SU1418340A1 - Method of treating aluminium cast iron - Google Patents

Abstract

The invention relates to metallurgy and foundry, in particular to the technology of after-furnace treatment of aluminum cast iron. The purpose of the invention is to reduce the foaming, improve the quality of the resulting casting and improve the micro-alloying process. The method of processing aluminum cast iron includes input to the bottom of the casting ladle before filling it with aluminum cast iron. A refining additive in the amount of 0.8–3.0% by weight of cast iron is introduced together with aluminum. The charge is held for 5–10 min after filling the ladle until formation of pshak, under the layer of which ferrobor is introduced in the amount of 0.15–0-0, 45% by weight of cast iron. 1 hp f-ly, 4 tab. (/)

Description

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The invention relates to metallurgy and foundry, in particular to the technology of external processing of aluminum cast iron.

The purpose of the invention is to reduce the formation of filaments, improve the quality of the casting and improve the micro-alloying process.

The results of the processing of liquid aluminum cast iron, depending on the order of input of the components, are given in: Table 1.

This method helps to prevent foaming and thereby eliminate the appearance of defects in the castings, as well as to ensure the possibility of stable micro-alloying of aluminum cast iron with boron, since the simultaneous melting of the refining additive with aluminum reduces the oxygen potential when the metal mirror is coated with slag. The digestibility of the introduced microadditives reaches 80-90%.,

The proposed method takes into account the characteristics of the thermodynamic properties of aluminum and e: a higher affinity for oxygen, therefore it is introduced together with a refining additive, which melts at a temperature intermediate between the melting point of aluminum and. melting point of cast iron. At the beginning, the pig aluminum and its waste melt and by the time of its overheating, when it begins to oxidize vigorously, liquid-fluid slag appears, protecting the iron surface from oxidation.

The proposed method: allows the use of various versions of the known cryolite-containing additives, however, new systems of refining additives have been developed, which are used 1-1e most efficiently when using the method.

Option 1. Content of components,%: cryolite 10-20; alumina 15-2.5; hexachloroethane 5-15; fluorine calcium rest

Option 2. Content of components,%: eutectic calcium carbide 8-14; lime 20-35; silica 35-45 alumina the rest.

The proposed method provides simultaneous refining and microalloying of the melt while ensuring uniform distribution of the injected component (boron).

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This increases the degree of assimilation of the micro-doping additive by eliminating its adsorbent, and on non-metallic inclusions and films, which are effectively neutralized by the refining additive by the time the doping component is introduced.

In addition, it is possible to use a wide range of refined additives with a relatively low concentration of cryolite, which greatly improves the sanitary and hygienic working conditions.

Example. The proposed method was tested in the manufacture of ruts for pouring glass containers. The metal was smelted in an ICT-5 induction furnace. The initial cast iron had the following chemical composition,%, carbon 3,2 silicon 0,9; manganese 0.6; sulfur 0.08; phosphorus 0.12. In the casting ladle, after heating up to 650–800 ° C, pig aluminum was loaded and worked together with it. finishing additive in the amount of 0.8-3.0% by weight of the processed iron. Aluminum was taken at a rate of 1.5%, and boron at a rate of 0.03%. After the bucket was filled with liquid iron, it was held for 5-10 minutes to form as a result of a refining additive shpak, a layer of ferroboron was introduced at 1370 ° C in the amount of Oz1 5-0.45 %, after which, liquid iron was poured into molds,.

The results of the processing of aluminum iron, depending on the amount of the additive and ferroboron, are presented in table. 2,

As can be seen from the table below. 2 data the lower limit of the input components is limited by 4) the impact of the effect and the final results of processing, and the upper - by the adaptability of the process

The effect of the amount of the refining additive on the degree of absorption of the alloy. the main additives and the quality of the metal are presented in Table. 3

The effect of the exposure time of the liquid melt on the degree of assimilation of the alloying additive and the casting properties of aluminum cast iron are given in Table 4,

The results of testing the proposed method are highly stable. Experienced castings have

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significantly less scrap for captives and shells.

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Claims (1)

1. A method of treating aluminum cast iron, including inserting a casting ladle to the bottom before filling it with aluminum cast iron, characterized in that, in order to reduce the foaming, to improve the quality of the casting and pulleys the microalloying process, together with aluminum, a refining additive is introduced in an amount of 0.8–3.0% of the cast iron mass, holding the min after filling the ladle before the formation of the donkey, iodine layer of which is introduced by the ferroborus in the amount of 0.15–0.45 % by weight of cast iron. 2, a method according to claim 1, characterized in that a mixture of cryolite and eutectic calcium carbide is introduced as a refining additive. t a o l i c e 1 Proposed Beyond the proposed limits one 2 Table 2 0.14 0.46 6-8 20 50 3.2 8.0 1.5 1.5 1.5 1.5 1.5 5.0 7.5 10.0 15.0 2.0 Table3 0 Good Cryolite 20 Same Alumina 18 MININ  Hexa-5 Chloroethane The presence of Fluoride Else calcium defect like captivity The presence of slag inclusions Table4 750 750 700 550 700