SU1520130A1 - Inoculant - Google Patents

Abstract

The invention relates to metallurgy and can be used for pig iron treatment. The purpose of the invention is to reduce the cost of the modifier while maintaining the level of mechanical properties of cast iron. The modifier contains components in the following ratio, wt.%: MG 0.5-3.4

BA 0.1-5.0

CA 0.1-2.0

rare earth elements 0.1-5.0

AL 0.1-2.5

TI 0.1-25

SI 45-65 and FE the rest. The change in the ratio of TI in the proposed modifier provides a reduction in its cost of 1.06-1.54 times. At the same time, the modified cast iron has the following mechanical properties: σ _in 480-650 MPa

δ 3,2-10,5%

HB 187-270. 2 tab.

Description

This invention relates to the field of metallurgy, in particular to the development of modifier compositions for the treatment of cast iron.

The purpose of the invention is to reduce the cost of the modifier while maintaining the level of mechanical properties of cast iron.

The choice of the boundary limits of comonents in the proposed modifier composition is determined by the following.

The lower limit of magnesium is set from its minimum required content in the iron to obtain a compact form of graphite, and the upper limit is determined by the appearance of the poreo effect at. interaction with cast iron.

Rare earth metals, calcium and barium bind surfactant impurities, sulfur and oxygen, suppress the formation of ledeburite, increase the degree of spheroidization of graphite, increase the absorption of magnesium.

The lower limit of rare earth metals, barium and calcium is 0.1 wt.% Due to the manifestation of their effect. The content of rare-earth metals and barium over 5 wt.% Does not lead to an increase in the efficiency of the alloy, but increases its cost.

The amount of dsalc more than 2 wt.% Leads to the appearance of a refractory material that contaminates the casting.

 Aluminum and titanium in the established limits provide magnesium protection from oxidation and enhance the action of alkaline earth metals. SOSP tsD

WITH

keeping them below 0.1 wP does not sufficiently protect magnesium from interaction with oxygen, and above 2.5 wt.% Ti and A1 form an independent phase in the alloy and degrade the quality of the cast iron.

When the silicon content is 45–65 wt.%, Optimal graphitizing melt processing is provided and the modifier solubility is satisfactory.

The smelting of the modifier of the proposed composition is carried out in an induction furnace with a graphite crucible by silicothermic reduction of the charge components.

Made modifiers are introduced into liquid iron. In the amount of 2.0% of the mass of metal. The composition of the initial cast iron is as follows,%: C 3.6; Si 1.9; Mn, U, 5; P 0.15; S 0.03. The chemical composition of the cast iron after modification, its mechanical properties and the shape of graphite are monitored. The modification is carried out in the ladle by adding a modifier to the bottom before pouring the iron with the subsequent casting on a centrifugal pipe-casting machine. Modification temperature lAOO C.

Chemical compositions of known and proposed modifiers, as well as

properties of cast iron after treatment with these modifiers are presented in table. 1 and 2 respectively.

The proposed modifier has a cost of 1.06-1.54 lower than the known one, however, when used for pig iron treatment, the level of mechanical properties is the same.

Claims (1)

Invention Formula The modifier containing magnesium, barium, calcium, rare earth elements, aluminum, titanium, silicon and iron, characterized in that, with the chain reducing the cost of the modifier while maintaining the level of mechanical properties of the iron, it additionally contains components in an ice ratio, wt.%: s s 0.5-3.4 0.1-5.0 0.1-2.0 0.1-5.0 0.1-2.5 0.1-2.5 45-65 Else Table 1