SU1235924A1 - Method of producing steel - Google Patents

Description

The invention relates to ferrous metal, and more specifically to methods for producing steel, for example in a converter, followed by secondary treatment and continuous casting of metal.

The purpose of the invention is to reduce the residence time of the metal in the ladle, increase the efficiency of secondary treatment of the metal and the quality of the steel.

In the case of extra-furnace processing of the metal embedded in the converter carried out on the steel truck, time is the most important factor determining the possibility of after-treatment and its effectiveness and the possibility of increasing the quality of the metal. The lack of time is determined by the tight schedule of the converter system — the installation for out-of-furnace processing — UNRS. The rate of operation of this entire system determines the rapidity of smelting metal in the converter, and the impossibility of breaking this rhythm is determined by the condition that continuous casting of the metal is carried out by the method of smelting to smelting and any rhythm disturbance leads to a decrease in the performance of the continuous casting plant and deterioration of the metal.

When implementing previously known methods of after-treatment of metal, a metal sample is taken, poured for express analysis, and the results of this analysis are expected, since. the mass of deoxidizing and doping materials is determined from the results of the analysis obtained. Waiting for data analysis takes 6-10 minutes.

Purging the metal with argon, measuring the temperature and sampling the metal carried out on one steel truck before swapping the bucket to another allows you to combine the swapping of the ladle with the metal from one steel truck to another with performing an express analysis of the metal sample.

The proposed sequence of technological operations makes it possible to reduce the duration of secondary treatment by 6–9 min, which is 15–45% of the entire duration of this treatment. The resulting time reserve can be used to reintroduce alloying materials to correct the chemical composition of the steel to obtain a narrower chemical composition, which allows

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It improves the quality of the metal. Improving the quality of the metal is achieved by the fact that it is possible to carry out technological operations for out-of-furnace processing in optimal conditions, i.e. without forcing.

The filling of the surface of the melt after the termination of the purging of the metal with argon by the heat insulating material also has a positive effect on the quality of the non-metal, since in this case the casting of the metal is performed at the optimum temperature. This procedure is most advisable to carry out after termination of the purging with argon, since only in this case the heat insulating material does not lose its thermal resistance due to the active interaction with the metal during the process of its purging with argon.

The feasibility of using granulated blast furnace slag as a heat insulating barrier is due to its availability at metallurgical plants and low cost.

It is advisable to blow the metal on the first steel truck for at least 2 minutes, as the temperature does not have time to be equalized with decreasing the blow, as well as the chemical composition of the metal. Purging more than 4 minutes is also not advisable, as this leads to an unreasonable expenditure of time. Blowing the metal with argon on the second steel truck before introducing deoxidizing and alloying materials is necessary for liquefying the slag around the tuyere to the extent that it does not prevent the penetration of the input materials into the metal. The time of this flushing of the metal with argon is determined by the capacity of the casting ladle and is 0.5 minutes for the ladles. with a capacity of .130, t and 1.5 min for buckets with a capacity of more than 300 tons.

Purging the metal with argon for 2 min after the introduction of the last portion of the deoxidizing and alloying materials is necessary for their dissolution and leveling by the bucket volume. Shorter time does not ensure the normal implementation of this process.

Blowing the metal for 8 minutes is necessary when a larger portion of the last portion is added. Purging more than 8 minutes is impractical, as this leads to waste of time.

Example 1. In the production of 08U steel, metal is molded into a 350 ton converter. A ladle with released smelting on a steel truck servicing the converter is delivered to a secondary treatment plant located above the steel routes leading from the converter. In this plant, the metal is purged with argon for 4 minutes, the temperature is measured and a sample is taken of the metal, which is sent by air mail for rapid analysis. After that, the metal bucket is relocated to another steel truck, on which the bucket is delivered to the out-of-furnace treatment plant, located above the additional steel transport routes, which are located between the main routes leading from the converters.

The metal was flushed with argon for 1.3 minutes, and then an aluminum substrate in the amount of 700 kg and a manganese metal were introduced into the ladle in two portions of 300 kg each. After charging, the last portion of manganese metal is purged with argon for 8 minutes. After the end of the purge, the surface of the melt is filled up with a granulated domain donkey in the amount of 1.0 kg / ton of metal.

As a result, the autolist of the WWS group is obtained due to the optimal combination of the chemical composition of steel for manganese (0.22%) and aluminum (0.047%).

Example 2. In the production of steel, mark 17G1S metal is smelted

Editor I. Derbak Order 3062/24

Compiled by V. Saramutin Tehred L. Oleinik

Circulation 552 VNRSHPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d.

Production and printing company, Uzhgorod, st. Project, 4

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in a 160 ton converter. A bucket with metal released on a steel truck serving the converter is delivered to a secondary treatment plant, where the metal is flushed with argon for 3 minutes, the temperature is measured and a metal sample is taken for rapid analysis. After that, the metal bucket is relocated to another steel truck, which is fed to another after-treatment plant, located above the additional steel transport routes.

The metal is rinsed with argon for 1 min, then 20 kg of silicon-manganese and 130 kg of ferrosilicon are seated in a ladle, the mass of which is determined according to the results of rapid analysis. After the addition of these materials, the metal is purged with argon for 4 minutes. After termination of the purge, the surface of the melt is crushed with vermiculite in a quantity of -. The amount of 1.1 kg / t of steel. Then the ladle is fed by the same steel truck to the continuous casting department and the metal is poured onto the GNSS. Due to the additional introduction of ferroalloys, the upper vintage limits for the content of manganese and silicon were obtained, which makes it possible to increase the yield strength to 45 kg / mm instead of 38.3 kg / mm.

In addition, the main steel routes are unloaded to perform other technological operations, such as transporting slag, empty steel-casting ladles, and the like.

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Claims (3)

1. METHOD OF PRODUCING STEEL, including steelmaking in steel of a melting unit, for example, a converter, discharge into a ladle, after-furnace treatment of metal, transportation of a ladle on a steelmaking truck, rearrangement from one steelmaking truck to another, continuous casting of steel, which is characterized by reduce the time spent by the metal in the bucket, increase the efficiency of out-of-furnace metal processing and the quality of steel; after release, the metal is purged with argon for 2-4 minutes in the bucket located on the first steel truck, the temperature is measured, a sample is taken and sends it to analysis, whereupon the bucket rearrange into another ladle, metal purged with argon for 0,51,5 min administered according to the analysis deoxidizing and alloying, and casting before serving purged with argon for 2-8 min. · 2. The method according to π.1, characterized in that after the last purge with argon, a heat-insulating backfill is introduced onto the melt surface in the ladle. 3. The method nd claims 1 and 2, characterized in that as a heat-insulating backfill using granulated blast furnace head. SU „, 1235924