SU1416516A1 - Exothermal composition for alloying and refining steel - Google Patents

Abstract

The invention relates to the field of ferrous metallurgy, specifically to steelmaking and foundry production for you, and concerns the compositions of exothermic mixtures used for metal processing. The aim of the invention is to improve the quality of steel and increase the absorption of vanadium and titanium. The exothermic mixture for alloying and refining steel contains, May. %: vanadium slag 49-57; aluminum 9-13; silicon 8-12; calcium - 3-6; 19-24 titanium concentrate. The use of the mixture allows to increase the yield strength of steel by 44-46 MPa; relative elongation of 2.7-2.9%; relative narrowing of 11.3-11.6%; impact strength at 20 ° C at 1.1-1.3 MJ / m. The degree of assimilation of vanadium and titanium increases, respectively, by 2-3 and by 34-38%. 2 tab. "(L with:

Description

four

O5

cl

The invention relates to ferrous metallurgy, specifically to steel making and foundry, and concerns the compositions of exothermic mixtures used for metal processing.

The aim of the invention is to improve the quality of steel and increase the absorption of vanadium and titanium.

The exothermic mixture for alloying and refining steel contains vanadium tlak, aluminum, silicon, calcium and titanium concentrate in the following ratio of ingredients, wt.%:

Vanadium slag 49-57 Aluminum9 13

Silicon8-12

Calcium3-16

19-24 titanium concentrate Vanadium slag is a source of vanadium and titanium oxides, which are necessary for the steel to be doped with these elements, and also contains iron oxides, which are involved in exothermic processes when interacting with dissolving agents. The requirements for the parameters of vanadium slag are consistent with TU 14-11-178-79. The use of such a material in an amount of less than 49 wt% does not ensure the production of metal with a given vanadium and titanium concentrations. The quality of the metal decreases accordingly (its oxidation increases), the mechanical properties of the steel deteriorate, and the quality of the metal increases. The consumption of vanadium slag over 57 wt.% Is inexpedient, as this increases the amount of ballast oxides introduced and deteriorates slagging conditions, which leads to: a decrease in the degree of assimilation of alloying elements and the quality of the metal.

Titanium concentrate is also a supplier of titanium and iron oxides. The use of this material compensates for the lack of vanadium: slag amount of titanium oxides and provides a given concentration of this element in steel. The total amount of iron oxides introduced when sharing vanadium gshakom and titanium concentrate, causes the most

five

0

0 s about 5

0

five

intensive exothermic processes. The latter determines the effective use of deoxidizing agents, reduces their losses, and also eliminates the need to use other sources of iron oxides. Characteristics of titanium concentrates corresponded to MPTU-2491-50 TU 48-4-236-72, TU-48-A-267-73. The use of this concentrate in an amount of less than 19 wt.% Does not ensure the production of metal with a given titanium concept. At the same time, the concentration of oxygen and non-metallic inclusions increases, the content of finely dispersed nitrides of this element in steel decreases, its quality decreases, and the waste grows. A titanium concentrate content of more than 24 wt.% Increases the amount of ballast oxides injected, which leads to deterioration of the formation conditions and, accordingly, to a decrease in the assimilation of alloying elements, the quality of the metal, increases the deoxidation dangers and increases the cost of steel.

The amount of deoxidizing agents (aluminum, silicon, calcium) provides for the reduction of vanadium and titanium from the composition of the mentioned materials for steel alloying and its deoxidation. The active development of exothermic processes in the interaction of deoxidizers with iron oxides of vanadium and titanium raw materials is aimed at a more complete assimilation of alloying and deoxidizing agents. With the consumption of deoxidizers in the amount of less than the lower limit limit (9 wt.% Aluminum, 8 wt.% Silicon, 3 wt.% Calcium), the degree of absorption of vanadium and titanium decreases, the required concentrations of these elements in steel are not reached, the metal is over-oxidized, decreases its quality increases as the rejects are cast at the stone-like fracture, the consumption of ferrovanadium and ferrotitanium increases, and, accordingly, the cost of steel. The consumption of deoxidizers above the upper limit of the limit (13 wt.% Aluminum, 12 wt.% Silicon, 6 wt.% Calcium) is impractical because it does not result in a subsequent increase in the absorption rate of vanadium and titanium, the irrecoverable loss of deoxidizers and the cost of steel increase. Technical characteristic of aluminum complied

314

TU 48-01-73-71. The source of silicon and calcium was silicocalcium.

For alloying and refining of steel with the proposed composition of the exothermic mixture, smelting was carried out in 10 tons of electric arc furnace with the main lining, 35HMFL steel. The mixture was given in the recovery period of smelting, or in the ladle in the amount of 15-22 kg / t of steel. A mixture of known composition was used for comparison.

Table 1 presents the compositions of the proposed refining-doping exothermic mixture: compositions 1 and 2 correspond to the boundary values of the contents of the components of the mixture, composition 3 is average, and 4 to 10 differ from the suggested contents of the components of the mixture.

Melting steel using the proposed composition of the mixture improves the quality of the metal (see Table 2) by reducing the oxygen concentration by 19-27% and non-metallic inclusions by 25-30%. The degree of assimilation of vanadium is increased by 2-3%, and that of titanium by 34-38%. All this ensures that the mechanical properties of steel are: the yield strength at

6

 Mlla, temporary resistance by 12-15 MPa, relative elongation by 2.7 2.9%, relative contraction by 1.3-1 1.6%, 5 free viscosity at + 2G ° C by 1.1-1, 3 MJ / m, and at 1.1-1.2 MJ / m. The casting marriage (stone-like fracture) cast from steel using the proposed composition of the mixture is absent, and in molded products obtained from steel smelted using the composition of a known mixture was 6%.

Formula of invention

An exothermic mixture for alloying and refining steel, containing vanadium slag, aluminum, silicon and calcium, characterized in that, in order to improve the quality of steel and increase the absorption rate of vanadium and titanium, it additionally contains titanium concentrate in the following ratio of components, wt. .%:

Vanadium pshak 49-57 Aluminum 9-13

Silicon8-12

Calcium3-6

Titanium concentrate 19-24 Table 1

ten

69

13

12

If} I. with I tMi mf t f-m tininvtinom- -4 e

t4fnfO (nC4CV | t4t ts fv | "4

cn

P4

r CM

o "4 y n tvl CO m en o o

o I) e - m U1 f r f-

"4 t4

e

OS

about n

2 S 5

Ltd

year

§Schm

oo

oo

Yes

t

four"

CO

e

four

cho

n

t

HZ

l

t-

4t

r

f4

"

t-x

vO

W -i- -

00

CO

1L

to

in

PI

m t

in "h

-

"H

1L (S

f

MS

o

44

in

- - in

00

"H

(H

° m

00

"4 fO

m

"

ri

 -from

"H-mc

Oi O O

 vD r

ech (H N Ot (G O

 - e - "n- tvfin m- o CT --- -

r. (

x in

with

Yu

sh

Che

"

00

-

in in

- Sch

9

o

S

(P

about

- 00 U1 -

vO

g

 - vO

 oh oh

Sch about about about

o en o o o

00 00

gd

00

oo

Ltd

sh

P

oh oh

oo

sh

eight

about

1L

oh oh

w w o about

t - about sh from 000

Ltd

Claims (1)

Claim An exothermic mixture for alloying and refining steel, containing vanadium slag, aluminum, silicon and calcium, characterized in that, in order to improve the quality of steel and increase the degree of assimilation of vanadium and titanium, it additionally contains titanium concentrate in the following ratio, wt.%: Vanadium Slag 49-57 Aluminum9-13 Silicon8-12 Calcium 3-6 Titanium Concentrate