SU1397492A1 - Graphitizing composition of mixture for inoculating cast iron - Google Patents

Abstract

The invention relates to foundry production, namely, compositions for graphitization of the processing of cast iron and can be used to improve the quality of iron casting. The aim of the invention is to reduce chipping of castings, reducing the cost of the mixture and waste disposal. The graphitizing viral composition of the mixture for modifying the pig iron contains, in wt%: aluminum furnace spackles 15–30, charcoal, barium carbonate treatment, 10–20, and screening of iron – silicon – ligatum .. ry — the rest. The use of the mixture virtually eliminates edge bleaching of castings and reduces the cost of the mixture by half. 3 tab. .

Description

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The invention relates to foundry production, and to the composition dp of graphitizing treatment of cast iron, and dp can be used to improve the quality of iron casting.

The purpose of the invention is to reduce edge chill castings, reducing the cost of the mixture and waste waste

The graphitizing composition of the mixture for the modification of cast iron contains furnace slags of aluminum production, screenings of iron – silicon magnesium ligatures (CCM) and charcoal treated with: barium carbonate, next; ratio of components, wt.%; Kiln aluminum shpaki

production15-30

Charcoal treated with carbon dioxide

Reem. 10-20

; Eliminated LCMP

Aluminum furnace slags included in the proposed graphitizing mixture contain components in the following ratio, in May.%:

Aluminum 15-36

Silicon 10-25

Carbide cream

ki 10--25.

Alumina30-35

Monooxycarbide

Aluminum Else

Silicon carbide, alumina, monooxy and aluminum carbide present in the furnace pits are substrates for the nucleation of additional centers of crystallization 11 and s raffit. The lower limit of the content of furnace slags of aluminum production in the mixture (15 wt.%) Is set on the basis of ensuring the required reduction in the amount of edge chill. The upper limit (30 wt.%) Is limited due to the negative effect of aluminum on gas shrinking porosity and cervical propensity. cast iron to film formation.

The use of a mixture of charcoal treated charcoal in a graphitizing composition is justified by its high activity. The charcoal powder of fractions 0.05–0.4 mm, introduced into the mixture in amounts of 10–20 wt.% 5, forms additional graphitization centers, thereby increasing their total amount in the iron, and ensures a lower probability.

crystallization of bays with the formation of structurally free carbides, which reduces the tendency of iron to edge bleaching. In addition, the BaSOd present in its composition, decomposed into BaO and CO, promotes intensive mixing of the melt of the CO / M melt, increasing the uniform distribution of graphite inclusions in the BaO metal volume as an additional graphitization center.

Entering more than 20% by weight of barium-treated charcoal into the mixture leads to flotation of graphite inclusions in cast iron and its uneven distribution and the appearance of structurally free carbides in certain zones of castings due to carbon depletion. the coal in the mixture does not provide a stable effect of the mixture as a result of its dissolution; In this case, the nucleating effect of graphite inclusions is insignificant, the effectiveness of modification is determined only by the action of furnace slags, aluminum production and screenings

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Introducing the LCMP dropout into the mixture contributes to its activity when interacting with the liquid metal. This is caused by the presence of magnesium in its composition, which ensures an intense bubbling of the melt due to its 1-boiling boiling point (). This assimilates carbon uptake from charcoal. In addition, the elimination of the LCMP is itself a graphitizing additive in the Modification of cast iron, as it contains up to 55 masi Si ,. Fractional composition of screening of ligature not more than 1 MT-I. This waste is generated by crushing the LCMP to produce high quality nodular cast iron. Quantity (waste is up to 30% of the mass of the modifier, until now they have not been used.

An example, The effectiveness of a graphitizing composition of a mixture is assessed using special technological samples that allow one to create real conditions for obtaining edge chill in castings. The sample design is a ring with d -100 MMj 1 a (, 120 mm and a height of 30 mm. The technological bay is adjacent to the t-shchne part of the ring.

5 mm wide over the entire diameter of the ring and 1.5 mm thick. The edge chill is assessed visually by measuring the amount of chill on the ring and the bay.

Cast iron is carried out in an induction crucible furnace with a capacity of 50 kg with an acid lining of crucibles.

. The chemical composition of cast iron after a mixture of known mixture and the proposed, blowing, May.%: C 3.25; Si 2.1; Mp 0.64; P 0.1i S 0.06; C. g 0.08.

The graphitizing mixture is fed to the bottom of the ladle when the metal is expelled from the furnace at. The mixture is prepared by means of 15 mechanical mixing of aluminum furnace kilns, pre-crushed to a fraction of 1–3 mm, of aluminum components and the composition of the mixtures proposed with the same consumption equal to 0.

The proposed graphitizing mixture contributes to the elimination of chill blend compared with the known composition.

Table 3 presents the cost

The compositions of the proposed mixture and lower cost than lime lime mixture.

Claims (1)

Invention Formula The graphitizing composition of the cast iron modification mixture, containing 20 carbon-containing, aluminum-soda materials and iron-silicon sph, characterized in that with reducing the edge of the castings, reducing the cost of waste recycling, it combines aluminum slag, as carbon soda, as aluminum-containing material. material - a charcoal angle worked by barium carbonate, as an iron-silicon alloy sowing an iron-silicon-magnesium league in the following ratio of processed charcoal barium carbonate, fractions 0.05–0.4 mm and screening ZhMP. Mixing time 5 minutes. The mixing time has been established experimentally and is limited by the possibility of stratification of the mixture. In preparing the known and proposed mixtures, ferro-silicobarium FSB-15, graphite, black GLFZ, aluminum powder, aluminum slags, screening HPLC-2, charcoal, treated coal are used. sour barium. The compositions of the proposed mixture are prepared on the lower, middle, upper, as well as below the lower and upper upper limits of the content of components, the known composition of the mixture is applied with the content of components at an average level. The compositions of the mixtures are given in table.1. Table 2 shows the results of measuring the amount of chillings depending on on the content of the components in the known and proposed mixture compositions with the same consumption of 0.3. The proposed graphitizing composition of the mixture contributes to the elimination of edge chill in comparison with the known composition. Table 3 shows the cost. known mixture and offer, The compositions of the proposed mixture have a lower cost than limestone composition of the mixture. Invention Formula The graphitizing composition of the mixture. For modifying the cast iron, containing carbon-containing, aluminum-containing materials and iron-silicon alloy, characterized in that, in order to reduce edge bleaching of castings, reduce the cost of the mixture and utilize the waste, it contains aluminum. Furnace slags of aluminum production live, as carbonaceous-. material - charcoal treated with barium carbonate, as an iron-silicon alloy - screening of iron-silicon magnesium alloy in the following ratio of components Comrade, wt.%: Furnace slags of aluminum production 15-30 Charcoal, barium carbonate 10–20 Screening of iron-silicon magnesium ligature Else Known 13.5 Table 3.2 0.9 1.2 0.2 Table 1 25 71.5 Continuation of table 2 five The composition of the mixture 3 4 5 6 Bleed mm in the casting body casting 0,3O OO 3.51.3 3.0 1.0 Tyb NCA)