SU823445A1 - Method of producing ingots from aluminium secondary alloy - Google Patents

Description

 V; . . one. . , -., ...: The invention relates to; to metal metallurgy metapsu and alloys, in particular to the production of castings from aluminum alloys. The known method of producing aluminum alloy from the beer, which includes melting the charge and introducing alloying elements into the melt, M, however, blending on the optimum composition is practically impossible due to the wide fluctuations in the content of the alloying elements in the original aluminum alloy ingots supplied by metallurgical plants. In addition, the production of castings without shrinkage defects depends on the temperature of the metal and the speed of its pouring, the completeness of pouring, arrived and the temperature regime of the mold, etc. The purpose of the invention is to eliminate shrinkage cracks and cracks by transferring the center shrinkage shell; into small dispersed porosity. The goal is achieved by the fact that the pressure is delivered in an induction furnace with the addition of K in the melt 0.33-1.5% of the weight of 14 EX 14 isl of an oxidized silicon. Silicon is added to the induction furnace during smelting of the secondary aluminum alloy. (As a result, in each bath, nervous crystals of the intermetapical compound containing a / 0 eminium, {fem., Iron, etc., which are ket in the alloy structure, are prepared) About the same method in the same condition with the same average chemical composition. The melting point of intermetallic roshenshny about 15OO C, and it crystallizes more than the main alloy, which leads to an increase in the crystallization interval during solidification casting. And an increase in the crystallization interval leads to a decrease in the concentrated shrinkage shell due to the development of fine M scattered PS of truth. At the same time, the scale of the porosity does not

almost all mechanical properties are reflected. Marriage castings for concentrated shrinkage defects and cracks are eliminated completely or significantly reduced.

PREMIER In the foundry of the enterprise, the AL1OV alloy is melted in an IAT / 2.5 furnace according to the charge, containing,%:

Secondary alloy AK7MB

36

Primary aluminum

7.2 Silumin

Crystalline silicon 0.6

 Magnesium OD

Metallurgical return

The rest

production

Alloy fabrication technology does not differ from standard "hops"

For the mechanical sheet, samples are poured into a chill mold, heated to 25 ° C. The porosity is determined on macrosections made from castings.

The data obtained show that the introduction of silicon in an amount from 0 to 3% to 1.5%, significantly altering the structure of the slurry due to the appearance of primary crystals of refractory intermetallic compounds, reduces the size of concentrated shrink shells.

With the introduction of silicon in an amount greater than 5%, there is no concentrated loosening, but the total porosity increases, which, however, exceeds the allowable score (3) on the standard scale. The optimal amount of silicon introduced is O, 9%.

When melting in a CAT-250 furnace, silicon is required to use elevated temperatures to dissolve silicon, and this leads to the breaking of silicon and the dissolution of intermetallic compounds. No effect is found in this case,

This method provides high mechanical and technological properties of casting. During the production of a heel of shaped castings in a chill mold, a sharp decrease in faka due to shrinkage defects is observed.

The application of the proposed method for the treatment of radiation of the casting of aluminum secondary alloy makes it possible to obtain high-quality castings from a cheap, charge with an increased amount of high-grade aluminum. At the same time, the amount of recycled aluminum in the charge increases by 10%, which significantly reduces the cost of casting.

20

F o rm y

invented and

The method of obtaining castings from aluminum secondary alloy, including the melting of the charge and the introduction of alloying elements into the melt. Characterized by the fact that, in order to eliminate shrinkage loosening and cracks formed during crystallization in places with insufficient power, melting is carried out in an induction furnace with addition of 0.31 in the melt, based on the weight of the mixture of crystalline silicon.

Sources of information taken into account in the examination

1. The Foundry, 1959, No. 3, p. 12.

Claims (1)

Claim A method of producing castings from an aluminum secondary alloy, including melting the batch and introducing alloying elements into the melt, characterized in that, in order to eliminate shrinkage loosening and cracks formed during crystallization in places with insufficient nutrition, melting is carried out in an induction furnace with melt addition 0 , 31.5% by weight of the charge of crystalline silicon.