UA126044U - COMPACT MATERIAL FOR BUCKET STEEL TREATMENT - Google Patents

Abstract

The ladle compacting material contains the major components of iron, silicon, calcium and barium.

Description

The useful model belongs to the field of ferrous metallurgy, in particular to additive materials for ladle processing of steel.

Additive materials containing alkaline earth metals for ladle processing of steel (LZ3M) are used in the form of lump (fractionated) or powder double or triple alloys of LZM. GOST 4762-91 regulates the composition of the main components of calcium alloys:

ZO 905 Sa and up to 25 95 Ge. US standards, for example, set concentrations of calcium 25-30 95 and silicon 50-75 95. Barium alloys according to TU 0823000-006-311780390-2001 contain 55-65 95 5 and 20-25905 Va zh Re other. Certified LZM alloys contain silicon, which is a connecting element between iron, calcium and barium, forming complex intermetallics - silicides, which provide thermodynamic, mechanical and thermal strength of alloys.

Ferrosilicocalcium alloys (patent of Ukraine Mo 102626, p22c35, published on November 10, 2015) containing (wt. 95): (10-50) Ca and (15-50) Bi - ( 25-65) Ee with a different density of 3.4-5.6 g/cm3 and a liquidus temperature of 1150-1300 "C, corresponding to the composition of solid solutions based on intermetallics - silicides of iron and calcium.

The essence of a useful model is that in liquid steel, solid solutions of silicides dissolve and are in a liquid state up to temperatures of thermal stability, which depends on the composition of silicides. Analysis of the structural and chemical state of iron and calcium silicides on polygonal state diagrams shows that iron silicides of stoichiometric composition, for example, Rebig2, which correspond to the composition of ferrosilicon grade FS45, disintegrate at temperatures of 1400-1600 "C, silicocalcium of the SKZO grade (5iz Ca) disintegrates at temperature of 1250-1500 "С. Therefore, at liquid steel temperatures of 21,600 "C, iron and silicon silicides are kept in a liquid state, while calcium goes into a gaseous state, which causes an increased pyro effect during ladle processing of steel. Barium silicides, unlike calcium silicides, disintegrate in liquid steel with the formation of liquid barium without pyro effect.Known methods of reducing the pyro effect of calcium alloys due to the use of phlegmators and low-alloy alloys reduce the efficiency of ladle processing due to increased costs and time of inserting flux cored wires.

Complex barium alloys not only reduce the pyro effect, but also increase the quality of steel by reducing the contamination of the metal melt with non-metallic inclusions (1). Calcium and barium do not dissolve in liquid iron and are in the form of non-metallic inclusions - oxides, sulfides, oxysulfides, which are formed and removed from the metal at different rates. The latter is related to the different physical and chemical nature of LZM, which is determined by the quantum mechanical parameters of calcium and barium atoms. First of all, non-metallic inclusions that contain barium are formed and removed, for example, barium silicates, the amount of which depends on the oxidation of the metal and the grade composition of the alloy (21.

The basis of the useful model is the task of increasing the efficiency of ladle processing of steel with alkaline earth metals due to the optimization of the composition of ferrosilicocalciumbarium complex alloys.

Table

Ferrosilicocalciumbarium alloys for powder wires and m p/p Stoichiometric. chemical composition, mass 95 Vin Vintage salary Notes 10111111 Low silicon alloys.///77777711Ї11111111111111111Ї11111111111111 and

Seleeovsvy vetla in 81 sedge ooo 7 6 (|RepbipSayuVa» | 30.8 | 15.4 | 40.0 | 13.7 | 3.49 | FsiB5KAOBa!5 | R-Z3.8-40 g/cm? 10101111 High silicon alloys. d//7777711Ї11111111111111Ї1111111111С 8 | RebivSayeVa, | 8.5 | 341 | 38.5 | 20.8 | 1.73 | Foz5K35Ba?O | y

Selyuovya ditch Tue 11821 seovvyuvm ooo 70 | beZigsayuva (| 6.0 | 36.2 45y | 12.9 | 1.6 | FoZBKaBBato 1/7 M 13 | ReZimSayuva | 44 | 53.1 | 31.6 | 10.8 | 08 | FoBOKZOBato | P-2.3-2.9 g/cm?

The task is solved by the fact that the compact material for ladle processing of steel in the form of powder wires, containing the main components of iron, silicon, calcium, according to a useful model, additionally contains barium, with a ratio of ingredients (wt. Os): silicon 15-55 calcium 20-50 barium 5-20 iron other.

Stoichiometric mixtures of components containing Genbi - Sa and Va, as well as their alloys, corresponding to the composition of solid solutions based on complex intermetallics - silicides, are used as a powder-coated wire filler.

The table shows the classification and grade composition of ferrosilicocalciumbarium alloys based on complex intermetallics - silicides. The stoichiometric composition of complex silicides is determined on the basis of structural and chemical reactions between the intermediate phases of the binary and ternary polygonal diagrams of the Ee-5i, Ca-5i, Ba-5i and Be-5i-Ca, Re-51i-Ba systems.

Ferrosilicocalciumbarium alloys are divided into low silicon (15-2095 9) and high silicon (30-55 95 5i). Low-silicon alloys (1, 2, 3) are formed in the system of binary Rugby - Sarbi - Vagbi and ternary silicides (4, 5, 6, 7) RebiSa - RGebiVag, high-silicon alloys are formed (8, 9, 10) in the system Rezi - Sabi - Vabi and Rezig2 - Sabig - Vabig (11, 12, 13, 14).

The liquidus temperatures (T, "C") and the density of alloys (p, g/cm") are calculated additively based on the melting temperatures of the initial components of the structural and chemical reactions of formation and on the chemical composition of complex alloys, respectively.

The grade composition of alloys is characterized by the ratio (Ca and Ba): 5i, which determines the chemical activity in the processes of refining the metal melt and modifying non-metallic inclusions. For low-silicon alloys, this ratio is 3.0-4.0, for high-silicon alloys - 0.7-1.7. Tl is 1000-1250 "С, p-2.0-3.0 g/cm?. Alloys (4-7) with a high iron content of 25-30 95 and a density of 3.5-4.0 g/cm" can be used as lump filler materials.

The given classification of alloys for powder wires is the basis of the system certification of compact materials for ladle processing of steel

The high efficiency of complex barium alloys in comparison with ferrosilicocalcium results from the analysis of the deoxidation mechanism during ladle treatment of steel with alloys FS15K30 (GebiSag): p-4.0 g/cm, Tlya-1150 "C, and FS15K35Bag0 (Re;5i;Sat2Vag): p -4.0 g/cm3, Tl-1050 "C,

From the deoxidation represented by the reactions: 7(BeziSag)men28|O|me - 7Eeme- 7(51O» 2Sad)nmv (1) (Re?5i7Cai2Vag)men28|Oime -- 7Reme-6(51O» 2Sad)nmv--(5iO » 2Sad)nmv (2)

When alloys are consumed in the amount of 1.0 kg/t, the degree of deoxidation and the number of non-metallic inclusions that have formed are practically the same, while the number of remote NMVs is 30 95 more for reaction (2) due to barium silicates absent in the metal. In addition, the amount of calcium silicates, which form brittle silicates, also decreased by 30 95, which significantly increases the purity of steel and its quality.

Sources of information: 1. Ryabchikov I.V. Silicon ferroalloy and modifier of the new generation.

Production and application / I.V. Ryabchikov, V.G. Myzyn, V.V. Andreev // Chelyabinsk: YuUrdu, 2013 -295 p. 2. Belov B.F. Analysis of the structural and chemical state and classification of oxide and metallic phases of systems! iron-silicon - barium-oxygen. Message 2. Dupleko-system

EeO-5102 - BaO /Re-5i-Ba/. B.F. Belov, A.I. Trotsan, I.L. Brodetsky et al. // Casting processes 2016 - Mo 6 (120). - P. 3-12.

Claims (1)

UTILITY MODEL FORMULA Compact material for ladle processing of steel, containing the main components of iron, silicon, calcium, which differs in that it additionally contains barium, when the ratio of ingredients (wt. In): silicon 15-55 calcium 20-50 barium 5-25 iron other.