SU836112A1 - Mixture for treatment of cast iron - Google Patents

Description

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Iybreteniya refers to ferrous metallurgy, in particular to mixtures for refining and modifying pig iron.

A refining-modifying mixture containing, by weight, is known. %: Silicocalcium 20.0-90.0 Sodium chloride and (or) rare earth

2,0-60,0 metals One or more components from the group: Magnesium chloride or, barium, magnesium fluoride, barium carbonate oxides, fluorides, carbonates of rare-earth metals 2, 0-40,0 1. tals

The disadvantage of the mixture is low refining and modifying ability with respect to sulfur and gases during the processing of cast iron.

The closest in composition and purpose is a refining-modifying mixture, used

when processing liquid iron. The mixture consists of one or more reducing co1 ot halves, oxides, oxides or other compounds of alkali metal, alkaline earth metals, magnesium in an amount of 70-95% and a reducing agent in an amount of 5-30%, which is calcium carbide, alone or mixed with calcium silicide. To remove sulfur from 0.04% to 0.006%, the treatment is carried out 2-3 times with a mixture consumption of about 1% 2 for each treatment.

The disadvantage of the mixture lies in the fact that it has a relatively low refining ability from sulfur, as a result of which a large amount of the mixture is consumed. With an initial sulfur content of 0.12% in cast iron, the consumption of the mixture reaches 3-4%. In addition, expensive components such as fluorides, chlorides, oxides are used in the mixture.

The purpose of the invention is to increase the modifying ability of the mixture and increase the strength properties of the treated iron.

The goal is achieved by the fact that a mixture containing calcium carbide, oxides and halides of magnesium and alkali metals, reducing metals, additional

contains carbon, while oxides and halides of magnesium and alkali metals and metal-reducing agents are introduced by a magnesium donut in the following ratio of components, weight. %:

Carbon0.05-10.0

Calcium carbide 0.5-10., O

Magnesium slag 80.0-95.5

In this case, magnesium slag is used

of the following composition, wt.%:

Magnesium oxide 0.2-30.0 Magnesium chloride 0.5-20.0 Sodium chloride 1.0-5.0 Potassium chloride 0.5-20 Calcium fluoride., O Magnesium5.0-50.0

Aluminum 0.05-3., O

Manganese0.01-2.0

The presence of a mixture of magnesium slag waste production of magnesium alloys in the amount of 80-95, L%, containing such an active metal modifier as magnesium / refining elements in the form of chlorides and fluorides and microalloying elements aluminum and margan DG allows deeply desulfurizing and modifying the metal , getting cast iron with a vertexular or spherical shape of graphite.

When the content of magnesium slag in the mixture exceeds 80%, the formation of spherical graphite is slowed down, and the mechanical properties of the cast iron are reduced. When the content of magnesium slag is more than 95.5%, strong carbides are formed in the cast iron structure. This leads to the production of chill castings, there is a need for long-term high-temperature heat treatment of its i

Carbide Kshtsi increases the refining ability of the mixture. The presence in the mixture of less than 0.5% calcium carbide makes it less active with respect to

to sulfur, and with a CaC content of more than 10%, the resulting slag becomes refractory and unreactive.

The carbon in the mixture, in combination with calcium carbide, contributes to the creation of a reducing medium, the formation of active centers of crystallization of graphite, the grinding of graphite, the elimination of chill, and the reduction of shrinkage.

When the carbon content is less than 0.05%, nucleation of graphite is ineffective. Enter graphite into the mixture in an amount of more than 10% leads to the formation of sang. In the presence of calcium carbide, the graphitizing effect is enhanced.

The mixture preparation technology is as follows. Magnesium slag and calcium carbide crushed to a fraction of 5 mm are mixed with graphite in the indicated ratios. The prepared mixture is packaged in portions of 1–20 kg in paper or plastic bags and used to treat cast iron, for example, under a bell.

An example. Cast iron containing, weight. %, carbon 3.8; kreMni: 2.65; manganese 0.6; chromium 0.07; phosphorus 0.06; sulfur 0.04-0.12, melted in an induction furnace with a capacity of 30 kg. The field of melting the cast iron and heating it to 1450 ° C is carried out by treating the metal with an amount of 2%, which is introduced by a bell-type device. After the end of the pyroelectric effect, the cast iron is stirred, scrubbed from the surface of the metal that has formed and cast samples for chemical and metallographic analyzes of the cast iron.

The compositions of the mixtures are given in the table. In addition, a comparative treatment of the pig iron with mixtures whose composition deviates by the ratio of components from the proposed one (mixtures 5 and 6) is carried out.

1 2 3 4 5 6

Claims (2)

50.0 60.0 64.0 65.0 46.0 42.0 5 83611 As can be seen from the table, the use of mixtures 1–4 allows for the effective desulfurization of cast iron and, in fact, sent its strength properties. -, Claim 5 1. A mixture for treating cast iron containing calcium carbide, oxides and halides of magnesium and alkali metals. metal reducing agent, which means that, in order to increase the modifying capacity of the mixture and increase the strength properties of the treated iron, it is in addition. It contains carbon, and oxides and halides of magnesium and alkali metals15 and metal reducing agents are introduced by magnesium slag in the following ratio of components, weight. %: 6 Carbon 0.05-10 Calcium carbide 0.5-10 Magnesium slag 80-95.5 2; Laugh under item 1, characterized by the fact that magnesium slag has the following composition, weight. %: magnesium oxide 0.2-30.0 Magnesium chloride 0.5-20.0 Sodium chloride 1.0-5.0 Potassium chloride 0.5-20.0 Calcium fluoride 3.0-10.0 Magnesium 5, 0-50.0 Aluminum 0.05-3.0 Manganese 0.01-2.0, Sources of information taken into account in examination 1, Japan Patent No. 51-12443, cl. 10 J 155.1, 1976. 2. Patent of Great Britain 1,498959, cl. C 7 D, 1978.