SU1357120A1 - Slag-forming sand and method of producing same - Google Patents

Abstract

The invention relates to the field of metallurgy, namely to compositions and methods for producing slag-forming materials and mixtures used in the casting of steel into a mold using the siphon method. The purpose of the invention is. improving the quality of the ingot surface, reducing the content of non-metallic inclusions in steel and improving sanitary and hygienic working conditions. This is achieved by using a slag-forming material containing blast-furnace slag, wt;%: 85 ... 93 and a technical drill 7 ... 15. A method for producing slag-forming material in the form of slabs consists in introducing into the molten blast-furnace slag a technical drill previously dried. at a temperature of 60 ... 100 C for 30 ... 40 minutes, holding the resulting melt at a temperature of 1400 ... 1. 1500 ° C for 15 ... 30 minutes, casting it into molds and subsequent heat treatment of the obtained plates. The slag-forming material and the method for its preparation ensure the achievement of the objective of the invention due to the optimum combination of the physical properties of the material and its slag melt. to remove nonmetallic inclusions from steel more completely, reliably scatter the metal surface from oxidation. The use of the material is safe from the point of view of dust and gas emission. Material consumption 2.5 ... 3.5 kg / t steel. 2 sec. f-ly, 2 tab. with S (L elo

Description

The invention relates to metallurgy, in particular, to compositions and methods for the preparation of slag-forming materials and mixtures used in casting steel into molds using the siphon method. The purpose of the invention is to improve the surface quality of ingots, reduce the content of non-metallic inclusions in steel and improve sanitary and hygienic working conditions. I

In table 1 shows the compositions of the proposed slag-forming material

Table

The method for producing slag-forming material in the form of slabs according to the invention is as follows.

In the melt located in the electric arc furnace blast furnace slag at 1400 ... 1500 C add the necessary

the number of technical drills (table 1)

pre-dried at 60 ... 100 ° C for 30 ... 40 min. The resulting melt with the addition of borax is kept in an oven at the specified temperature for 15 ... 30 minutes, then cooled to 1280 ... 1320 ° C and poured into metal molds with a size of 240-24030 .. 35 mm. After soaking in the forms for 2; .. 3 minutes, the plates are subjected to heat treatment, consisting in aging at 750 ° C for 30 minutes, heating to 900 ° C and holding at this temperature for 1 hour. The resulting plates have a bulk density of 2700. . .2800

The necessity of drying the technical borax at 60 ... 100 ° C for 30 ... 40 minutes is caused by the undesirable presence of moisture in it, which contributes to the porisation of the melt obtained and, as a consequence, to increase its viscosity.

Melt holding at 1400 ... for 15 ... 30 minutes after

The introduction of dried technical borax into the blast-furnace slag is necessary for the complete and uniform distribution of the bu- f. melt, which provides slag-forming material in the form of slabs of uniform chemical composition and stable physical characteristics,

10 The obtained slag-forming material in the form of slabs with a weight of 4.7 ... 5.7 kg was used when casting liJXlSCF ball-and-hardening steel into molds into ingots of 2.73 tons.

the bottom of the molds at the rate of consumption of slag-forming material in the amount of 2.5 ... 3.5 kg / t of steel.

Table 2 presents the properties and

20 test results of the slag-forming material obtained by the proposed method.

table 2

Slag temperature melting point 1280

1265 1240

but

and.

0.06 0.06 0.06

390

375 360

1.37 1.40 1.85

The surface quality of the ingots was removed when they were cleaned on the adjuvant.

.3. 13

on p tiball scale. The assessment of the contamination became non-metallic inclusions was carried out by determining the percentage of contamination of the visual fields and the maximum score.

Claims (1)

From the data presented in Table 2, it follows that the slag-forming material obtained by the proposed method has a sufficiently low melting point, and its melt is characterized by elevated viscosity values and low surface tensions. Thanks to the specified slag melt properties, conditions are provided for more complete removal of non-metallic inclusions from steel and reliable protection of the metal surface from oxidation. As a result of the use of slag-forming material, the surface quality of the ingots is improved and the content of non-metallic inclusions in steel is reduced, and the use of material during steel casting eliminates the possibility of dust and toxic gaseous products entering the atmosphere. Invention Formula 1, Slag-forming mixture mainly for slabs used for Editor E. Papp Order 5925/8 Compiled by V.Malkov Tehred M.Didyk Proofreader A.Zimokosov Circulation 741. Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 204 Casting steel in No. 1, containing blast-furnace slag and a flux additive, characterized in that, in order to improve the surface quality of the ingots, reduce the content of non-metallic inclusions in steel and improve sanitary and hygienic working conditions, it contains as a fluxing additive technical borax the following ratio of ingredients, wt.%: Domain 1Sh1ak 85-93 Technical drill 7-15 2G; A method for producing a slag-forming mixture mainly for plates used to cast steel into molds, including mixing blast furnace slag with a fluxing additive, characterized in that, in order to improve the surface quality of the ingots, reduce the content of non-metallic inclusions in the steel, and improve sanitary and hygienic working conditions, blast furnace slag is used in liquid form, and the flux additive is dried at 60 ... 100 ° C for 30 ... 40 minutes, and the resulting melt is held at 1400 ... 1500 ° C for 15 ... 30 minutes.