RU2491354C2 - Powder wire for secondary refining of iron-carbon melt (versions) - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: in accordance with the first version powder wire comprises a steel shell and a powder filler containing 30-70 wt % of rare earth metal alloy with iron and silicon and calcium silicon or a mixture of calcium silicon and metal calcium, balance, with the content of calcium and rare earth metals in a filler, accordingly, 6-30 wt % and 6-21 wt %. The second version of the wire consists of a steel shell and a powder filler containing 50-90 wt % of alloy with iron and silicon and metal calcium, balance, besides, the content of rare earth metals in the filler makes 6-25 wt %. The third version of the wire consists of a steel shell and a powder filler - alloy of rare earth metals with iron and silicon, containing 4-30 wt % of calcium, besides, content of rare earth metals in the filler makes 4-25 wt %.

EFFECT: improved efficiency of modification and microalloying due to reduction of quantity of oxide and sulfide inclusions in a finished metal.

15 cl, 2 tbl

Description

The invention relates to ferrous metallurgy and can be used in the technology of ladle processing of metallurgical melts with powder materials for the purpose of deoxidation, modification and microalloying in the manufacture of critical metal products, including in cold-resistant and corrosion-resistant versions.

Known flux-cored wire with a filler for out-of-furnace steel processing, consisting of a steel sheath and a filler containing a mechanical mixture of ground powdered silicocalcium grades SK-20 or SK-30 and rare-earth metals (REM) in the form of powder or granules with the following components in the filler, wt .%:

Silicocalcium grades SK-20 or SK-30 40-98 REM 2-60

In addition, the content of the filler and the steel shell is, respectively, 51-75 and 25-49, wt.%, And the fill factor of the flux-cored wire is 0.5-0.75 (see cl. RF No. 2355781, class C. 21C 7 / 00, declared July 10, 2007, published May 20, 2009 “Flux cored wire with silicocalcium filler with rare-earth metals for out-of-furnace steel processing”).

The disadvantage of this invention is the low and unstable assimilation of rare-earth metals by the melt associated with the use of these materials in the form of chemical elements, as well as because of the specified limits of the flux-cored wire filling. The high activity of these elements can lead to their oxidation long before the direct processing of the melt, and as a result, the efficiency of processing of rare-earth metals significantly decreases. A mandatory requirement for the manufacture of high-quality flux-cored wire is the uniformity of volumetric filling along the length of the riot, and when converted to weighted filling, the permissible deviation is up to 5%. Regulation of fluctuations in the content of the filler in the flux-cored wire within the specified limits can lead, in one case, to insufficient filling and in some areas to voids, in another case to overflow and possible opening of the lock and spilling of the filler when the flux-cored wire is introduced into the melt, which results in unstable assimilation of filler ingredients.

The closest in technical essence, the achieved result and selected as a prototype is a wire for out-of-furnace treatment of metallurgical melts, consisting of a steel sheath and powder filler containing calcium and silicon, characterized in that the filler additionally contains iron and rare-earth metals in the following ratio of filler ingredients, wt.%:

Calcium 8-25 Silicon 35-50 REM 8-20 Iron rest,

and the ratio between calcium and REM is (0.8 ... 2.2): 1. In this case, calcium can be in the filler in the form of an alloy with silicon, 10-50% of calcium can be in the filler in its pure form, and the filler wire may additionally contain aluminum and magnesium in an amount of 0.1 ... 5.0 wt.% Each (cm item of the Russian Federation No. 2318026, according to class C21C 7/00, declared on 02.20.2006, published on 02.27.2008 “Wire for out-of-furnace treatment of metallurgical melts”).

The disadvantage of the prototype is the low efficiency of such a wire, due to the high oxidation of rare-earth metals even before the melt is processed, as well as the use of a mixture of calcium-containing materials and rare-earth metals in the filler (this is usually mainly cerium and lanthanum), which is unable to quickly form more " tenacious "high-temperature compounds with calcium due to poor miscibility of their melts. In addition, the filler contains no other materials capable of enhancing the modifying and refining effects in the processing of the melt.

The present invention in accordance with the first embodiment of the inventive wire is to increase the strength, ductility and toughness of the metal.

The technical result obtained by the implementation of the invention in accordance with the first embodiment of the inventive wire is to reduce the number of oxide and sulfide inclusions in the finished metal by increasing the efficiency of the modification and refinement of the melt.

This problem is solved due to the fact that in the known flux-cored wire for out-of-furnace treatment of iron-carbon melt, consisting of a steel shell and a powder filler containing rare earth metals (REM) and calcium in the form of silicocalcium or a mixture of silicocalcium and calcium metal, according to the invention, rare earth metals in the composition of the filler are in the form of a ligature of rare-earth metals with iron and silicon in the following ratio of the components of the filler,% wt .:

Rare Earth Ligature with iron and silicon 30-70 Silicocalcium or mixture silicocalcium and calcium metal rest,

when the content of calcium and rare earth metals in the filler, respectively, 6-30 wt.% and 6-21 wt.%.

The filler may additionally contain 1-30 wt.% Ferrosilicobarium and / or ferrosilicocalcium with barium, as well as 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals.

As an analogue and prototype for the inventive wire in accordance with the second embodiment, the same technical solutions are selected as for the first option. They have the same disadvantages as indicated above.

When creating the invention in accordance with the second embodiment of the wire, the task was also to increase the strength, ductility and toughness of the metal.

The technical result obtained by the implementation of the invention in accordance with the second embodiment of the wire is also to reduce the number of oxide and sulfide inclusions in the finished metal by increasing the efficiency of the modification and refinement of the melt.

The specified task in accordance with the second embodiment of the inventive wire is solved due to the fact that in the known filler wire for out-of-furnace treatment of the iron-carbon melt, consisting of a steel sheath and a powder filler containing rare earth metals and calcium, according to the invention, rare earth metals in the filler are in the form ligatures with iron and silicon, and calcium in the form of calcium metal in the following ratio of the components of the filler,% wt .:

Rare Earth Ligature with iron and silicon 50-90 Calcium metal rest,

moreover, the content in the filler of rare earth metals is 6-25 wt.%

The filler may additionally contain 1-30 wt.% Ferrosilicobarium and / or ferrosilicocalcium with barium, as well as 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals.

As an analogue and prototype for the inventive wire in accordance with the third embodiment, the same technical solutions are selected as for the first option. They have the same disadvantages as indicated above.

When creating the invention in accordance with the third embodiment of the wire, the task was also to increase the strength, ductility and toughness of the metal.

The technical result obtained by the implementation of the invention in accordance with the third embodiment of the wire is also to reduce the number of oxide and sulfide inclusions in the finished metal by increasing the efficiency of the modification and refinement of the melt.

The specified task in accordance with the third embodiment of the claimed wire is solved due to the fact that in the known flux-cored wire for out-of-furnace treatment of an iron-carbon melt, consisting of a steel shell and a powder filler containing rare earth metals and calcium, according to the invention, a rare earth metal ligature with iron and silicon containing 4-30 wt.% calcium, and the content of rare earth metals is 4-25 wt.%.

The filler may additionally contain 1-30 wt.% Silicocalcium and / or calcium metal, 1-30 wt.% Ferrosilicobarium and / or ferrosilicon calcium with barium, 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals, and the filler contains 1-30 wt.% Ligatures of rare earth metals with iron and silicon.

Studies conducted on the sources of patent and scientific and technical information have shown that the inventive cored wire is not known and does not follow explicitly from the studied prior art, i.e. meets the criteria of novelty and inventive step.

The inventive cored wire can be manufactured at any enterprise specializing in this industry, because this requires well-known materials and standard equipment, and is widely used in the manufacture of steel products, i.e. is industrially applicable.

The task of modification during out-of-furnace steel processing is to improve the structure and increase the mechanical properties of the metal.

The modification, which, as a rule, is carried out by introducing calcium-containing materials into the melt, leads to:

a) additional deoxidation and desulfurization of steel;

b) a change in the morphology and composition of the resulting non-metallic inclusions, a reduction in the number of oxides, oxysulfides, sulfides;

c) purification of grain boundaries and near-boundary sections from particles, eutectics and segregation, leading to embrittlement of the metal;

d) the formation of a homogeneous and fine-grained grain structure of the metal.

The solutions to each of these problems, ceteris paribus, depend on the composition of the modifying materials used, and their introduction into the melt in the form of a flux-cored wire ensures their more effective use, since it prevents premature interaction of these chemically active substances with slag and metal.

It was experimentally established that the introduction of flux-cored wire into the filler composition, along with calcium-containing material (silicocalcium or metallic calcium) of rare-earth metals in the form of a ligature with iron and silicon, leads to additional deoxidation and desulfurization of the melt, binding to high-temperature (T pl. - 1315-1600 ° C) compounds of colored impurities (zinc, antimony, copper, etc.), preventing their release in the form of low-temperature eutectics, the formation of other rare-earth metals containing phases capable of inhibiting the growth of primary dendrites. Due to this, the efficiency of the modifying effect of calcium on a) increases in a) a change in the morphology and composition of non-metallic inclusions, which improves the conditions for removal of the formed particles from the melt - oxides, sulfides, b) for cleaning grain boundaries, c) for the uniformity of the formed metal structure. In addition, the consumption of calcium-containing materials for steel processing is reduced.

All the advantages of the use of rare-earth metals during modification are realized only if they are used in the form of compounds that are readily soluble in steel, for example, the alloy of rare-earth metals with iron and silicon, with the release of extremely chemically active elements from them (heat of formation of Ce ₂ O ₃ - 1821 kJ / mol, La ₂ O ₃ - 1792 kJ / mol, compared with CaO - 636 kJ / mol).

Therefore, the use of rare-earth metals in the form of pure chemical elements as a filler of cored wire is almost impossible.

The practice of using flux-cored wire with a filler containing REM for modifying steel has shown that positive results are achieved when the ligature of the filler contains REM-iron-silicon in an amount of 30-70 wt.% With the remaining content of silicocalcium or its mixture with calcium metal. In this case, the calcium content should be in the range of 6-30 wt.%, And REM - 6-21 wt.%. A lower content of calcium prevents the modification of inclusions, and a larger one reduces the proportion of rare-earth metals in the filler. The content of rare-earth metals less than 6 wt.% Does not have a significant effect on the improvement of the modification, and more than 21 wt.% Reduces the proportion of calcium needed for modification.

It was experimentally shown that the flux-cored wire filler can also be a mixture of the REM-iron-silicon ligature in the amount of 50-90 wt.% And calcium metal - the rest, with the content of REM 6-25 wt.%. The lower limit of the content of rare-earth metals is due to the need to have in the filler a sufficient amount of these elements for interaction with oxygen and non-ferrous metals. Upper - the presence in the filler sufficient to modify the content of metallic calcium.

REM ligature with iron and silicon may also contain some calcium. Our experiments have shown the positive effect of such a filler of a flux-cored wire containing 4-30 wt.% Calcium on the structure and properties of the resulting metal products with a rare earth content of 4-25 wt.%.

In addition, it was found that the addition of barium in the form of ferrosilicobarium and / or an alloy of ferrosilicocalcium with barium having higher temperatures of existence in the melt, compared with metallic calcium and silicocalcium, in the amount of barium-containing compounds 1-30 wt.% Reinforces the modifying melt processing effect. The upper limit of the content of ferrosilicobarium and / or ferrosilicocalcium with barium is limited by the need to have the right amount of rare-earth metals and calcium in the filler.

The refining of the melt from non-metallic inclusions after the modification operation and, accordingly, the metal purity by oxides and sulfides is improved if the filler additionally contains 3-30 wt.% Flux from alkaline earth and / or alkali metal salts, for example, CaCl ₂ , CaF ₂ , Na ₂ CO ₃ and others. This effect is noticeable, starting with 3 wt.% Flux, and when the flux content is more than 30 wt.%, The proportion of modifying elements and rare-earth metals in the filler of the flux-cored wire decreases.

An example implementation of the method.

The method was used in the manufacture of metal products from 20GL steel, which had a composition at the outlet from the electric furnace, wt.%: 0.18-0.23C, 0.87-0.94Mn, 0.18-0.23 Si, 0.022-0.027S, 0.012 -0.014P, 0.11-0.15 Cr, 0.08-0.11 Ni, 0.022-0.028Al, Fe - the rest.

The material of the filler flux-cored wire for modification was obtained by mixing in various ratios of phases and alloys: silicocalcium (20 and 30 wt.% Ca), metallic calcium, ferrosilicobarium (22 wt.% Ba), ferrosilicon-barium (13 wt.% Ca, 15 wt.% Ba), ligatures of ferrosilicon REM (30 wt.% REM, 30 wt.% Si, iron - the rest and 12 wt.% REM, 30 wt.% Si, iron - the rest), ligatures FeSiPЗMCa (30 wt.% REM, 30 wt. Wt.% Si, 4 wt.% Ca, iron - the rest and 4 wt.% REM, 30 wt.% Si, 30 wt.% Ca, iron - the rest), fluorspar (CaF ₂ ), calcium chlorides (CaCl ₂ ) sodium carbonate (Na ₂ CO ₃ ) and chlorine potassium horide (KCl). The compositions of the filler cored wire are shown in table 1.

The prototype material had a composition of silicocalcium 25 (25 wt.% Ca) + REM (15 wt.%).

Produced mixtures of various compositions and material according to the prototype had a fraction of 0-2 mm and rolled into a steel shell 0.4 mm thick, receiving a flux-cored wire with a diameter of 14 mm

During the experiments, the melt was released from the electric furnace into a 10-ton ladle and, after deoxidation by ferrosilicon and aluminum, was treated with cored wire with various fillers. Each bucket was treated with a wire with a different composition of fillers. The filler consumption in the experiments was 1.2 kg / ton of melt

During processing in all cases, the melt was purged with argon.

Next, the metal was poured into molds, and after crystallization, the parts were subjected to heat treatment - normalization at 850 ° C.

Contamination with non-metallic inclusions, as well as mechanical properties were evaluated in the finished metal.

Table 2 presents the results of determining the content of oxides and sulfides, as well as the temporary resistance - σ _B ; elongation - δ and impact strength (KCV) at - 60 ° C - a _H in the metal processed according to the prototype and according to the options presented in table 1.

From the data in tables 1 and 2, it is seen that:

1. The use of a flux-cored wire with a filler, according to the prototype (var. 0), leads to high contamination of the metal with oxide and oxysulfide (1.6 points), as well as sulfide (1.2 points) inclusions, low temporary resistance (55 kgf / cm ² ), relative elongation (28%) and low temperature impact strength (1.5 kgf * m / cm ² ).

2. The use of wire with a filler, according to claims 1 to 3 of the claims of the claimed invention (options 1-5,7-9, 11-14), provides, in comparison with the prototype, the reduction of pollution by oxide, oxysulfide (0.8 -1.1 points) and sulfide (0.5-0.6 points) inclusions, as well as an increase in temporary resistance (59-63 kgf / cm ² ), elongation (30-33%) and impact strength (1.9 -2.4 kgf * m / cm ² ).

3. The use of flux-cored wire with a filler, according to paragraphs 4-6 of the claims of the claimed invention (options 15-24), leads, in comparison with the prototype, to reduce pollution by oxide, oxysulfide (0.85-1.0 points) and sulfide (0.5-0.6 points) inclusions, increasing the temporary resistance (61-64 kgf / cm ² ), elongation (32-33%) and impact strength (2.2-2.4 kgf * m / cm ² ).

4. The use of wire with a filler, according to PP.7-15 of the claims of the claimed invention (options 25-48), provides, in comparison with the prototype, the reduction of pollution by oxide, oxysulfide (0.9-1.0 points) and sulfide (0.5-0.6 points) to inclusions, increasing the temporary resistance (61-64 kgf / cm), elongation (31-33%) and impact strength (2.0-2.4 kgf * m / cm ² ) .

5. The use of cored wire with a filler having a composition different from that claimed in the claims (var. 6, 10) does not lead to an improvement in structure and properties, compared with the prototype.

Table 1 Phase composition and content of elements in cored wire fillers No. p / p The composition of the filler cored wire, wt.% The content of elements, wt.% SiCa30 and SiCa20 Ca _met Ligature FeSiPЗM Ligature FeSiPЗMCa FeSiBa FeSiBaCa CaF ₂ CaCl ₂ Na ₂ CO ₃ Kcl Sa REM one thirty - 70 - - - - - 6 21 2 twenty 10 70 - - - - - 16 21 3 fifty fifteen 35 - - - - - thirty eleven four fifty 10 40 - - - - - twenty 12 5 70 - thirty - - - - - 21 6 6 70 fifteen fifteen - - - - - 35 3 7 49 - fifty - one - - - fifteen fifteen 8 thirty 10 fifty - 5 5 - - 19 fifteen 9 thirty - 40 - 10 twenty - - fifteen 10 10 10 - fifty - 40 - - - 3 fifteen eleven fifty - 47 - - - 3 - fifteen fourteen 12 thirty 5 35 - - - fifteen fifteen 29th eleven 13 27 5 35 - 3 - fifteen fifteen 27 eleven fourteen 25 5 35 - - twenty - 10 5 25 eleven fifteen - 10 90 - - - - - 10 25 16 - thirty 70 - - - - - thirty twenty 17 - fifty fifty - - - - - fifty 6 eighteen - 10 80 - 5 5 - - 10 25 19 - 49 fifty - one - - - 49 6 twenty - twenty fifty - fifteen fifteen - - twenty 6 21 - twenty fifty - - - fifteen fifteen - - thirty 12 22 - 47 fifty - - - - - - 3 47 fifteen 23 - 40 fifty - - 5 - 5 - - 40 fifteen 24 - twenty fifty - fifteen - - - fifteen - thirty 12 25 - - - one hundred - - - - - - four 25 26 - - - one hundred - - - - - - thirty four 27 - one - 99 - - - - - - thirty 24 28 25 5 - 70 - - - - - - 28 eighteen 29th - - - 99 one - - - - - thirty twenty thirty - - - 70 - thirty - - - - twenty twenty 31 - one - 69 thirty - - - - - 10 fifteen 32 25 5 - 69 - one - - - - twenty fifteen 33 - - - 97 - - - 3 - - 29th twenty

34 - - - 70 - - fifteen - 10 5 twenty fourteen 35 25 5 - 67 - - - 3 - - thirty 12 36 - one - 69 - - fifteen - 5 10 21 fourteen 37 - - - 69 one - - - thirty - 25 fourteen 38 5 - - 62 - thirty - 3 - - 25 12 39 - - one 99 - - - - - - thirty twenty 40 - - thirty 70 - - - - - - twenty 25 41 one - thirty 69 - - - - - - twenty 25 42 - 25 one 74 - - - - - - 25 fifteen 43 - - thirty 69 one - - - - - twenty eighteen 44 5 - one 74 - twenty - - - - fifteen 12 45 - - thirty 67 - - - 3 - - 9 17 46 - 10 one 69 - - fifteen - 5 - 12 twenty 47 10 - one 69 one - - - fifteen - 10 twenty 48 - - thirty 57 10 - 3 - - - eighteen 21

table 2 Contamination and mechanical properties of metal treated with cored wire with various fillers Option No. (Table 1) Inclusion pollution, point Mechanical properties Oxides + Oxisulfides Sulfides σ _B , kgf / cm ² δ,% a _N , kgf * m / cm ² 0 (prototype) 1,6 1,2 55 28 1,5 one 1.05 0.6 59 31 1.9 2 1.1 0.6 60 thirty 1.9 3 1,0 0.55 61 31 1.9 four 1.05 0.55 61 32 2.0 5 1,0 0.6 60 31 1.9 6 1,6 1,2 54 29th 1,5 7 1,0 0.6 61 31 1.9 8 0.95 0.6 62 32 2.0 9 0.9 0.55 63 33 2,3 10 1.65 1.3 53 28 1.4 eleven 0.95 0.5 63 32 2.0 12 0.85 0.5 62 33 2.2 13 0.85 0.5 62 32 2.2 fourteen 0.8 0.5 63 33 2,4 fifteen 1,0 0.6 61 32 2,3 16 1,0 0.5 62 32 2.2 17 0.95 0.5 62 32 2.2 eighteen 1,0 0.6 61 33 2,3 19 0.95 0.5 62 32 2.2 twenty 0.9 0.5 64 33 2,4 21 0.85 0.5 63 32 2,4 22 0.9 0.5 63 32 2,3 23 0.9 0.5 64 33 2,4 24 0.9 0.5 63 33 2,4 25 1,0 0.6 61 32 2.0 26 1,0 0.6 61 33 2.0 27 0.95 0.6 61 32 2.0 28 0.95 0.55 62 32 2.1 29th 0.95 0.55 62 33 2.2 thirty 0.9 0.55 62 33 2.2 31 0.9 0.6 62 32 2.2 32 0.95 0.55 62 32 2.1 33 0.95 0.6 61 32 2.1 34 0.9 0.55 62 33 2,3 35 0.9 0.5 61 33 2,4 36 0.9 0.55 61 33 2,3 37 0.9 0.5 62 33 2,3 38 0.9 0.5 62 33 2,3 39 1,0 0.6 62 32 2.0

40 0.95 0.6 63 31 2.1 41 0.95 0.6 64 31 2.1 42 0.95 0.6 63 32 2.1 43 0.95 0.55 63 33 2.1 44 0.9 0.55 62 33 2.2 45 0.95 0.6 63 31 2.1 46 0.9 0.55 62 32 2.2 47 0.9 0.5 63 33 2,3 48 0.9 0.55 62 33 2.2

Thus, from the data presented in Tables 1 and 2, it follows that a decrease in the content of oxide, oxysulfide, and sulfide inclusions in the finished metal and high values of temporary resistance, elongation, and impact strength of the metal occur only in the case of a flux-cored wire with a filler having the composition corresponding to the claimed in the claims.

Claims (15)

1. A flux-cored wire for out-of-furnace treatment of an iron-carbon melt, consisting of a steel shell and a powder filler containing rare-earth metals and calcium in the form of silicocalcium or a mixture of silicocalcium and calcium metal, characterized in that the rare-earth metals in the filler are in the form of a ligature with iron and silicon in the following ratio of components of the filler, wt.%:
Rare Earth Ligature with iron and silicon 30-70 Silicocalcium or mixture silicocalcium and calcium metal Rest,
moreover, the content in the filler of calcium is 6-30 wt.%, and the content of rare earth metals 6-21 wt.%. 2. The flux cored wire according to claim 1, characterized in that the filler additionally contains 1-30 wt.% Ferrosilicobarium and / or ferrosilicon with barium. 3. The flux cored wire according to claim 1 or 2, characterized in that the filler additionally contains 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals. 4. A flux-cored wire for out-of-furnace treatment of an iron-carbon melt, consisting of a steel shell and a powder filler containing rare-earth metals and calcium, characterized in that the rare-earth metals in the filler are in the form of a ligature with iron and silicon, and calcium in the form of metallic calcium in the following the ratio of the components of the filler, wt.%:
Rare Earth Ligature with iron and silicon 50-90 Calcium metal Rest,
moreover, the content in the filler of rare earth metals is 6-25 wt.%. 5. The flux cored wire according to claim 4, characterized in that the filler additionally contains 1-30 wt.% Ferrosilicobarium and / or ferrosilicon with barium. 6. The flux cored wire according to claim 4 or 5, characterized in that the filler additionally contains 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals. 7. A flux-cored wire for out-of-furnace treatment of an iron-carbon melt, consisting of a steel shell and a powder filler containing rare earth metals and calcium, characterized in that as a filler a ligature of rare-earth metals with iron and silicon containing 4-30 wt.% Calcium, and the content of rare earth metals is 4-25 wt.% 8. The flux cored wire according to claim 7, characterized in that the filler additionally contains 1-30 wt.% Silicocalcium and / or calcium metal. 9. The flux cored wire according to claim 7 or 8, characterized in that the filler additionally contains 1-30 wt.% Ferrosilicobarium and / or ferrosilicon with barium. 10. The flux cored wire according to claim 7 or 8, characterized in that the filler additionally contains 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals. 11. The flux cored wire according to claim 9, characterized in that the filler additionally contains 3-30 wt.% Flux from salts of alkaline earth and / or alkali metals. 12. The flux cored wire according to claim 7 or 8, characterized in that the filler contains 1-30 wt.% Ligatures of rare earth metals with iron and silicon. 13. The flux cored wire according to claim 9, characterized in that the filler contains 1-30 wt.% Ligatures of rare earth metals with iron and silicon. 14. The cored wire according to claim 10, characterized in that the filler contains 1-30 wt.% Ligatures of rare earth metals with iron and silicon. 15. The cored wire according to claim 11, characterized in that the filler contains 1-30 wt.% Ligatures of rare earth metals with iron and silicon.