SU1446182A1 - Innoculator - Google Patents

Abstract

The invention relates to foundry production, namely, modifiers for out-of-furnace melt processing of pig iron. The purpose of the invention is to increase the duration of the modifying effect. The modifier contains the following ratio of components, wt.% Cerium 27-31; magnesium 3.5-4.0; copper 12-13; silicon 16-18; aluminum - the rest. The addition of silicon modifier to the composition and a change in the ratio of other components contributes to a 4-5-fold increase in the duration of the modifying effect due to the more active epigastric nucleating effect of the modifier components. The proposed modifier can be used in the manufacture of castings for machine tooling using the continuous method. 1 tab. with f (L with:

Description

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Cerium

Magnesium

Copper

Silicon

Aluminum

The invention relates to foundry, in particular, modifiers for out-of-furnace melt processing of pig iron.

The purpose of the invention is to increase the duration of the modifying effect.

The modifier containing cerium, magnesium, copper, aluminum, additionally contains silicon in the following ratio of components, wt,%, 27-31 3.5-4.0 12-13 16-18 Else

Silicon in the composition of the proposed modifier in the presence of chemically active elements (aluminum, magnesium, cerium) exhibits an active epigastric nucleating effect that favorably affects the structure of cast iron and contributes to an increase in the duration of the modifying effect. The proposed limit of silicon content in the modifier is associated with a sharp decrease the duration of the modifying effect when the content of silicon in the modifier is below 16% or above 18%.

Cerium is an active deoxidizing body and has an intensively modifying effect on cast iron. When cerium content in the modifier is less than 27%, the duration of the modifying effect decreases. When the scientific research institute exceeds the upper limit of its content in the modifier (31%), its own whitening cast iron elimination of cerium appears, as a result of which the modifying effect of the use of the proposed modifier is reduced.

Magnesium, well refined alloy from impurities dissolved in iron. The interaction with sulfur, oxygen, nitrogen, magnesium also forms refractory compounds that serve as substrates for graphite nucleation. If the content of magnesium is less than 3.5%, the modifying effect of the additive decreases, and the upper limit does not allow an increase in the time during which the modifier is beneficial on the structure.

Med. Has the most significant effect on the eutectic transition in the non-chugun, i.e., on the conditions for forming the structure of the metal matrix.

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contribute to the formation of fine perlite. When copper content in the modifier is below the lower limit, this effect of copper does not manifest itself, and when it is contained above the upper limit, copper has a strong effect on the increase in melt supercooling during the crystallization period, which reduces the overall modifying effect.

The proposed modifier melts VCG-1-50 with a graphite crucible TG-75 in an induction furnace. The following materials were used as charge materials: cerium MC-75, magnesium MG-2, copper M-1, silicon Kp1, aluminum AB97. Aluminum was initially loaded onto the bottom of the crucible, after the melting of which other components were introduced. Cerium and magnesium were injected last before casting.

For comparative tests of modifiers of the known and proposed compositions, in the HGCH-1-50 induction furnace with a capacity of 60 kg, cast iron of the following chemical composition was smelted,%: carbon 3.1; silicon 2; manganese 0.9; chromium 0.17; Nickel 0.57; sulfur 0.04; phosphorus O, 1bo The initial cast iron was poured into rods weighing 0.300 kg. Then the iron rods were melted in a silith furnace at a temperature in alumina crucibles. After melting and holding at a given temperature of 7 minutes, modifiers were introduced into the molten iron in an amount of 0.2% by weight of the iron. The known composition was introduced in the bell, and the proposed - wrapped in steel foil. Comparison of the effectiveness of the modifiers was carried out by varying the chill depth of the technological wedge sample. Samples were poured immediately after the modification, and also after 2.6 and 10 minutes of exposure at the temperature,

The compositions of the modifiers and the test results are presented in the table.

Claims (1)

The test results showed that the additional input of silicon into the composition when the ratio of its other components changes; leads to a significant (4-5 times) increase in the duration of the modifying effect. Invention Formula A modifier containing cerium, magnesium, copper, aluminum, O tl and h a1360 ° C 27.0 1.1 Ostal- 37.0 1.7 mine 16.0 remaining- 3.5 12.0 noe 29.0 17.0 3.75 12.5 31.0 18.0 4.00 13.0 4.2 22.034,546,456.2 6.09,19,29,8 6.19,09,19,8 5,88,99,09,7