INSTITUTE OF TECHNOLOGY OF METALS | |||||||||||
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DEVELOPMENTS OF THE INSTITUTE :: FREEZING-UP TECHNOLOGY OF CONTINUOUS- ITERATIVE CASTING This technology is applicable for production of hollow cylindrical castings with a specified length from special
wear-resistant cast irons (Ñ× - grey cast iron with lamellar graphite;
Â×ØÃ - high-strength cast iron with globular graphite; ÁÂÕ× - white high-chromium cast iron with trigonal-type carbides)
and also bronzes. It makes it possible to produce castings with preset structure and physical&mechanical properties
in a continuous-iterative mode at the expense of directional solidification and heat treatment combined in
a united production process. The casting process includes filling a steel water-cooled crystallizer
with molten metal from a drag (bottom) of the crystallizer, soaking a casting to form it and its extraction
from the crystallizer up with simultaneous introduction of a new portion of melt. The metal is fed into the crystallizer
with the aid of a disposable metal feeder lined with the fire-resistant material.
The process is executed in a continuous-iterative mode,
whose rate is determined by the solidification rate of the casting with required width in the crystallizer.
Advantages: The main distinctive feature of this technology is manufacturing hollow castings without using a core in the stationary (not rotated) water-cooled metal mold. Singularities of the casting formation mechanism ensure heightened density, specified structure and hardness, lack of blow-holes, slag inclusions, shrinkage porosity and cracks. The structural component distribution in the castings is not reproduced by any known productive methods for castings of that kind. The metal matrix structure required (in a range from pearlitic to ferritic one for gray cast irons) is obtained without additional heat treatment. . A complex solution of a problem of utilization of own reflexive waste (chips, technological crop ends and gates) whose fraction in a charge can reach 70 Å 80 % without lowering the quality of casting is also provided. Possible application fields:
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