Chill Casting

Chill Casting

 

a method for the production of shaped castings in metal permanent (or chill) molds. In contrast to other casting methods using metal molds (pressure-die casting, centrifugal casting, and so on), in chill casting the mold is filled with molten alloy and the alloy hardens without any outside influence on it other than gravity.

The main operations and processes in chill casting are cleaning of the die to remove the old lining, heating to 200°-300°C, coating the working cavity with a new layer of lining, installation of cores, assembly of the mold, pouring of the metal, cooling, and removal of the finished casting. The process of crystallization of the melt is accelerated during chill casting, which promotes the formation of castings with a dense, finegrained structure and, therefore, good airtightness and superior physiocochemical properties. However, iron castings require subsequent annealing because of the formation of carbides on the surface. Multiple use causes warping of the mold and an increase in the dimensions of the castings at right angles to the plane of the parting line.

Chill casting is used to produce castings from iron, steel, aluminum, magnesium, and other alloys. It is particularly effective in the production of castings for aluminum and magnesium alloys, which have relatively low melting points, making possible the use of a single mold up to 10,000 times (with installation of metal cores). Up to 45 percent of all castings from these alloys are produced by chill casting. In chill casting, the range of cooling rates of alloys and of formation of various structures is broadened. Steel has a relatively high melting point. In the production of steel castings, the durability of permanent molds decreases sharply, and most surfaces are formed by the cores; therefore, the chill casting method is used for steel casting to a lesser extent than for the casting of nonferrous metals.

REFERENCES

Kokil’noe lit’e. Moscow, 1967.
Petrichenko, A. M. Teoriia i tekhnologiia kokil’nogo lit’ia. [Kiev, 1967].

N. P. DUBININ

References in periodicals archive ?
In general, grain refining is normally employed during chill casting mechanism; the structure refined by increasing the heat extraction occurs from the surface and corresponding increase at the solidification rate [11].
The company is installing furnaces and a direct chill casting unit and work is expected to begin soon.
The 29 papers cover markets and cast house layouts, controlling melt loss, furnaces and refractories, safety, melt quality and treatment, direct chill casting, ingot and continuous casting, and alloys and heat treatment.
Russian physical metallurgist Eskin (Netherlands Institute for Metals Research, Delft) analyzes the formation of structure, properties, and defects in the as-cast material and correlates them with the physical phenomena that are involved in the solidification and with the process parameters of direct chill casting. He covers the development of the technology, the solidification of aluminum alloys, solidification patterns and structure formation during casting, macro-segregation, and hot tearing.
Other subjects covered are direct chill casting and plastic deformation of magnesium alloys, strengthening of case Mg alloys by friction stir processing, the effect of twinning on the mechanical behavior of Mg- Zn-Y alloys, and spray coatings for improving galvanic corrosion and slide wear resistance of Mg alloys.
Ltd., Chicago, has begun construction on a new manufacturing facility in Lafayette, Ind., that will include direct chill casting capability.
These proceedings from the conference in September 2005 include industry trends and profiles in Russia and the Middle East as well as such topics as safety and the environment (including molten metal splash testing of protective clothing and new ways with rotary furnaces), reduction/cast house interface (the potroom/casthouse interface and integrating planning and scheduling), DC casting (structure features related to hot tears during direct chill casting and slab casting improvements), ingot casting and foundry alloys (development of an ingot caster filling system and using alloys), furnace technology including several new designs, degassing, and filtrations and inclusions including a new filter technology.