Technological features of piston casting

The results of studies of obtaining complex castings from aluminum alloys using the self-filling method are presented. The influence of a number of technological parameters (pouring time, chill cooling mode, the use of self-filling, etc.) on the quality of the resulting piston castings has been studied. The optimal time for filling the chill mold was determined when casting pistons. It is shown that the chill mold cooling mode has a significant impact on the quality of castings.

Automation of Batch Casting of Cast Iron Melts in the Chill Mold in the Production of Castings of Machine Parts for the Mining Industry

The analysis of the basic parameters of the dosage of molten iron in metal forms using the magnetodynamic installation MDN-6CH. A schematic diagram has been developed for controlling the electromagnetic systems of the unit. The technology of dosing and pouring metal into the chill mold has been developed in the manufacture of cast iron balls with a diameter of 40 and 120 mm. At the optimal casting temperature, the electrical parameters of the inductor (voltage Ui, current Ii, power Ri) were in the range Ui = 250-300 V, Ii = 480-520 A, Ri = 140-160 kW. When reducing the mass of metal in the crucible MDN-6CH using a control scheme made switching inductor from a voltage of 300 V to 250 V. The power was reduced by 15-20 kW, and the temperature of the metal remained within the tolerance of the technology of metal casting. Using the adopted dosing scheme, it became possible to cast metal at constant parameters of the electromagnetic system and the time of pouring. The technology of dispensing and pouring metal into the mold for the production of cast iron balls with a diameter of 40 and 120 mm was carried out at an inductor voltage of 300 V, and the electromagnet - 220 V. The initial level of metal on the drain socket was equal to 20 mm. The molding time of molds in the manufacture of balls with a diameter of 40 mm was 7.3 s, and balls with a diameter of 120 mm - 16.2 s. The operating time of the electromechanical actuator was set in the manufacture of balls with a diameter of 40 mm - 0.35 s, and balls with a diameter of 120 mm - 0.75s. The consumption of metal in the manufacture of balls with a diameter of 40 and 120 mm was in the range of 0.7-0.75 kg / s and 1.65-1.70 kg / s, respectively. The metal casting was carried out at temperatures of 1320-1340 ° C and 1360-1380 ° C. The dosage accuracy was determined by weighing the metal of the poured balls and the molding system of the mold. Mathematical processing of the results of the dosing showed that in the manufacture of balls with a diameter of 40 mm at a temperature of 1320 °C the error of dosing is 10-11%. With increasing iron temperature, the dosage error decreases and at a metal temperature of 1370 °C is 5-6%. In the manufacture of balls with a diameter of 120 mm at a temperature of iron 1330, the dosage error is 7-8%, and at a temperature of 1360 ° C - 3-4%. The study of the characteristics of the casting and dosing process of cast iron in the chill mold allowed us to develop the technology of casting cast iron melts, which provided the required metering accuracy and high productivity of the conveyor production of grinding bodies.

Investigation of Electromagnetic Influence on the Liquid Heart of Aluminium Ingots at Continuous Casting in a Direct Chill Mold

The mathematical model of system "inductor-ingot" for investigation electromagnetic process at the continuous casting of aluminum ingots in a direct chill mold is considered in this article. Calculation at various parameters of a power line is made, electromechanical characteristics of stirrer are found. The frequency range at which electromagnetic influence of an inductor on a liquid heart of an ingot is most effective is established. The results of mathematical and physical modeling which have shown reliability of mathematical model are compared

The End-to-End Simulation of Semi-Continuous Casting and Subsequent Hot Rolling with Account of Microstructure

Basing on the developed methodology for data transfer between the ProCAST and Deform-3D software products, which allows exporting geometry, temperature, residual stresses and microstructure of the casting, it is simulated semi-continuous casting of ingots from aluminum alloy 5182 into a direct chill mold and their following hot rolling in a reversing rolling stand to with aim to study microstructure the evolution.

Effect of composition and morphology of non-metallic inclusions on fracture toughness in as-cast AHSS

A set of water-cooling copper-chill mold equipment is designed to study the precipitation behavior of different inclusion types in test steel under different cooling conditions, as well as its effects on the steel mechanical properties. As the results reveal, slow cooling treatment near the solidus temperature of test steel is conducive to forming more MnS + Al2O3 composite inclusions. The impact energy (−16 °C) of slow-cooled cast ingots at the core position is 28% higher than that of the air-cooled ingots. Scanning electron microscopy analysis of the specimens shows that small cracks are formed around single Al2O3 inclusions, but no cracks were found around composite inclusions. A calculation model of the tessellated stress of composite inclusions in steel is introduced to verify this phenomenon. The calculation demonstrates that, with a cover of ductile MnS, stress concentration around the composite inclusion is significantly decreased as compared with the single Al2O3 inclusion in the test steel.

A HALF OF A METAL BIPARTITE MOLD OF THE SEIMA-TURBINO PERIOD FROM THE UPPER IRTYSH REGION

We describe a rare fi nd—part of a Middle Bronze Age bipartite metal chill mold from the Upper Irtysh basin, used for casting three socketed javelin heads of the Seima-Turbino type. The use of metal molds (chill molds) for bronze casting is a sophisticated technique that is rather rare even at the present time. Having originated in the Bronze Age, it was subsequently abandoned for a long time. Chill molds indicate an advanced and effi cient bronze casting. In terms of the gate system, the specimen is a hinged vertically split chill mold. In Eurasia, the technique of casting javelin heads in chill molds was practiced until the Early Iron Age. In Western Siberia, it originated no later than the Middle Bronze Age. At that time, bronze casting in molds made of metal, stone, clay, and organic materials was highly developed. Apparently, the Upper Irtysh basin, including western Altai, was the region from whence prototypical metal molds had spread and were subsequently replicated in less valuable and less technologically effi cient materials such as clay.

INFLUENCE OF METHODS FOR ALTI MASTER ALLOY PRODUCTION ON ITS STRUCTURE AND EFFICIENCY IN ALUMINUM ALLOY MODIFICATION

A comparative study on the effect of methods for obtaining AlTi4 modifying master alloys on the sizes of Al3Ti intermetallics is made. It is found that increasing cooling rates at solidification from 10–15 °C/s (crystallization in a hot cast iron mold, a plate 30 mm in thickness) to 60–65 °C/s (crystallization in a cold cast iron chill mold, a rod 20 mm in diameter, 170 mm in length) reduces the length and thickness of needle-shaped intermetallics almost twice (397×23 to 215×13 μm). At the same time, lower electrical conductivity and higher alloy density in a solid state are observed. Melt modification with 0,5 wt.% magnesium addition causes the formation of homogeneous 98×3 μm fine-needle intermetallics. The addition of magnesium slightly reduces electrical conductivity and density compared with the AlTi4 master alloy crystallized at the same cooling rate (60–65 °C/s). Modification of A97 grade aluminum and AK9ch alloy (Al–Si–Mg system) with the specified master alloys at the same amount of titanium added (0,01 wt.%) exerts hereditary influence on the density and electrical conductivity, and macrograin (A97) and dendrites of aluminium (AK9ch). The maximum modifying effect is provided by the AlTi4 master alloy containing 0,5 wt.% magnesium. When introduced into the alloy, it contributes to the formation of 10 μm aluminum dendrites 1427 pcs/mm2 in total in the alloy structure. When the AK9ch alloy is modified with the master alloy crystallized at cooling rates of 10–15 °C/s, 28 μm dendrites 672 pcs/mm2 in total are formed in the alloy structure. It is suggested to use density and electrical conductivity determination methods for express evaluation of master alloy modifying effectiveness.