SU1071644A1 - Method for making steel - Google Patents

Abstract

METHOD OF MANUFACTURING STEEL, including preliminary raskisl | metal in the manganese-containing alloy in the steel-smelting furnace and the final deoxidation of the metal in the ladle is manganese-containing. alloy and alkaline containing alkali earth metals {{З о о о о о, and so that, in order to reduce the consumption of manganese and increase the uniformity of its distribution in steel, 20-40% of the total amount of manganese introduced into the steel prior to filling, with a metal of 1/2 the volume of the bucket, and the rest of the deoxidizing agent containing 1 DZM, are introduced into the bucket together with 40-60% of the deoxidizing agent while filling with metal from 1/2 to 3/4 of the bucket volume, manganese to (L SCHZM, introduced into the ladle, is in the range of 5-40. with:

Description

h:

four

four; The invention relates to ferrous metallurgy, in particular to the production of manganese-containing steel. There is a known method of smelting manganese-containing steel in a steel-smelting furnace, including the introduction of manganese alloys both into the furnace and into the furnace — and with a ladle upon release. In the production of carbon rail steel, ferromanganese is introduced into the furnace in an amount equivalent to 50% by weight of the total required manganese content in the steel, the remaining 50% is added to the ladle along with ulT ferrosilicon. The disadvantage of this method is the comparatively high loss of manganese and its uneven distribution in the volume of the metal in the ladle. The closest to the proposed technical solution and the achieved effect is a method of steel smelting, including the preliminary deoxidation of the metal with manganese-containing alloys in the steel-smelting furnace, the release of metal and slag from the furnace and the final deoxidation of the metal in the ladle with the mixture of the Mn-A1 alloy and silicocalcium. The amount of margins transferred to the ladle is 6.1% of the total manganese introduced into the metal. The presence of calcium in the deoxidizing mixture, which evaporates at the temperature of the liquid steel and mixes the metal, promotes the averaging of the steel composition and more uniform distribution of manganese in it. At the same time, calcium, as an element with a much higher affinity for oxygen than manganese, also contributes to less oxidation of manganese and a decrease in its carbon monoxide s21. The disadvantage is that with the known method of introduction calcium rapidly evaporates and its action as a deoxidizing agent and the element actively mixing the metal quickly ceases. The portions of metal that re-enter the furnace in the absence of calcium are deacidified by manganese dissolved in the steel. Therefore, the waste of manganese remains relatively high and the necessary uniformity in its distribution over the bucket volume is not reached. The aim of the invention is to reduce the consumption of manganese and increase its uniform distribution in steel. . . . This goal is achieved by the fact that according to a known method of steel production, including preliminary metal deoxidation with a manganese-containing alloy in a steel-smelting furnace and the final deoxidation of a metal in a ladle with a manganese-containing alloy and a deoxidizer containing alkaline earth metals (schm), 20-40% of the total amount entered Manganese steel is placed in a ladle. Together with 4060% of a deoxidizing agent containing alkaline earth metals, before filling the metal with 1/2 the volume of the ladle, and the rest of the deoxidizing agent containing alkaline earth metals is introduced when it is filled. and the metal of 1/2 - 3/4 of the bucket volume, wherein the ratio Mn: SCHZM introduced into the ladle is in the pre-. affairs 5-40. . The alkaline earth metal due to its higher affinity for oxygen compared to manganese protects the latter from oxidation. Intensive evaporation of alkaline earth metals at the temperature of liquid steel from a deoxidizing agent injected into steel in the course of production up to the filling of a 3/4 ladle, additionally mixes the metal and ensures uniform distribution of manganese. If one transfers less than 20% of the total amount of manganese injected into the bucket, then no noticeable effect is obtained in reducing its carbon loss. When transferring manganese more than 40%, there is a danger of shallow metal deoxidation in the furnace and re-boiling of the bath. Joint introduction of a manganese alloy with 40-60% of a deoxidizing agent containing alkaline earth metals is limited by the fact that with a smaller amount of deoxidizing manganese is not prevented its increased waste, and with a larger amount, there is a noticeable unevenness in the distribution of manganese over the volume of the metal. Manganese alloy together with the first part of the deoxidizing agent containing alkaline earth metal is introduced into the ladle before filling with 1/2 the volume of the bucket with metal, and the remaining amount of deoxidizing agent containing alkaline earth metal is introduced with filling with 1/2 to 3/4 of the bucket volume. During these periods, the water content of manganese alloy and a deoxidizing agent containing evaporating temperatures of liquid steel SZSM, the metal is more intensively mixed during ejection, and the greatest effect is achieved in the absorption and distribution of manganese before the appearance of furnace slag. The ratio Mp: SCHM within 5-40 is due to the fact that, with a smaller value, the 1E of manganese is not evenly distributed in the ladle, as there are not enough SCHM to intensively mix the metal. In addition, when the ratio Mp: SCHZM less than 5, the waste of manganese rises. At a ratio of more than 40, the uniformity deteriorates in the distribution of manganese over the volume of the metal. .

Example. At the Nizhny Tagil Metallurgical Combine in 430 ton open-hearth furnaces smelted rail steel according to the proposed method. The table presents the results of the experimental heats at raelich

the amount of manganese-containing ferroalloy additive in the furnace and in the ladle at different ratios of Mp: SCHZM in alloys, which sit down in the ladle, and with different methods of their input.

0.15 (13.3) casting 44.2) oven 50%

kovpsh 5o% 0,11

 four .

oven 60%

buckets 40% 0.16

5 V oven 70%

In buckets 30%, 0.15

In the oven 80%

In buckets 20% 0.14 7. In the oven 90% 0.16 SiMn In buckets 10%

0.17 SiMn (12) SiCa tS 1.3

+ MpA1 (l)

SiMn SCHZM-raskisSiMn (b) SiMn (6) 46.9 SCHZM-deoxidizing agent (3.2)

SiMn (7.5) SiMn (5)

SCHM-oxidizing agent (3,2) 40

SiMn SiMn (3.7) (a, 5) csm-deoxidizing agent 4.6 20.1

SiMn SiMn (.2,5) 5,0 tlO.5) TsZM-deoxidizing agent: (12) SiMn (1,2), 2.4 SchSM-deoxidizing agent 3.2

0.94 0.89 23.6 2.37 0.04

1.00 0.89 26.0. 0.0 0.04

0.90 0.90 12.2 13.8 0.05

0.97 13.8 12.2 0.03

0.94

40, 91 0.91 16.5 9.5 0.02

0.97 0.89 22.7 3.3. 0.03

0.99 0.90 25.2 0.8 0.05

The results of the experimental heats were compared with the data obtained in the smelting of rail steel by a known method, in which Si-Ca was used as a p. Oxidant containing CZM and Mp-A1 alloy containing 58.0% Mn and 11% L1.

According to the proposed method of steel production, silicon-calcium-titanium alloys with Calcium content from 3.0% (options 2-5) to 11.7% of variant, you 6-7) are used as a deoxidizing agent containing CZM. In order to limit the effectiveness of the proposed and known methods, they compare the results relating to steel with a close content of margpc. In this case, a reduction in the manganese burnout and an absolute deviation are determined. V3 its content by

Table continuation

80

0.0

550

325

450

110

25

ladle volume, which is controlled during casting 25-28 metal ingots.

In the second, basic variant (for comparison), only the SCHM-alloy is seated in the ladles. The carbon monoxide content on this heat was 26%, which is close to the values obtained for the known method.

In the third variant, silicomanganese in the amount of 50% of its total consumption was applied to the ladle for deoxidation of the starches together with a deoxidizing agent containing alkaline earth metals. The ratio of MP: SCH 46.9.

In the fourth embodiment, the silico-manganese was introduced into the ladle in the amount of 40% of its total consumption, together with 60% of a deoxidizing agent containing CZM, before filling with metal

1/2 bucket volume. The remaining 40% of BFM-deoxidizing agent containing alkaline earth metals, B1VOD1 or before filling 3/4 of the volume of the ladle with metal. Ratio

4a .; ;. ; . /:

In the fifth variant, the amount of silicon of Komargan manus, which was planted in buckets, was 30% of the total consumption for deoxidation ejSo, and the amount of raskolifel containing SchSM, in a mixture - 50% of its consumption in the bucket. The remaining 50% deoxidizing agent containing alkaline earth metals was introduced after the addition of ipMecH, starting with 1/2 and eacan | chiva.3 / 4 filling the volume of the ladle with metal. Sots1 ochenle} MP: 1TsZM 20.1.

In the sixth variant, 20% of the silico-manganese was added to the total amount of dehydration — together with 40% of the deoxidizing agent containing alkaline earth metals, and the remaining 60% of the oxidant containing alkaline earth metals was added after the mixture was added. The ratio of Mp $ SCHZM 5.: 25

In the seventh variant, silicate manganese was added to the ladles in a mixture with a deoxidizing agent containing alkaline earth metals, in the amount of 10% of the total consumption. The ratio of MP: SCHZM 2.4. Jq

In the experimental variants of steel production, the addition of silicomanganese was produced: carried along with a deoxidizing agent, containing TS1m SCHZM, before filling the metal with 1/2 of the ladle, and the remainder was deoxidizing and containing SCHM, preliminarily for stirring the steel, was placed in the ladle with full -: Scientific Research Institute of metal 1/2 - 3/4 of the bucket volume. This sequence of deoxidizing agents is determined by the EXAMPLE 40 and is the most optimal. Experienced Options 3-7 offers.

rail steel with an additive of deoxidizers before filling 1/2 the volume of the ladle with metal leads to an increase in the dbsmutory deviations of the manganese content in the steel to 0.05-0.07%, which indicates worse conditions for averaging manganese in the volume of the ladle compared to the known technology and method ;

The obtained results show that ITO reduces the consumption of manganese to the amount of silicomanganese transferred to the ladle .. However, transferring more than 40% of manganese to the ladle is impractical, since its distribution becomes uneven: LENIA,:, .... :; v ...:. ,

The most uniform distribution of manganese over the volume of cruss when transferring silicomanganese from the furnace to the ladle to reduce its consumption is achieved in options 4-6, for which the absolute deviations in manganese content during the course of casting are 0.02-0.03% against 0.04% by the known method and the base variant (2nd variant according to the table}, and the reduction of the manganese carbon loss is 3.3–12.2%. These figures are achieved by transferring 20-40% manganese-containing alloy to the holding alloy. its consumption, KoTopj rtt is introduced together with 40-60% deoxidizing agent containing 1CZM , 1/2 of the volume of the bucket is filled with metal, and the rest of the deoxidizing agent containing alkaline earth metals is introduced during the filling of metals 1/2 1/2 - 3/4 of the bucket volume. Optimally, the ratio Mp: alkaline metal is 5: 40.

The specific exonomic effect when using the proposed method for the production of rail steel is 0.24 rubles per ton of steel.

Claims (1)

(577 METHOD FOR PRODUCING STEEL, including preliminary deoxidation of metal with a manganese-containing alloy in a steel-smelting furnace and final deoxidation of metal in a ladle with a manganese-containing *. Alloy and deoxidizer containing alkaline earth metals' ((CZN), heat treatment 'in that, in order to reduce the consumption of manganese and increase the uniformity of its distribution in steel, 20-40% of the total amount of manganese introduced into the steel is planted in the bucket together with 40-60% of the deoxidizer containing alkali metal oxide until it is filled with metal 1 / 2 volumes of a bucket, and 'ost battening part deoxidizer containing alkali-earth metals, when metal filling is introduced from 1/2 to 3/4 of the bucket volume, the ratio of manganese to the alkali-earth metals, introduced into the ladle is in the range 5-40. „” SU.1071644 with a leach containing alkaline earth metals (SHCHM), 20-40% of the total amount of manganese introduced into the steel is seated in the bucket together with 4060% of the deoxidizer containing SHZM until 1/2 of the bucket is filled with metal, and the rest of the deoxidant containing SHCHZM, enter · when filling with metal 1/2 - 3/4 of the volume of the bucket, while the ratio of Mn: SHCHZ introduced into the bucket is in the range of 5-40. ShchZM due to higher affinity for oxygen compared with manganese protect the latter. The disadvantage of this method is comp-15 RT of oxidation. Intensive evaporation of alkali metal oxide at the temperature of liquid steel from the deoxidizer introduced into the steel during the production process, up to filling 3/4 of the bucket, additionally mixes the metal and ensures uniform distribution of manganese. .If transferring less than 20% of the total amount of manganese introduced into the bucket, then a noticeable effect in reducing its fumes is not achieved. When transferring manganese more than 40%, there is a risk of a shallow deoxidation of the metal in the furnace and boiling the bath again. The joint introduction of a manganese alloy with 40-60% of a deoxidizer containing alkali metal oxide is limited by the fact that with a smaller amount of Hej deoxidant, intense oxidation of manganese is prevented and, as a result, its increased waste, and with a larger amount, a noticeable unevenness in the distribution of manganese ^{: the} volume of metal .