SU1715852A1 - Method of refining treatment for producing flaked graphite cast iron - Google Patents

Abstract

The invention relates to metallurgy and can be used for the refining treatment of cast iron with lamellar graphite for castings. The goal is to increase the processing efficiency and reduce cast rejects. Smelting low-silicon materials and carbonizing the melt are melted, and 85–90 mS% of a graphitizing component is introduced into the ladle in the amount determined from the equation M-2- (0.001 + +), where M is the% of mis-metal by weight of cast iron; tc — prevailing wall thickness of the casting, m; then the melt is blown with air with an intensity of (1-4) 1 0 6m3 / kg s, and the duration of the purge -Ј- - (s) is determined from the expression Ј 2 ,, where t is the mass of the metal to be treated (kg), then before draining the metal from the ladle into the casting device at 1670-1730 K introduces the remaining amount of the graphitizing component. The proposed method provides an increase (G6 1,, 3 times and survivability of the modifying effect 2.2-3 times, 1 table.

Description

The invention relates to the field of metallurgy, mainly foundry, and can be used. used for refining iron processing with lamellar graphite for castings

The aim of the invention is to increase the efficiency of secondary treatment and reduce scrap castings.

Example Special cast iron of chemical composition, mas: С 3,10-3,50; Si 2.05-2.30; . Mh 0.60-0.90; C .0.25; Ni 0.10; Si 0.50-1.0; Ge 0,012-0,015; , 14j, 30, melted in ICT-10M2 induction furnaces for pouring non-flask molds on automatic lines Disamamatic. From the furnace, the melt of the initial cast iron is poured into a dispensing bucket with a capacity of 700 kg heated to 1100 K, at the bottom of which, before discharging the metal, depending on the silicon content in the melt (1.4 - 1.7 wt%), 1.0- 1.7 wt.% FS75 or FSB5Ba7 ferrosilicon "After filling the ladle 1/3 with metal

a jet is injected (depending on the thickness of the casting walls being processed) 0.02-0.08 masD of cerium mismettal Mts50Zhb. The ladle is connected to the dried compressed air line and is blown through porous

sd

J 1

bottom elements with intensity (Os5 ° p.5.0) "10 bm3 / kg s for 12-30 s„

The bucket is transferred to the casting span, slag is scraped off the metal surface, the temperature is measured by a thermocouple immersion, and when the metal is discharged into the casting device with a capacity of 150 kg under stream at 1660-1760 K, 0.06-0.20 wt% of ferrosilicon FS75 or FSb5Ba7 . The technological samples and parts of the compressors of industrial refrigerators with a wall thickness of 0.005-0.015 m with an interval of 2 minutes are filled. After knocking out castings and process samples, metallographic and mechanical tests are carried out.

At the same time, eutectic cast iron with lamellar graphite is melted and processed by a known method, castings and mechanical tests are cast in similar conditions.

The proposed. Method of refining processing of cast iron is tested with a positive effect in buckets with a capacity of 1.0; 2.0; 3.0; 5.0; 10.0} and 15.0 t

The results of the comparative tests are given in the table.

In comparison with the known, the proposed method of processing cast iron for castings provides an extension of the survivability of the modifying effect in 2

ten

15

158524

3 times the reduction in the size of graphite inclusions by; the reduction of rejects for bleaching and shrinkage from 6.2 to

5 2.7.

Claims (1)

Invention Formula The method of refining processing of cast iron with lamellar graphite for castings, including smelting low-silicon charge materials, carburizing the melt, releasing the melt into the ladle, to the bottom of which the graphitizing component — ferrosilicobarium — is introduced into the ladle, being fed under the stream of the melt when discharging the brassmetal methyl acetate. melt in an air ladle, o t - characterized by the fact that, in order to increase the processing efficiency 20 and reducing castings rejection, before the metal is introduced into the ladle, 85 to 90 masD of the graphitizing component are introduced into the ladle, cerium metal metals are introduced in an amount determined from equation ; mishmetal from; mass of cast iron; tf is the prevailing wall thickness of the casting, m, then the melt is blown with air with intensity (1 - 0 x10 bm3 / kg s, and the duration 2 (c) is determined from the expressed 2.4-10 sh, where m is the mass of the metal being processed, kg, then before the metal is drained from the ladle into the filling device at 1670-1730 K, the remaining amount of the graffitizing component is introduced. 25 thirty purge жени 35 Table continuation J.60 1.39 3.5 "Z.OI MS 12 186 ZJ9 193 5 9B 180 .E 1,3 6.2