SU1700059A1 - Hot metal recarburizer - Google Patents

Abstract

The invention relates to metallurgy, horse-peTrifce, to varieties of heated refractory tips for carburizing pig iron heated by electric current. The purpose of the invention is to increase the efficiency of carburizing and the quality of the pig iron produced. The nozzle includes carbonaceous matter and additionally contains charcoal impregnated with barium carbonate, with the following composites content, in May.%: Carbon-containing material 80-9U; Charcoal impregnated with coal, - LRHMGLNM barium, 10-20. 2 tabl,

Description

The invention relates to metallurgy, and more precisely to varieties of electric refractory heated refractory nozzles for carburizing pig iron smelted in various fused units.

The aim of the invention is to increase the efficiency of carburization and improve the quality of the pig iron produced.

A refractory electrically heated carburizing cast iron nozzle 3 including carbon-containing material, additionally contains barium-treated charcoal, in the following component ratio 9% by weight: carbon-containing fireproof material 80-90; charcoal treated with barium carbonate, 10-20.

Introduction to the composition of nozzles charcoal treated carbon

barchem; provides the highest possible graphitization of the processed iron, which is especially important for casting, thin-walled glass panels. At the same time, the BaCOj present in the coal is divided into BgO and CO. CO, in turn, creates a reducing atmosphere and contributes to the reduction of oxides of the amch slag entering the packing with the iron. Particles of BaO vtchkats with additional centers of the kriste p1pchzatsin dg nucleation and epitaxial graphite inclusions on them.

The treatment (pgopatka) of charcoal with barium carbonate is carried out by dipping a portion of coal into a barium carbonate melt and mixing, resulting in barium carbonate aancj and removing charcoal and: - melting and holding the carbon through barium before hardening the carbonic barium.

WITH

Ltd

SP

with

The compositions of the proposed nozzles are given in table. 1, and their properties in relation to the known - in Table. 2

Analysis of the results shows that the proposed nozzle has significant advantages compared to the known one, which is explained by both the increase in the duration of the modifying effect for the year of the presence of VASO and the high h cmporaturon of the melt treatment of a /: a.

A metallographic analysis of the treated cast iron showed that the cast iron matrix is pearlitic with minor inclusions of ferrite. As a result of processing, the content of carbon and silicon in the iron increases, however, the graphite inclusions in the processed iron are smaller and more compact. The graphite wall varies from G2 to Gf5, and the dispersion of perlite increases from Pd1.4 to Pd1.0, which is due to the following: during high-temperature treatment of cast iron, deactivating potential embryos occurs, Eo-first. as a result of their dissolution, and secondly, as a result of their emergence from the melt with a decrease in its viscosity. This increases the stability of the liquid melt to overcooling 5, therefore the process of separating graphite from a liquid melt begins

later, with a deeper supercooling, which leads to the spontaneous formation of a large number of uniformly distributed graphitisapia centers, and the resulting graphite inclusions are smaller. All these changes in the chemical composition and structure of cast iron as a result of processing in the nozzle of the proposed composition lead, on the one hand, to a certain decrease in hardness HB due to an increase in the amount of graphite, on the other hand, to an increase in the microhardness of perlite due to an increase in its dispersity. In general, the strength properties after treatment increase, which is also influenced by the reduction of non-metallic inclusions and gases in the iron. Formulas

and s o b

rete n i

A carburizing pig iron nozzle comprising carbonaceous material, characterized in that in order to increase the carburization efficiency and quality of the pig iron produced, it additionally contains charcoal impregnated with barium carbonate, in the following ratio of components, wt.%: Carbon-containing material 80- 90; charcoal impregnated with barium carbonate 10-20. i

Table 1

Table 2

Zvezdiy: without modification with modioooriem

3.66

3.49- 3.59

3.55-3.62

3.12 3.5

2.76- 2.94

2.91- 3.07

ten

Continued tab

1370

27.4

1352-1360

22, 1 - 22.8

23E4- 24.0

S3

Claims (4)

Claim A nozzle for carbonization of cast iron, including carbon-containing material, characterized in that, in order to increase the efficiency of carbonization and improve the quality of cast iron, it additionally contains charcoal impregnated with carbon dioxide, in the following ratio, wt.%: Carbon-containing material-80-90 ; charcoal impregnated with barium carbonate 10-20. · I Table! Composition The content of components, wt.% Carbon-containing refractory material (electrode battle) Charcoal treated with BaCO ₃ 1 80 20 2 85 fifteen 3 90 10 Table 2 Composition Content Value Temperature eleme ntov,% bleached cast iron - MM barely from Si botkp ° C Mechanical properties g- KG mm * 300 3.73 3.70 3.21 2.5 3.16 3.0 1370 29.1 6.5 1370 28.3 6 ι 700059 • Continuation of tabl Composition Content. Value Temperature elements,% bleached cast iron mm barely FROM Si Botkn ° C Mechanical properties σ mm ^ 300 3 Known: without 3.66 3.12 3,5 1370 27.4 modifications 2,762,94 13521360 22, 122.8 With Modification 3,553.62 2,913,07 1 3521360 23,424,0 4 _{ 3.