RU2347003C2 - Method of producing alloy - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention refers to ferrous metallurgy, particularly to method of producing alloy for refining of steel. The method consists in galvanic coating of protective aluminium cover on the surface of solid particles of ferromanganese in amino-ether electrolyte at current density from 0.5 to 12 A/m² and electrolyte temperature of 15-35°C with successive holding of ferromanganese particles on cathode from 15 to 200 s till formation of aluminium coating of 5-40 mcm thickness.

EFFECT: producing thin aluminium containing layer and using ferroalloy for alloying steel with limited contents of aluminium.

1 ex

Description

The invention relates to the field of ferrous metallurgy, in particular to a method for producing a ligature for steel refining.

A known method of producing a ligature, comprising introducing solid particles into the melt and obtaining a coating on solid particles. In this method, granular magnesium is introduced into the molten stream of a silicon-containing ferroalloy / 1 /.

The closest is a method of obtaining a ligature, including the introduction of solid particles of ferromanganese into a molten aluminum or aluminum-containing material, where the coating process is carried out at 800-900 ° C with a holding time of 60-300 s to form a film with a thickness of 0.516-1.506 mm / 2 /.

This method is intended to obtain an aluminum coating on ferromanganese particles and to create a dense and durable coating of aluminum or aluminum-containing material on ferromanganese to obtain local zones during alloying, deoxidation and refining of manganese-containing steels.

However, ferromanganese in a protective shell obtained by this method, due to the large thickness of the film, and therefore the large mass of introduced aluminum into the melt, cannot be used for alloying steels in which the aluminum content is limited.

The objective of the invention is to obtain a thin layer of aluminum on the surface of the particles of ferromanganese.

The problem is achieved in that the protective coating is applied galvanically to the surface of ferromanganese. Galvanic deposition of aluminum coating in an amino ether electrolyte, where the coating process is carried out at a current density of 0.5 to 12 A / m ² and an electrolyte temperature of 15-35 ° C with exposure of ferromanganese particles on the cathode from 15 to 200 s to form an aluminum coating with a thickness 5-40 microns. Anodes are aluminum. It is obvious that dissolution of a coating of this thickness in a liquid metal has practically no effect on the aluminum content in steel.

The rationale for the exposure time is illustrated by an example.

For example, when the exposure time is less than 15 s, spotting of the resulting coating is observed and the coating thickness is less than 5 microns. At a holding time of 200 s in the given range of temperatures and current density, the coating thickness is 40 μm. A further increase in the exposure time will lead to an increase in the coating thickness (40 μm), which increases the excess Al content in the steel upon alloying with ferromanganese.

The temperature range is explained in the following example. At temperatures below 15 ° C at a current density of 0.5 to 12 A / m ^{2, the} electrolyte has a low cathodic polarization and, accordingly, the process is characterized by a low speed. At temperatures above 35 ° C at a current density of 0.5 to 12 A / m ^2, the deposition rate becomes constant and a further increase in temperature does not increase the deposition rate.

This method of obtaining the ligature is as follows:

- the application of aluminum coating on ferromanganese is carried out at the cathode in a galvanic bath.

- solid particles of ferromanganese are immersed in an electrolyte of the following chemical composition (in molar fractions): AlCl ₃ (0.36-0.38), N-butylamine (0.12-0.17), diethyl ether (0.5-0, 52) at a temperature of 15-35 ° C and incubated in it for 15-200 s.

The result is a dense and durable coating with a thickness of 5-40 microns.

In the smelting of manganese-containing steels, ferromanganese with a protective coating of aluminum was used as a ligature, which made it possible to increase the degree of assimilation of manganese in steel by 12% compared to ordinary ferromanganese.

The use of aluminum-coated ferromanganese particles provides the creation of artificial local zones in which favorable conditions are created for the alloying and deoxidation process, which makes it possible to stably obtain higher values of the manganese content in steel and reduce the consumption of ferromanganese.

Information sources

1. RF patent №2058416, cl. C22C 35/00, 04/20/96.

2. RF patent No. 2202647, cl. С22С 35/00, 04/20/2003.

Claims (1)

A method of obtaining a ligature based on ferromanganese, comprising applying a protective aluminum coating to the surface of solid particles of ferromanganese, characterized in that the coating is carried out in an amino ester electrolyte at a current density of 0.5 to 12 A / m ² and an electrolyte temperature of 15-35 ° C with exposure of particles of ferromanganese at the cathode from 15 to 200 s to form an aluminum coating with a thickness of 5-40 microns.