SU908901A1 - Composition for modifying crude iron - Google Patents

Description

(54) MIXTURE FOR MODIFICATION OF IRON

I

The invention relates to foundry and can be used to modify gray iron.

The known mixture for modifying pig iron containing boron, ferrosilicon, and cryptocrystalline graphite. However, the introduction of an increased amount of boron in the liquid metal causes additional stabilization of cementite due to the occurrence of boron VdS in the melt. In addition, the specific consumption of the mixture is high, which reaches 1.5% of the weight of the pig iron being processed.

Closest to the present invention is a mixture of 2, which contains components in the following ratio, wt.%:

Technical born

acid1 - 3

Silikokaltsiy17-37

Graphite60 - 80

This mixture is intended to increase the strength properties of castings and to improve its absorption by the iron.

The disadvantages of the known mixture are low duration of action, increased consumption and a slight increase in the strength properties of castings.

The purpose of the invention is to increase the duration of the modifying effect, to reduce the specific consumption of the mixture, to increase the mechanical properties of the iron.

The goal is achieved by the fact that the mixture for the modification of cast iron,

15 containing boric acid, silicocalcium and graphite, additionally contains silicobarium in the following ratio, wt.%: Technical borne

20 acid2-5

Silikokaltsy 30 - 40 Silikobariy15 - 30

GraphiteExtrous 3 Barium in cast iron, being an active deoxidizing agent, desulfurizer and. gasifier, increases the duration of the modifying agent and improves the mechanical properties of cast iron with a simultaneous decrease in the specific consumption. The modifier is a mechanical mixture of graphite powder with crushed silicocalcium, silicobarium and boric acid (fraction 2-5 mm). Primer p. The cast iron containing, in wt.%, Is modified: carbon 3.44; silicon 0.87; Marga 0.74; phosphorus 0.15; sulfur 0.085. The modifier is introduced into the bottom of the bucket at 1380-1400 ° C. For the tests, I prepare the following mixtures, which are injected into the bottom of the bucket at 1380-1400 Sos: tav 1, wt.%: Technical boric acid2 Silicocalcium 30 Silobarium-15 Graphite .53 Composition 2, wt.%: Technical Boric Acid3 Silicacalcium35 Silicobarium25 Graphite 37 Composition 3, wt.%: Technical boric acid5 Silicocalcium. 40

Offered 1 2 3

Known

8 10 10 5 Silikobarmy30 Graphite25 The optimum consumption and duration of the modifying effect of the known mixture and the proposed one are given in table. I. The optimum consumption of the mixture is determined by the absence of cementite in the fracture of a billet of cast iron treated with a modifier. The mechanical properties and structure of the cast irons modified by the above mentioned and known compounds are given in Table 2. The use of the modifying mixture increases the duration of the modifying effect, reduces the specific consumption of the modifier, and contributes to the refining of the iron for harmful impurities. Components of the modifying mixture are not scarce, cheap and manufactured on an industrial scale. The preparation of the modifying mixture in the presence of components does not constitute technological difficulties. Increasing the duration of the modifying effect allows to obtain castings from cast iron without chill, eliminates the need for subsequent heat treatment and thereby shortens the cycle of suitable parts, reduces the cost of products by 30%. In addition, due to the refining of the metal, the strength properties of gray cast iron increase by approximately the grade and the specific consumption of the mixture is reduced by 0.1-0.2%. Table 1

We offer 3,622,5190

23.4

4.3

4.4

Claims (2)

24 39.0 3.6 21.0 180 Formula of the Invention A mixture for the modification of cast iron containing technical boric acid, silicocalcium, graphite, which, in order to increase the duration of the modifying effect, reduce the specific consumption of the mixture and improve the mechanical properties cast iron, it additionally contains silikobari in the following ratio, wt.%: table 2 Perlite 10.0% thinly lamellar (front 0.6 - 0.8) Perlite is 100% thin 190 lamellar (front 0.6 - 0.8) Perlite is 100% thin 190 plate, (front 0,6-0,8) Known Perlite 100% finely lamellar, (front 0.8 - 1.0) Technical borne 2-5 acid Silicocalcium 30 - 40 Silicobarium 15 - 30 Graphite Else Information sources taken into account in the examination 1. USSR author's certificate 4.1285, cl. From 21 to 1/00, 1974. 2. Authors certificate of the USSR 99565, cl. C 22 C 37/00, 1973.