RU2241059C1 - Method for producing of addition alloy for steel deoxidation - Google Patents

Abstract

FIELD: metallurgy and foundry.

SUBSTANCE: method includes mixing of aluminum and titanium powders with followed pressure. Additionally in powder composition iron powder is introduced. Composition contains (mass %): aluminum 4-38, titanium 6-60 and balance: iron. Pressure is carried out at 2000-25000 kg/cm²; powders are manufactured from chip produced as waste product.

EFFECT: reduced steel contamination by alumina, being capable of degrading of steel mechanical properties and workability.

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Description

The invention relates to the field of metallurgy of ferrous metals and to foundry.

A known method of producing aluminum-titanium alloys by fusion of aluminum and titanium, passing at high temperatures [1]. In this way, ligatures with a titanium content of 2-5% are obtained, which is associated with a sharp increase in the melting temperature with an increase in the content of the refractory component. Obtaining aluminum-titanium ligatures is a labor-intensive and energy-intensive process, which significantly increases the cost of the material obtained.

As a prototype, a method for producing aluminum-titanium alloys by mixing fine powders of aluminum and titanium is considered: titanium powder, for example, grade PTEM-2 10-30 wt.%, Aluminum powder, for example grade ASD-1 70-90 wt.%, Followed by pressing at a pressure of 100-350 kg / cm ² [2]. This alloy was used to modify aluminum alloys, but it can also be used for deoxidation of steel. Obtaining powder aluminum-titanium ligatures is an expensive process, due to the use of industrial aluminum powders ASD-1 and PTEM-2 guitar, which significantly increases the cost of the material obtained. In addition, there are limitations when using this ligature for steel deoxidation due to the significant amount of aluminum.

These shortcomings are addressed by the proposed solution.

The objective of the invention is the preparation of cheaper material used for deoxidation of steel.

The technical result is to reduce the degree of infection of steel with alumina. Alumina reduces mechanical properties and degrades the workability of steel.

This technical result is achieved by the fact that in the method of preparing the master alloy for the deoxidation of steels by mixing powders of aluminum and titanium, followed by pressing the resulting mixture, iron powder is additionally introduced into the mixture of powders of aluminum and titanium in the following ratio of components, wt.%:

4-38 aluminum powder

Titanium Powder 6-60

Iron powder

and pressing is carried out at a pressure of 2000-2500 kg / cm ² , powders are used from shavings - waste products.

The ligature is prepared as follows. Chips of titanium, aluminum and iron are crushed in a ball mill or in other aggregates. Then the crushed chips are sieved through sieves of a certain cell size. After this, the mixing of the powders in the mixer. The percentage of components depends on the required chemical composition of the ligature. Next, the ligatures are pressed. The resulting ligatures, depending on the required chemical composition for titanium, are introduced into steel.

Example 1 of the method.

The ground iron, gytan, and aluminum were sieved through sieves with a mesh size of 1 mm. After that, the powders were mixed in the following proportions, wt.%:

Aluminum Powder 38

Powder guitar 60

Iron powder 2

In the mixer for 10 min, the powders were mixed and dosed 200 g each, followed by pressing the ligature in the mold. The geometric dimensions of the mold, mm:

Diameter 50

Height 100

Pressing pressure 2000 kg / cm ² .

In the prepared alloy 35 L at a temperature of 1600 ° C immersed pseudo-ligature in an amount of 2 kg / 1000 kg Chemical analysis of samples of the obtained metal showed the absorption of titanium in steel more than 90%.

Physico-mechanical properties of steel treated with this pseudo-ligature correspond to GOST 977-88.

In examples 2 and 3, the amount of ingredients was changed.

The data in examples 2, 3, where the ratio of the components and the pressing pressure changes, are shown in the table:

If pressed at a pressure of less than 2000 kg / cm ² - insufficient briquette strength, and at a pressure of more than 2500 kg / cm ² - inappropriate cost of ligature.

An increase in the amount of aluminum powder over 38% leads to steel contamination with alumina, and a decrease of less than 4% reduces the digestibility of pseudo-ligature.

A decrease in the content of titanium powder of less than 6% reduces the quality of deoxidation, and with a content of titanium powder of more than 60%, difficulties arise in the manufacture of briquettes.

The iron content is selected from the desired composition of the ligature for titanium and aluminum.

The proposed ligature is inexpensive, since the starting material is a waste product in the form of chips, which are crushed into powder, easily digestible and has the mechanical characteristics required by GOST.

Sources of information

1. Bondarev B.I., Napalkov V.I. and other Modification of aluminum wrought alloys. - M., 1979, p.122.

2. RF patent No. 2087574, C 22 C1 / 04, 1997

Claims (1)

A method of preparing a ligature for steel deoxidation, comprising mixing aluminum and titanium powders with subsequent pressing, characterized in that the iron powder is additionally introduced into the powder mixture in the following ratio of components, wt.%: Aluminum 4-38 Titanium 6-60 Iron Else pressing is carried out at a pressure of 2000-2500 kg / cm ² , and the powders are made from waste chips.