The paper presents the comparative results of mechanical tensile testing at room (20 ± 10°C) and reduced (–196 ± 5°C) temperature of the cold- and hot-rolled samples of a semi-finished sheet product ...made of alloy 1580. The test samples were obtained from the 12 mm thick hot-rolled as well as 2 and 4.5 mm thick cold-rolled semi-finished products. The tests were performed in compliance with GOST 1497-84 and GOST 22706-77. According to the test results, the strength and plastic characteristics of the semi-finished sheet product made of alloy 1580 are higher at the lower temperature compared to those measured at the room temperature. Specifically, the ultimate tensile strength of the samples is higher by 20%, yield point — by 11%, and percent elongation — by 40%.
The structure and properties of cold-rolled strips with a thickness of 3 mm from an experimental aluminum alloy 1580 with a lower scandium content of 0.03% (wt.) relative to the grade of the aluminum ...alloy and a 5083 similar alloy without scandium were studied. Ingots obtained at the laboratory installation of semicontinuous casting of the foundry department of the Siberian Federal University (Siberian Federal University, Russia, Krasnoyarsk) were used. The preparation of ingots for rolling included milling up to sizes of 40 × 100 × 145 mm and annealing according to a two-stage mode: at a temperature of 350 °C for 3 h (first stage) and at a temperature of 425 °C for 4 h (second stage). Hot rolling was carried out in the laboratory of the Department of Metal Forming at the Siberian Federal University at a temperature of 450 °C on a two-roll hot rolling mill with a roll diameter of 330 mm and a barrel length of 520 mm to a thickness of 5 mm, which corresponded to a total reduction of 88% with a single reduction of 2–5%. For cold rolling, a two-roll sheet rolling mill with a roll diameter of 200 mm and a barrel length of 400 mm grade LS 400 AUTO was used. Rolling was carried out to a thickness of 3 mm with a single reduction of 2–5%, and then the strip was annealed. The results of determining the mechanical properties by tension by the universal LFM400 machine showed that with an increase in the annealing temperature in the range from 250 to 350 °C for 3 h, ultimate tensile strength of the cold-rolled strips of aluminum alloy 1580 decreases from 385 to 365 MPa. For aluminum alloy 5083, a decrease in this strength characteristic is also observed from 345 to 320 MPa. A decreasing tendency with increasing annealing temperature was also observed for the conditional yield strength
R
p
, and over the entire range of annealing temperatures, the values of
R
p
for strips of alloy 1580 were higher than for alloy 5083 by 35–40 MPa, which amounted to 14–17% The values of the plastic properties, for which the value of the elongation to failure was analyzed, were close throughout the range of annealing temperatures for both alloys. The results of the analysis of micro- and fine structure allowed to conclude that an increase in the strength properties of cold-rolled and annealed sheets from the experimental alloy 1580, compared with alloy 5083, is a consequence of the addition of scandium in the experimental alloy 1580, which leads to an increase in the temperature of recrystallization of the alloy, preserving it contains a subgrain structure and dispersion hardening caused by precipitation of Al
3
(Sc, Zr) phase particles during the decomposition of a solid solution.
Weldability of industrial alloy 1580 sheets by friction stir welding is studied. Specimens investigated are from 1580 grade aluminum alloy cards 210 × 300 mm in size and 4.5 mm thick in an annealed ...condition, prepared by cold rolling under Russian metallurgical enterprise industrial conditions. In this work tasks of testing welded specimen mechanical properties by static tensile tests, studying welded seam structure and assessing the of the welded seam quality by X-ray analysis, and conducting static bending tests are resolved. It is shown that use of friction stir welding for joining sheets of alloy 1580 makes it possible to obtain a high quality weld, characterized by the absence of defects confirmed by X-ray studies. In this case the welded seam strength coefficient is 0.97, and workpieces welded by this method have high static bending test indices.
Abstract
The article discusses the results of the development and research of controlled electrical preheating of casting troughs and intermediate tanks in the system of transport trays for pouring ...aluminum melt. Electric heating contributes to high-quality and safe pouring of the melt in the cold shop. The heating of the casting track links eliminates the possibility of an explosion when the melt contacts water or ice, and also maintains the fluidity of the metal and limits the temperature gradient in the melt. Evaluation of the efficiency of the heater system was carried out on the basis of mathematical modeling of thermohydrodynamic processes in the melt. Acceptable characteristics of the section of the trays were determined to improve the distribution of metal by the melting and casting complex. To ensure the electrical safety of the equipment, it is proposed to power the heaters at a reduced voltage. Changing the intensity of heating is implemented by switching the windings of a group of power transformers from a delta connection to a star connection. Preheating controls are built in the form of a relay-contactor subsystem integrated into the microcontroller control system of the foundry complex.
A study of the properties of industrial sheets made of alloy 1580, including the determination of mechanical properties for tensile strength, impact strength, manufacturability during machining and ...shape- changing operations of sheet stamping, as well as during welding, has been carried out. The comparison of technological properties of alloy 1580 sheets with the properties of sheets made of aluminum alloy 1560, 1160, and 1201 has been performed. It has been established that alloy 1580 and 1560 sheets have similar properties in terms of machinability, manufacturability during shape-changing operations of sheet stamping, and weldability by electron beam welding. It is shown that the characteristics of the alloy 1580 during machining and shaping during sheet stamping are generally close to those of alloys 1160, 1201, and the absence of the need for hardening heat treatment (quenching followed by aging) and the high isotropy of the properties of semi-finished products are the advantages of the alloy 1580. The conducted studies indicate the prospects of using sheet semi-finished products of alloy 1580 for the manufacture of critical parts in various fields of mechanical engineering, such as aviation, space industry, automotive construction and shipbuilding.
In the ANSYS Fluent program, a computer simulation was performed for the production of ingots from aluminum alloy 5052 at a semi-continuous casting plant (SCCP). This method analyzed the nature of ...the melt temperature distribution in the metal path with two types of refractory coatings and estimated the heat loss during the melt passage from the mixer to the mold of the casting machine. The findings reveal that during the experimental verification of the casting of ingots, the results of the direct temperature measurements differed by no more than 2%–3% from the temperatures obtained by modeling, and the replacement of metal path cartridges made of refractory concrete with a density of 2090 kg/m
3
for concrete with a density of 1300 kg/m
3
reduced heat losses during the casting of ingots on the SCCP and reduced the temperature of the start of casting of alloy 5052 by 45°C, decreasing the hydrogen concentration in castings from 0.18–0.19 to 0.15 cm
3
/100 g.
The results of a comparative study of the mechanical properties of frac balls made of Mg–Al alloy are presented. Such balls are used in frac sleeves and made by different methods such as metal ...forming and casting. The microstructures of magnesium-alloy samples made by metal forming (commercial) and coquille casting (prototype) for the production of frac balls are examined. Electron microprobe analysis of the phase composition of the commercial and prototype samples is performed. The average tensile strength and offset yield strength of deformable and casting Mg–Al alloys are determined. The results of 20-hour dissolution of balls made of prototype and commercial magnesium alloys in formation water which is an aqueous solution of NaCl at a concentration of 30 g/liter are presented.
The results of experimental studies on the development of a method for obtaining titanium-containing bar ligature, the study of its structure and modifying ability are presented. The distinctive ...features of the new technology are the use of titanium sponge and/or titanium shavings as titanium raw materials, the primary alloying of aluminum with titanium, and then boron, the introduction of titanium in two stages: initially, 2/3 of the titanium metal raw materials are dissolved in the aluminum melt, and the remaining amount is introduced after the reduction of potassium tetrafluoroborate. Pre-impregnation of the titanium sponge with halide-containing flux and the use of a briquetted mixture of KBF
4
+ Al-powder are also provided. The experimental technology for the preparation of the Al–Ti–B melt is described, the extraction of titanium and boron into the ligature is calculated, its microstructure is investigated, and the chemical and molecular compositions of the resulting slags are determined. Deformation treatment for the production of bar ligature was carried out by the method of direct extrolling which made it possible to level the defects of the cast structure. It is established that the use of high-speed crystallization-deformation in the implementation of the combined direct extrolling process makes it possible to obtain alloying bars of a given diameter at minimal energy consumption with the required complex of mechanical and operational properties. A quantitative assessment of the modifying ability of the experimental cast-iron ligature and the deformed cast-iron rod obtained by the direct extrolling method was carried out in comparison with the mass-produced cast-iron ligature produced by KBM Affilips (the Netherlands/Belgium). Based on theoretical and experimental studies, the composition and technology for producing Al–Ti–B modifying ligature using titanium sponge and/or shavings and potassium tetrafluoroborate with a content of 3.0 ± 0.3% titanium and 1.0 ± 0.2% boron as alloying additives have been developed, which meets the requirements for the composition of aluminum ligatures.
The ProCAST software package was used to simulate the crystallization of a slab ingot on an installation for semi-continuous casting of aluminum alloys, which made it possible to determine the ...distribution of temperature, solid phase volume and melt flow velocities during the crystallization of slab ingots with a cross section of 200 × 60 mm at various casting parameters. Verification of the model was carried out on a physical model of the installation, which represents a model of an industrial casting unit for semi-continuous casting. 1580 aluminum-magnesium alloy was used as a simulation object. In the ingot obtained by physical simulation carried out according to computer simulation modes, no surface or internal defects were detected, and the hydrogen concentration in it was 0.17 cm
3
/100 g, which meets the requirements of regulatory documents.
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