Review

“Research of influence of technology of desoxydating and alloying steels on degree of mastering of alloying elements”

Introduction

In modern conditions active introduction of the Ukrainian manufacturers of a steel in the world market demands corresponding certification of the metal products answering under qualitative characteristics to the international standards. It is reached by presence at the enterprises of ferrous metallurgy of Ukraine and, in particular, in steel-smelting manufacture of the necessary equipment and highly effective technological processes of melt and teem steels, and also use of hi-tech and more economic materials.

Theme urgency

The production technology of a steel now in use, provides at release of metal from the steel-smelting unit in a ladle preliminary deoxidation. For desoxydating use aluminium, ferrosilicon, silicocalcium. Alternatively FeSi the complex deoxidant, a kind silicon carbide (SiC), certain fraction and a chemical compound is offered to application.

The offered technology of the deoxidation is based on high affinity to oxygen of carbide of silicon, thus activity of a complex deoxidant (SiC) is close to activity of aluminium and on many above, than separately at silicon and carbon.

Now in the presence of units the furnace-ladle, definitive of deoxidation also can be provided SiC by a way of deoxidation slag in a ladle, thereby partially to refuse aluminium.

Other positive factor, the fact of considerable improvement of quality of a steel on structure of nonmetallic inclusions is.

The basic results

According to the received data of skilled swimming trunks with use of carbide of silicon metallurgical (SiC), it is visible that degree of mastering of elements Si, C, Mn on metal release in a ladle, depends on the carbon maintenance, - the more the carbon maintenance, the above degree of mastering of elements.

The analysis of the received results (under comparable entry conditions: the fusion weight, duration of processing on “installation of a ladle furnace”, the electric power expense, initial chemical structure of metal, the expense of deoxidants) has shown the following:

• Mastering of silicon from release prior to the beginning of fusion processing on “installation of a ladle furnace” on skilled and comparative swimming trunks practically do not differ (31,4 % and 30,6 %, accordingly)
• Through mastering of carbon, silicon and manganese above on skilled swimming trunks — 96,3 %; 44,1 % and 92,6 % against 87,4 %; 38,0 % and 88,0 % on comparative, accordingly
• Degree of desulphurizing and use degree to exhaust on sulphur removal also above on skilled swimming trunks — 76,4 % and 7,1 % against 72,8 % and 6,3 % on comparative

Slightly best degree desulphurizing speaks skilled swimming trunks that on comparative swimming trunks for “increase in carbon” metal were used anthracite (EXPERT) which bring additional quantity of sulphur and ashes, worsening thereby indicators of process of refinement of metal.

Higher of silicon and manganese mastering are connected with the physical and chemical processes occurring at mastering of carbide of silicon by metal therefore activity of oxygen decreases in a greater degree, than at use ferrosilicon and, accordingly, the silicon and manganese charcoal fumes in the given conditions are less.

Conclusions

Through mastering of elements of skilled swimming trunks with use of carbide of silicon metallurgical above, than comparative swimming trunks with use ferrosilicon FeSi65 and FeSi45.

Economic benefit at use of carbide of silicon instead of ferrosilicon FeSi65 and FeSi45 at melt of a steel of the mark St3sp spilt on the “сontinuous casting machine” open stream, has made 19,25 grn/t, including at replacement FeSi65 by carbide of silicon 4,46 grn/t and at replacement FeSi45 by carbide of silicon 1,67 grn/t, accordingly.

Considering absence in carbide of silicon of the harmful impurity which are present in ferrosilicon (the nonferrous metals, the dissolved gases), and also at its use in technology of extraoven processing of a steel on “ installation of a ladle furnace”, it is necessary to expect improvement of quality indicators on mechanical properties, the maintenance of nonmetallic inclusions and gases in ready hire, and as consequence, reduction of expenses by manufacture of some marks became not demanding additional processing in the form of pumping out.

The literature

1. I. S. Kajnarskij, E. V. Degtyaryov Karborundovye Refractories. Kharkov. 1963. — 252 p.
2. V. E. Lejkin, P. A. Saharuk Electrometallurgy of a steel and ferroalloys. Moscow. 1960. — 600 p.
3. The Metallurgical and mining industry. 2002. #10. p. 103–104
4. Forty Items thermodynamic's Priests the analysis of process of reception of carbide of silicon from a rice peel //Chemistry questions and chemical technology. — 2003.—#1.— p. 142–145.
5. D. A. Djudkin, S. Ju. Bat manufacture of a steel on the unit a ladle-furnace. Donetsk. 2003. — 305 p.
6. D. A. Djudkin, V. V. Kisilenko Proizvodstvo of a steel. Moscow. 2008. — 544 p.

The note

At a writing of the given author's abstract qualifying work of the master is not finished yet. Date of definitive end of work: on December, 1st, 2011 the Full text of work and materials on a work theme can be received at the author or its supervisor of studies after the named date.