure: an increase in the level of elastic deformation of the crystal lattice and fragmentation of coherent scattering regions.

FEATURES OF STRUCTURE FORMATION IN THE JOINING ZONE OF COPPER-STEEL COMPOSITE COPPER M3 + STEEL 30CRMNSIA AFTER EXPLOSION WELDING AND THERMAL IMPROVEMENT

The results of optical and electron microscopic metallographic studies and energy-dispersive analysis of the structure and composition in the zone of connection of copper M3 with steel 30 CrMnSiA after explosion welding, subsequent quenching from a temperature of 880 ° C and high tempering at a temperature of 520 ° C are presented. The change in the distribution of hardness and chemical elements over the cross section of the bimetal, the formation of martensite in melts after quenching and its decomposition during high tempering are shown.