SU1458412A1 - Iron modifier - Google Patents

Abstract

The invention relates to metallurgy and can be used in the production of castings from high-strength cast iron. The purpose of the invention is the preparation of spherical graphite. The new modifier contains (wt.%) Silicobarium 10-50 and chips of magnesium alloy - the rest. Additional entry of barium into the molten iron ensures stable production of iron with a spherical shape, an increase in the tensile strength of Gg by 1.2 times, plasticity S by 2.5-4 times while reducing the consumption of modifier by 5.5 times. 2 tab.

Description

one

The invention relates to metallurgy, in particular to the development of modifiers for cast iron.

The purpose of the invention is to reduce the consumption of modifier, increase the stability of production and improve the mechanical properties of cast iron.

The presence of the silicobari modifier in the proposed method facilitates the introduction of thermodynamically active barium into the pig iron melt, which binds non-ferrous metal impurities introduced into the iron with magnesium alloy chips into resistant intermetallic compounds of the Zn and Bau type, which are removed from the melt into the slag. In this way, nodular graphite is stably produced in cast iron under these conditions.

When the content of silikobari in the mixture is less than 10%, the main amount of thermodynamically active barium introduced into the cast iron is consumed

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desulfurization and deoxidation of cast iron, as a result of which the effect of barium on the removal of non-ferrous metal impurities from the cast iron does not appear and spherical graphite does not form in the structure.

When the silicobar content in the mixture is more than 50%, the spherical shape of graphite inclusions in the cast iron is significantly deteriorated due to the effect of its over-modifying with excess barium.

The modifier is prepared by mechanically mixing the components j. It is also possible to prepare pressed briquettes.

Comparative tests of the known and proposed modifier were made by modifying the pig iron smelted in an induction furnace at the rate of 0.6% modifier input into the melt. The original cast iron had the following chemical composition, wt.%:

ate

00

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C 3.5-3.7; Si. 2., A-2.6; Wn 0.4-0.6; Cr 0.2; P 0.1; S 0.02. The modifier was introduced into the chamber of a sealed bucket of the TsNIITMUSh design with a capacity of 750 kg of cast iron.

Table 1 presents the modifiers of the proposed and known brands.

The microstructure of cast iron was assessed by metallographic, mechanical tests conducted by standard methods.

The results are presented in a tabl, 2. From the data in Table 2, it can be seen that the spherical shape of graphite and the good mechanical properties are stably obtained by using modifiers of the proposed composition, while using a well-known modifier, spherical graphite is formed in the structure with low mechanical characteristics of the metal and increased consumption. modifier.

The proposed: modifier allows stably to obtain nodular cast iron, which has high mechanical properties. Magnesium alloy shavings are a waste from the machining of magnesium alloy castings, and nowadays it is not widely used for the processing of cast iron. Its application to the composition of the iron modifier is an economically effective, resource: saving, ayuvim process.

The proposed modifier allows the modification of the molten iron in sealed

ladles or autoclaves, and also in a mold.

Forg.1uhla invention

A cast iron modifier containing chips of magnesium alloy and silicon-containing ferroalloy, characterized in that, in order to reduce its consumption, increase the production stability and improve the mechanical properties of nodular cast iron by neutralizing the harmful effect on the graphite form of zinc impurities when it is contained in magnesium alloy up to 5%, it contains as silicon-containing ferroalloy silicobarium in the following ratio of components, May.%:

Silicobaric 10-50

Magnesium shavings

AlloyE rest

Table 1

table 2

Claims (1)

Claim The modifier of cast iron, containing chips of a magnesium alloy and a silicon-containing ferroalloy, is that in order to reduce its consumption, increase the stability of production and improve the mechanical properties of cast iron with spherical graphite by neutralizing the harmful effects of impurities on the form of graphite zinc, when its content in a magnesium alloy is up to 5%, it contains sipicobarium as a silicon-containing ferroalloy in the following ratio of components, May: Sipicobarium 10-50 Magnesium Alloy Chips Table 1 Modifier The composition of the modifier, wt.% With Magnesium Alloy Silicobarium Ferrosilicon Proposed ί 90 10 - 2 60 40 - fifty fifty - Famous ny 10 table 2 ”“ - ——.... —----— ------- Modifier Consumption The form Mechanical Medium modifi- gra- properties quadra kator fita - “------ tichnoe deviation MPa % stony foliage f SH,% _________________ ______________ ___________ _____________1________ _{_} ____ The nature of non-metallic inclusions in the structure Proposal be 1 0.6 SH 645 2,5 10 2 0.6 SH 620 3.0 9.8 3 0.6 SH 612 4.3 7.6 Famous 0.6 pg 148 51.0 Zn _x Ba ,. fl I If Zn _v Mg ^