SU1296590A1 - Method for inoculating cast iron - Google Patents

Abstract

The invention relates to metallurgy and can be used in the production of iron castings with cascade modification of iron. The purpose of the invention is to increase the fluidity of the iron and increase its plasticity. A new method of modifying pig iron includes a ladle treatment of the melt with 0.3-0.8% of the FSGRASMZV ligature and 0.02-0.1% of the VASO- flux and intraform treatment with SMg7KO alloys, 3 in the amount of 0.4-0.9% and FS60Ba22 in amount of 0.1-0 / 3%; Replacement of the alloy STCISH on; FSBORNING at bucket processing and additional input of BasO flux into the ladle, as well as replacement of LCMC alloy with SMg7KO, 3 and additional input of FSBOBA22 alloy during intra-modifying, provided an increase of 2.4-2.8 times the fluidity of pig iron and 2.5-3 , 5 times its plasticity. 2 tab. with sl ko so oi ate de (

Description

The invention relates to metallurgy, in particular to the development of methods for cascade modification of cast iron in the production of castings with high strength and high ductility.

The purpose of the invention is to increase the fluidity of cast iron and increase its plasticity.

The essence of the invention is to replace the modifier containing rare earth elements with a composite alloy FSZORZMZOB and to introduce additional Vaso j flux into the ladle with the molten iron. In the internal treatment of this melt, the LCM alloy is replaced by the magnesium-containing alloy SMg7KO, 3, and is additionally subjected to treatment with the ferro-silicate bar FSBOBa22.

The modifier for producing high-strength nodular cast iron, modifying in the form of SMg7KO, according to TU 14-5-134-81 is manufactured by People by the Electrometallurgical Combine.

The composition of the modifier ferrosilicon magnesium calcium REM SMg7KO, 3%: Crhenium 40-50, kalidium 0.2-0.5, magnesium 5-7i REM 0.5-1.0, the rest of iron, As the REM used ligature ferrosilicoRZM THEZORMSOB according to TU 14-5-136-81, produced by the Kluchevsky Ferroalloy Plant. The composition of the ligature FeZORZMZOB,%: silicon 38-42, REM 30-40, aluminum 4-5, the rest of iron. A modifier of ferrosilicone type FSBOBa22 according to TU 14-5-160-84, produced by Yermakovsky Ferroalloy Plant, was used. The composition of ferrosilicone barium is FSBOBa22,%: silicon 55-65, barium 20-25, the rest is iron. The use of the FeZORZMOB ligature, which is the cheapest compared to other rare-earth ligatures, makes it possible to obtain a stably-chugun structure without cement.it with random process deviations, while other ligatures (Sh-40, Siitmish) with an increase in the number of their input or by lowering the carbon equivalent of cast iron, they have the opposite effect - they increase the amount of cementite.

The SMg7KO modifier, 3, is effective for the intraform modification of cast iron, which makes it possible to produce spherical graphite and perlite-ferritic matrix in cast iron.

The use of ferrosilicobar allowed to reduce the total amount of the modifier SMg7KO, 3 in the form due to the spheroidizing effect of barium and calcium. Reducing the total amount of modifier in the form and the presence of barium increased the fluidity of the iron.

Getting more rounded and shallow

inclusions of graphite, as well as the best impregnation of parts with liquid iron helps to improve the plastic properties of iron.

Cast iron with spherical. Graphite is obtained by modifying with one SMG7KO, 3 in the form of unstable and with an amount of at least 1.5%.

Pre-modifying a large amount of bucket

 FeZORZMOB, together with barium carbonate, eliminates the harmful effects of impurities, deoxidizes, refines and modifies the metal, preparing it for further processing in the form.

When barium carbonate is introduced into the molten iron casting of the pouring ladle, it decomposes with carbon dioxide gas. Carbon dioxide in the form of bubbles, adsorbing to heavy non-metaplichrami REM inclusions, helps them to ascend;

Cast iron that is well processed in a ladle requires a smaller amount of modifier in the form, and therefore,

less rejuvenates metal in shape. increasing its fluidity.

The combination of two simultaneously introduced modifiers SMg7KO, 3 and ferrosilicobari FSBOBA22 allows

to increase the graphitizing and ferritizing effects, to obtain graphite with more correct forg-s and ferritic matrix, to increase the plasticity, without reducing the strength.

Example. The starting metal was smelted in an acid-lined ICT-016 induction furnace. The composition of cast iron,%; 3.72 С; 2.16 Si-i and, 53 Mp; 0.04 s; 0.06 MF; 0.067 p. Liquid iron was modified with 0.3% Scemish-1 in a ladle and the mold was poured with 1.5% LCM put into the reaction chamber (tal, 1. prototype method).

According to the proposed method (table. 1)

they introduced the modifier FeZORZMZOB in amounts of 0.2-0.9% together with 0.01-0.15% of carbon dioxide barium, and 0.3-1,, 0% SMg7KO, 3 and 0.05-0 were simultaneously injected into the form, 4% FSBOB22.

312

A wedge was cast in the form to cut samples for mechanical properties (GOST 7293-79) and covers with a wall thickness of 10-40 mm ..

In tab. Figure 2 shows the results of modifying the iron according to the known and proposed methods, the mechanical properties, the fluidity and the presence of defects on and inside the castings.

As can be seen from the table. 1 and 2, replacement of the alloy containing rare-earth elements, SceMish with the FSZORZZOB alloy, additional treatment of the melt with VASO flux, as well as replacement of the LCMK alloy with the SMg7KO alloy, 3 using ferrosilicobarium provided in the proposed method an increase in the fluidity of pig iron from 300 to 720-860 mm and an increase in plasticity from 5.5 to 13.9-18.2%. :

Consumption modifiers for the known and proposed methods

Prototype

1 2 3 4 5 6 7 8 9 10

0.3 Proposed

904

Claims (1)

Invention Formula The method of modifying the cast iron, including treating the melt in the ladle with a reagent containing rare earth metals, and intraform treating with a spheroidizing graphite reagent, is about tl and h. so that, in order to increase the fluidity of the pig iron and increase its plasticity, as a reagent for processing in the forgings, an alloy of PFMS in the amount of 0.3-0.8% is used at the same time with which the melt is additionally treated with VASO flux in the amount of 0.02-0.1%, and in the intraform treatment, as the reagent, SMg7KO alloy, 3 in the amount of 0.4-0.9 wt.% and ferrosilicobarium FS60Ba22 in the amount of 0.1-0.3 wt.% are used as the reagent. Table 1 1.5 lkt 20% 61.7 Ferrite 100% 66.3 Ferrite 90% + perlite 10% 62.4 Continuing tabt ;. one 14.2 18.2 13.9 800 No 860 No 720 No Oh oh Ferrite 80% + perlite 20% 57.2 Continued table. 2 179 9.1 650 No 13